Resguardo inicial

linux-7.2.3/drivers/pci/endpoint/Kconfig

@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# PCI Endpoint Support
+#
+
+menu "PCI Endpoint"
+
+config PCI_ENDPOINT
+	bool "PCI Endpoint Support"
+	depends on HAVE_PCI
+	help
+	   Enable this configuration option to support configurable PCI
+	   endpoint. This should be enabled if the platform has a PCI
+	   controller that can operate in endpoint mode.
+
+	   Enabling this option will build the endpoint library, which
+	   includes endpoint controller library and endpoint function
+	   library.
+
+	   If in doubt, say "N" to disable Endpoint support.
+
+config PCI_ENDPOINT_CONFIGFS
+	bool "PCI Endpoint Configfs Support"
+	depends on PCI_ENDPOINT
+	select CONFIGFS_FS
+	help
+	   This will enable the configfs entry that can be used to
+	   configure the endpoint function and used to bind the
+	   function with an endpoint controller.
+
+config PCI_ENDPOINT_MSI_DOORBELL
+	bool "PCI Endpoint MSI Doorbell Support"
+	depends on PCI_ENDPOINT && GENERIC_MSI_IRQ
+	help
+	  This enables the EP's MSI interrupt controller to function as a
+	  doorbell. The RC can trigger doorbell in EP by writing data to a
+	  dedicated BAR, which the EP maps to the controller's message address.
+
+source "drivers/pci/endpoint/functions/Kconfig"
+
+endmenu

linux-7.2.3/drivers/pci/endpoint/Makefile

@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for PCI Endpoint Support
+#
+
+obj-$(CONFIG_PCI_ENDPOINT_CONFIGFS)	+= pci-ep-cfs.o
+obj-$(CONFIG_PCI_ENDPOINT)		+= pci-epc-core.o pci-epf-core.o\
+					   pci-epc-mem.o functions/
+obj-$(CONFIG_PCI_ENDPOINT_MSI_DOORBELL)	+= pci-ep-msi.o

linux-7.2.3/drivers/pci/endpoint/functions/Kconfig

@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# PCI Endpoint Functions
+#
+
+config PCI_EPF_TEST
+	tristate "PCI Endpoint Test driver"
+	depends on PCI_ENDPOINT
+	select CONFIGFS_FS
+	select CRC32
+	help
+	   Enable this configuration option to enable the test driver
+	   for PCI Endpoint.
+
+	   If in doubt, say "N" to disable Endpoint test driver.
+
+config PCI_EPF_NTB
+	tristate "PCI Endpoint NTB driver"
+	depends on PCI_ENDPOINT
+	select CONFIGFS_FS
+	help
+	  Select this configuration option to enable the Non-Transparent
+	  Bridge (NTB) driver for PCI Endpoint. NTB driver implements NTB
+	  controller functionality using multiple PCIe endpoint instances.
+	  It can support NTB endpoint function devices created using
+	  device tree.
+
+	  If in doubt, say "N" to disable Endpoint NTB driver.
+
+config PCI_EPF_VNTB
+	tristate "PCI Endpoint Virtual NTB driver"
+	depends on PCI_ENDPOINT
+	depends on NTB
+	select CONFIGFS_FS
+	help
+	  Select this configuration option to enable the Non-Transparent
+	  Bridge (NTB) driver for PCIe Endpoint. NTB driver implements NTB
+	  between PCI Root Port and PCIe Endpoint.
+
+	  If in doubt, say "N" to disable Endpoint NTB driver.
+
+config PCI_EPF_MHI
+	tristate "PCI Endpoint driver for MHI bus"
+	depends on PCI_ENDPOINT && MHI_BUS_EP
+	help
+	   Enable this configuration option to enable the PCI Endpoint
+	   driver for Modem Host Interface (MHI) bus in Qualcomm Endpoint
+	   devices such as SDX55.
+
+	   If in doubt, say "N" to disable Endpoint driver for MHI bus.

linux-7.2.3/drivers/pci/endpoint/functions/Makefile

@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for PCI Endpoint Functions
+#
+
+obj-$(CONFIG_PCI_EPF_TEST)		+= pci-epf-test.o
+obj-$(CONFIG_PCI_EPF_NTB)		+= pci-epf-ntb.o
+obj-$(CONFIG_PCI_EPF_VNTB) 		+= pci-epf-vntb.o
+obj-$(CONFIG_PCI_EPF_MHI)		+= pci-epf-mhi.o

