Resguardo inicial

linux-7.2.3/drivers/pci/msi/Makefile

@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the PCI/MSI
+obj-$(CONFIG_PCI)			+= pcidev_msi.o
+obj-$(CONFIG_PCI_MSI)			+= api.o msi.o irqdomain.o
+obj-$(CONFIG_PCI_MSI_ARCH_FALLBACKS)	+= legacy.o

linux-7.2.3/drivers/pci/msi/api.c

@@ -0,0 +1,411 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI MSI/MSI-X — Exported APIs for device drivers
+ *
+ * Copyright (C) 2003-2004 Intel
+ * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
+ * Copyright (C) 2016 Christoph Hellwig.
+ * Copyright (C) 2022 Linutronix GmbH
+ */
+
+#include <linux/export.h>
+#include <linux/irq.h>
+
+#include "msi.h"
+
+/**
+ * pci_enable_msi() - Enable MSI interrupt mode on device
+ * @dev: the PCI device to operate on
+ *
+ * Legacy device driver API to enable MSI interrupts mode on device and
+ * allocate a single interrupt vector. On success, the allocated vector
+ * Linux IRQ will be saved at @dev->irq. The driver must invoke
+ * pci_disable_msi() on cleanup.
+ *
+ * NOTE: The newer pci_alloc_irq_vectors() / pci_free_irq_vectors() API
+ * pair should, in general, be used instead.
+ *
+ * Return: 0 on success, errno otherwise
+ */
+int pci_enable_msi(struct pci_dev *dev)
+{
+	int rc = __pci_enable_msi_range(dev, 1, 1, NULL);
+	if (rc < 0)
+		return rc;
+	return 0;
+}
+EXPORT_SYMBOL(pci_enable_msi);
+
+/**
+ * pci_disable_msi() - Disable MSI interrupt mode on device
+ * @dev: the PCI device to operate on
+ *
+ * Legacy device driver API to disable MSI interrupt mode on device,
+ * free earlier allocated interrupt vectors, and restore INTx emulation.
+ * The PCI device Linux IRQ (@dev->irq) is restored to its default
+ * pin-assertion IRQ. This is the cleanup pair of pci_enable_msi().
+ *
+ * NOTE: The newer pci_alloc_irq_vectors() / pci_free_irq_vectors() API
+ * pair should, in general, be used instead.
+ */
+void pci_disable_msi(struct pci_dev *dev)
+{
+	if (!pci_msi_enabled() || !dev || !dev->msi_enabled)
+		return;
+
+	guard(msi_descs_lock)(&dev->dev);
+	pci_msi_shutdown(dev);
+	pci_free_msi_irqs(dev);
+}
+EXPORT_SYMBOL(pci_disable_msi);
+
+/**
+ * pci_msix_vec_count() - Get number of MSI-X interrupt vectors on device
+ * @dev: the PCI device to operate on
+ *
+ * Return: number of MSI-X interrupt vectors available on this device
+ * (i.e., the device's MSI-X capability structure "table size"), -EINVAL
+ * if the device is not MSI-X capable, other errnos otherwise.
+ */
+int pci_msix_vec_count(struct pci_dev *dev)
+{
+	u16 control;
+
+	if (!dev->msix_cap)
+		return -EINVAL;
+
+	pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control);
+	return msix_table_size(control);
+}
+EXPORT_SYMBOL(pci_msix_vec_count);
+
+/**
+ * pci_enable_msix_range() - Enable MSI-X interrupt mode on device
+ * @dev:     the PCI device to operate on
+ * @entries: input/output parameter, array of MSI-X configuration entries
+ * @minvec:  minimum required number of MSI-X vectors
+ * @maxvec:  maximum desired number of MSI-X vectors
+ *
+ * Legacy device driver API to enable MSI-X interrupt mode on device and
+ * configure its MSI-X capability structure as appropriate.  The passed
+ * @entries array must have each of its members "entry" field set to a
+ * desired (valid) MSI-X vector number, where the range of valid MSI-X
+ * vector numbers can be queried through pci_msix_vec_count().  If
+ * successful, the driver must invoke pci_disable_msix() on cleanup.
+ *
+ * NOTE: The newer pci_alloc_irq_vectors() / pci_free_irq_vectors() API
+ * pair should, in general, be used instead.
+ *
+ * Return: number of MSI-X vectors allocated (which might be smaller
+ * than @maxvecs), where Linux IRQ numbers for such allocated vectors
+ * are saved back in the @entries array elements' "vector" field. Return
+ * -ENOSPC if less than @minvecs interrupt vectors are available.
+ * Return -EINVAL if one of the passed @entries members "entry" field
+ * was invalid or a duplicate, or if plain MSI interrupts mode was
+ * earlier enabled on device. Return other errnos otherwise.
+ */
+int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
+			  int minvec, int maxvec)
+{
+	return __pci_enable_msix_range(dev, entries, minvec, maxvec, NULL, 0);
+}
+EXPORT_SYMBOL(pci_enable_msix_range);
+
+/**
+ * pci_msix_can_alloc_dyn - Query whether dynamic allocation after enabling
+ *			    MSI-X is supported
+ *
+ * @dev:	PCI device to operate on
+ *
+ * Return: True if supported, false otherwise
+ */
+bool pci_msix_can_alloc_dyn(struct pci_dev *dev)
+{
+	if (!dev->msix_cap)
+		return false;
+
+	return pci_msi_domain_supports(dev, MSI_FLAG_PCI_MSIX_ALLOC_DYN, DENY_LEGACY);
+}
+EXPORT_SYMBOL_GPL(pci_msix_can_alloc_dyn);
+
+/**
+ * pci_msix_alloc_irq_at - Allocate an MSI-X interrupt after enabling MSI-X
+ *			   at a given MSI-X vector index or any free vector index
+ *
+ * @dev:	PCI device to operate on
+ * @index:	Index to allocate. If @index == MSI_ANY_INDEX this allocates
+ *		the next free index in the MSI-X table
+ * @affdesc:	Optional pointer to an affinity descriptor structure. NULL otherwise
+ *
+ * Return: A struct msi_map
+ *
+ *	On success msi_map::index contains the allocated index (>= 0) and
+ *	msi_map::virq contains the allocated Linux interrupt number (> 0).
+ *
+ *	On fail msi_map::index contains the error code and msi_map::virq
+ *	is set to 0.
+ */
+struct msi_map pci_msix_alloc_irq_at(struct pci_dev *dev, unsigned int index,
+				     const struct irq_affinity_desc *affdesc)
+{
+	struct msi_map map = { .index = -ENOTSUPP };
+
+	if (!dev->msix_enabled)
+		return map;
+
+	if (!pci_msix_can_alloc_dyn(dev))
+		return map;
+
+	return msi_domain_alloc_irq_at(&dev->dev, MSI_DEFAULT_DOMAIN, index, affdesc, NULL);
+}
+EXPORT_SYMBOL_GPL(pci_msix_alloc_irq_at);
+
+/**
+ * pci_msix_free_irq - Free an interrupt on a PCI/MSI-X interrupt domain
+ *
+ * @dev:	The PCI device to operate on
+ * @map:	A struct msi_map describing the interrupt to free
+ *
+ * Undo an interrupt vector allocation. Does not disable MSI-X.
+ */
+void pci_msix_free_irq(struct pci_dev *dev, struct msi_map map)
+{
+	if (WARN_ON_ONCE(map.index < 0 || map.virq <= 0))
+		return;
+	if (WARN_ON_ONCE(!pci_msix_can_alloc_dyn(dev)))
+		return;
+	msi_domain_free_irqs_range(&dev->dev, MSI_DEFAULT_DOMAIN, map.index, map.index);
+}
+EXPORT_SYMBOL_GPL(pci_msix_free_irq);
+
+/**
+ * pci_disable_msix() - Disable MSI-X interrupt mode on device
+ * @dev: the PCI device to operate on
+ *
+ * Legacy device driver API to disable MSI-X interrupt mode on device,
+ * free earlier-allocated interrupt vectors, and restore INTx.
+ * The PCI device Linux IRQ (@dev->irq) is restored to its default pin
+ * assertion IRQ. This is the cleanup pair of pci_enable_msix_range().
+ *
+ * NOTE: The newer pci_alloc_irq_vectors() / pci_free_irq_vectors() API
+ * pair should, in general, be used instead.
+ */
+void pci_disable_msix(struct pci_dev *dev)
+{
+	if (!pci_msi_enabled() || !dev || !dev->msix_enabled)
+		return;
+
+	guard(msi_descs_lock)(&dev->dev);
+	pci_msix_shutdown(dev);
+	pci_free_msi_irqs(dev);
+}
+EXPORT_SYMBOL(pci_disable_msix);
+
+/**
+ * pci_alloc_irq_vectors() - Allocate multiple device interrupt vectors
+ * @dev:      the PCI device to operate on
+ * @min_vecs: minimum required number of vectors (must be >= 1)
+ * @max_vecs: maximum desired number of vectors
+ * @flags:    One or more of:
+ *
+ *            * %PCI_IRQ_MSIX      Allow trying MSI-X vector allocations
+ *            * %PCI_IRQ_MSI       Allow trying MSI vector allocations
+ *
+ *            * %PCI_IRQ_INTX      Allow trying INTx interrupts, if and
+ *              only if @min_vecs == 1
+ *
+ *            * %PCI_IRQ_AFFINITY  Auto-manage IRQs affinity by spreading
+ *              the vectors around available CPUs
+ *
+ * Allocate up to @max_vecs interrupt vectors on device. MSI-X irq
+ * vector allocation has a higher precedence over plain MSI, which has a
+ * higher precedence over legacy INTx emulation.
