Resguardo inicial

linux-7.2.3/arch/mips/bmips/dma.c

@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <linux/types.h>
+#include <linux/dma-map-ops.h>
+#include <asm/bmips.h>
+#include <asm/io.h>
+
+bool bmips_rac_flush_disable;
+
+void arch_sync_dma_for_cpu_all(void)
+{
+	void __iomem *cbr = bmips_cbr_addr;
+	u32 cfg;
+
+	if (boot_cpu_type() != CPU_BMIPS3300 &&
+	    boot_cpu_type() != CPU_BMIPS4350 &&
+	    boot_cpu_type() != CPU_BMIPS4380)
+		return;
+
+	if (unlikely(bmips_rac_flush_disable))
+		return;
+
+	/* Flush stale data out of the readahead cache */
+	cfg = __raw_readl(cbr + BMIPS_RAC_CONFIG);
+	__raw_writel(cfg | 0x100, cbr + BMIPS_RAC_CONFIG);
+	__raw_readl(cbr + BMIPS_RAC_CONFIG);
+}