linux-7.2.3/drivers/pci/endpoint/functions/pci-epf-mhi.c

@@ -0,0 +1,995 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI EPF driver for MHI Endpoint devices
+ *
+ * Copyright (C) 2023 Linaro Ltd.
+ * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+ */
+
+#include <linux/dmaengine.h>
+#include <linux/mhi_ep.h>
+#include <linux/module.h>
+#include <linux/of_dma.h>
+#include <linux/platform_device.h>
+#include <linux/pci-epc.h>
+#include <linux/pci-epf.h>
+
+#define MHI_VERSION_1_0 0x01000000
+
+#define to_epf_mhi(cntrl) container_of(cntrl, struct pci_epf_mhi, cntrl)
+
+/* Platform specific flags */
+#define MHI_EPF_USE_DMA BIT(0)
+
+struct pci_epf_mhi_dma_transfer {
+	struct pci_epf_mhi *epf_mhi;
+	struct mhi_ep_buf_info buf_info;
+	struct list_head node;
+	dma_addr_t paddr;
+	enum dma_data_direction dir;
+	size_t size;
+};
+
+struct pci_epf_mhi_ep_info {
+	const struct mhi_ep_cntrl_config *config;
+	struct pci_epf_header *epf_header;
+	enum pci_barno bar_num;
+	u32 epf_flags;
+	u32 msi_count;
+	u32 mru;
+	u32 flags;
+};
+
+#define MHI_EP_CHANNEL_CONFIG(ch_num, ch_name, direction)	\
+	{							\
+		.num = ch_num,					\
+		.name = ch_name,				\
+		.dir = direction,				\
+	}
+
+#define MHI_EP_CHANNEL_CONFIG_UL(ch_num, ch_name)		\
+	MHI_EP_CHANNEL_CONFIG(ch_num, ch_name, DMA_TO_DEVICE)
+
+#define MHI_EP_CHANNEL_CONFIG_DL(ch_num, ch_name)		\
+	MHI_EP_CHANNEL_CONFIG(ch_num, ch_name, DMA_FROM_DEVICE)
+
+static const struct mhi_ep_channel_config mhi_v1_channels[] = {
+	MHI_EP_CHANNEL_CONFIG_UL(0, "LOOPBACK"),
+	MHI_EP_CHANNEL_CONFIG_DL(1, "LOOPBACK"),
+	MHI_EP_CHANNEL_CONFIG_UL(2, "SAHARA"),
+	MHI_EP_CHANNEL_CONFIG_DL(3, "SAHARA"),
+	MHI_EP_CHANNEL_CONFIG_UL(4, "DIAG"),
+	MHI_EP_CHANNEL_CONFIG_DL(5, "DIAG"),
+	MHI_EP_CHANNEL_CONFIG_UL(6, "SSR"),
+	MHI_EP_CHANNEL_CONFIG_DL(7, "SSR"),
+	MHI_EP_CHANNEL_CONFIG_UL(8, "QDSS"),
+	MHI_EP_CHANNEL_CONFIG_DL(9, "QDSS"),
+	MHI_EP_CHANNEL_CONFIG_UL(10, "EFS"),
+	MHI_EP_CHANNEL_CONFIG_DL(11, "EFS"),
+	MHI_EP_CHANNEL_CONFIG_UL(12, "MBIM"),
+	MHI_EP_CHANNEL_CONFIG_DL(13, "MBIM"),
+	MHI_EP_CHANNEL_CONFIG_UL(14, "QMI"),
+	MHI_EP_CHANNEL_CONFIG_DL(15, "QMI"),
+	MHI_EP_CHANNEL_CONFIG_UL(16, "QMI"),
+	MHI_EP_CHANNEL_CONFIG_DL(17, "QMI"),
+	MHI_EP_CHANNEL_CONFIG_UL(18, "IP-CTRL-1"),
+	MHI_EP_CHANNEL_CONFIG_DL(19, "IP-CTRL-1"),
+	MHI_EP_CHANNEL_CONFIG_UL(20, "IPCR"),
+	MHI_EP_CHANNEL_CONFIG_DL(21, "IPCR"),
+	MHI_EP_CHANNEL_CONFIG_UL(32, "DUN"),
+	MHI_EP_CHANNEL_CONFIG_DL(33, "DUN"),
+	MHI_EP_CHANNEL_CONFIG_UL(46, "IP_SW0"),
+	MHI_EP_CHANNEL_CONFIG_DL(47, "IP_SW0"),
+};
+
+static const struct mhi_ep_cntrl_config mhi_v1_config = {
+	.max_channels = 128,
+	.num_channels = ARRAY_SIZE(mhi_v1_channels),
+	.ch_cfg = mhi_v1_channels,
+	.mhi_version = MHI_VERSION_1_0,
+};
+
+static struct pci_epf_header sdx55_header = {
+	.vendorid = PCI_VENDOR_ID_QCOM,
+	.deviceid = 0x0306,
+	.baseclass_code = PCI_BASE_CLASS_COMMUNICATION,
+	.subclass_code = PCI_CLASS_COMMUNICATION_MODEM & 0xff,
+	.interrupt_pin	= PCI_INTERRUPT_INTA,
+};
+
+static const struct pci_epf_mhi_ep_info sdx55_info = {
+	.config = &mhi_v1_config,
+	.epf_header = &sdx55_header,
+	.bar_num = BAR_0,
+	.epf_flags = PCI_BASE_ADDRESS_MEM_TYPE_32,
+	.msi_count = 32,
+	.mru = 0x8000,
+};
+
+static struct pci_epf_header sm8450_header = {
+	.vendorid = PCI_VENDOR_ID_QCOM,
+	.deviceid = 0x0306,
+	.baseclass_code = PCI_CLASS_OTHERS,
+	.interrupt_pin = PCI_INTERRUPT_INTA,
+};
+
+static const struct pci_epf_mhi_ep_info sm8450_info = {
+	.config = &mhi_v1_config,
+	.epf_header = &sm8450_header,
+	.bar_num = BAR_0,
+	.epf_flags = PCI_BASE_ADDRESS_MEM_TYPE_32,
+	.msi_count = 32,
+	.mru = 0x8000,
+	.flags = MHI_EPF_USE_DMA,
+};
+
+static struct pci_epf_header sa8775p_header = {
+	.vendorid = PCI_VENDOR_ID_QCOM,
+	.deviceid = 0x0116,
+	.baseclass_code = PCI_CLASS_OTHERS,
+	.interrupt_pin = PCI_INTERRUPT_INTA,
+};
+
+static const struct pci_epf_mhi_ep_info sa8775p_info = {
+	.config = &mhi_v1_config,
+	.epf_header = &sa8775p_header,
+	.bar_num = BAR_0,
+	.epf_flags = PCI_BASE_ADDRESS_MEM_TYPE_32,
+	.msi_count = 32,
+	.mru = 0x8000,
+	.flags = MHI_EPF_USE_DMA,
+};
+
+struct pci_epf_mhi {
+	const struct pci_epc_features *epc_features;
+	const struct pci_epf_mhi_ep_info *info;
+	struct mhi_ep_cntrl mhi_cntrl;
+	struct pci_epf *epf;
+	struct mutex lock;
+	void __iomem *mmio;
+	resource_size_t mmio_phys;
+	struct dma_chan *dma_chan_tx;
+	struct dma_chan *dma_chan_rx;
+	struct workqueue_struct *dma_wq;
+	struct work_struct dma_work;
+	struct list_head dma_list;
+	spinlock_t list_lock;
+	u32 mmio_size;
+	int irq;
+};
+
+static size_t get_align_offset(struct pci_epf_mhi *epf_mhi, u64 addr)
+{
+	return addr & (epf_mhi->epc_features->align -1);
+}
+
+static int __pci_epf_mhi_alloc_map(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr,
+				 phys_addr_t *paddr, void __iomem **vaddr,
+				 size_t offset, size_t size)
+{
+	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
+	struct pci_epf *epf = epf_mhi->epf;
+	struct pci_epc *epc = epf->epc;
+	int ret;
+
+	*vaddr = pci_epc_mem_alloc_addr(epc, paddr, size + offset);
+	if (!*vaddr)
+		return -ENOMEM;
+
+	ret = pci_epc_map_addr(epc, epf->func_no, epf->vfunc_no, *paddr,
+			       pci_addr - offset, size + offset);
+	if (ret) {
+		pci_epc_mem_free_addr(epc, *paddr, *vaddr, size + offset);
+		return ret;
+	}
+
+	*paddr = *paddr + offset;
+	*vaddr = *vaddr + offset;
+
+	return 0;
+}
+
+static int pci_epf_mhi_alloc_map(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr,
+				 phys_addr_t *paddr, void __iomem **vaddr,
+				 size_t size)
+{
+	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
+	size_t offset = get_align_offset(epf_mhi, pci_addr);
+
+	return __pci_epf_mhi_alloc_map(mhi_cntrl, pci_addr, paddr, vaddr,
+				      offset, size);
+}
+
+static void __pci_epf_mhi_unmap_free(struct mhi_ep_cntrl *mhi_cntrl,
+				     u64 pci_addr, phys_addr_t paddr,
+				     void __iomem *vaddr, size_t offset,
+				     size_t size)
+{
+	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
+	struct pci_epf *epf = epf_mhi->epf;
+	struct pci_epc *epc = epf->epc;
+
+	pci_epc_unmap_addr(epc, epf->func_no, epf->vfunc_no, paddr - offset);
+	pci_epc_mem_free_addr(epc, paddr - offset, vaddr - offset,
+			      size + offset);
+}
+
+static void pci_epf_mhi_unmap_free(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr,
+				   phys_addr_t paddr, void __iomem *vaddr,
+				   size_t size)
+{
+	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
+	size_t offset = get_align_offset(epf_mhi, pci_addr);
+
+	__pci_epf_mhi_unmap_free(mhi_cntrl, pci_addr, paddr, vaddr, offset,
+				 size);
+}
+
+static void pci_epf_mhi_raise_irq(struct mhi_ep_cntrl *mhi_cntrl, u32 vector)
+{
+	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
+	struct pci_epf *epf = epf_mhi->epf;
+	struct pci_epc *epc = epf->epc;
+
+	/*
+	 * MHI supplies 0 based MSI vectors but the API expects the vector
+	 * number to start from 1, so we need to increment the vector by 1.
+	 */
+	pci_epc_raise_irq(epc, epf->func_no, epf->vfunc_no, PCI_IRQ_MSI,
+			  vector + 1);
+}
+
+static int pci_epf_mhi_iatu_read(struct mhi_ep_cntrl *mhi_cntrl,
+				 struct mhi_ep_buf_info *buf_info)
+{
+	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
+	size_t offset = get_align_offset(epf_mhi, buf_info->host_addr);
+	void __iomem *tre_buf;
+	phys_addr_t tre_phys;
+	int ret;
+
+	mutex_lock(&epf_mhi->lock);
+
+	ret = __pci_epf_mhi_alloc_map(mhi_cntrl, buf_info->host_addr, &tre_phys,
+				      &tre_buf, offset, buf_info->size);
+	if (ret) {
+		mutex_unlock(&epf_mhi->lock);
+		return ret;
+	}
+
+	memcpy_fromio(buf_info->dev_addr, tre_buf, buf_info->size);
+
+	__pci_epf_mhi_unmap_free(mhi_cntrl, buf_info->host_addr, tre_phys,
+				 tre_buf, offset, buf_info->size);
+
+	mutex_unlock(&epf_mhi->lock);
+
+	if (buf_info->cb)
+		buf_info->cb(buf_info);
+
+	return 0;
+}
+
+static int pci_epf_mhi_iatu_write(struct mhi_ep_cntrl *mhi_cntrl,
+				  struct mhi_ep_buf_info *buf_info)
+{
+	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
+	size_t offset = get_align_offset(epf_mhi, buf_info->host_addr);
+	void __iomem *tre_buf;
+	phys_addr_t tre_phys;
+	int ret;
+
+	mutex_lock(&epf_mhi->lock);
+
+	ret = __pci_epf_mhi_alloc_map(mhi_cntrl, buf_info->host_addr, &tre_phys,
+				      &tre_buf, offset, buf_info->size);
+	if (ret) {
+		mutex_unlock(&epf_mhi->lock);
+		return ret;
+	}
+
+	memcpy_toio(tre_buf, buf_info->dev_addr, buf_info->size);
+
+	__pci_epf_mhi_unmap_free(mhi_cntrl, buf_info->host_addr, tre_phys,
+				 tre_buf, offset, buf_info->size);
+
+	mutex_unlock(&epf_mhi->lock);
+
+	if (buf_info->cb)
+		buf_info->cb(buf_info);
+
+	return 0;
+}
+
+static void pci_epf_mhi_dma_callback(void *param)
+{
+	complete(param);
+}
+
+static int pci_epf_mhi_edma_read(struct mhi_ep_cntrl *mhi_cntrl,
+				 struct mhi_ep_buf_info *buf_info)
+{
+	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
+	struct device *dma_dev = epf_mhi->epf->epc->dev.parent;
+	struct dma_chan *chan = epf_mhi->dma_chan_rx;
+	struct device *dev = &epf_mhi->epf->dev;
+	DECLARE_COMPLETION_ONSTACK(complete);
+	struct dma_async_tx_descriptor *desc;
+	struct dma_slave_config config = {};
+	dma_cookie_t cookie;
+	dma_addr_t dst_addr;
+	int ret;
+
+	if (buf_info->size < SZ_4K)