+ *
+ * Upon a successful allocation, the caller should use pci_irq_vector()
+ * to get the Linux IRQ number to be passed to request_threaded_irq().
+ * The driver must call pci_free_irq_vectors() on cleanup.
+ *
+ * Return: number of allocated vectors (which might be smaller than
+ * @max_vecs), -ENOSPC if less than @min_vecs interrupt vectors are
+ * available, other errnos otherwise.
+ */
+int pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
+			  unsigned int max_vecs, unsigned int flags)
+{
+	return pci_alloc_irq_vectors_affinity(dev, min_vecs, max_vecs,
+					      flags, NULL);
+}
+EXPORT_SYMBOL(pci_alloc_irq_vectors);
+
+/**
+ * pci_alloc_irq_vectors_affinity() - Allocate multiple device interrupt
+ *                                    vectors with affinity requirements
+ * @dev:      the PCI device to operate on
+ * @min_vecs: minimum required number of vectors (must be >= 1)
+ * @max_vecs: maximum desired number of vectors
+ * @flags:    allocation flags, as in pci_alloc_irq_vectors()
+ * @affd:     affinity requirements (can be %NULL).
+ *
+ * Same as pci_alloc_irq_vectors(), but with the extra @affd parameter.
+ * Check that function docs, and &struct irq_affinity, for more details.
+ */
+int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
+				   unsigned int max_vecs, unsigned int flags,
+				   struct irq_affinity *affd)
+{
+	struct irq_affinity msi_default_affd = {0};
+	int nvecs = -ENOSPC;
+
+	if (flags & PCI_IRQ_AFFINITY) {
+		if (!affd)
+			affd = &msi_default_affd;
+	} else {
+		if (WARN_ON(affd))
+			affd = NULL;
+	}
+
+	if (flags & PCI_IRQ_MSIX) {
+		nvecs = __pci_enable_msix_range(dev, NULL, min_vecs, max_vecs,
+						affd, flags);
+		if (nvecs > 0)
+			return nvecs;
+	}
+
+	if (flags & PCI_IRQ_MSI) {
+		nvecs = __pci_enable_msi_range(dev, min_vecs, max_vecs, affd);
+		if (nvecs > 0)
+			return nvecs;
+	}
+
+	/* use INTx IRQ if allowed */
+	if (flags & PCI_IRQ_INTX) {
+		if (min_vecs == 1 && dev->irq) {
+			/*
+			 * Invoke the affinity spreading logic to ensure that
+			 * the device driver can adjust queue configuration
+			 * for the single interrupt case.
+			 */
+			if (affd)
+				irq_create_affinity_masks(1, affd);
+			pci_intx(dev, 1);
+			return 1;
+		}
+	}
+
+	return nvecs;
+}
+EXPORT_SYMBOL(pci_alloc_irq_vectors_affinity);
+
+/**
+ * pci_irq_vector() - Get Linux IRQ number of a device interrupt vector
+ * @dev: the PCI device to operate on
+ * @nr:  device-relative interrupt vector index (0-based); has different
+ *       meanings, depending on interrupt mode:
+ *
+ *         * MSI-X     the index in the MSI-X vector table
+ *         * MSI       the index of the enabled MSI vectors
+ *         * INTx      must be 0
+ *
+ * Return: the Linux IRQ number, or -EINVAL if @nr is out of range
+ */
+int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
+{
+	unsigned int irq;
+
+	if (!dev->msi_enabled && !dev->msix_enabled)
+		return !nr ? dev->irq : -EINVAL;
+
+	irq = msi_get_virq(&dev->dev, nr);
+	return irq ? irq : -EINVAL;
+}
+EXPORT_SYMBOL(pci_irq_vector);
+
+/**
+ * pci_irq_get_affinity() - Get a device interrupt vector affinity
+ * @dev: the PCI device to operate on
+ * @nr:  device-relative interrupt vector index (0-based); has different
+ *       meanings, depending on interrupt mode:
+ *
+ *         * MSI-X     the index in the MSI-X vector table
+ *         * MSI       the index of the enabled MSI vectors
+ *         * INTx      must be 0
+ *
+ * Return: MSI/MSI-X vector affinity, NULL if @nr is out of range or if
+ * the MSI(-X) vector was allocated without explicit affinity
+ * requirements (e.g., by pci_enable_msi(), pci_enable_msix_range(), or
+ * pci_alloc_irq_vectors() without the %PCI_IRQ_AFFINITY flag). Return a
+ * generic set of CPU IDs representing all possible CPUs available
+ * during system boot if the device is in legacy INTx mode.
+ */
+const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr)
+{
+	int idx, irq = pci_irq_vector(dev, nr);
+	struct msi_desc *desc;
+
+	if (WARN_ON_ONCE(irq <= 0))
+		return NULL;
+
+	desc = irq_get_msi_desc(irq);
+	/* Non-MSI does not have the information handy */
+	if (!desc)
+		return cpu_possible_mask;
+
+	/* MSI[X] interrupts can be allocated without affinity descriptor */
+	if (!desc->affinity)
+		return NULL;
+
+	/*
+	 * MSI has a mask array in the descriptor.
+	 * MSI-X has a single mask.
+	 */
+	idx = dev->msi_enabled ? nr : 0;
+	return &desc->affinity[idx].mask;
+}
+EXPORT_SYMBOL(pci_irq_get_affinity);
+
+/**
+ * pci_free_irq_vectors() - Free previously allocated IRQs for a device
+ * @dev: the PCI device to operate on
+ *
+ * Undo the interrupt vector allocations and possible device MSI/MSI-X
+ * enablement earlier done through pci_alloc_irq_vectors_affinity() or
+ * pci_alloc_irq_vectors().
+ *
+ * WARNING: Do not call this function if the device has been enabled
+ * with pcim_enable_device(). In that case, IRQ vectors are automatically
+ * managed via pcim_msi_release() and calling pci_free_irq_vectors() can
+ * lead to double-free issues.
+ */
+void pci_free_irq_vectors(struct pci_dev *dev)
+{
+	pci_disable_msix(dev);
+	pci_disable_msi(dev);
+}
+EXPORT_SYMBOL(pci_free_irq_vectors);
+
+/**
+ * pci_restore_msi_state() - Restore cached MSI(-X) state on device
+ * @dev: the PCI device to operate on
+ *
+ * Write the Linux-cached MSI(-X) state back on device. This is
+ * typically useful upon system resume, or after an error-recovery PCI
+ * adapter reset.
+ */
+void pci_restore_msi_state(struct pci_dev *dev)
+{
+	__pci_restore_msi_state(dev);
+	__pci_restore_msix_state(dev);
+}
+EXPORT_SYMBOL_GPL(pci_restore_msi_state);
+
+/**
+ * pci_msi_enabled() - Are MSI(-X) interrupts enabled system-wide?
+ *
+ * Return: true if MSI has not been globally disabled through ACPI FADT,
+ * PCI bridge quirks, or the "pci=nomsi" kernel command-line option.
+ */
+bool pci_msi_enabled(void)
+{
+	return pci_msi_enable;
+}
+EXPORT_SYMBOL(pci_msi_enabled);

linux-7.2.3/drivers/pci/msi/irqdomain.c

@@ -0,0 +1,431 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI Message Signaled Interrupt (MSI) - irqdomain support
+ */
+#include <linux/acpi_iort.h>
+#include <linux/irqdomain.h>
+#include <linux/of_irq.h>
+
+#include "msi.h"
+
+int pci_msi_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+	struct irq_domain *domain;
+
+	domain = dev_get_msi_domain(&dev->dev);
+	if (domain && irq_domain_is_hierarchy(domain))
+		return msi_domain_alloc_irqs_all_locked(&dev->dev, MSI_DEFAULT_DOMAIN, nvec);
+
+	return pci_msi_legacy_setup_msi_irqs(dev, nvec, type);
+}
+
+void pci_msi_teardown_msi_irqs(struct pci_dev *dev)
+{
+	struct irq_domain *domain;
+
+	domain = dev_get_msi_domain(&dev->dev);
+	if (domain && irq_domain_is_hierarchy(domain)) {
+		msi_domain_free_irqs_all_locked(&dev->dev, MSI_DEFAULT_DOMAIN);
+	} else {
+		pci_msi_legacy_teardown_msi_irqs(dev);
+		msi_free_msi_descs(&dev->dev);
+	}
+}
+
+/**
+ * pci_msi_domain_write_msg - Helper to write MSI message to PCI config space
+ * @irq_data:	Pointer to interrupt data of the MSI interrupt
+ * @msg:	Pointer to the message
+ */
+static void pci_msi_domain_write_msg(struct irq_data *irq_data, struct msi_msg *msg)
+{
+	struct msi_desc *desc = irq_data_get_msi_desc(irq_data);
+
+	/*
+	 * For MSI-X desc->irq is always equal to irq_data->irq. For
+	 * MSI only the first interrupt of MULTI MSI passes the test.
+	 */
+	if (desc->irq == irq_data->irq)
+		__pci_write_msi_msg(desc, msg);
+}
+
+/*
+ * Per device MSI[-X] domain functionality
+ */
+static void pci_device_domain_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
+{
+	arg->desc = desc;
+	arg->hwirq = desc->msi_index;
+}
+
+static void cond_shutdown_parent(struct irq_data *data)
+{
+	struct msi_domain_info *info = data->domain->host_data;
+
+	if (unlikely(info->flags & MSI_FLAG_PCI_MSI_STARTUP_PARENT))
+		irq_chip_shutdown_parent(data);
+	else if (unlikely(info->flags & MSI_FLAG_PCI_MSI_MASK_PARENT))
+		irq_chip_mask_parent(data);
+}
+
+static unsigned int cond_startup_parent(struct irq_data *data)
+{
+	struct msi_domain_info *info = data->domain->host_data;
+
+	if (unlikely(info->flags & MSI_FLAG_PCI_MSI_STARTUP_PARENT))
+		return irq_chip_startup_parent(data);
+	else if (unlikely(info->flags & MSI_FLAG_PCI_MSI_MASK_PARENT))
+		irq_chip_unmask_parent(data);
+
+	return 0;
+}
+
+static void pci_irq_shutdown_msi(struct irq_data *data)
+{
+	struct msi_desc *desc = irq_data_get_msi_desc(data);
+
+	pci_msi_mask(desc, BIT(data->irq - desc->irq));
+	cond_shutdown_parent(data);
+}
+
+static unsigned int pci_irq_startup_msi(struct irq_data *data)
+{
+	struct msi_desc *desc = irq_data_get_msi_desc(data);
+	unsigned int ret = cond_startup_parent(data);
+
+	pci_msi_unmask(desc, BIT(data->irq - desc->irq));
+	return ret;
+}
+
+static void pci_irq_mask_msi(struct irq_data *data)
+{
+	struct msi_desc *desc = irq_data_get_msi_desc(data);
+
+	pci_msi_mask(desc, BIT(data->irq - desc->irq));
+}
+
+static void pci_irq_unmask_msi(struct irq_data *data)
+{
+	struct msi_desc *desc = irq_data_get_msi_desc(data);
+
+	pci_msi_unmask(desc, BIT(data->irq - desc->irq));
+}
+
+#ifdef CONFIG_GENERIC_IRQ_RESERVATION_MODE
+# define MSI_REACTIVATE		MSI_FLAG_MUST_REACTIVATE
+#else
+# define MSI_REACTIVATE		0
+#endif
+
+#define MSI_COMMON_FLAGS	(MSI_FLAG_FREE_MSI_DESCS |	\
+				 MSI_FLAG_ACTIVATE_EARLY |	\
+				 MSI_FLAG_DEV_SYSFS |		\
+				 MSI_REACTIVATE)
+
+static const struct msi_domain_template pci_msi_template = {
+	.chip = {
+		.name			= "PCI-MSI",
+		.irq_startup		= pci_irq_startup_msi,
+		.irq_shutdown		= pci_irq_shutdown_msi,
+		.irq_mask		= pci_irq_mask_msi,
+		.irq_unmask		= pci_irq_unmask_msi,
+		.irq_write_msi_msg	= pci_msi_domain_write_msg,
+		.flags			= IRQCHIP_ONESHOT_SAFE,
+	},
+
+	.ops = {
+		.set_desc		= pci_device_domain_set_desc,
+	},
+
+	.info = {
+		.flags			= MSI_COMMON_FLAGS | MSI_FLAG_MULTI_PCI_MSI,
+		.bus_token		= DOMAIN_BUS_PCI_DEVICE_MSI,
+	},
+};
+
+static void pci_irq_shutdown_msix(struct irq_data *data)
+{
+	pci_msix_mask(irq_data_get_msi_desc(data));
+	cond_shutdown_parent(data);
+}
+
+static unsigned int pci_irq_startup_msix(struct irq_data *data)
+{
+	unsigned int ret = cond_startup_parent(data);
+
+	pci_msix_unmask(irq_data_get_msi_desc(data));
+	return ret;
+}
+
+static void pci_irq_mask_msix(struct irq_data *data)
+{
+	pci_msix_mask(irq_data_get_msi_desc(data));
+}
+
+static void pci_irq_unmask_msix(struct irq_data *data)
+{
+	pci_msix_unmask(irq_data_get_msi_desc(data));
+}
+
+void pci_msix_prepare_desc(struct irq_domain *domain, msi_alloc_info_t *arg,
+			   struct msi_desc *desc)
+{
+	/* Don't fiddle with preallocated MSI descriptors */
+	if (!desc->pci.mask_base)
+		msix_prepare_msi_desc(to_pci_dev(desc->dev), desc);
+}
+EXPORT_SYMBOL_GPL(pci_msix_prepare_desc);
+
+static const struct msi_domain_template pci_msix_template = {
+	.chip = {
+		.name			= "PCI-MSIX",
+		.irq_startup		= pci_irq_startup_msix,
+		.irq_shutdown		= pci_irq_shutdown_msix,
+		.irq_mask		= pci_irq_mask_msix,
+		.irq_unmask		= pci_irq_unmask_msix,
+		.irq_write_msi_msg	= pci_msi_domain_write_msg,
+		.flags			= IRQCHIP_ONESHOT_SAFE,
+	},
+
+	.ops = {
+		.prepare_desc		= pci_msix_prepare_desc,
+		.set_desc		= pci_device_domain_set_desc,
+	},
+
+	.info = {
+		.flags			= MSI_COMMON_FLAGS | MSI_FLAG_PCI_MSIX |
+					  MSI_FLAG_PCI_MSIX_ALLOC_DYN,
+		.bus_token		= DOMAIN_BUS_PCI_DEVICE_MSIX,
+	},
+};
+
+static bool pci_match_device_domain(struct pci_dev *pdev, enum irq_domain_bus_token bus_token)
+{
+	return msi_match_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN, bus_token);
+}
+
+static bool pci_create_device_domain(struct pci_dev *pdev, const struct msi_domain_template *tmpl,
+				     unsigned int hwsize)
+{
+	struct irq_domain *domain = dev_get_msi_domain(&pdev->dev);
+
+	if (!domain || !irq_domain_is_msi_parent(domain))
+		return true;
+
+	return msi_create_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN, tmpl,
+					    hwsize, NULL, NULL);
+}
+
+/**
+ * pci_setup_msi_device_domain - Setup a device MSI interrupt domain
+ * @pdev:	The PCI device to create the domain on
+ * @hwsize:	The maximum number of MSI vectors
+ *
+ * Return:
+ *  True when:
+ *	- The device does not have a MSI parent irq domain associated,
+ *	  which keeps the legacy architecture specific and the global
+ *	  PCI/MSI domain models working
+ *	- The MSI domain exists already
+ *	- The MSI domain was successfully allocated
+ *  False when:
+ *	- MSI-X is enabled
+ *	- The domain creation fails.
+ *
+ * The created MSI domain is preserved until:
+ *	- The device is removed
+ *	- MSI is disabled and a MSI-X domain is created
+ */
+bool pci_setup_msi_device_domain(struct pci_dev *pdev, unsigned int hwsize)
+{
+	if (WARN_ON_ONCE(pdev->msix_enabled))
+		return false;
+
+	if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSI))
+		return true;
+	if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSIX))
+		msi_remove_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN);
+
+	return pci_create_device_domain(pdev, &pci_msi_template, hwsize);
+}
+
+/**
+ * pci_setup_msix_device_domain - Setup a device MSI-X interrupt domain
+ * @pdev:	The PCI device to create the domain on
+ * @hwsize:	The size of the MSI-X vector table
+ *
+ * Return:
+ *  True when:
+ *	- The device does not have a MSI parent irq domain associated,
+ *	  which keeps the legacy architecture specific and the global
+ *	  PCI/MSI domain models working
+ *	- The MSI-X domain exists already
+ *	- The MSI-X domain was successfully allocated
+ *  False when:
+ *	- MSI is enabled
+ *	- The domain creation fails.
+ *
+ * The created MSI-X domain is preserved until:
+ *	- The device is removed
+ *	- MSI-X is disabled and a MSI domain is created
+ */
+bool pci_setup_msix_device_domain(struct pci_dev *pdev, unsigned int hwsize)
+{
+	if (WARN_ON_ONCE(pdev->msi_enabled))
+		return false;
+
+	if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSIX))
+		return true;
+	if (pci_match_device_domain(pdev, DOMAIN_BUS_PCI_DEVICE_MSI))
+		msi_remove_device_irq_domain(&pdev->dev, MSI_DEFAULT_DOMAIN);
+
+	return pci_create_device_domain(pdev, &pci_msix_template, hwsize);
+}
+
+/**
+ * pci_msi_domain_supports - Check for support of a particular feature flag
+ * @pdev:		The PCI device to operate on
+ * @feature_mask:	The feature mask to check for (full match)
+ * @mode:		If ALLOW_LEGACY this grants the feature when there is no irq domain
+ *			associated to the device. If DENY_LEGACY the lack of an irq domain
+ *			makes the feature unsupported
+ */
+bool pci_msi_domain_supports(struct pci_dev *pdev, unsigned int feature_mask,
+			     enum support_mode mode)
+{
+	struct msi_domain_info *info;
+	struct irq_domain *domain;
+	unsigned int supported;
+
+	domain = dev_get_msi_domain(&pdev->dev);
+
+	if (!domain || !irq_domain_is_hierarchy(domain)) {
+		if (IS_ENABLED(CONFIG_PCI_MSI_ARCH_FALLBACKS))
+			return mode == ALLOW_LEGACY;
+		return false;
+	}
+
+	if (!irq_domain_is_msi_parent(domain)) {
+		/*
+		 * For "global" PCI/MSI interrupt domains the associated
+		 * msi_domain_info::flags is the authoritative source of
+		 * information.