+		return pci_epf_mhi_iatu_read(mhi_cntrl, buf_info);
+
+	mutex_lock(&epf_mhi->lock);
+
+	config.direction = DMA_DEV_TO_MEM;
+	config.src_addr = buf_info->host_addr;
+
+	ret = dmaengine_slave_config(chan, &config);
+	if (ret) {
+		dev_err(dev, "Failed to configure DMA channel\n");
+		goto err_unlock;
+	}
+
+	dst_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
+				  DMA_FROM_DEVICE);
+	ret = dma_mapping_error(dma_dev, dst_addr);
+	if (ret) {
+		dev_err(dev, "Failed to map remote memory\n");
+		goto err_unlock;
+	}
+
+	desc = dmaengine_prep_slave_single(chan, dst_addr, buf_info->size,
+					   DMA_DEV_TO_MEM,
+					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
+	if (!desc) {
+		dev_err(dev, "Failed to prepare DMA\n");
+		ret = -EIO;
+		goto err_unmap;
+	}
+
+	desc->callback = pci_epf_mhi_dma_callback;
+	desc->callback_param = &complete;
+
+	cookie = dmaengine_submit(desc);
+	ret = dma_submit_error(cookie);
+	if (ret) {
+		dev_err(dev, "Failed to do DMA submit\n");
+		goto err_unmap;
+	}
+
+	dma_async_issue_pending(chan);
+	ret = wait_for_completion_timeout(&complete, msecs_to_jiffies(1000));
+	if (!ret) {
+		dev_err(dev, "DMA transfer timeout\n");
+		dmaengine_terminate_sync(chan);
+		ret = -ETIMEDOUT;
+	} else {
+		ret = 0;
+	}
+
+err_unmap:
+	dma_unmap_single(dma_dev, dst_addr, buf_info->size, DMA_FROM_DEVICE);
+err_unlock:
+	mutex_unlock(&epf_mhi->lock);
+
+	return ret;
+}
+
+static int pci_epf_mhi_edma_write(struct mhi_ep_cntrl *mhi_cntrl,
+				  struct mhi_ep_buf_info *buf_info)
+{
+	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
+	struct device *dma_dev = epf_mhi->epf->epc->dev.parent;
+	struct dma_chan *chan = epf_mhi->dma_chan_tx;
+	struct device *dev = &epf_mhi->epf->dev;
+	DECLARE_COMPLETION_ONSTACK(complete);
+	struct dma_async_tx_descriptor *desc;
+	struct dma_slave_config config = {};
+	dma_cookie_t cookie;
+	dma_addr_t src_addr;
+	int ret;
+
+	if (buf_info->size < SZ_4K)
+		return pci_epf_mhi_iatu_write(mhi_cntrl, buf_info);
+
+	mutex_lock(&epf_mhi->lock);
+
+	config.direction = DMA_MEM_TO_DEV;
+	config.dst_addr = buf_info->host_addr;
+
+	ret = dmaengine_slave_config(chan, &config);
+	if (ret) {
+		dev_err(dev, "Failed to configure DMA channel\n");
+		goto err_unlock;
+	}
+
+	src_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
+				  DMA_TO_DEVICE);
+	ret = dma_mapping_error(dma_dev, src_addr);
+	if (ret) {
+		dev_err(dev, "Failed to map remote memory\n");
+		goto err_unlock;
+	}
+
+	desc = dmaengine_prep_slave_single(chan, src_addr, buf_info->size,
+					   DMA_MEM_TO_DEV,
+					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
+	if (!desc) {
+		dev_err(dev, "Failed to prepare DMA\n");
+		ret = -EIO;
+		goto err_unmap;
+	}
+
+	desc->callback = pci_epf_mhi_dma_callback;
+	desc->callback_param = &complete;
+
+	cookie = dmaengine_submit(desc);
+	ret = dma_submit_error(cookie);
+	if (ret) {
+		dev_err(dev, "Failed to do DMA submit\n");
+		goto err_unmap;
+	}
+
+	dma_async_issue_pending(chan);
+	ret = wait_for_completion_timeout(&complete, msecs_to_jiffies(1000));
+	if (!ret) {
+		dev_err(dev, "DMA transfer timeout\n");
+		dmaengine_terminate_sync(chan);
+		ret = -ETIMEDOUT;
+	} else {
+		ret = 0;
+	}
+
+err_unmap:
+	dma_unmap_single(dma_dev, src_addr, buf_info->size, DMA_TO_DEVICE);
+err_unlock:
+	mutex_unlock(&epf_mhi->lock);
+
+	return ret;
+}
+
+static void pci_epf_mhi_dma_worker(struct work_struct *work)
+{
+	struct pci_epf_mhi *epf_mhi = container_of(work, struct pci_epf_mhi, dma_work);
+	struct device *dma_dev = epf_mhi->epf->epc->dev.parent;
+	struct pci_epf_mhi_dma_transfer *itr, *tmp;
+	struct mhi_ep_buf_info *buf_info;
+	unsigned long flags;
+	LIST_HEAD(head);
+
+	spin_lock_irqsave(&epf_mhi->list_lock, flags);
+	list_splice_tail_init(&epf_mhi->dma_list, &head);
+	spin_unlock_irqrestore(&epf_mhi->list_lock, flags);
+
+	list_for_each_entry_safe(itr, tmp, &head, node) {
+		list_del(&itr->node);
+		dma_unmap_single(dma_dev, itr->paddr, itr->size, itr->dir);
+		buf_info = &itr->buf_info;
+		buf_info->cb(buf_info);
+		kfree(itr);
+	}
+}
+
+static void pci_epf_mhi_dma_async_callback(void *param)
+{
+	struct pci_epf_mhi_dma_transfer *transfer = param;
+	struct pci_epf_mhi *epf_mhi = transfer->epf_mhi;
+
+	spin_lock(&epf_mhi->list_lock);
+	list_add_tail(&transfer->node, &epf_mhi->dma_list);
+	spin_unlock(&epf_mhi->list_lock);
+
+	queue_work(epf_mhi->dma_wq, &epf_mhi->dma_work);
+}
+
+static int pci_epf_mhi_edma_read_async(struct mhi_ep_cntrl *mhi_cntrl,
+				       struct mhi_ep_buf_info *buf_info)
+{
+	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
+	struct device *dma_dev = epf_mhi->epf->epc->dev.parent;
+	struct pci_epf_mhi_dma_transfer *transfer = NULL;
+	struct dma_chan *chan = epf_mhi->dma_chan_rx;
+	struct device *dev = &epf_mhi->epf->dev;
+	DECLARE_COMPLETION_ONSTACK(complete);
+	struct dma_async_tx_descriptor *desc;
+	struct dma_slave_config config = {};
+	dma_cookie_t cookie;
+	dma_addr_t dst_addr;
+	int ret;
+
+	mutex_lock(&epf_mhi->lock);
+
+	config.direction = DMA_DEV_TO_MEM;
+	config.src_addr = buf_info->host_addr;
+
+	ret = dmaengine_slave_config(chan, &config);
+	if (ret) {
+		dev_err(dev, "Failed to configure DMA channel\n");
+		goto err_unlock;
+	}
+
+	dst_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
+				  DMA_FROM_DEVICE);
+	ret = dma_mapping_error(dma_dev, dst_addr);
+	if (ret) {
+		dev_err(dev, "Failed to map remote memory\n");
+		goto err_unlock;
+	}
+
+	desc = dmaengine_prep_slave_single(chan, dst_addr, buf_info->size,
+					   DMA_DEV_TO_MEM,
+					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
+	if (!desc) {
+		dev_err(dev, "Failed to prepare DMA\n");
+		ret = -EIO;
+		goto err_unmap;
+	}
+
+	transfer = kzalloc_obj(*transfer);
+	if (!transfer) {
+		ret = -ENOMEM;
+		goto err_unmap;
+	}
+
+	transfer->epf_mhi = epf_mhi;
+	transfer->paddr = dst_addr;
+	transfer->size = buf_info->size;
+	transfer->dir = DMA_FROM_DEVICE;
+	memcpy(&transfer->buf_info, buf_info, sizeof(*buf_info));
+
+	desc->callback = pci_epf_mhi_dma_async_callback;
+	desc->callback_param = transfer;
+
+	cookie = dmaengine_submit(desc);
+	ret = dma_submit_error(cookie);
+	if (ret) {
+		dev_err(dev, "Failed to do DMA submit\n");
+		goto err_free_transfer;
+	}
+
+	dma_async_issue_pending(chan);
+
+	goto err_unlock;
+
+err_free_transfer:
+	kfree(transfer);
+err_unmap:
+	dma_unmap_single(dma_dev, dst_addr, buf_info->size, DMA_FROM_DEVICE);
+err_unlock:
+	mutex_unlock(&epf_mhi->lock);
+
+	return ret;
+}
+
+static int pci_epf_mhi_edma_write_async(struct mhi_ep_cntrl *mhi_cntrl,
+					struct mhi_ep_buf_info *buf_info)
+{
+	struct pci_epf_mhi *epf_mhi = to_epf_mhi(mhi_cntrl);
+	struct device *dma_dev = epf_mhi->epf->epc->dev.parent;
+	struct pci_epf_mhi_dma_transfer *transfer = NULL;
+	struct dma_chan *chan = epf_mhi->dma_chan_tx;
+	struct device *dev = &epf_mhi->epf->dev;
+	DECLARE_COMPLETION_ONSTACK(complete);
+	struct dma_async_tx_descriptor *desc;
+	struct dma_slave_config config = {};
+	dma_cookie_t cookie;
+	dma_addr_t src_addr;
+	int ret;
+
+	mutex_lock(&epf_mhi->lock);
+
+	config.direction = DMA_MEM_TO_DEV;
+	config.dst_addr = buf_info->host_addr;
+
+	ret = dmaengine_slave_config(chan, &config);
+	if (ret) {
+		dev_err(dev, "Failed to configure DMA channel\n");
+		goto err_unlock;
+	}
+
+	src_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
+				  DMA_TO_DEVICE);
+	ret = dma_mapping_error(dma_dev, src_addr);
+	if (ret) {
+		dev_err(dev, "Failed to map remote memory\n");
+		goto err_unlock;
+	}
+
+	desc = dmaengine_prep_slave_single(chan, src_addr, buf_info->size,
+					   DMA_MEM_TO_DEV,
+					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
+	if (!desc) {
+		dev_err(dev, "Failed to prepare DMA\n");
+		ret = -EIO;
+		goto err_unmap;
+	}
+
+	transfer = kzalloc_obj(*transfer);
+	if (!transfer) {
+		ret = -ENOMEM;
+		goto err_unmap;
+	}
+
+	transfer->epf_mhi = epf_mhi;
+	transfer->paddr = src_addr;
+	transfer->size = buf_info->size;
+	transfer->dir = DMA_TO_DEVICE;
+	memcpy(&transfer->buf_info, buf_info, sizeof(*buf_info));
+
+	desc->callback = pci_epf_mhi_dma_async_callback;
+	desc->callback_param = transfer;
+
+	cookie = dmaengine_submit(desc);
+	ret = dma_submit_error(cookie);
+	if (ret) {
+		dev_err(dev, "Failed to do DMA submit\n");
+		goto err_free_transfer;
+	}
+
+	dma_async_issue_pending(chan);
+
+	goto err_unlock;
+
+err_free_transfer:
+	kfree(transfer);
+err_unmap:
+	dma_unmap_single(dma_dev, src_addr, buf_info->size, DMA_TO_DEVICE);
+err_unlock:
+	mutex_unlock(&epf_mhi->lock);
+
+	return ret;
+}
+
+struct epf_dma_filter {
+	struct device *dev;
+	u32 dma_mask;
+};
+
+static bool pci_epf_mhi_filter(struct dma_chan *chan, void *node)
+{
+	struct epf_dma_filter *filter = node;
+	struct dma_slave_caps caps;
+
+	memset(&caps, 0, sizeof(caps));
+	dma_get_slave_caps(chan, &caps);
+
+	return chan->device->dev == filter->dev && filter->dma_mask &
+					caps.directions;
+}
+
+static int pci_epf_mhi_dma_init(struct pci_epf_mhi *epf_mhi)
+{
+	struct device *dma_dev = epf_mhi->epf->epc->dev.parent;
+	struct device *dev = &epf_mhi->epf->dev;
+	struct epf_dma_filter filter;
+	dma_cap_mask_t mask;
+	int ret;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	filter.dev = dma_dev;