+		 */
+		info = domain->host_data;
+		supported = info->flags;
+	} else {
+		/*
+		 * For MSI parent domains the supported feature set
+		 * is available in the parent ops. This makes checks
+		 * possible before actually instantiating the
+		 * per device domain because the parent is never
+		 * expanding the PCI/MSI functionality.
+		 */
+		supported = domain->msi_parent_ops->supported_flags;
+	}
+
+	return (supported & feature_mask) == feature_mask;
+}
+
+/*
+ * Users of the generic MSI infrastructure expect a device to have a single ID,
+ * so with DMA aliases we have to pick the least-worst compromise. Devices with
+ * DMA phantom functions tend to still emit MSIs from the real function number,
+ * so we ignore those and only consider topological aliases where either the
+ * alias device or RID appears on a different bus number. We also make the
+ * reasonable assumption that bridges are walked in an upstream direction (so
+ * the last one seen wins), and the much braver assumption that the most likely
+ * case is that of PCI->PCIe so we should always use the alias RID. This echoes
+ * the logic from intel_irq_remapping's set_msi_sid(), which presumably works
+ * well enough in practice; in the face of the horrible PCIe<->PCI-X conditions
+ * for taking ownership all we can really do is close our eyes and hope...
+ */
+static int get_msi_id_cb(struct pci_dev *pdev, u16 alias, void *data)
+{
+	u32 *pa = data;
+	u8 bus = PCI_BUS_NUM(*pa);
+
+	if (pdev->bus->number != bus || PCI_BUS_NUM(alias) != bus)
+		*pa = alias;
+
+	return 0;
+}
+
+/**
+ * pci_msi_domain_get_msi_rid - Get the MSI requester id (RID)
+ * @domain:	The interrupt domain
+ * @pdev:	The PCI device.
+ *
+ * The RID for a device is formed from the alias, with a firmware
+ * supplied mapping applied
+ *
+ * Returns: The RID.
+ */
+u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)
+{
+	struct device_node *of_node;
+	u32 rid = pci_dev_id(pdev);
+
+	pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
+
+	of_node = irq_domain_get_of_node(domain);
+	rid = of_node ? of_msi_xlate(&pdev->dev, &of_node, rid) :
+			iort_msi_map_id(&pdev->dev, rid);
+
+	return rid;
+}
+
+/**
+ * pci_msi_map_rid_ctlr_node - Get the MSI controller fwnode_handle and MSI requester id (RID)
+ * @domain:	The interrupt domain
+ * @pdev:	The PCI device
+ * @node:	Pointer to store the MSI controller fwnode_handle
+ *
+ * Use the firmware data to find the MSI controller fwnode_handle for @pdev.
+ * If found map the RID and initialize @node with it. @node value must
+ * be set to NULL on entry.
+ *
+ * Returns: The RID.
+ */
+u32 pci_msi_map_rid_ctlr_node(struct irq_domain *domain, struct pci_dev *pdev,
+			      struct fwnode_handle **node)
+{
+	u32 rid = pci_dev_id(pdev);
+
+	pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
+
+	/* Check whether the domain fwnode is an OF node */
+	if (irq_domain_get_of_node(domain)) {
+		struct device_node *msi_ctlr_node = NULL;
+
+		rid = of_msi_xlate(&pdev->dev, &msi_ctlr_node, rid);
+		if (msi_ctlr_node)
+			*node = of_fwnode_handle(msi_ctlr_node);
+	} else {
+		rid = iort_msi_xlate(&pdev->dev, rid, node);
+	}
+
+	return rid;
+}
+
+/**
+ * pci_msi_get_device_domain - Get the MSI domain for a given PCI device
+ * @pdev:	The PCI device
+ *
+ * Use the firmware data to find a device-specific MSI domain
+ * (i.e. not one that is set as a default).
+ *
+ * Returns: The corresponding MSI domain or NULL if none has been found.
+ */
+struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
+{
+	struct irq_domain *dom;
+	u32 rid = pci_dev_id(pdev);
+
+	pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
+	dom = of_msi_map_get_device_domain(&pdev->dev, rid, DOMAIN_BUS_PCI_MSI);
+	if (!dom)
+		dom = iort_get_device_domain(&pdev->dev, rid,
+					     DOMAIN_BUS_PCI_MSI);
+	return dom;
+}

linux-7.2.3/drivers/pci/msi/legacy.c

@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI Message Signaled Interrupt (MSI).
+ *
+ * Legacy architecture specific setup and teardown mechanism.
+ */
+#include "msi.h"
+
+/* Arch hooks */
+int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
+{
+	return -EINVAL;
+}
+
+void __weak arch_teardown_msi_irq(unsigned int irq)
+{
+}
+
+int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+	struct msi_desc *desc;
+	int ret;
+
+	/*
+	 * If an architecture wants to support multiple MSI, it needs to
+	 * override arch_setup_msi_irqs()
+	 */
+	if (type == PCI_CAP_ID_MSI && nvec > 1)
+		return 1;
+
+	msi_for_each_desc(desc, &dev->dev, MSI_DESC_NOTASSOCIATED) {
+		ret = arch_setup_msi_irq(dev, desc);
+		if (ret)
+			return ret < 0 ? ret : -ENOSPC;
+	}
+
+	return 0;
+}
+
+void __weak arch_teardown_msi_irqs(struct pci_dev *dev)
+{
+	struct msi_desc *desc;
+	int i;
+
+	msi_for_each_desc(desc, &dev->dev, MSI_DESC_ASSOCIATED) {
+		for (i = 0; i < desc->nvec_used; i++)
+			arch_teardown_msi_irq(desc->irq + i);
+	}
+}
+
+static int pci_msi_setup_check_result(struct pci_dev *dev, int type, int ret)
+{
+	struct msi_desc *desc;
+	int avail = 0;
+
+	if (type != PCI_CAP_ID_MSIX || ret >= 0)
+		return ret;
+
+	/* Scan the MSI descriptors for successfully allocated ones. */
+	msi_for_each_desc(desc, &dev->dev, MSI_DESC_ASSOCIATED)
+		avail++;
+
+	return avail ? avail : ret;
+}
+
+int pci_msi_legacy_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+	int ret = arch_setup_msi_irqs(dev, nvec, type);
+
+	ret = pci_msi_setup_check_result(dev, type, ret);
+	if (!ret)
+		ret = msi_device_populate_sysfs(&dev->dev);
+	return ret;
+}
+
+void pci_msi_legacy_teardown_msi_irqs(struct pci_dev *dev)
+{
+	msi_device_destroy_sysfs(&dev->dev);
+	arch_teardown_msi_irqs(dev);
+}

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

@@ -0,0 +1,988 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI Message Signaled Interrupt (MSI)
+ *
+ * Copyright (C) 2003-2004 Intel
+ * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
+ * Copyright (C) 2016 Christoph Hellwig.
+ */
+#include <linux/bitfield.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+
+#include "../pci.h"
+#include "msi.h"
+
+bool pci_msi_enable = true;
+
+/**
+ * pci_msi_supported - check whether MSI may be enabled on a device
+ * @dev: pointer to the pci_dev data structure of MSI device function
+ * @nvec: how many MSIs have been requested?
+ *
+ * Look at global flags, the device itself, and its parent buses
+ * to determine if MSI/-X are supported for the device. If MSI/-X is
+ * supported return 1, else return 0.
+ **/
+static int pci_msi_supported(struct pci_dev *dev, int nvec)
+{
+	struct pci_bus *bus;
+
+	/* MSI must be globally enabled and supported by the device */
+	if (!pci_msi_enable)
+		return 0;
+
+	if (!dev || dev->no_msi)
+		return 0;
+
+	/*
+	 * You can't ask to have 0 or less MSIs configured.
+	 *  a) it's stupid ..
+	 *  b) the list manipulation code assumes nvec >= 1.
+	 */
+	if (nvec < 1)
+		return 0;
+
+	/*
+	 * Any bridge which does NOT route MSI transactions from its
+	 * secondary bus to its primary bus must set NO_MSI flag on
+	 * the secondary pci_bus.
+	 *
+	 * The NO_MSI flag can either be set directly by:
+	 * - arch-specific PCI host bus controller drivers (deprecated)
+	 * - quirks for specific PCI bridges
+	 *
+	 * or indirectly by platform-specific PCI host bridge drivers by
+	 * advertising the 'msi_domain' property, which results in
+	 * the NO_MSI flag when no MSI domain is found for this bridge
+	 * at probe time.
+	 */
+	for (bus = dev->bus; bus; bus = bus->parent)
+		if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
+			return 0;
+
+	return 1;
+}
+
+static void pcim_msi_release(void *pcidev)
+{
+	struct pci_dev *dev = pcidev;
+
+	dev->is_msi_managed = false;
+	pci_free_irq_vectors(dev);
+}
+
+/*
+ * Needs to be separate from pcim_release to prevent an ordering problem
+ * vs. msi_device_data_release() in the MSI core code.
+ *
+ * TODO: Remove the legacy side-effect of pcim_enable_device() that
+ * activates automatic IRQ vector management. This design is dangerous
+ * and confusing because it switches normally un-managed functions
+ * into managed mode. Drivers should explicitly manage their IRQ vectors
+ * without this implicit behavior.
+ *
+ * The current implementation uses both pdev->is_managed and
+ * pdev->is_msi_managed flags, which adds unnecessary complexity.
+ * This should be simplified in a future kernel version.
+ */
+static int pcim_setup_msi_release(struct pci_dev *dev)
+{
+	int ret;
+
+	if (!pci_is_managed(dev) || dev->is_msi_managed)
+		return 0;
+
+	ret = devm_add_action(&dev->dev, pcim_msi_release, dev);
+	if (ret)
+		return ret;
+
+	dev->is_msi_managed = true;
+	return 0;
+}
+
+/*
+ * Ordering vs. devres: msi device data has to be installed first so that
+ * pcim_msi_release() is invoked before it on device release.
+ */
+static int pci_setup_msi_context(struct pci_dev *dev)
+{
+	int ret = msi_setup_device_data(&dev->dev);
+
+	if (ret)
+		return ret;
+
+	return pcim_setup_msi_release(dev);
+}
+
+/*
+ * Helper functions for mask/unmask and MSI message handling
+ */
+
+void pci_msi_update_mask(struct msi_desc *desc, u32 clear, u32 set)
+{
+	struct pci_dev *dev = msi_desc_to_pci_dev(desc);
+	raw_spinlock_t *lock = &dev->msi_lock;
+	unsigned long flags;
+
+	if (!desc->pci.msi_attrib.can_mask)
+		return;
+
+	raw_spin_lock_irqsave(lock, flags);
+	desc->pci.msi_mask &= ~clear;
+	desc->pci.msi_mask |= set;
+	pci_write_config_dword(dev, desc->pci.mask_pos, desc->pci.msi_mask);
+	raw_spin_unlock_irqrestore(lock, flags);
+}
+
+/**
+ * pci_msi_mask_irq - Generic IRQ chip callback to mask PCI/MSI interrupts
+ * @data:	pointer to irqdata associated to that interrupt
+ */
+void pci_msi_mask_irq(struct irq_data *data)
+{
+	struct msi_desc *desc = irq_data_get_msi_desc(data);
+
+	__pci_msi_mask_desc(desc, BIT(data->irq - desc->irq));
+}
+EXPORT_SYMBOL_GPL(pci_msi_mask_irq);
+
+/**
+ * pci_msi_unmask_irq - Generic IRQ chip callback to unmask PCI/MSI interrupts
+ * @data:	pointer to irqdata associated to that interrupt
+ */
+void pci_msi_unmask_irq(struct irq_data *data)
+{
+	struct msi_desc *desc = irq_data_get_msi_desc(data);
+
+	__pci_msi_unmask_desc(desc, BIT(data->irq - desc->irq));
+}
+EXPORT_SYMBOL_GPL(pci_msi_unmask_irq);
+
+void __pci_read_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
+{
+	struct pci_dev *dev = msi_desc_to_pci_dev(entry);
+
+	BUG_ON(dev->current_state != PCI_D0);
+
+	if (entry->pci.msi_attrib.is_msix) {
+		void __iomem *base = pci_msix_desc_addr(entry);
+
+		if (WARN_ON_ONCE(entry->pci.msi_attrib.is_virtual))
+			return;
+
+		msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR);
+		msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR);
+		msg->data = readl(base + PCI_MSIX_ENTRY_DATA);
+	} else {
+		int pos = dev->msi_cap;
+		u16 data;
+
+		pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_LO,
+				      &msg->address_lo);
+		if (entry->pci.msi_attrib.is_64) {
+			pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_HI,
+					      &msg->address_hi);
+			pci_read_config_word(dev, pos + PCI_MSI_DATA_64, &data);
+		} else {
+			msg->address_hi = 0;
+			pci_read_config_word(dev, pos + PCI_MSI_DATA_32, &data);
+		}
+		msg->data = data;
+	}
+}
+
+static inline void pci_write_msg_msi(struct pci_dev *dev, struct msi_desc *desc,
+				     struct msi_msg *msg)
+{
+	int pos = dev->msi_cap;
+	u16 msgctl;
+
+	pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
+	FIELD_MODIFY(PCI_MSI_FLAGS_QSIZE, &msgctl, desc->pci.msi_attrib.multiple);
+	pci_write_config_word(dev, pos + PCI_MSI_FLAGS, msgctl);
+
+	pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_LO, msg->address_lo);
+	if (desc->pci.msi_attrib.is_64) {
+		pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_HI,  msg->address_hi);
+		pci_write_config_word(dev, pos + PCI_MSI_DATA_64, msg->data);
+	} else {
+		pci_write_config_word(dev, pos + PCI_MSI_DATA_32, msg->data);
+	}
+	/* Ensure that the writes are visible in the device */
+	pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
+}
+
+static inline void pci_write_msg_msix(struct msi_desc *desc, struct msi_msg *msg)
+{
+	void __iomem *base = pci_msix_desc_addr(desc);
+	u32 ctrl = desc->pci.msix_ctrl;
+	bool unmasked = !(ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT);
+
+	if (desc->pci.msi_attrib.is_virtual)
+		return;
+	/*
+	 * The specification mandates that the entry is masked
+	 * when the message is modified:
+	 *
+	 * "If software changes the Address or Data value of an
+	 * entry while the entry is unmasked, the result is
+	 * undefined."
+	 */
+	if (unmasked)
+		pci_msix_write_vector_ctrl(desc, ctrl | PCI_MSIX_ENTRY_CTRL_MASKBIT);
+
+	writel(msg->address_lo, base + PCI_MSIX_ENTRY_LOWER_ADDR);
+	writel(msg->address_hi, base + PCI_MSIX_ENTRY_UPPER_ADDR);
+	writel(msg->data, base + PCI_MSIX_ENTRY_DATA);
+
+	if (unmasked)
+		pci_msix_write_vector_ctrl(desc, ctrl);
+
+	/* Ensure that the writes are visible in the device */
+	readl(base + PCI_MSIX_ENTRY_DATA);
+}
+
+void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
+{
+	struct pci_dev *dev = msi_desc_to_pci_dev(entry);
+
+	if (dev->current_state != PCI_D0 || pci_dev_is_disconnected(dev)) {
+		/* Don't touch the hardware now */
+	} else if (entry->pci.msi_attrib.is_msix) {
+		pci_write_msg_msix(entry, msg);
+	} else {
+		pci_write_msg_msi(dev, entry, msg);
+	}
+
+	entry->msg = *msg;
+
+	if (entry->write_msi_msg)
+		entry->write_msi_msg(entry, entry->write_msi_msg_data);
+}
+
+void pci_write_msi_msg(unsigned int irq, struct msi_msg *msg)
+{
+	struct msi_desc *entry = irq_get_msi_desc(irq);
+
+	__pci_write_msi_msg(entry, msg);
+}
+EXPORT_SYMBOL_GPL(pci_write_msi_msg);
+
+
+/* PCI/MSI specific functionality */
+
+static void pci_intx_for_msi(struct pci_dev *dev, int enable)
+{
+	if (!(dev->dev_flags & PCI_DEV_FLAGS_MSI_INTX_DISABLE_BUG))
+		pci_intx(dev, enable);
+}
+
+static void pci_msi_set_enable(struct pci_dev *dev, int enable)
+{
+	u16 control;
+
+	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
+	control &= ~PCI_MSI_FLAGS_ENABLE;
+	if (enable)
+		control |= PCI_MSI_FLAGS_ENABLE;
+	pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
+}
+
+static int msi_setup_msi_desc(struct pci_dev *dev, int nvec,
+			      struct irq_affinity_desc *masks)
+{
+	struct msi_desc desc;
+	u16 control;
+
+	/* MSI Entry Initialization */
+	memset(&desc, 0, sizeof(desc));
+
+	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
+	/* Lies, damned lies, and MSIs */
+	if (dev->dev_flags & PCI_DEV_FLAGS_HAS_MSI_MASKING)
+		control |= PCI_MSI_FLAGS_MASKBIT;
+	if (pci_msi_domain_supports(dev, MSI_FLAG_NO_MASK, DENY_LEGACY))
+		control &= ~PCI_MSI_FLAGS_MASKBIT;
+
+	desc.nvec_used			= nvec;
+	desc.pci.msi_attrib.is_64	= !!(control & PCI_MSI_FLAGS_64BIT);
+	desc.pci.msi_attrib.can_mask	= !!(control & PCI_MSI_FLAGS_MASKBIT);
+	desc.pci.msi_attrib.default_irq	= dev->irq;
+	desc.pci.msi_attrib.multi_cap	= FIELD_GET(PCI_MSI_FLAGS_QMASK, control);
+	desc.pci.msi_attrib.multiple	= ilog2(__roundup_pow_of_two(nvec));
+	desc.affinity			= masks;
+
+	if (control & PCI_MSI_FLAGS_64BIT)
+		desc.pci.mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
+	else
+		desc.pci.mask_pos = dev->msi_cap + PCI_MSI_MASK_32;
+
+	/* Save the initial mask status */
+	if (desc.pci.msi_attrib.can_mask)
+		pci_read_config_dword(dev, desc.pci.mask_pos, &desc.pci.msi_mask);
+
+	return msi_insert_msi_desc(&dev->dev, &desc);
+}
+
+static int msi_verify_entries(struct pci_dev *dev)
+{
+	struct msi_desc *entry;
+	u64 address;
+
+	if (dev->msi_addr_mask == DMA_BIT_MASK(64))
+		return 0;
+
+	msi_for_each_desc(entry, &dev->dev, MSI_DESC_ALL) {
+		address = (u64)entry->msg.address_hi << 32 | entry->msg.address_lo;
+		if (address & ~dev->msi_addr_mask) {
+			pci_err(dev, "arch assigned 64-bit MSI address %#llx above device MSI address mask %#llx\n",
+				address, dev->msi_addr_mask);
+			break;
+		}
+	}
+	return !entry ? 0 : -EIO;
+}
+
+static int __msi_capability_init(struct pci_dev *dev, int nvec, struct irq_affinity_desc *masks)
+{
+	int ret = msi_setup_msi_desc(dev, nvec, masks);
+	struct msi_desc *entry, desc;
+
+	if (ret)
+		return ret;
+
+	/* All MSIs are unmasked by default; mask them all */
+	entry = msi_first_desc(&dev->dev, MSI_DESC_ALL);
+	pci_msi_mask(entry, msi_multi_mask(entry));
+	/*
+	 * Copy the MSI descriptor for the error path because
+	 * pci_msi_setup_msi_irqs() will free it for the hierarchical
+	 * interrupt domain case.