+	filter.dma_mask = BIT(DMA_MEM_TO_DEV);
+	epf_mhi->dma_chan_tx = dma_request_channel(mask, pci_epf_mhi_filter,
+						   &filter);
+	if (IS_ERR_OR_NULL(epf_mhi->dma_chan_tx)) {
+		dev_err(dev, "Failed to request tx channel\n");
+		return -ENODEV;
+	}
+
+	filter.dma_mask = BIT(DMA_DEV_TO_MEM);
+	epf_mhi->dma_chan_rx = dma_request_channel(mask, pci_epf_mhi_filter,
+						   &filter);
+	if (IS_ERR_OR_NULL(epf_mhi->dma_chan_rx)) {
+		dev_err(dev, "Failed to request rx channel\n");
+		ret = -ENODEV;
+		goto err_release_tx;
+	}
+
+	epf_mhi->dma_wq = alloc_workqueue("pci_epf_mhi_dma_wq", WQ_PERCPU, 0);
+	if (!epf_mhi->dma_wq) {
+		ret = -ENOMEM;
+		goto err_release_rx;
+	}
+
+	INIT_LIST_HEAD(&epf_mhi->dma_list);
+	INIT_WORK(&epf_mhi->dma_work, pci_epf_mhi_dma_worker);
+	spin_lock_init(&epf_mhi->list_lock);
+
+	return 0;
+
+err_release_rx:
+	dma_release_channel(epf_mhi->dma_chan_rx);
+	epf_mhi->dma_chan_rx = NULL;
+err_release_tx:
+	dma_release_channel(epf_mhi->dma_chan_tx);
+	epf_mhi->dma_chan_tx = NULL;
+
+	return ret;
+}
+
+static void pci_epf_mhi_dma_deinit(struct pci_epf_mhi *epf_mhi)
+{
+	destroy_workqueue(epf_mhi->dma_wq);
+	dma_release_channel(epf_mhi->dma_chan_tx);
+	dma_release_channel(epf_mhi->dma_chan_rx);
+	epf_mhi->dma_chan_tx = NULL;
+	epf_mhi->dma_chan_rx = NULL;
+}
+
+static int pci_epf_mhi_epc_init(struct pci_epf *epf)
+{
+	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
+	const struct pci_epf_mhi_ep_info *info = epf_mhi->info;
+	struct pci_epf_bar *epf_bar = &epf->bar[info->bar_num];
+	struct pci_epc *epc = epf->epc;
+	struct device *dev = &epf->dev;
+	int ret;
+
+	epf_bar->phys_addr = epf_mhi->mmio_phys;
+	epf_bar->size = epf_mhi->mmio_size;
+	epf_bar->barno = info->bar_num;
+	epf_bar->flags = info->epf_flags;
+	ret = pci_epc_set_bar(epc, epf->func_no, epf->vfunc_no, epf_bar);
+	if (ret) {
+		dev_err(dev, "Failed to set BAR: %d\n", ret);
+		return ret;
+	}
+
+	ret = pci_epc_set_msi(epc, epf->func_no, epf->vfunc_no,
+			      order_base_2(info->msi_count));
+	if (ret) {
+		dev_err(dev, "Failed to set MSI configuration: %d\n", ret);
+		return ret;
+	}
+
+	ret = pci_epc_write_header(epc, epf->func_no, epf->vfunc_no,
+				   epf->header);
+	if (ret) {
+		dev_err(dev, "Failed to set Configuration header: %d\n", ret);
+		return ret;
+	}
+
+	epf_mhi->epc_features = pci_epc_get_features(epc, epf->func_no, epf->vfunc_no);
+	if (!epf_mhi->epc_features)
+		return -ENODATA;
+
+	if (info->flags & MHI_EPF_USE_DMA) {
+		ret = pci_epf_mhi_dma_init(epf_mhi);
+		if (ret) {
+			dev_err(dev, "Failed to initialize DMA: %d\n", ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void pci_epf_mhi_epc_deinit(struct pci_epf *epf)
+{
+	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
+	const struct pci_epf_mhi_ep_info *info = epf_mhi->info;
+	struct pci_epf_bar *epf_bar = &epf->bar[info->bar_num];
+	struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
+	struct pci_epc *epc = epf->epc;
+
+	if (mhi_cntrl->mhi_dev) {
+		mhi_ep_power_down(mhi_cntrl);
+		if (info->flags & MHI_EPF_USE_DMA)
+			pci_epf_mhi_dma_deinit(epf_mhi);
+		mhi_ep_unregister_controller(mhi_cntrl);
+	}
+
+	pci_epc_clear_bar(epc, epf->func_no, epf->vfunc_no, epf_bar);
+}
+
+static int pci_epf_mhi_link_up(struct pci_epf *epf)
+{
+	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
+	const struct pci_epf_mhi_ep_info *info = epf_mhi->info;
+	struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
+	struct pci_epc *epc = epf->epc;
+	struct device *dev = &epf->dev;
+	int ret;
+
+	mhi_cntrl->mmio = epf_mhi->mmio;
+	mhi_cntrl->irq = epf_mhi->irq;
+	mhi_cntrl->mru = info->mru;
+
+	/* Assign the struct dev of PCI EP as MHI controller device */
+	mhi_cntrl->cntrl_dev = epc->dev.parent;
+	mhi_cntrl->raise_irq = pci_epf_mhi_raise_irq;
+	mhi_cntrl->alloc_map = pci_epf_mhi_alloc_map;
+	mhi_cntrl->unmap_free = pci_epf_mhi_unmap_free;
+	mhi_cntrl->read_sync = mhi_cntrl->read_async = pci_epf_mhi_iatu_read;
+	mhi_cntrl->write_sync = mhi_cntrl->write_async = pci_epf_mhi_iatu_write;
+	if (info->flags & MHI_EPF_USE_DMA) {
+		mhi_cntrl->read_sync = pci_epf_mhi_edma_read;
+		mhi_cntrl->write_sync = pci_epf_mhi_edma_write;
+		mhi_cntrl->read_async = pci_epf_mhi_edma_read_async;
+		mhi_cntrl->write_async = pci_epf_mhi_edma_write_async;
+	}
+
+	/* Register the MHI EP controller */
+	ret = mhi_ep_register_controller(mhi_cntrl, info->config);
+	if (ret) {
+		dev_err(dev, "Failed to register MHI EP controller: %d\n", ret);
+		if (info->flags & MHI_EPF_USE_DMA)
+			pci_epf_mhi_dma_deinit(epf_mhi);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int pci_epf_mhi_link_down(struct pci_epf *epf)
+{
+	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
+	const struct pci_epf_mhi_ep_info *info = epf_mhi->info;
+	struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
+
+	if (mhi_cntrl->mhi_dev) {
+		mhi_ep_power_down(mhi_cntrl);
+		if (info->flags & MHI_EPF_USE_DMA)
+			pci_epf_mhi_dma_deinit(epf_mhi);
+		mhi_ep_unregister_controller(mhi_cntrl);
+	}
+
+	return 0;
+}
+
+static int pci_epf_mhi_bus_master_enable(struct pci_epf *epf)
+{
+	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
+	const struct pci_epf_mhi_ep_info *info = epf_mhi->info;
+	struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
+	struct device *dev = &epf->dev;
+	int ret;
+
+	/*
+	 * Power up the MHI EP stack if link is up and stack is in power down
+	 * state.
+	 */
+	if (!mhi_cntrl->enabled && mhi_cntrl->mhi_dev) {
+		ret = mhi_ep_power_up(mhi_cntrl);
+		if (ret) {
+			dev_err(dev, "Failed to power up MHI EP: %d\n", ret);
+			if (info->flags & MHI_EPF_USE_DMA)
+				pci_epf_mhi_dma_deinit(epf_mhi);
+			mhi_ep_unregister_controller(mhi_cntrl);
+		}
+	}
+
+	return 0;
+}
+
+static int pci_epf_mhi_bind(struct pci_epf *epf)
+{
+	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
+	struct pci_epc *epc = epf->epc;
+	struct device *dev = &epf->dev;
+	struct platform_device *pdev = to_platform_device(epc->dev.parent);
+	struct resource *res;
+	int ret;
+
+	/* Get MMIO base address from Endpoint controller */
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mmio");
+	if (!res) {
+		dev_err(dev, "Failed to get \"mmio\" resource\n");
+		return -ENODEV;
+	}
+
+	epf_mhi->mmio_phys = res->start;
+	epf_mhi->mmio_size = resource_size(res);
+
+	epf_mhi->mmio = ioremap(epf_mhi->mmio_phys, epf_mhi->mmio_size);
+	if (!epf_mhi->mmio)
+		return -ENOMEM;
+
+	ret = platform_get_irq_byname(pdev, "doorbell");
+	if (ret < 0) {
+		iounmap(epf_mhi->mmio);
+		return ret;
+	}
+
+	epf_mhi->irq = ret;
+
+	return 0;
+}
+
+static void pci_epf_mhi_unbind(struct pci_epf *epf)
+{
+	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
+	const struct pci_epf_mhi_ep_info *info = epf_mhi->info;
+	struct pci_epf_bar *epf_bar = &epf->bar[info->bar_num];
+	struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
+	struct pci_epc *epc = epf->epc;
+
+	/*
+	 * Forcefully power down the MHI EP stack. Only way to bring the MHI EP
+	 * stack back to working state after successive bind is by getting Bus
+	 * Master Enable event from host.
+	 */
+	if (mhi_cntrl->mhi_dev) {
+		mhi_ep_power_down(mhi_cntrl);
+		if (info->flags & MHI_EPF_USE_DMA)
+			pci_epf_mhi_dma_deinit(epf_mhi);
+		mhi_ep_unregister_controller(mhi_cntrl);
+	}
+
+	iounmap(epf_mhi->mmio);
+	pci_epc_clear_bar(epc, epf->func_no, epf->vfunc_no, epf_bar);
+}
+
+static const struct pci_epc_event_ops pci_epf_mhi_event_ops = {
+	.epc_init = pci_epf_mhi_epc_init,
+	.epc_deinit = pci_epf_mhi_epc_deinit,
+	.link_up = pci_epf_mhi_link_up,
+	.link_down = pci_epf_mhi_link_down,
+	.bus_master_enable = pci_epf_mhi_bus_master_enable,
+};
+
+static int pci_epf_mhi_probe(struct pci_epf *epf,
+			     const struct pci_epf_device_id *id)
+{
+	struct pci_epf_mhi_ep_info *info =
+			(struct pci_epf_mhi_ep_info *)id->driver_data;
+	struct pci_epf_mhi *epf_mhi;
+	struct device *dev = &epf->dev;
+
+	epf_mhi = devm_kzalloc(dev, sizeof(*epf_mhi), GFP_KERNEL);
+	if (!epf_mhi)
+		return -ENOMEM;
+
+	epf->header = info->epf_header;
+	epf_mhi->info = info;
+	epf_mhi->epf = epf;
+
+	epf->event_ops = &pci_epf_mhi_event_ops;
+
+	mutex_init(&epf_mhi->lock);
+
+	epf_set_drvdata(epf, epf_mhi);
+
+	return 0;
+}
+
+static const struct pci_epf_device_id pci_epf_mhi_ids[] = {
+	{ .name = "pci_epf_mhi_sa8775p", .driver_data = (kernel_ulong_t)&sa8775p_info },
+	{ .name = "pci_epf_mhi_sdx55", .driver_data = (kernel_ulong_t)&sdx55_info },
+	{ .name = "pci_epf_mhi_sm8450", .driver_data = (kernel_ulong_t)&sm8450_info },
+	{},
+};
+
+static const struct pci_epf_ops pci_epf_mhi_ops = {
+	.unbind	= pci_epf_mhi_unbind,
+	.bind	= pci_epf_mhi_bind,
+};
+
+static struct pci_epf_driver pci_epf_mhi_driver = {
+	.driver.name	= "pci_epf_mhi",
+	.probe		= pci_epf_mhi_probe,
+	.id_table	= pci_epf_mhi_ids,
+	.ops		= &pci_epf_mhi_ops,
+	.owner		= THIS_MODULE,
+};
+
+static int __init pci_epf_mhi_init(void)
+{
+	return pci_epf_register_driver(&pci_epf_mhi_driver);
+}
+module_init(pci_epf_mhi_init);
+
+static void __exit pci_epf_mhi_exit(void)
+{
+	pci_epf_unregister_driver(&pci_epf_mhi_driver);
+}
+module_exit(pci_epf_mhi_exit);
+
+MODULE_DESCRIPTION("PCI EPF driver for MHI Endpoint devices");
+MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
+MODULE_LICENSE("GPL");

linux-7.2.3/drivers/pci/endpoint/pci-ep-cfs.c

@@ -0,0 +1,777 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * configfs to configure the PCI endpoint
+ *
+ * Copyright (C) 2017 Texas Instruments
+ * Author: Kishon Vijay Abraham I <kishon@ti.com>
+ */
+
+#include <linux/module.h>
+#include <linux/idr.h>
+#include <linux/slab.h>
+
+#include <linux/pci-epc.h>
+#include <linux/pci-epf.h>
+#include <linux/pci-ep-cfs.h>
+
+static DEFINE_IDR(functions_idr);
+static DEFINE_MUTEX(functions_mutex);
+static struct config_group *functions_group;
+static struct config_group *controllers_group;
+
+struct pci_epf_group {
+	struct config_group group;
+	struct config_group primary_epc_group;
+	struct config_group secondary_epc_group;
+	struct pci_epf *epf;
+	int index;
+};
+
+struct pci_epc_group {
+	struct config_group group;
+	struct pci_epc *epc;
+	bool start;
+};
+
+static inline struct pci_epf_group *to_pci_epf_group(struct config_item *item)
+{
+	return container_of(to_config_group(item), struct pci_epf_group, group);
+}
+
+static inline struct pci_epc_group *to_pci_epc_group(struct config_item *item)
+{
+	return container_of(to_config_group(item), struct pci_epc_group, group);
+}
+
+static int pci_secondary_epc_epf_link(struct config_item *epf_item,
+				      struct config_item *epc_item)
+{
+	int ret;
+	struct pci_epf_group *epf_group = to_pci_epf_group(epf_item->ci_parent);
+	struct pci_epc_group *epc_group = to_pci_epc_group(epc_item);
+	struct pci_epc *epc = epc_group->epc;
+	struct pci_epf *epf = epf_group->epf;
+
+	ret = pci_epc_add_epf(epc, epf, SECONDARY_INTERFACE);
+	if (ret)
+		return ret;
+
+	ret = pci_epf_bind(epf);
+	if (ret) {
+		pci_epc_remove_epf(epc, epf, SECONDARY_INTERFACE);
+		return ret;
+	}
+
+	/* Send any pending EPC initialization complete to the EPF driver */
+	pci_epc_notify_pending_init(epc, epf);
+
+	return 0;
+}
+
+static void pci_secondary_epc_epf_unlink(struct config_item *epf_item,
+					 struct config_item *epc_item)
+{
+	struct pci_epf_group *epf_group = to_pci_epf_group(epf_item->ci_parent);
+	struct pci_epc_group *epc_group = to_pci_epc_group(epc_item);
+	struct pci_epc *epc;
+	struct pci_epf *epf;
+
+	WARN_ON_ONCE(epc_group->start);
+
+	epc = epc_group->epc;
+	epf = epf_group->epf;
+	pci_epf_unbind(epf);
+	pci_epc_remove_epf(epc, epf, SECONDARY_INTERFACE);
+}
+
+static const struct configfs_item_operations pci_secondary_epc_item_ops = {
+	.allow_link	= pci_secondary_epc_epf_link,
+	.drop_link	= pci_secondary_epc_epf_unlink,
+};
+
+static const struct config_item_type pci_secondary_epc_type = {
+	.ct_item_ops	= &pci_secondary_epc_item_ops,
+	.ct_owner	= THIS_MODULE,
+};
+
+static struct config_group
+*pci_ep_cfs_add_secondary_group(struct pci_epf_group *epf_group)
+{
+	struct config_group *secondary_epc_group;
+
+	secondary_epc_group = &epf_group->secondary_epc_group;
+	config_group_init_type_name(secondary_epc_group, "secondary",
+				    &pci_secondary_epc_type);
+	configfs_add_default_group(secondary_epc_group, &epf_group->group);
+
+	return secondary_epc_group;
+}
+
+static int pci_primary_epc_epf_link(struct config_item *epf_item,
+				    struct config_item *epc_item)
+{
+	int ret;
+	struct pci_epf_group *epf_group = to_pci_epf_group(epf_item->ci_parent);
+	struct pci_epc_group *epc_group = to_pci_epc_group(epc_item);
+	struct pci_epc *epc = epc_group->epc;
+	struct pci_epf *epf = epf_group->epf;
+
+	ret = pci_epc_add_epf(epc, epf, PRIMARY_INTERFACE);
+	if (ret)
+		return ret;
+
+	ret = pci_epf_bind(epf);
+	if (ret) {
+		pci_epc_remove_epf(epc, epf, PRIMARY_INTERFACE);
+		return ret;
+	}
+
+	/* Send any pending EPC initialization complete to the EPF driver */
+	pci_epc_notify_pending_init(epc, epf);
+
+	return 0;
+}
+
+static void pci_primary_epc_epf_unlink(struct config_item *epf_item,
+				       struct config_item *epc_item)
+{
+	struct pci_epf_group *epf_group = to_pci_epf_group(epf_item->ci_parent);
+	struct pci_epc_group *epc_group = to_pci_epc_group(epc_item);
+	struct pci_epc *epc;
+	struct pci_epf *epf;
+
+	WARN_ON_ONCE(epc_group->start);
+
+	epc = epc_group->epc;
+	epf = epf_group->epf;
+	pci_epf_unbind(epf);
+	pci_epc_remove_epf(epc, epf, PRIMARY_INTERFACE);
+}
+
+static const struct configfs_item_operations pci_primary_epc_item_ops = {
+	.allow_link	= pci_primary_epc_epf_link,
+	.drop_link	= pci_primary_epc_epf_unlink,
+};
+
+static const struct config_item_type pci_primary_epc_type = {
+	.ct_item_ops	= &pci_primary_epc_item_ops,
+	.ct_owner	= THIS_MODULE,
+};
+
+static struct config_group
+*pci_ep_cfs_add_primary_group(struct pci_epf_group *epf_group)
+{
+	struct config_group *primary_epc_group = &epf_group->primary_epc_group;
+
+	config_group_init_type_name(primary_epc_group, "primary",
+				    &pci_primary_epc_type);
+	configfs_add_default_group(primary_epc_group, &epf_group->group);
+
+	return primary_epc_group;
+}
+
+static ssize_t pci_epc_start_store(struct config_item *item, const char *page,
+				   size_t len)
+{
+	int ret;
+	bool start;
+	struct pci_epc *epc;
+	struct pci_epc_group *epc_group = to_pci_epc_group(item);
+
+	epc = epc_group->epc;
+
+	if (kstrtobool(page, &start) < 0)
+		return -EINVAL;
+
+	if (start == epc_group->start)
+		return -EALREADY;
+
+	if (!start) {
+		pci_epc_stop(epc);
+		epc_group->start = 0;
+		return len;
+	}
+
+	ret = pci_epc_start(epc);
+	if (ret) {
+		dev_err(&epc->dev, "failed to start endpoint controller\n");
+		return -EINVAL;
+	}
+
+	epc_group->start = start;
+
+	return len;
+}
+
+static ssize_t pci_epc_start_show(struct config_item *item, char *page)
+{
+	return sysfs_emit(page, "%d\n", to_pci_epc_group(item)->start);
+}
+
+CONFIGFS_ATTR(pci_epc_, start);
+
+static struct configfs_attribute *pci_epc_attrs[] = {
+	&pci_epc_attr_start,
+	NULL,
+};
+
+static int pci_epc_epf_link(struct config_item *epc_item,
+			    struct config_item *epf_item)
+{
+	int ret;
+	struct pci_epf_group *epf_group = to_pci_epf_group(epf_item);
+	struct pci_epc_group *epc_group = to_pci_epc_group(epc_item);
+	struct pci_epc *epc = epc_group->epc;
+	struct pci_epf *epf = epf_group->epf;
+
+	ret = pci_epc_add_epf(epc, epf, PRIMARY_INTERFACE);
+	if (ret)
+		return ret;
+
+	ret = pci_epf_bind(epf);
+	if (ret) {
+		pci_epc_remove_epf(epc, epf, PRIMARY_INTERFACE);
+		return ret;
+	}
+
+	/* Send any pending EPC initialization complete to the EPF driver */
+	pci_epc_notify_pending_init(epc, epf);
+
+	return 0;
+}
+
+static void pci_epc_epf_unlink(struct config_item *epc_item,
+			       struct config_item *epf_item)
+{
+	struct pci_epc *epc;
+	struct pci_epf *epf;
+	struct pci_epf_group *epf_group = to_pci_epf_group(epf_item);
+	struct pci_epc_group *epc_group = to_pci_epc_group(epc_item);
+
+	WARN_ON_ONCE(epc_group->start);
+
+	epc = epc_group->epc;
+	epf = epf_group->epf;
+	pci_epf_unbind(epf);
+	pci_epc_remove_epf(epc, epf, PRIMARY_INTERFACE);
+}
+
+static const struct configfs_item_operations pci_epc_item_ops = {
+	.allow_link	= pci_epc_epf_link,
+	.drop_link	= pci_epc_epf_unlink,
+};
+
+static const struct config_item_type pci_epc_type = {
+	.ct_item_ops	= &pci_epc_item_ops,
+	.ct_attrs	= pci_epc_attrs,
+	.ct_owner	= THIS_MODULE,
+};
+
+struct config_group *pci_ep_cfs_add_epc_group(const char *name)
+{
+	int ret;
+	struct pci_epc *epc;
+	struct config_group *group;
+	struct pci_epc_group *epc_group;
+
+	epc_group = kzalloc_obj(*epc_group);
+	if (!epc_group) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	group = &epc_group->group;
+
+	config_group_init_type_name(group, name, &pci_epc_type);
+	ret = configfs_register_group(controllers_group, group);
+	if (ret) {
+		pr_err("failed to register configfs group for %s\n", name);
+		goto err_register_group;
+	}
+
+	epc = pci_epc_get(name);
+	if (IS_ERR(epc)) {
+		ret = PTR_ERR(epc);
+		goto err_epc_get;
+	}
+
+	epc_group->epc = epc;
+
+	return group;
+
+err_epc_get:
+	configfs_unregister_group(group);
+
+err_register_group:
+	kfree(epc_group);
+
+err:
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL(pci_ep_cfs_add_epc_group);
+
+void pci_ep_cfs_remove_epc_group(struct config_group *group)
+{
+	struct pci_epc_group *epc_group;
+
+	if (!group)
+		return;
+
+	epc_group = container_of(group, struct pci_epc_group, group);
+	pci_epc_put(epc_group->epc);
+	configfs_unregister_group(&epc_group->group);
+	kfree(epc_group);
+}
+EXPORT_SYMBOL(pci_ep_cfs_remove_epc_group);
+
+#define PCI_EPF_HEADER_R(_name)						       \
+static ssize_t pci_epf_##_name##_show(struct config_item *item,	char *page)    \
+{									       \
+	struct pci_epf *epf = to_pci_epf_group(item)->epf;		       \
+	if (WARN_ON_ONCE(!epf->header))					       \
+		return -EINVAL;						       \
+	return sysfs_emit(page, "0x%04x\n", epf->header->_name);	       \
+}
+
+#define PCI_EPF_HEADER_W_u32(_name)					       \
+static ssize_t pci_epf_##_name##_store(struct config_item *item,	       \
+				       const char *page, size_t len)	       \
+{									       \
+	u32 val;							       \
+	struct pci_epf *epf = to_pci_epf_group(item)->epf;		       \
+	if (WARN_ON_ONCE(!epf->header))					       \
+		return -EINVAL;						       \
+	if (kstrtou32(page, 0, &val) < 0)				       \
+		return -EINVAL;						       \
+	epf->header->_name = val;					       \
+	return len;							       \
+}
+
+#define PCI_EPF_HEADER_W_u16(_name)					       \
+static ssize_t pci_epf_##_name##_store(struct config_item *item,	       \
+				       const char *page, size_t len)	       \
+{									       \
+	u16 val;							       \
+	struct pci_epf *epf = to_pci_epf_group(item)->epf;		       \
+	if (WARN_ON_ONCE(!epf->header))					       \
+		return -EINVAL;						       \
+	if (kstrtou16(page, 0, &val) < 0)				       \
+		return -EINVAL;						       \
+	epf->header->_name = val;					       \
+	return len;							       \
+}
+
+#define PCI_EPF_HEADER_W_u8(_name)					       \
+static ssize_t pci_epf_##_name##_store(struct config_item *item,	       \
+				       const char *page, size_t len)	       \
+{									       \
+	u8 val;								       \
+	struct pci_epf *epf = to_pci_epf_group(item)->epf;		       \
+	if (WARN_ON_ONCE(!epf->header))					       \
+		return -EINVAL;						       \
+	if (kstrtou8(page, 0, &val) < 0)				       \
+		return -EINVAL;						       \
+	epf->header->_name = val;					       \
+	return len;							       \
+}
+