+	 */
+	memcpy(&desc, entry, sizeof(desc));
+
+	/* Configure MSI capability structure */
+	ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSI);
+	if (ret)
+		goto err;
+
+	ret = msi_verify_entries(dev);
+	if (ret)
+		goto err;
+
+	/* Set MSI enabled bits	*/
+	dev->msi_enabled = 1;
+	pci_intx_for_msi(dev, 0);
+	pci_msi_set_enable(dev, 1);
+
+	pcibios_free_irq(dev);
+	dev->irq = entry->irq;
+	return 0;
+err:
+	pci_msi_unmask(&desc, msi_multi_mask(&desc));
+	pci_free_msi_irqs(dev);
+	return ret;
+}
+
+/**
+ * msi_capability_init - configure device's MSI capability structure
+ * @dev: pointer to the pci_dev data structure of MSI device function
+ * @nvec: number of interrupts to allocate
+ * @affd: description of automatic IRQ affinity assignments (may be %NULL)
+ *
+ * Setup the MSI capability structure of the device with the requested
+ * number of interrupts.  A return value of zero indicates the successful
+ * setup of an entry with the new MSI IRQ.  A negative return value indicates
+ * an error, and a positive return value indicates the number of interrupts
+ * which could have been allocated.
+ */
+static int msi_capability_init(struct pci_dev *dev, int nvec,
+			       struct irq_affinity *affd)
+{
+	/* Reject multi-MSI early on irq domain enabled architectures */
+	if (nvec > 1 && !pci_msi_domain_supports(dev, MSI_FLAG_MULTI_PCI_MSI, ALLOW_LEGACY))
+		return 1;
+
+	/*
+	 * Disable MSI during setup in the hardware, but mark it enabled
+	 * so that setup code can evaluate it.
+	 */
+	pci_msi_set_enable(dev, 0);
+
+	struct irq_affinity_desc *masks __free(kfree) =
+		affd ? irq_create_affinity_masks(nvec, affd) : NULL;
+
+	guard(msi_descs_lock)(&dev->dev);
+	return __msi_capability_init(dev, nvec, masks);
+}
+
+int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
+			   struct irq_affinity *affd)
+{
+	int nvec;
+	int rc;
+
+	if (!pci_msi_supported(dev, minvec) || dev->current_state != PCI_D0)
+		return -EINVAL;
+
+	/* Check whether driver already requested MSI-X IRQs */
+	if (dev->msix_enabled) {
+		pci_info(dev, "can't enable MSI (MSI-X already enabled)\n");
+		return -EINVAL;
+	}
+
+	if (maxvec < minvec)
+		return -ERANGE;
+
+	if (WARN_ON_ONCE(dev->msi_enabled))
+		return -EINVAL;
+
+	/* Test for the availability of MSI support */
+	if (!pci_msi_domain_supports(dev, 0, ALLOW_LEGACY))
+		return -ENOTSUPP;
+
+	nvec = pci_msi_vec_count(dev);
+	if (nvec < 0)
+		return nvec;
+	if (nvec < minvec)
+		return -ENOSPC;
+
+	rc = pci_setup_msi_context(dev);
+	if (rc)
+		return rc;
+
+	if (!pci_setup_msi_device_domain(dev, nvec))
+		return -ENODEV;
+
+	if (nvec > maxvec)
+		nvec = maxvec;
+
+	for (;;) {
+		if (affd) {
+			nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
+			if (nvec < minvec)
+				return -ENOSPC;
+		}
+
+		rc = msi_capability_init(dev, nvec, affd);
+		if (rc == 0)
+			return nvec;
+
+		if (rc < 0)
+			return rc;
+		if (rc < minvec)
+			return -ENOSPC;
+
+		nvec = rc;
+	}
+}
+
+/**
+ * pci_msi_vec_count - Return the number of MSI vectors a device can send
+ * @dev: device to report about
+ *
+ * This function returns the number of MSI vectors a device requested via
+ * Multiple Message Capable register. It returns a negative errno if the
+ * device is not capable sending MSI interrupts. Otherwise, the call succeeds
+ * and returns a power of two, up to a maximum of 2^5 (32), according to the
+ * MSI specification.
+ **/
+int pci_msi_vec_count(struct pci_dev *dev)
+{
+	int ret;
+	u16 msgctl;
+
+	if (!dev->msi_cap)
+		return -EINVAL;
+
+	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
+	ret = 1 << FIELD_GET(PCI_MSI_FLAGS_QMASK, msgctl);
+
+	return ret;
+}
+EXPORT_SYMBOL(pci_msi_vec_count);
+
+/*
+ * Architecture override returns true when the PCI MSI message should be
+ * written by the generic restore function.
+ */
+bool __weak arch_restore_msi_irqs(struct pci_dev *dev)
+{
+	return true;
+}
+
+void __pci_restore_msi_state(struct pci_dev *dev)
+{
+	struct msi_desc *entry;
+	u16 control;
+
+	if (!dev->msi_enabled)
+		return;
+
+	entry = irq_get_msi_desc(dev->irq);
+
+	pci_intx_for_msi(dev, 0);
+	pci_msi_set_enable(dev, 0);
+	if (arch_restore_msi_irqs(dev))
+		__pci_write_msi_msg(entry, &entry->msg);
+
+	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
+	pci_msi_update_mask(entry, 0, 0);
+	FIELD_MODIFY(PCI_MSI_FLAGS_QSIZE, &control, entry->pci.msi_attrib.multiple);
+	control |= PCI_MSI_FLAGS_ENABLE;
+	pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
+}
+
+void pci_msi_shutdown(struct pci_dev *dev)
+{
+	struct msi_desc *desc;
+
+	if (!pci_msi_enable || !dev || !dev->msi_enabled)
+		return;
+
+	pci_msi_set_enable(dev, 0);
+	pci_intx_for_msi(dev, 1);
+	dev->msi_enabled = 0;
+
+	/* Return the device with MSI unmasked as initial states */
+	desc = msi_first_desc(&dev->dev, MSI_DESC_ALL);
+	if (!WARN_ON_ONCE(!desc))
+		pci_msi_unmask(desc, msi_multi_mask(desc));
+
+	/* Restore dev->irq to its default pin-assertion IRQ */
+	dev->irq = desc->pci.msi_attrib.default_irq;
+	pcibios_alloc_irq(dev);
+}
+
+/* PCI/MSI-X specific functionality */
+
+static void pci_msix_clear_and_set_ctrl(struct pci_dev *dev, u16 clear, u16 set)
+{
+	u16 ctrl;
+
+	pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &ctrl);
+	ctrl &= ~clear;
+	ctrl |= set;
+	pci_write_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, ctrl);
+}
+
+static void __iomem *msix_map_region(struct pci_dev *dev,
+				     unsigned int nr_entries)
+{
+	resource_size_t phys_addr;
+	u32 table_offset;
+	unsigned long flags;
+	u8 bir;
+
+	pci_read_config_dword(dev, dev->msix_cap + PCI_MSIX_TABLE,
+			      &table_offset);
+	bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR);
+	flags = pci_resource_flags(dev, bir);
+	if (!flags || (flags & IORESOURCE_UNSET))
+		return NULL;
+
+	table_offset &= PCI_MSIX_TABLE_OFFSET;
+	phys_addr = pci_resource_start(dev, bir) + table_offset;
+
+	return ioremap(phys_addr, nr_entries * PCI_MSIX_ENTRY_SIZE);
+}
+
+/**
+ * msix_prepare_msi_desc - Prepare a half initialized MSI descriptor for operation
+ * @dev:	The PCI device for which the descriptor is prepared
+ * @desc:	The MSI descriptor for preparation
+ *
+ * This is separate from msix_setup_msi_descs() below to handle dynamic
+ * allocations for MSI-X after initial enablement.
+ *
+ * Ideally the whole MSI-X setup would work that way, but there is no way to
+ * support this for the legacy arch_setup_msi_irqs() mechanism and for the
+ * fake irq domains like the x86 XEN one. Sigh...
+ *
+ * The descriptor is zeroed and only @desc::msi_index and @desc::affinity
+ * are set. When called from msix_setup_msi_descs() then the is_virtual
+ * attribute is initialized as well.
+ *
+ * Fill in the rest.
+ */
+void msix_prepare_msi_desc(struct pci_dev *dev, struct msi_desc *desc)
+{
+	desc->nvec_used				= 1;
+	desc->pci.msi_attrib.is_msix		= 1;
+	desc->pci.msi_attrib.is_64		= 1;
+	desc->pci.msi_attrib.default_irq	= dev->irq;
+	desc->pci.mask_base			= dev->msix_base;
+
+
+	if (!pci_msi_domain_supports(dev, MSI_FLAG_NO_MASK, DENY_LEGACY) &&
+	    !desc->pci.msi_attrib.is_virtual) {
+		void __iomem *addr = pci_msix_desc_addr(desc);
+
+		desc->pci.msi_attrib.can_mask = 1;
+		/* Workaround for SUN NIU insanity, which requires write before read */
+		if (dev->dev_flags & PCI_DEV_FLAGS_MSIX_TOUCH_ENTRY_DATA_FIRST)
+			writel(0, addr + PCI_MSIX_ENTRY_DATA);
+		desc->pci.msix_ctrl = readl(addr + PCI_MSIX_ENTRY_VECTOR_CTRL);
+	}
+}
+
+static int msix_setup_msi_descs(struct pci_dev *dev, struct msix_entry *entries,
+				int nvec, struct irq_affinity_desc *masks)
+{
+	int ret = 0, i, vec_count = pci_msix_vec_count(dev);
+	struct irq_affinity_desc *curmsk;
+	struct msi_desc desc;
+
+	memset(&desc, 0, sizeof(desc));
+
+	for (i = 0, curmsk = masks; i < nvec; i++, curmsk++) {
+		desc.msi_index = entries ? entries[i].entry : i;
+		desc.affinity = masks ? curmsk : NULL;
+		desc.pci.msi_attrib.is_virtual = desc.msi_index >= vec_count;
+
+		msix_prepare_msi_desc(dev, &desc);
+
+		ret = msi_insert_msi_desc(&dev->dev, &desc);
+		if (ret)
+			break;
+	}
+	return ret;
+}
+
+static void msix_update_entries(struct pci_dev *dev, struct msix_entry *entries)
+{
+	struct msi_desc *desc;
+
+	if (entries) {
+		msi_for_each_desc(desc, &dev->dev, MSI_DESC_ALL) {
+			entries->vector = desc->irq;
+			entries++;
+		}
+	}
+}
+
+static void msix_mask_all(void __iomem *base, int tsize)
+{
+	u32 ctrl = PCI_MSIX_ENTRY_CTRL_MASKBIT;
+	int i;
+
+	for (i = 0; i < tsize; i++, base += PCI_MSIX_ENTRY_SIZE)
+		writel(ctrl, base + PCI_MSIX_ENTRY_VECTOR_CTRL);
+}
+
+DEFINE_FREE(free_msi_irqs, struct pci_dev *, if (_T) pci_free_msi_irqs(_T));
+
+static int __msix_setup_interrupts(struct pci_dev *__dev, struct msix_entry *entries,
+				   int nvec, struct irq_affinity_desc *masks)
+{
+	struct pci_dev *dev __free(free_msi_irqs) = __dev;
+
+	int ret = msix_setup_msi_descs(dev, entries, nvec, masks);
+	if (ret)
+		return ret;
+
+	ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX);
+	if (ret)
+		return ret;
+
+	/* Check if all MSI entries honor device restrictions */
+	ret = msi_verify_entries(dev);
+	if (ret)
+		return ret;
+
+	msix_update_entries(dev, entries);
+	retain_and_null_ptr(dev);
+	return 0;
+}
+
+static int msix_setup_interrupts(struct pci_dev *dev, struct msix_entry *entries,
+				 int nvec, struct irq_affinity *affd)
+{
+	struct irq_affinity_desc *masks __free(kfree) =
+		affd ? irq_create_affinity_masks(nvec, affd) : NULL;
+
+	guard(msi_descs_lock)(&dev->dev);
+	return __msix_setup_interrupts(dev, entries, nvec, masks);
+}
+
+/**
+ * msix_capability_init - configure device's MSI-X capability
+ * @dev: pointer to the pci_dev data structure of MSI-X device function
+ * @entries: pointer to an array of struct msix_entry entries
+ * @nvec: number of @entries
+ * @affd: Optional pointer to enable automatic affinity assignment
+ *
+ * Setup the MSI-X capability structure of device function with a
+ * single MSI-X IRQ. A return of zero indicates the successful setup of
+ * requested MSI-X entries with allocated IRQs or non-zero for otherwise.
+ **/
+static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
+				int nvec, struct irq_affinity *affd)
+{
+	int ret, tsize;
+	u16 control;
+
+	/*
+	 * Some devices require MSI-X to be enabled before the MSI-X
+	 * registers can be accessed.  Mask all the vectors to prevent
+	 * interrupts coming in before they're fully set up.
+	 */
+	pci_msix_clear_and_set_ctrl(dev, 0, PCI_MSIX_FLAGS_MASKALL |
+				    PCI_MSIX_FLAGS_ENABLE);
+
+	/* Mark it enabled so setup functions can query it */
+	dev->msix_enabled = 1;
+
+	pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control);
+	/* Request & Map MSI-X table region */
+	tsize = msix_table_size(control);
+	dev->msix_base = msix_map_region(dev, tsize);
+	if (!dev->msix_base) {
+		ret = -ENOMEM;
+		goto out_disable;
+	}
+
+	ret = msix_setup_interrupts(dev, entries, nvec, affd);
+	if (ret)
+		goto out_disable;
+
+	/* Disable INTX */
+	pci_intx_for_msi(dev, 0);
+
+	if (!pci_msi_domain_supports(dev, MSI_FLAG_NO_MASK, DENY_LEGACY)) {
+		/*
+		 * Ensure that all table entries are masked to prevent
+		 * stale entries from firing in a crash kernel.
+		 *
+		 * Done late to deal with a broken Marvell NVME device
+		 * which takes the MSI-X mask bits into account even
+		 * when MSI-X is disabled, which prevents MSI delivery.
+		 */
+		msix_mask_all(dev->msix_base, tsize);
+	}
+	pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0);
+
+	pcibios_free_irq(dev);
+	return 0;
+
+out_disable:
+	dev->msix_enabled = 0;
+	pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL | PCI_MSIX_FLAGS_ENABLE, 0);
+
+	return ret;
+}
+
+static bool pci_msix_validate_entries(struct pci_dev *dev, struct msix_entry *entries, int nvec)
+{
+	bool nogap;
+	int i, j;
+
+	if (!entries)
+		return true;
+
+	nogap = pci_msi_domain_supports(dev, MSI_FLAG_MSIX_CONTIGUOUS, DENY_LEGACY);
+
+	for (i = 0; i < nvec; i++) {
+		/* Check for duplicate entries */
+		for (j = i + 1; j < nvec; j++) {
+			if (entries[i].entry == entries[j].entry)
+				return false;
+		}
+		/* Check for unsupported gaps */
+		if (nogap && entries[i].entry != i)
+			return false;
+	}
+	return true;
+}
+
+int __pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries, int minvec,
+			    int maxvec, struct irq_affinity *affd, int flags)
+{
+	int hwsize, rc, nvec = maxvec;
+
+	if (maxvec < minvec)
+		return -ERANGE;
+
+	if (dev->msi_enabled) {
+		pci_info(dev, "can't enable MSI-X (MSI already enabled)\n");
+		return -EINVAL;
+	}
+
+	if (WARN_ON_ONCE(dev->msix_enabled))
+		return -EINVAL;
+
+	/* Check MSI-X early on irq domain enabled architectures */
+	if (!pci_msi_domain_supports(dev, MSI_FLAG_PCI_MSIX, ALLOW_LEGACY))
+		return -ENOTSUPP;
+
+	if (!pci_msi_supported(dev, nvec) || dev->current_state != PCI_D0)
+		return -EINVAL;
+
+	hwsize = pci_msix_vec_count(dev);
+	if (hwsize < 0)
+		return hwsize;
+
+	if (!pci_msix_validate_entries(dev, entries, nvec))
+		return -EINVAL;
+
+	if (hwsize < nvec) {
+		/* Keep the IRQ virtual hackery working */
+		if (flags & PCI_IRQ_VIRTUAL)
+			hwsize = nvec;
+		else
+			nvec = hwsize;
+	}
+
+	if (nvec < minvec)
+		return -ENOSPC;
+
+	rc = pci_setup_msi_context(dev);
+	if (rc)
+		return rc;
+
+	if (!pci_setup_msix_device_domain(dev, hwsize))
+		return -ENODEV;
+
+	for (;;) {
+		if (affd) {
+			nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
+			if (nvec < minvec)
+				return -ENOSPC;
+		}
+
+		rc = msix_capability_init(dev, entries, nvec, affd);
+		if (rc == 0)
+			return nvec;
+
+		if (rc < 0)
+			return rc;
+		if (rc < minvec)
+			return -ENOSPC;
+
+		nvec = rc;
+	}
+}
+
+void __pci_restore_msix_state(struct pci_dev *dev)
+{
+	struct msi_desc *entry;
+	bool write_msg;
+
+	if (!dev->msix_enabled)
+		return;
+
+	/* route the table */
+	pci_intx_for_msi(dev, 0);
+	pci_msix_clear_and_set_ctrl(dev, 0,
+				PCI_MSIX_FLAGS_ENABLE | PCI_MSIX_FLAGS_MASKALL);
+
+	write_msg = arch_restore_msi_irqs(dev);
+
+	scoped_guard (msi_descs_lock, &dev->dev) {
+		msi_for_each_desc(entry, &dev->dev, MSI_DESC_ALL) {
+			if (write_msg)
+				__pci_write_msi_msg(entry, &entry->msg);
+			pci_msix_write_vector_ctrl(entry, entry->pci.msix_ctrl);
+		}
+	}
+
+	pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0);
+}
+
+void pci_msix_shutdown(struct pci_dev *dev)
+{
+	struct msi_desc *desc;
+
+	if (!pci_msi_enable || !dev || !dev->msix_enabled)
+		return;
+
+	if (pci_dev_is_disconnected(dev)) {
+		dev->msix_enabled = 0;
+		return;
+	}
+
+	/* Return the device with MSI-X masked as initial states */
+	msi_for_each_desc(desc, &dev->dev, MSI_DESC_ALL)
+		pci_msix_mask(desc);
+
+	pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
+	pci_intx_for_msi(dev, 1);
+	dev->msix_enabled = 0;
+	pcibios_alloc_irq(dev);
+}
+
+/* Common interfaces */
+
+void pci_free_msi_irqs(struct pci_dev *dev)
+{
+	pci_msi_teardown_msi_irqs(dev);
+
+	if (dev->msix_base) {
+		iounmap(dev->msix_base);
+		dev->msix_base = NULL;
+	}
+}
+
+#ifdef CONFIG_PCIE_TPH
+/**
+ * pci_msix_write_tph_tag - Update the TPH tag for a given MSI-X vector
+ * @pdev:	The PCIe device to update
+ * @index:	The MSI-X index to update
+ * @tag:	The tag to write
+ *
+ * Returns: 0 on success, error code on failure
+ */
+int pci_msix_write_tph_tag(struct pci_dev *pdev, unsigned int index, u16 tag)
+{
+	struct msi_desc *msi_desc;
+	struct irq_desc *irq_desc;
+	unsigned int virq;
+
+	if (!pdev->msix_enabled)
+		return -ENXIO;
+
+	virq = msi_get_virq(&pdev->dev, index);
+	if (!virq)
+		return -ENXIO;
+
+	guard(msi_descs_lock)(&pdev->dev);
+
+	/*
+	 * This is a horrible hack, but short of implementing a PCI
+	 * specific interrupt chip callback and a huge pile of
+	 * infrastructure, this is the minor nuisance. It provides the
+	 * protection against concurrent operations on this entry and keeps
+	 * the control word cache in sync.