+static ssize_t pci_epf_msi_interrupts_store(struct config_item *item,
+					    const char *page, size_t len)
+{
+	u8 val;
+
+	if (kstrtou8(page, 0, &val) < 0)
+		return -EINVAL;
+
+	to_pci_epf_group(item)->epf->msi_interrupts = val;
+
+	return len;
+}
+
+static ssize_t pci_epf_msi_interrupts_show(struct config_item *item,
+					   char *page)
+{
+	return sysfs_emit(page, "%d\n",
+			  to_pci_epf_group(item)->epf->msi_interrupts);
+}
+
+static ssize_t pci_epf_msix_interrupts_store(struct config_item *item,
+					     const char *page, size_t len)
+{
+	u16 val;
+
+	if (kstrtou16(page, 0, &val) < 0)
+		return -EINVAL;
+
+	to_pci_epf_group(item)->epf->msix_interrupts = val;
+
+	return len;
+}
+
+static ssize_t pci_epf_msix_interrupts_show(struct config_item *item,
+					    char *page)
+{
+	return sysfs_emit(page, "%d\n",
+			  to_pci_epf_group(item)->epf->msix_interrupts);
+}
+
+PCI_EPF_HEADER_R(vendorid)
+PCI_EPF_HEADER_W_u16(vendorid)
+
+PCI_EPF_HEADER_R(deviceid)
+PCI_EPF_HEADER_W_u16(deviceid)
+
+PCI_EPF_HEADER_R(revid)
+PCI_EPF_HEADER_W_u8(revid)
+
+PCI_EPF_HEADER_R(progif_code)
+PCI_EPF_HEADER_W_u8(progif_code)
+
+PCI_EPF_HEADER_R(subclass_code)
+PCI_EPF_HEADER_W_u8(subclass_code)
+
+PCI_EPF_HEADER_R(baseclass_code)
+PCI_EPF_HEADER_W_u8(baseclass_code)
+
+PCI_EPF_HEADER_R(cache_line_size)
+PCI_EPF_HEADER_W_u8(cache_line_size)
+
+PCI_EPF_HEADER_R(subsys_vendor_id)
+PCI_EPF_HEADER_W_u16(subsys_vendor_id)
+
+PCI_EPF_HEADER_R(subsys_id)
+PCI_EPF_HEADER_W_u16(subsys_id)
+
+PCI_EPF_HEADER_R(interrupt_pin)
+PCI_EPF_HEADER_W_u8(interrupt_pin)
+
+CONFIGFS_ATTR(pci_epf_, vendorid);
+CONFIGFS_ATTR(pci_epf_, deviceid);
+CONFIGFS_ATTR(pci_epf_, revid);
+CONFIGFS_ATTR(pci_epf_, progif_code);
+CONFIGFS_ATTR(pci_epf_, subclass_code);
+CONFIGFS_ATTR(pci_epf_, baseclass_code);
+CONFIGFS_ATTR(pci_epf_, cache_line_size);
+CONFIGFS_ATTR(pci_epf_, subsys_vendor_id);
+CONFIGFS_ATTR(pci_epf_, subsys_id);
+CONFIGFS_ATTR(pci_epf_, interrupt_pin);
+CONFIGFS_ATTR(pci_epf_, msi_interrupts);
+CONFIGFS_ATTR(pci_epf_, msix_interrupts);
+
+static struct configfs_attribute *pci_epf_attrs[] = {
+	&pci_epf_attr_vendorid,
+	&pci_epf_attr_deviceid,
+	&pci_epf_attr_revid,
+	&pci_epf_attr_progif_code,
+	&pci_epf_attr_subclass_code,
+	&pci_epf_attr_baseclass_code,
+	&pci_epf_attr_cache_line_size,
+	&pci_epf_attr_subsys_vendor_id,
+	&pci_epf_attr_subsys_id,
+	&pci_epf_attr_interrupt_pin,
+	&pci_epf_attr_msi_interrupts,
+	&pci_epf_attr_msix_interrupts,
+	NULL,
+};
+
+static int pci_epf_vepf_link(struct config_item *epf_pf_item,
+			     struct config_item *epf_vf_item)
+{
+	struct pci_epf_group *epf_vf_group = to_pci_epf_group(epf_vf_item);
+	struct pci_epf_group *epf_pf_group = to_pci_epf_group(epf_pf_item);
+	struct pci_epf *epf_pf = epf_pf_group->epf;
+	struct pci_epf *epf_vf = epf_vf_group->epf;
+
+	return pci_epf_add_vepf(epf_pf, epf_vf);
+}
+
+static void pci_epf_vepf_unlink(struct config_item *epf_pf_item,
+				struct config_item *epf_vf_item)
+{
+	struct pci_epf_group *epf_vf_group = to_pci_epf_group(epf_vf_item);
+	struct pci_epf_group *epf_pf_group = to_pci_epf_group(epf_pf_item);
+	struct pci_epf *epf_pf = epf_pf_group->epf;
+	struct pci_epf *epf_vf = epf_vf_group->epf;
+
+	pci_epf_remove_vepf(epf_pf, epf_vf);
+}
+
+static void pci_epf_release(struct config_item *item)
+{
+	struct pci_epf_group *epf_group = to_pci_epf_group(item);
+
+	mutex_lock(&functions_mutex);
+	idr_remove(&functions_idr, epf_group->index);
+	mutex_unlock(&functions_mutex);
+	pci_epf_destroy(epf_group->epf);
+	kfree(epf_group);
+}
+
+static const struct configfs_item_operations pci_epf_ops = {
+	.allow_link		= pci_epf_vepf_link,
+	.drop_link		= pci_epf_vepf_unlink,
+	.release		= pci_epf_release,
+};
+
+static const struct config_item_type pci_epf_type = {
+	.ct_item_ops	= &pci_epf_ops,
+	.ct_attrs	= pci_epf_attrs,
+	.ct_owner	= THIS_MODULE,
+};
+
+/**
+ * pci_epf_type_add_cfs() - Help function drivers to expose function specific
+ *                          attributes in configfs
+ * @epf: the EPF device that has to be configured using configfs
+ * @group: the parent configfs group (corresponding to entries in
+ *         pci_epf_device_id)
+ *
+ * Invoke to expose function specific attributes in configfs.
+ *
+ * Return: A pointer to a config_group structure or NULL if the function driver
+ * does not have anything to expose (attributes configured by user) or if
+ * the function driver does not implement the add_cfs() method.
+ *
+ * Returns an error pointer if this function is called for an unbound EPF device
+ * or if the EPF driver add_cfs() method fails.
+ */
+static struct config_group *pci_epf_type_add_cfs(struct pci_epf *epf,
+						 struct config_group *group)
+{
+	struct config_group *epf_type_group;
+
+	if (!epf->driver) {
+		dev_err(&epf->dev, "epf device not bound to driver\n");
+		return ERR_PTR(-ENODEV);
+	}
+
+	if (!epf->driver->ops->add_cfs)
+		return NULL;
+
+	mutex_lock(&epf->lock);
+	epf_type_group = epf->driver->ops->add_cfs(epf, group);
+	mutex_unlock(&epf->lock);
+
+	return epf_type_group;
+}
+
+static void pci_ep_cfs_add_type_group(struct pci_epf_group *epf_group)
+{
+	struct config_group *group;
+
+	group = pci_epf_type_add_cfs(epf_group->epf, &epf_group->group);
+	if (!group)
+		return;
+
+	if (IS_ERR(group)) {
+		dev_err(&epf_group->epf->dev,
+			"failed to create epf type specific attributes: %pe\n",
+			group);
+		return;
+	}
+
+	configfs_add_default_group(group, &epf_group->group);
+}
+
+static void pci_epf_cfs_add_sub_groups(struct pci_epf_group *epf_group)
+{
+	struct config_group *group;
+
+	group = pci_ep_cfs_add_primary_group(epf_group);
+	if (IS_ERR(group)) {
+		dev_err(&epf_group->epf->dev,
+			"failed to create 'primary' EPC interface: %pe\n",
+			group);
+		return;
+	}
+
+	group = pci_ep_cfs_add_secondary_group(epf_group);
+	if (IS_ERR(group)) {
+		dev_err(&epf_group->epf->dev,
+			"failed to create 'secondary' EPC interface: %pe\n",
+			group);
+		return;
+	}
+
+	pci_ep_cfs_add_type_group(epf_group);
+}
+
+static struct config_group *pci_epf_make(struct config_group *group,
+					 const char *name)
+{
+	struct pci_epf_group *epf_group;
+	struct pci_epf *epf;
+	char *epf_name;
+	int index, err;
+
+	epf_group = kzalloc_obj(*epf_group);
+	if (!epf_group)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_lock(&functions_mutex);
+	index = idr_alloc(&functions_idr, epf_group, 0, 0, GFP_KERNEL);
+	mutex_unlock(&functions_mutex);
+	if (index < 0) {
+		err = index;
+		goto free_group;
+	}
+
+	epf_group->index = index;
+
+	config_group_init_type_name(&epf_group->group, name, &pci_epf_type);
+
+	epf_name = kasprintf(GFP_KERNEL, "%s.%d",
+			     group->cg_item.ci_name, epf_group->index);
+	if (!epf_name) {
+		err = -ENOMEM;
+		goto remove_idr;
+	}
+
+	epf = pci_epf_create(epf_name);
+	if (IS_ERR(epf)) {
+		err = PTR_ERR(epf);
+		pr_err("failed to create endpoint function device (%s): %d\n",
+			epf_name, err);
+		goto free_name;
+	}
+
+	epf->group = &epf_group->group;
+	epf_group->epf = epf;
+
+	kfree(epf_name);
+
+	pci_epf_cfs_add_sub_groups(epf_group);
+
+	return &epf_group->group;
+
+free_name:
+	kfree(epf_name);
+
+remove_idr:
+	mutex_lock(&functions_mutex);
+	idr_remove(&functions_idr, epf_group->index);
+	mutex_unlock(&functions_mutex);
+
+free_group:
+	kfree(epf_group);
+
+	return ERR_PTR(err);
+}
+
+static void pci_epf_drop(struct config_group *group, struct config_item *item)
+{
+	config_item_put(item);
+}
+
+static const struct configfs_group_operations pci_epf_group_ops = {
+	.make_group     = &pci_epf_make,
+	.drop_item      = &pci_epf_drop,
+};
+
+static const struct config_item_type pci_epf_group_type = {
+	.ct_group_ops	= &pci_epf_group_ops,
+	.ct_owner	= THIS_MODULE,
+};
+
+struct config_group *pci_ep_cfs_add_epf_group(const char *name)
+{
+	struct config_group *group;
+
+	group = configfs_register_default_group(functions_group, name,
+						&pci_epf_group_type);
+	if (IS_ERR(group))
+		pr_err("failed to register configfs group for %s function: %pe\n",
+		       name, group);
+
+	return group;
+}
+EXPORT_SYMBOL(pci_ep_cfs_add_epf_group);
+
+void pci_ep_cfs_remove_epf_group(struct config_group *group)
+{
+	if (IS_ERR_OR_NULL(group))
+		return;
+
+	list_del(&group->group_entry);
+	configfs_unregister_default_group(group);
+}
+EXPORT_SYMBOL(pci_ep_cfs_remove_epf_group);
+
+static const struct config_item_type pci_functions_type = {
+	.ct_owner	= THIS_MODULE,
+};
+
+static const struct config_item_type pci_controllers_type = {
+	.ct_owner	= THIS_MODULE,
+};
+
+static const struct config_item_type pci_ep_type = {
+	.ct_owner	= THIS_MODULE,
+};
+
+static struct configfs_subsystem pci_ep_cfs_subsys = {
+	.su_group = {
+		.cg_item = {
+			.ci_namebuf = "pci_ep",
+			.ci_type = &pci_ep_type,
+		},
+	},
+	.su_mutex = __MUTEX_INITIALIZER(pci_ep_cfs_subsys.su_mutex),
+};
+
+static int __init pci_ep_cfs_init(void)
+{
+	int ret;
+	struct config_group *root = &pci_ep_cfs_subsys.su_group;
+
+	config_group_init(root);
+
+	ret = configfs_register_subsystem(&pci_ep_cfs_subsys);
+	if (ret) {
+		pr_err("Error %d while registering subsystem %s\n",
+		       ret, root->cg_item.ci_namebuf);
+		goto err;
+	}
+
+	functions_group = configfs_register_default_group(root, "functions",
+							  &pci_functions_type);
+	if (IS_ERR(functions_group)) {
+		ret = PTR_ERR(functions_group);
+		pr_err("Error %d while registering functions group\n",
+		       ret);
+		goto err_functions_group;
+	}
+
+	controllers_group =
+		configfs_register_default_group(root, "controllers",
+						&pci_controllers_type);
+	if (IS_ERR(controllers_group)) {
+		ret = PTR_ERR(controllers_group);
+		pr_err("Error %d while registering controllers group\n",
+		       ret);
+		goto err_controllers_group;
+	}
+
+	return 0;
+
+err_controllers_group:
+	configfs_unregister_default_group(functions_group);
+
+err_functions_group:
+	configfs_unregister_subsystem(&pci_ep_cfs_subsys);
+
+err:
+	return ret;
+}
+module_init(pci_ep_cfs_init);
+
+static void __exit pci_ep_cfs_exit(void)
+{
+	configfs_unregister_default_group(controllers_group);
+	configfs_unregister_default_group(functions_group);
+	configfs_unregister_subsystem(&pci_ep_cfs_subsys);
+}
+module_exit(pci_ep_cfs_exit);
+
+MODULE_DESCRIPTION("PCI EP CONFIGFS");
+MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");