+	 */
+	irq_desc = irq_to_desc(virq);
+	if (!irq_desc)
+		return -ENXIO;
+
+	guard(raw_spinlock_irq)(&irq_desc->lock);
+	msi_desc = irq_data_get_msi_desc(&irq_desc->irq_data);
+	if (!msi_desc || msi_desc->pci.msi_attrib.is_virtual)
+		return -ENXIO;
+
+	FIELD_MODIFY(PCI_MSIX_ENTRY_CTRL_ST, &msi_desc->pci.msix_ctrl, tag);
+	pci_msix_write_vector_ctrl(msi_desc, msi_desc->pci.msix_ctrl);
+	/* Flush the write */
+	readl(pci_msix_desc_addr(msi_desc));
+	return 0;
+}
+#endif
+
+/* Misc. infrastructure */
+
+struct pci_dev *msi_desc_to_pci_dev(struct msi_desc *desc)
+{
+	return to_pci_dev(desc->dev);
+}
+EXPORT_SYMBOL(msi_desc_to_pci_dev);
+
+void pci_no_msi(void)
+{
+	pci_msi_enable = false;
+}

linux-7.2.3/drivers/pci/msi/msi.h

@@ -0,0 +1,129 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <linux/pci.h>
+#include <linux/msi.h>
+
+#define msix_table_size(flags)	((flags & PCI_MSIX_FLAGS_QSIZE) + 1)
+
+int pci_msi_setup_msi_irqs(struct pci_dev *dev, int nvec, int type);
+void pci_msi_teardown_msi_irqs(struct pci_dev *dev);
+
+/* Mask/unmask helpers */
+void pci_msi_update_mask(struct msi_desc *desc, u32 clear, u32 set);
+
+static inline void pci_msi_mask(struct msi_desc *desc, u32 mask)
+{
+	pci_msi_update_mask(desc, 0, mask);
+}
+
+static inline void pci_msi_unmask(struct msi_desc *desc, u32 mask)
+{
+	pci_msi_update_mask(desc, mask, 0);
+}
+
+static inline void __iomem *pci_msix_desc_addr(struct msi_desc *desc)
+{
+	return desc->pci.mask_base + desc->msi_index * PCI_MSIX_ENTRY_SIZE;
+}
+
+/*
+ * This internal function does not flush PCI writes to the device.  All
+ * users must ensure that they read from the device before either assuming
+ * that the device state is up to date, or returning out of this file.
+ * It does not affect the msi_desc::msix_ctrl cache either. Use with care!
+ */
+static inline void pci_msix_write_vector_ctrl(struct msi_desc *desc, u32 ctrl)
+{
+	void __iomem *desc_addr = pci_msix_desc_addr(desc);
+
+	if (desc->pci.msi_attrib.can_mask)
+		writel(ctrl, desc_addr + PCI_MSIX_ENTRY_VECTOR_CTRL);
+}
+
+static inline void pci_msix_mask(struct msi_desc *desc)
+{
+	desc->pci.msix_ctrl |= PCI_MSIX_ENTRY_CTRL_MASKBIT;
+	pci_msix_write_vector_ctrl(desc, desc->pci.msix_ctrl);
+	/* Flush write to device */
+	readl(desc->pci.mask_base);
+}
+
+static inline void pci_msix_unmask(struct msi_desc *desc)
+{
+	desc->pci.msix_ctrl &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT;
+	pci_msix_write_vector_ctrl(desc, desc->pci.msix_ctrl);
+}
+
+static inline void __pci_msi_mask_desc(struct msi_desc *desc, u32 mask)
+{
+	if (desc->pci.msi_attrib.is_msix)
+		pci_msix_mask(desc);
+	else
+		pci_msi_mask(desc, mask);
+}
+
+static inline void __pci_msi_unmask_desc(struct msi_desc *desc, u32 mask)
+{
+	if (desc->pci.msi_attrib.is_msix)
+		pci_msix_unmask(desc);
+	else
+		pci_msi_unmask(desc, mask);
+}
+
+/*
+ * PCI 2.3 does not specify mask bits for each MSI interrupt.  Attempting to
+ * mask all MSI interrupts by clearing the MSI enable bit does not work
+ * reliably as devices without an INTx disable bit will then generate a
+ * level IRQ which will never be cleared.
+ */
+static inline __attribute_const__ u32 msi_multi_mask(struct msi_desc *desc)
+{
+	/* Don't shift by >= width of type */
+	if (desc->pci.msi_attrib.multi_cap >= 5)
+		return 0xffffffff;
+	return (1 << (1 << desc->pci.msi_attrib.multi_cap)) - 1;
+}
+
+void msix_prepare_msi_desc(struct pci_dev *dev, struct msi_desc *desc);
+
+/* Subsystem variables */
+extern bool pci_msi_enable;
+
+/* MSI internal functions invoked from the public APIs */
+void pci_msi_shutdown(struct pci_dev *dev);
+void pci_msix_shutdown(struct pci_dev *dev);
+void pci_free_msi_irqs(struct pci_dev *dev);
+int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec, struct irq_affinity *affd);
+int __pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries, int minvec,
+			    int maxvec,  struct irq_affinity *affd, int flags);
+void __pci_restore_msi_state(struct pci_dev *dev);
+void __pci_restore_msix_state(struct pci_dev *dev);
+
+/* irq_domain related functionality */
+
+enum support_mode {
+	ALLOW_LEGACY,
+	DENY_LEGACY,
+};
+
+bool pci_msi_domain_supports(struct pci_dev *dev, unsigned int feature_mask, enum support_mode mode);
+bool pci_setup_msi_device_domain(struct pci_dev *pdev, unsigned int hwsize);
+bool pci_setup_msix_device_domain(struct pci_dev *pdev, unsigned int hwsize);
+
+/* Legacy (!IRQDOMAIN) fallbacks */
+
+#ifdef CONFIG_PCI_MSI_ARCH_FALLBACKS
+int pci_msi_legacy_setup_msi_irqs(struct pci_dev *dev, int nvec, int type);
+void pci_msi_legacy_teardown_msi_irqs(struct pci_dev *dev);
+#else
+static inline int pci_msi_legacy_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+	WARN_ON_ONCE(1);
+	return -ENODEV;
+}
+
+static inline void pci_msi_legacy_teardown_msi_irqs(struct pci_dev *dev)
+{
+	WARN_ON_ONCE(1);
+}
+#endif

linux-7.2.3/drivers/pci/msi/pcidev_msi.c

@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MSI[X} related functions which are available unconditionally.
+ */
+#include "../pci.h"
+
+/*
+ * Disable the MSI[X] hardware to avoid screaming interrupts during boot.
+ * This is the power on reset default so usually this should be a noop.
+ */
+
+void pci_msi_init(struct pci_dev *dev)
+{
+	u16 ctrl;
+
+	dev->msi_cap = pci_find_capability(dev, PCI_CAP_ID_MSI);
+	if (!dev->msi_cap)
+		return;
+
+	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &ctrl);
+	if (ctrl & PCI_MSI_FLAGS_ENABLE) {
+		pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS,
+				      ctrl & ~PCI_MSI_FLAGS_ENABLE);
+	}
+
+	if (!(ctrl & PCI_MSI_FLAGS_64BIT))
+		dev->msi_addr_mask = DMA_BIT_MASK(32);
+}
+
+void pci_msix_init(struct pci_dev *dev)
+{
+	u16 ctrl;
+
+	dev->msix_cap = pci_find_capability(dev, PCI_CAP_ID_MSIX);
+	if (!dev->msix_cap)
+		return;
+
+	pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &ctrl);
+	if (ctrl & PCI_MSIX_FLAGS_ENABLE) {
+		pci_write_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS,
+				      ctrl & ~PCI_MSIX_FLAGS_ENABLE);
+	}
+}