linux-7.2.3/drivers/pci/endpoint/pci-ep-msi.c

@@ -0,0 +1,254 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI Endpoint *Controller* (EPC) MSI library
+ *
+ * Copyright (C) 2025 NXP
+ * Author: Frank Li <Frank.Li@nxp.com>
+ */
+
+#include <linux/align.h>
+#include <linux/cleanup.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/of_irq.h>
+#include <linux/pci-epc.h>
+#include <linux/pci-epf.h>
+#include <linux/pci-ep-cfs.h>
+#include <linux/pci-ep-msi.h>
+#include <linux/slab.h>
+
+static void pci_epf_write_msi_msg(struct msi_desc *desc, struct msi_msg *msg)
+{
+	struct pci_epc *epc;
+	struct pci_epf *epf;
+
+	epc = pci_epc_get(dev_name(msi_desc_to_dev(desc)));
+	if (IS_ERR(epc))
+		return;
+
+	epf = list_first_entry_or_null(&epc->pci_epf, struct pci_epf, list);
+
+	if (epf && epf->db_msg && desc->msi_index < epf->num_db)
+		memcpy(&epf->db_msg[desc->msi_index].msg, msg, sizeof(*msg));
+
+	pci_epc_put(epc);
+}
+
+static int pci_epf_alloc_doorbell_embedded(struct pci_epf *epf, u16 num_db)
+{
+	const struct pci_epc_aux_resource *doorbell = NULL;
+	struct pci_epf_doorbell_msg *msg;
+	struct pci_epc *epc = epf->epc;
+	size_t map_size = 0, off = 0;
+	dma_addr_t iova_base = 0;
+	phys_addr_t phys_base;
+	int count, ret, i;
+	u64 addr;
+
+	count = pci_epc_get_aux_resources_count(epc, epf->func_no,
+						epf->vfunc_no);
+	if (count < 0)
+		return count;
+	if (!count)
+		return -ENODEV;
+
+	struct pci_epc_aux_resource *res __free(kfree) =
+				kcalloc(count, sizeof(*res), GFP_KERNEL);
+	if (!res)
+		return -ENOMEM;
+
+	ret = pci_epc_get_aux_resources(epc, epf->func_no, epf->vfunc_no,
+					res, count);
+	if (ret)
+		return ret;
+
+	/* TODO: Support multiple DOORBELL_MMIO resources per EPC. */
+	for (i = 0; i < count; i++) {
+		if (res[i].type != PCI_EPC_AUX_DOORBELL_MMIO)
+			continue;
+
+		doorbell = &res[i];
+		break;
+	}
+	if (!doorbell)
+		return -ENODEV;
+	addr = doorbell->phys_addr;
+	if (!IS_ALIGNED(addr, sizeof(u32)))
+		return -EINVAL;
+
+	/*
+	 * Reuse the pre-exposed BAR window if available. Otherwise map the MMIO
+	 * doorbell resource here. Any required IOMMU mapping is handled
+	 * internally, matching the MSI doorbell semantics.
+	 */
+	if (doorbell->bar == NO_BAR) {
+		phys_base = addr & PAGE_MASK;
+		off = addr - phys_base;
+		map_size = PAGE_ALIGN(off + sizeof(u32));
+
+		iova_base = dma_map_resource(epc->dev.parent, phys_base,
+					     map_size, DMA_FROM_DEVICE, 0);
+		if (dma_mapping_error(epc->dev.parent, iova_base))
+			return -EIO;
+
+		addr = iova_base + off;
+	}
+
+	msg = kcalloc(num_db, sizeof(*msg), GFP_KERNEL);
+	if (!msg) {
+		ret = -ENOMEM;
+		goto err_unmap;
+	}
+
+	/*
+	 * Embedded doorbell backends (e.g. DesignWare eDMA interrupt emulation)
+	 * typically provide a single IRQ and do not offer per-doorbell
+	 * distinguishable address/data pairs. The EPC aux resource therefore
+	 * exposes one DOORBELL_MMIO entry (u.db_mmio.irq).
+	 *
+	 * Still, pci_epf_alloc_doorbell() allows requesting multiple doorbells.
+	 * For such backends we replicate the same address/data for each entry
+	 * and mark the IRQ as shared (IRQF_SHARED). Consumers must treat them
+	 * as equivalent "kick" doorbells.
+	 */
+	for (i = 0; i < num_db; i++)
+		msg[i] = (struct pci_epf_doorbell_msg) {
+			.msg.address_lo = (u32)addr,
+			.msg.address_hi = (u32)(addr >> 32),
+			.msg.data = doorbell->u.db_mmio.data,
+			.virq = doorbell->u.db_mmio.irq,
+			.irq_flags = IRQF_SHARED,
+			.type = PCI_EPF_DOORBELL_EMBEDDED,
+			.bar = doorbell->bar,
+			.offset = (doorbell->bar == NO_BAR) ? 0 :
+				  doorbell->bar_offset,
+			.iova_base = iova_base,
+			.iova_size = map_size,
+		};
+
+	epf->num_db = num_db;
+	epf->db_msg = msg;
+	return 0;
+
+err_unmap:
+	if (map_size)
+		dma_unmap_resource(epc->dev.parent, iova_base, map_size,
+				   DMA_FROM_DEVICE, 0);
+	return ret;
+}
+
+static int pci_epf_alloc_doorbell_msi(struct pci_epf *epf, u16 num_db)
+{
+	struct pci_epf_doorbell_msg *msg;
+	struct device *dev = &epf->dev;
+	struct pci_epc *epc = epf->epc;
+	struct irq_domain *domain;
+	int ret, i;
+
+	domain = of_msi_map_get_device_domain(epc->dev.parent, 0,
+					      DOMAIN_BUS_PLATFORM_MSI);
+	if (!domain) {
+		dev_err(dev, "Can't find MSI domain for EPC\n");
+		return -ENODEV;
+	}
+
+	if (!irq_domain_is_msi_parent(domain))
+		return -ENODEV;
+
+	if (!irq_domain_is_msi_immutable(domain)) {
+		dev_err(dev, "Mutable MSI controller not supported\n");
+		return -ENODEV;
+	}
+
+	dev_set_msi_domain(epc->dev.parent, domain);
+
+	msg = kzalloc_objs(struct pci_epf_doorbell_msg, num_db);
+	if (!msg)
+		return -ENOMEM;
+
+	for (i = 0; i < num_db; i++)
+		msg[i] = (struct pci_epf_doorbell_msg) {
+			.type = PCI_EPF_DOORBELL_MSI,
+			.bar = NO_BAR,
+		};
+
+	epf->num_db = num_db;
+	epf->db_msg = msg;
+
+	ret = platform_device_msi_init_and_alloc_irqs(epc->dev.parent, num_db,
+						      pci_epf_write_msi_msg);
+	if (ret) {
+		dev_err(dev, "Failed to allocate MSI\n");
+		kfree(msg);
+		epf->db_msg = NULL;
+		epf->num_db = 0;
+		return ret;
+	}
+
+	for (i = 0; i < num_db; i++)
+		epf->db_msg[i].virq = msi_get_virq(epc->dev.parent, i);
+
+	return 0;
+}
+
+int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 num_db)
+{
+	struct pci_epc *epc = epf->epc;
+	struct device *dev = &epf->dev;
+	int ret;
+
+	/* TODO: Multi-EPF support */
+	if (list_first_entry_or_null(&epc->pci_epf, struct pci_epf, list) != epf) {
+		dev_err(dev, "Doorbell doesn't support multiple EPF\n");
+		return -EINVAL;
+	}
+
+	if (epf->db_msg)
+		return -EBUSY;
+
+	ret = pci_epf_alloc_doorbell_msi(epf, num_db);
+	if (!ret)
+		return 0;
+
+	/*
+	 * Fall back to embedded doorbell only when platform MSI is unavailable
+	 * for this EPC.
+	 */
+	if (ret != -ENODEV)
+		return ret;
+
+	ret = pci_epf_alloc_doorbell_embedded(epf, num_db);
+	if (ret) {
+		dev_err(dev, "Failed to allocate doorbell: %d\n", ret);
+		return ret;
+	}
+
+	dev_info(dev, "Using embedded (DMA) doorbell fallback\n");
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pci_epf_alloc_doorbell);
+
+void pci_epf_free_doorbell(struct pci_epf *epf)
+{
+	struct pci_epf_doorbell_msg *msg0;
+	struct pci_epc *epc = epf->epc;
+
+	if (!epf->db_msg)
+		return;
+
+	msg0 = &epf->db_msg[0];
+	if (msg0->type == PCI_EPF_DOORBELL_MSI)
+		platform_device_msi_free_irqs_all(epf->epc->dev.parent);
+	else if (msg0->type == PCI_EPF_DOORBELL_EMBEDDED && msg0->iova_size)
+		dma_unmap_resource(epc->dev.parent, msg0->iova_base,
+				   msg0->iova_size, DMA_FROM_DEVICE, 0);
+
+	kfree(epf->db_msg);
+	epf->db_msg = NULL;
+	epf->num_db = 0;
+}
+EXPORT_SYMBOL_GPL(pci_epf_free_doorbell);

linux-7.2.3/drivers/pci/endpoint/pci-epc-mem.c

@@ -0,0 +1,275 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI Endpoint *Controller* Address Space Management
+ *
+ * Copyright (C) 2017 Texas Instruments
+ * Author: Kishon Vijay Abraham I <kishon@ti.com>
+ */
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <linux/pci-epc.h>
+
+/**
+ * pci_epc_mem_get_order() - determine the allocation order of a memory size
+ * @mem: address space of the endpoint controller
+ * @size: the size for which to get the order
+ *
+ * Reimplement get_order() for mem->page_size since the generic get_order
+ * always gets order with a constant PAGE_SIZE.
+ */
+static int pci_epc_mem_get_order(struct pci_epc_mem *mem, size_t size)
+{
+	int order;
+	unsigned int page_shift = ilog2(mem->window.page_size);
+
+	size--;
+	size >>= page_shift;
+#if BITS_PER_LONG == 32
+	order = fls(size);
+#else
+	order = fls64(size);
+#endif
+	return order;
+}
+
+/**
+ * pci_epc_multi_mem_init() - initialize the pci_epc_mem structure
+ * @epc: the EPC device that invoked pci_epc_mem_init
+ * @windows: pointer to windows supported by the device
+ * @num_windows: number of windows device supports
+ *
+ * Invoke to initialize the pci_epc_mem structure used by the
+ * endpoint functions to allocate mapped PCI address.
+ */
+int pci_epc_multi_mem_init(struct pci_epc *epc,
+			   struct pci_epc_mem_window *windows,
+			   unsigned int num_windows)
+{
+	struct pci_epc_mem *mem = NULL;
+	unsigned long *bitmap = NULL;
+	unsigned int page_shift;
+	size_t page_size;
+	int bitmap_size;
+	int pages;
+	int ret;
+	int i;
+
+	epc->num_windows = 0;
+
+	if (!windows || !num_windows)
+		return -EINVAL;
+
+	epc->windows = kzalloc_objs(*epc->windows, num_windows);
+	if (!epc->windows)
+		return -ENOMEM;
+
+	for (i = 0; i < num_windows; i++) {
+		page_size = windows[i].page_size;
+		if (page_size < PAGE_SIZE)
+			page_size = PAGE_SIZE;
+		page_shift = ilog2(page_size);
+		pages = windows[i].size >> page_shift;
+		bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
+
+		mem = kzalloc_obj(*mem);
+		if (!mem) {
+			ret = -ENOMEM;
+			i--;
+			goto err_mem;
+		}
+
+		bitmap = kzalloc(bitmap_size, GFP_KERNEL);
+		if (!bitmap) {
+			ret = -ENOMEM;
+			kfree(mem);
+			i--;
+			goto err_mem;
+		}
+
+		mem->window.phys_base = windows[i].phys_base;
+		mem->window.size = windows[i].size;
+		mem->window.page_size = page_size;
+		mem->bitmap = bitmap;
+		mem->pages = pages;
+		mutex_init(&mem->lock);
+		epc->windows[i] = mem;
+	}
+
+	epc->mem = epc->windows[0];
+	epc->num_windows = num_windows;
+
+	return 0;
+
+err_mem:
+	for (; i >= 0; i--) {
+		mem = epc->windows[i];
+		kfree(mem->bitmap);
+		kfree(mem);
+	}
+	kfree(epc->windows);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pci_epc_multi_mem_init);
+
+/**
+ * pci_epc_mem_init() - Initialize the pci_epc_mem structure
+ * @epc: the EPC device that invoked pci_epc_mem_init
+ * @base: Physical address of the window region
+ * @size: Total Size of the window region
+ * @page_size: Page size of the window region
+ *
+ * Invoke to initialize a single pci_epc_mem structure used by the
+ * endpoint functions to allocate memory for mapping the PCI host memory
+ */
+int pci_epc_mem_init(struct pci_epc *epc, phys_addr_t base,
+		     size_t size, size_t page_size)
+{
+	struct pci_epc_mem_window mem_window;
+
+	mem_window.phys_base = base;
+	mem_window.size = size;
+	mem_window.page_size = page_size;
+
+	return pci_epc_multi_mem_init(epc, &mem_window, 1);
+}
+EXPORT_SYMBOL_GPL(pci_epc_mem_init);
+
+/**
+ * pci_epc_mem_exit() - cleanup the pci_epc_mem structure
+ * @epc: the EPC device that invoked pci_epc_mem_exit
+ *
+ * Invoke to cleanup the pci_epc_mem structure allocated in
+ * pci_epc_mem_init().
+ */
+void pci_epc_mem_exit(struct pci_epc *epc)
+{
+	struct pci_epc_mem *mem;
+	int i;
+
+	if (!epc->num_windows)
+		return;
+
+	for (i = 0; i < epc->num_windows; i++) {
+		mem = epc->windows[i];
+		kfree(mem->bitmap);
+		kfree(mem);
+	}
+	kfree(epc->windows);
+
+	epc->windows = NULL;
+	epc->mem = NULL;
+	epc->num_windows = 0;
+}
+EXPORT_SYMBOL_GPL(pci_epc_mem_exit);
+
+/**
+ * pci_epc_mem_alloc_addr() - allocate memory address from EPC addr space
+ * @epc: the EPC device on which memory has to be allocated
+ * @phys_addr: populate the allocated physical address here
+ * @size: the size of the address space that has to be allocated
+ *
+ * Invoke to allocate memory address from the EPC address space. This
+ * is usually done to map the remote RC address into the local system.
+ */
+void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc,
+				     phys_addr_t *phys_addr, size_t size)
+{
+	void __iomem *virt_addr;
+	struct pci_epc_mem *mem;
+	unsigned int page_shift;
+	size_t align_size;
+	int pageno;
+	int order;
+	int i;
+
+	for (i = 0; i < epc->num_windows; i++) {
+		mem = epc->windows[i];
+		if (size > mem->window.size)
+			continue;
+
+		align_size = ALIGN(size, mem->window.page_size);
+		order = pci_epc_mem_get_order(mem, align_size);
+
+		mutex_lock(&mem->lock);
+		pageno = bitmap_find_free_region(mem->bitmap, mem->pages,
+						 order);
+		if (pageno >= 0) {
+			page_shift = ilog2(mem->window.page_size);
+			*phys_addr = mem->window.phys_base +
+				((phys_addr_t)pageno << page_shift);
+			virt_addr = ioremap(*phys_addr, align_size);
+			if (!virt_addr) {
+				bitmap_release_region(mem->bitmap,
+						      pageno, order);
+				mutex_unlock(&mem->lock);
+				continue;
+			}
+			mutex_unlock(&mem->lock);
+			return virt_addr;
+		}
+		mutex_unlock(&mem->lock);
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(pci_epc_mem_alloc_addr);
+
+static struct pci_epc_mem *pci_epc_get_matching_window(struct pci_epc *epc,
+						       phys_addr_t phys_addr)
+{
+	struct pci_epc_mem *mem;
+	int i;
+
+	for (i = 0; i < epc->num_windows; i++) {
+		mem = epc->windows[i];
+
+		if (phys_addr >= mem->window.phys_base &&
+		    phys_addr < (mem->window.phys_base + mem->window.size))
+			return mem;
+	}
+
+	return NULL;
+}
+
+/**
+ * pci_epc_mem_free_addr() - free the allocated memory address
+ * @epc: the EPC device on which memory was allocated
+ * @phys_addr: the allocated physical address
+ * @virt_addr: virtual address of the allocated mem space
+ * @size: the size of the allocated address space
+ *
+ * Invoke to free the memory allocated using pci_epc_mem_alloc_addr.
+ */
+void pci_epc_mem_free_addr(struct pci_epc *epc, phys_addr_t phys_addr,
+			   void __iomem *virt_addr, size_t size)
+{
+	struct pci_epc_mem *mem;
+	unsigned int page_shift;
+	size_t page_size;
+	int pageno;
+	int order;
+
+	mem = pci_epc_get_matching_window(epc, phys_addr);
+	if (!mem) {
+		pr_err("failed to get matching window\n");
+		return;
+	}
+
+	page_size = mem->window.page_size;
+	page_shift = ilog2(page_size);
+	iounmap(virt_addr);
+	pageno = (phys_addr - mem->window.phys_base) >> page_shift;
+	size = ALIGN(size, page_size);
+	order = pci_epc_mem_get_order(mem, size);
+	mutex_lock(&mem->lock);
+	bitmap_release_region(mem->bitmap, pageno, order);
+	mutex_unlock(&mem->lock);
+}
+EXPORT_SYMBOL_GPL(pci_epc_mem_free_addr);
+
+MODULE_DESCRIPTION("PCI EPC Address Space Management");
+MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");

linux-7.2.3/drivers/pci/endpoint/pci-epf-core.c

@@ -0,0 +1,699 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI Endpoint *Function* (EPF) library
+ *
+ * Copyright (C) 2017 Texas Instruments
+ * Author: Kishon Vijay Abraham I <kishon@ti.com>
+ */
+
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#include <linux/pci-epc.h>
+#include <linux/pci-epf.h>
+#include <linux/pci-ep-cfs.h>
+
+static DEFINE_MUTEX(pci_epf_mutex);
+
+static const struct bus_type pci_epf_bus_type;
+static const struct device_type pci_epf_type;
+
+/**
+ * pci_epf_unbind() - Notify the function driver that the binding between the
+ *		      EPF device and EPC device has been lost
+ * @epf: the EPF device which has lost the binding with the EPC device
+ *
+ * Invoke to notify the function driver that the binding between the EPF device
+ * and EPC device has been lost.
+ */
+void pci_epf_unbind(struct pci_epf *epf)
+{
+	struct pci_epf *epf_vf;
+
+	if (!epf->driver) {
+		dev_WARN(&epf->dev, "epf device not bound to driver\n");
+		return;
+	}
+
+	mutex_lock(&epf->lock);
+	list_for_each_entry(epf_vf, &epf->pci_vepf, list) {
+		if (epf_vf->is_bound)
+			epf_vf->driver->ops->unbind(epf_vf);
+	}
+	if (epf->is_bound)
+		epf->driver->ops->unbind(epf);
+	mutex_unlock(&epf->lock);
+	module_put(epf->driver->owner);
+}
+EXPORT_SYMBOL_GPL(pci_epf_unbind);
+
+/**
+ * pci_epf_bind() - Notify the function driver that the EPF device has been
+ *		    bound to a EPC device
+ * @epf: the EPF device which has been bound to the EPC device
+ *
+ * Invoke to notify the function driver that it has been bound to a EPC device
+ */
+int pci_epf_bind(struct pci_epf *epf)
+{
+	struct device *dev = &epf->dev;
+	struct pci_epf *epf_vf;
+	u8 func_no, vfunc_no;
+	struct pci_epc *epc;
+	int ret;
+
+	if (!epf->driver) {
+		dev_WARN(dev, "epf device not bound to driver\n");
+		return -EINVAL;
+	}
+
+	if (!try_module_get(epf->driver->owner))
+		return -EAGAIN;
+
+	mutex_lock(&epf->lock);
+	list_for_each_entry(epf_vf, &epf->pci_vepf, list) {
+		vfunc_no = epf_vf->vfunc_no;
+
+		if (vfunc_no < 1) {
+			dev_err(dev, "Invalid virtual function number\n");
+			ret = -EINVAL;
+			goto ret;
+		}
+
+		epc = epf->epc;
+		func_no = epf->func_no;
+		if (!IS_ERR_OR_NULL(epc)) {
+			if (!epc->max_vfs) {
+				dev_err(dev, "No support for virt function\n");
+				ret = -EINVAL;
+				goto ret;
+			}
+
+			if (vfunc_no > epc->max_vfs[func_no]) {
+				dev_err(dev, "PF%d: Exceeds max vfunc number\n",
+					func_no);
+				ret = -EINVAL;
+				goto ret;
+			}
+		}
+
+		epc = epf->sec_epc;
+		func_no = epf->sec_epc_func_no;
+		if (!IS_ERR_OR_NULL(epc)) {
+			if (!epc->max_vfs) {
+				dev_err(dev, "No support for virt function\n");
+				ret = -EINVAL;
+				goto ret;
+			}
+
+			if (vfunc_no > epc->max_vfs[func_no]) {
+				dev_err(dev, "PF%d: Exceeds max vfunc number\n",
+					func_no);
+				ret = -EINVAL;
+				goto ret;
+			}
+		}
+
+		epf_vf->func_no = epf->func_no;
+		epf_vf->sec_epc_func_no = epf->sec_epc_func_no;
+		epf_vf->epc = epf->epc;
+		epf_vf->sec_epc = epf->sec_epc;
+		ret = epf_vf->driver->ops->bind(epf_vf);
+		if (ret)
+			goto ret;
+		epf_vf->is_bound = true;
+	}
+
+	ret = epf->driver->ops->bind(epf);
+	if (ret)
+		goto ret;
+	epf->is_bound = true;
+
+	mutex_unlock(&epf->lock);
+	return 0;
+
+ret:
+	mutex_unlock(&epf->lock);
+	pci_epf_unbind(epf);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pci_epf_bind);
+
+/**
+ * pci_epf_add_vepf() - associate virtual EP function to physical EP function
+ * @epf_pf: the physical EP function to which the virtual EP function should be
+ *   associated
+ * @epf_vf: the virtual EP function to be added
+ *
+ * A physical endpoint function can be associated with multiple virtual
+ * endpoint functions. Invoke pci_epf_add_vepf() to add a virtual PCI endpoint
+ * function to a physical PCI endpoint function.
+ */
+int pci_epf_add_vepf(struct pci_epf *epf_pf, struct pci_epf *epf_vf)
+{
+	u32 vfunc_no;
+
+	if (IS_ERR_OR_NULL(epf_pf) || IS_ERR_OR_NULL(epf_vf))
+		return -EINVAL;
+
+	if (epf_pf->epc || epf_vf->epc || epf_vf->epf_pf)
+		return -EBUSY;
+
+	if (epf_pf->sec_epc || epf_vf->sec_epc)
+		return -EBUSY;
+
+	mutex_lock(&epf_pf->lock);
+	vfunc_no = find_first_zero_bit(&epf_pf->vfunction_num_map,
+				       BITS_PER_LONG);
+	if (vfunc_no >= BITS_PER_LONG) {
+		mutex_unlock(&epf_pf->lock);
+		return -EINVAL;
+	}
+
+	set_bit(vfunc_no, &epf_pf->vfunction_num_map);
+	epf_vf->vfunc_no = vfunc_no;
+
+	epf_vf->epf_pf = epf_pf;
+	epf_vf->is_vf = true;
+
+	list_add_tail(&epf_vf->list, &epf_pf->pci_vepf);
+	mutex_unlock(&epf_pf->lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pci_epf_add_vepf);
+
+/**
+ * pci_epf_remove_vepf() - remove virtual EP function from physical EP function
+ * @epf_pf: the physical EP function from which the virtual EP function should
+ *   be removed
+ * @epf_vf: the virtual EP function to be removed
+ *
+ * Invoke to remove a virtual endpoint function from the physical endpoint
+ * function.
+ */
+void pci_epf_remove_vepf(struct pci_epf *epf_pf, struct pci_epf *epf_vf)
+{
+	if (IS_ERR_OR_NULL(epf_pf) || IS_ERR_OR_NULL(epf_vf))
+		return;
+
+	mutex_lock(&epf_pf->lock);
+	clear_bit(epf_vf->vfunc_no, &epf_pf->vfunction_num_map);
+	epf_vf->epf_pf = NULL;
+	list_del(&epf_vf->list);
+	mutex_unlock(&epf_pf->lock);
+}
+EXPORT_SYMBOL_GPL(pci_epf_remove_vepf);
+
+static int pci_epf_get_required_bar_size(struct pci_epf *epf, size_t *bar_size,
+				size_t *aligned_mem_size,
+				enum pci_barno bar,
+				const struct pci_epc_features *epc_features,
+				enum pci_epc_interface_type type)
+{
+	u64 bar_fixed_size = epc_features->bar[bar].fixed_size;
+	size_t align = epc_features->align;
+	size_t size = *bar_size;
+
+	if (size < 128)
+		size = 128;
+
+	/* According to PCIe base spec, min size for a resizable BAR is 1 MB. */
+	if (epc_features->bar[bar].type == BAR_RESIZABLE && size < SZ_1M)
+		size = SZ_1M;
+
+	if (epc_features->bar[bar].type == BAR_FIXED && bar_fixed_size) {
+		if (size > bar_fixed_size) {
+			dev_err(&epf->dev,
+				"requested BAR size is larger than fixed size\n");
+			return -ENOMEM;
+		}
+		size = bar_fixed_size;
+	} else {
+		/* BAR size must be power of two */
+		size = roundup_pow_of_two(size);
+	}
+
+	*bar_size = size;
+
+	/*
+	 * The EPC's BAR start address must meet alignment requirements. In most
+	 * cases, the alignment will match the BAR size. However, differences
+	 * can occur—for example, when the fixed BAR size (e.g., 128 bytes) is
+	 * smaller than the required alignment (e.g., 4 KB).
+	 */
+	*aligned_mem_size = align ? ALIGN(size, align) : size;
+
+	return 0;
+}
+
+/**
+ * pci_epf_free_space() - free the allocated PCI EPF register space
+ * @epf: the EPF device from whom to free the memory
+ * @addr: the virtual address of the PCI EPF register space
+ * @bar: the BAR number corresponding to the register space
+ * @type: Identifies if the allocated space is for primary EPC or secondary EPC
+ *
+ * Invoke to free the allocated PCI EPF register space.
+ */
+void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar,
+			enum pci_epc_interface_type type)
+{
+	struct device *dev;
+	struct pci_epf_bar *epf_bar;
+	struct pci_epc *epc;
+
+	if (!addr)
+		return;
+
+	if (type == PRIMARY_INTERFACE) {
+		epc = epf->epc;
+		epf_bar = epf->bar;
+	} else {
+		epc = epf->sec_epc;
+		epf_bar = epf->sec_epc_bar;
+	}
+
+	dev = epc->dev.parent;
+	dma_free_coherent(dev, epf_bar[bar].mem_size, addr,
+			  epf_bar[bar].phys_addr);
+
+	epf_bar[bar].phys_addr = 0;
+	epf_bar[bar].addr = NULL;
+	epf_bar[bar].size = 0;
+	epf_bar[bar].mem_size = 0;
+	epf_bar[bar].barno = 0;
+	epf_bar[bar].flags = 0;
+}
+EXPORT_SYMBOL_GPL(pci_epf_free_space);
+
+/**
+ * pci_epf_alloc_space() - allocate memory for the PCI EPF register space
+ * @epf: the EPF device to whom allocate the memory
+ * @size: the size of the memory that has to be allocated
+ * @bar: the BAR number corresponding to the allocated register space
+ * @epc_features: the features provided by the EPC specific to this EPF
+ * @type: Identifies if the allocation is for primary EPC or secondary EPC
+ *
+ * Invoke to allocate memory for the PCI EPF register space.
+ * Flag PCI_BASE_ADDRESS_MEM_TYPE_64 will automatically get set if the BAR
+ * can only be a 64-bit BAR, or if the requested size is larger than 2 GB.
+ */
+void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
+			  const struct pci_epc_features *epc_features,
+			  enum pci_epc_interface_type type)
+{
+	struct pci_epf_bar *epf_bar;
+	dma_addr_t phys_addr;
+	struct pci_epc *epc;
+	struct device *dev;
+	size_t mem_size;
+	void *space;
+
+	if (pci_epf_get_required_bar_size(epf, &size, &mem_size, bar,
+					  epc_features, type))
+		return NULL;
+
+	if (type == PRIMARY_INTERFACE) {
+		epc = epf->epc;
+		epf_bar = epf->bar;
+	} else {
+		epc = epf->sec_epc;
+		epf_bar = epf->sec_epc_bar;
+	}
+
+	dev = epc->dev.parent;
+	space = dma_alloc_coherent(dev, mem_size, &phys_addr, GFP_KERNEL);
+	if (!space) {
+		dev_err(dev, "failed to allocate mem space\n");
+		return NULL;
+	}
+
+	epf_bar[bar].phys_addr = phys_addr;
+	epf_bar[bar].addr = space;
+	epf_bar[bar].size = size;
+	epf_bar[bar].mem_size = mem_size;
+	epf_bar[bar].barno = bar;
+	if (upper_32_bits(size) || epc_features->bar[bar].only_64bit)
+		epf_bar[bar].flags |= PCI_BASE_ADDRESS_MEM_TYPE_64;
+	else
+		epf_bar[bar].flags |= PCI_BASE_ADDRESS_MEM_TYPE_32;
+
+	return space;
+}
+EXPORT_SYMBOL_GPL(pci_epf_alloc_space);
+
+/**
+ * pci_epf_assign_bar_space() - Assign PCI EPF BAR space
+ * @epf: EPF device to assign the BAR memory
+ * @size: Size of the memory that has to be assigned
+ * @bar: BAR number for which the memory is assigned
+ * @epc_features: Features provided by the EPC specific to this EPF
+ * @type: Identifies if the assignment is for primary EPC or secondary EPC
+ * @bar_addr: Address to be assigned for the @bar
+ *
+ * Invoke to assign memory for the PCI EPF BAR.
+ * Flag PCI_BASE_ADDRESS_MEM_TYPE_64 will automatically get set if the BAR
+ * can only be a 64-bit BAR, or if the requested size is larger than 2 GB.
+ */
+int pci_epf_assign_bar_space(struct pci_epf *epf, size_t size,
+			     enum pci_barno bar,
+			     const struct pci_epc_features *epc_features,
+			     enum pci_epc_interface_type type,
+			     dma_addr_t bar_addr)
+{
+	size_t bar_size, aligned_mem_size;
+	struct pci_epf_bar *epf_bar;
+	dma_addr_t limit;
+	int pos;
+
+	if (!size)
+		return -EINVAL;
+
+	limit = bar_addr + size - 1;
+
+	/*
+	 *  Bits:		15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
+	 *  bar_addr:		U  U  U  U  U  U  0 X X X X X X X X X
+	 *  limit:		U  U  U  U  U  U  1 X X X X X X X X X
+	 *
+	 *  bar_addr^limit	0  0  0  0  0  0  1 X X X X X X X X X
+	 *
+	 *  U: unchanged address bits in range [bar_addr, limit]
+	 *  X: bit 0 or 1
+	 *
+	 *  (bar_addr^limit) & BIT_ULL(pos) will find the first set bit from MSB
+	 *  (pos). And value of (2 ^ pos) should be able to cover the BAR range.
+	 */
+	for (pos = 8 * sizeof(dma_addr_t) - 1; pos > 0; pos--)
+		if ((limit ^ bar_addr) & BIT_ULL(pos))
+			break;
+
+	if (pos == 8 * sizeof(dma_addr_t) - 1)
+		return -EINVAL;
+
+	bar_size = BIT_ULL(pos + 1);
+	if (pci_epf_get_required_bar_size(epf, &bar_size, &aligned_mem_size,
+					  bar, epc_features, type))
+		return -ENOMEM;
+
+	if (type == PRIMARY_INTERFACE)
+		epf_bar = epf->bar;
+	else
+		epf_bar = epf->sec_epc_bar;
+
+	epf_bar[bar].phys_addr = ALIGN_DOWN(bar_addr, aligned_mem_size);
+
+	if (epf_bar[bar].phys_addr + bar_size < limit)
+		return -ENOMEM;
+
+	epf_bar[bar].addr = NULL;
+	epf_bar[bar].size = bar_size;
+	epf_bar[bar].mem_size = aligned_mem_size;
+	epf_bar[bar].barno = bar;
+	if (upper_32_bits(size) || epc_features->bar[bar].only_64bit)
+		epf_bar[bar].flags |= PCI_BASE_ADDRESS_MEM_TYPE_64;
+	else
+		epf_bar[bar].flags |= PCI_BASE_ADDRESS_MEM_TYPE_32;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pci_epf_assign_bar_space);
+
+static void pci_epf_remove_cfs(struct pci_epf_driver *driver)
+{
+	struct config_group *group, *tmp;
+
+	if (!IS_ENABLED(CONFIG_PCI_ENDPOINT_CONFIGFS))
+		return;
+
+	mutex_lock(&pci_epf_mutex);
+	list_for_each_entry_safe(group, tmp, &driver->epf_group, group_entry)
+		pci_ep_cfs_remove_epf_group(group);
+	WARN_ON(!list_empty(&driver->epf_group));
+	mutex_unlock(&pci_epf_mutex);
+}
+
+/**
+ * pci_epf_unregister_driver() - unregister the PCI EPF driver
+ * @driver: the PCI EPF driver that has to be unregistered
+ *
+ * Invoke to unregister the PCI EPF driver.
+ */
+void pci_epf_unregister_driver(struct pci_epf_driver *driver)
+{
+	pci_epf_remove_cfs(driver);
+	driver_unregister(&driver->driver);
+}
+EXPORT_SYMBOL_GPL(pci_epf_unregister_driver);
+
+static int pci_epf_add_cfs(struct pci_epf_driver *driver)
+{
+	struct config_group *group;
+	const struct pci_epf_device_id *id;
+
+	if (!IS_ENABLED(CONFIG_PCI_ENDPOINT_CONFIGFS))
+		return 0;
+
+	INIT_LIST_HEAD(&driver->epf_group);
+
+	id = driver->id_table;
+	while (id->name[0]) {
+		group = pci_ep_cfs_add_epf_group(id->name);
+		if (IS_ERR(group)) {
+			pci_epf_remove_cfs(driver);
+			return PTR_ERR(group);
+		}
+
+		mutex_lock(&pci_epf_mutex);
+		list_add_tail(&group->group_entry, &driver->epf_group);
+		mutex_unlock(&pci_epf_mutex);
+		id++;
+	}
+
+	return 0;
+}
+
+/**
+ * __pci_epf_register_driver() - register a new PCI EPF driver
+ * @driver: structure representing PCI EPF driver
+ * @owner: the owner of the module that registers the PCI EPF driver
+ *
+ * Invoke to register a new PCI EPF driver.
+ */
+int __pci_epf_register_driver(struct pci_epf_driver *driver,
+			      struct module *owner)
+{
+	int ret;
+
+	if (!driver->ops)
+		return -EINVAL;
+
+	if (!driver->ops->bind || !driver->ops->unbind)
+		return -EINVAL;
+
+	driver->driver.bus = &pci_epf_bus_type;
+	driver->driver.owner = owner;
+
+	ret = driver_register(&driver->driver);
+	if (ret)
+		return ret;
+
+	pci_epf_add_cfs(driver);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(__pci_epf_register_driver);
+
+/**
+ * pci_epf_destroy() - destroy the created PCI EPF device
+ * @epf: the PCI EPF device that has to be destroyed.
+ *
+ * Invoke to destroy the PCI EPF device created by invoking pci_epf_create().
+ */
+void pci_epf_destroy(struct pci_epf *epf)
+{
+	device_unregister(&epf->dev);
+}
+EXPORT_SYMBOL_GPL(pci_epf_destroy);
+
+/**
+ * pci_epf_create() - create a new PCI EPF device
+ * @name: the name of the PCI EPF device. This name will be used to bind the
+ *	  EPF device to a EPF driver
+ *
+ * Invoke to create a new PCI EPF device by providing the name of the function
+ * device.
+ */
+struct pci_epf *pci_epf_create(const char *name)
+{
+	int ret;
+	struct pci_epf *epf;
+	struct device *dev;
+	int len;
+
+	epf = kzalloc_obj(*epf);
+	if (!epf)
+		return ERR_PTR(-ENOMEM);
+
+	len = strchrnul(name, '.') - name;
+	epf->name = kstrndup(name, len, GFP_KERNEL);
+	if (!epf->name) {
+		kfree(epf);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	/* VFs are numbered starting with 1. So set BIT(0) by default */
+	epf->vfunction_num_map = 1;
+	INIT_LIST_HEAD(&epf->pci_vepf);
+
+	dev = &epf->dev;
+	device_initialize(dev);
+	dev->bus = &pci_epf_bus_type;
+	dev->type = &pci_epf_type;
+	mutex_init(&epf->lock);
+
+	ret = dev_set_name(dev, "%s", name);
+	if (ret) {
+		put_device(dev);
+		return ERR_PTR(ret);
+	}
+
+	ret = device_add(dev);
+	if (ret) {
+		put_device(dev);
+		return ERR_PTR(ret);
+	}
+
+	return epf;
+}
+EXPORT_SYMBOL_GPL(pci_epf_create);
+
+/**
+ * pci_epf_align_inbound_addr() - Align the given address based on the BAR
+ *				  alignment requirement
+ * @epf: the EPF device
+ * @addr: inbound address to be aligned
+ * @bar: the BAR number corresponding to the given addr
+ * @base: base address matching the @bar alignment requirement
+ * @off: offset to be added to the @base address
+ *
+ * Helper function to align input @addr based on BAR's alignment requirement.
+ * The aligned base address and offset are returned via @base and @off.
+ *
+ * NOTE: The pci_epf_alloc_space() function already accounts for alignment.
+ * This API is primarily intended for use with other memory regions not
+ * allocated by pci_epf_alloc_space(), such as peripheral register spaces or
+ * the message address of a platform MSI controller.
+ *
+ * Return: 0 on success, errno otherwise.
+ */
+int pci_epf_align_inbound_addr(struct pci_epf *epf, enum pci_barno bar,
+			       u64 addr, dma_addr_t *base, size_t *off)
+{
+	/*
+	 * Most EP controllers require the BAR start address to be aligned to
+	 * the BAR size, because they mask off the lower bits.
+	 *
+	 * Alignment to BAR size also works for controllers that support
+	 * unaligned addresses.
+	 */
+	u64 align = epf->bar[bar].size;
+
+	*base = round_down(addr, align);
+	*off = addr & (align - 1);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pci_epf_align_inbound_addr);
+
+static void pci_epf_dev_release(struct device *dev)
+{
+	struct pci_epf *epf = to_pci_epf(dev);
+
+	kfree(epf->name);
+	kfree(epf);
+}
+
+static const struct device_type pci_epf_type = {
+	.release	= pci_epf_dev_release,
+};
+
+static const struct pci_epf_device_id *
+pci_epf_match_id(const struct pci_epf_device_id *id, const struct pci_epf *epf)
+{
+	while (id->name[0]) {
+		if (strcmp(epf->name, id->name) == 0)
+			return id;
+		id++;
+	}
+
+	return NULL;
+}
+
+static int pci_epf_device_match(struct device *dev, const struct device_driver *drv)
+{
+	struct pci_epf *epf = to_pci_epf(dev);
+	const struct pci_epf_driver *driver = to_pci_epf_driver(drv);
+
+	if (driver->id_table)
+		return !!pci_epf_match_id(driver->id_table, epf);
+
+	return !strcmp(epf->name, drv->name);
+}
+
+static int pci_epf_device_probe(struct device *dev)
+{
+	struct pci_epf *epf = to_pci_epf(dev);
+	struct pci_epf_driver *driver = to_pci_epf_driver(dev->driver);
+
+	if (!driver->probe)
+		return -ENODEV;
+
+	epf->driver = driver;
+
+	return driver->probe(epf, pci_epf_match_id(driver->id_table, epf));
+}
+
+static void pci_epf_device_remove(struct device *dev)
+{
+	struct pci_epf *epf = to_pci_epf(dev);
+	struct pci_epf_driver *driver = to_pci_epf_driver(dev->driver);
+
+	if (driver->remove)
+		driver->remove(epf);
+	epf->driver = NULL;
+}
+
+static const struct bus_type pci_epf_bus_type = {
+	.name		= "pci-epf",
+	.match		= pci_epf_device_match,
+	.probe		= pci_epf_device_probe,
+	.remove		= pci_epf_device_remove,
+};
+
+static int __init pci_epf_init(void)
+{
+	int ret;
+
+	ret = bus_register(&pci_epf_bus_type);
+	if (ret) {
+		pr_err("failed to register pci epf bus --> %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+module_init(pci_epf_init);
+
+static void __exit pci_epf_exit(void)
+{
+	bus_unregister(&pci_epf_bus_type);
+}
+module_exit(pci_epf_exit);
+
+MODULE_DESCRIPTION("PCI EPF Library");
+MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");