Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index d2a92dd..d9334f3 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -5,9 +5,10 @@
  * Copyright (c) 2006  SUSE Linux Products GmbH
  * Copyright (c) 2006  Tejun Heo <teheo@suse.de>
  */
-
+#include <linux/memblock.h> /* for max_pfn */
 #include <linux/acpi.h>
-#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
+#include <linux/dma-noncoherent.h>
 #include <linux/export.h>
 #include <linux/gfp.h>
 #include <linux/of_device.h>
@@ -45,45 +46,6 @@
 }
 
 /**
- * dmam_alloc_coherent - Managed dma_alloc_coherent()
- * @dev: Device to allocate coherent memory for
- * @size: Size of allocation
- * @dma_handle: Out argument for allocated DMA handle
- * @gfp: Allocation flags
- *
- * Managed dma_alloc_coherent().  Memory allocated using this function
- * will be automatically released on driver detach.
- *
- * RETURNS:
- * Pointer to allocated memory on success, NULL on failure.
- */
-void *dmam_alloc_coherent(struct device *dev, size_t size,
-			   dma_addr_t *dma_handle, gfp_t gfp)
-{
-	struct dma_devres *dr;
-	void *vaddr;
-
-	dr = devres_alloc(dmam_release, sizeof(*dr), gfp);
-	if (!dr)
-		return NULL;
-
-	vaddr = dma_alloc_coherent(dev, size, dma_handle, gfp);
-	if (!vaddr) {
-		devres_free(dr);
-		return NULL;
-	}
-
-	dr->vaddr = vaddr;
-	dr->dma_handle = *dma_handle;
-	dr->size = size;
-
-	devres_add(dev, dr);
-
-	return vaddr;
-}
-EXPORT_SYMBOL(dmam_alloc_coherent);
-
-/**
  * dmam_free_coherent - Managed dma_free_coherent()
  * @dev: Device to free coherent memory for
  * @size: Size of allocation
@@ -143,203 +105,334 @@
 }
 EXPORT_SYMBOL(dmam_alloc_attrs);
 
-#ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT
-
-static void dmam_coherent_decl_release(struct device *dev, void *res)
-{
-	dma_release_declared_memory(dev);
-}
-
-/**
- * dmam_declare_coherent_memory - Managed dma_declare_coherent_memory()
- * @dev: Device to declare coherent memory for
- * @phys_addr: Physical address of coherent memory to be declared
- * @device_addr: Device address of coherent memory to be declared
- * @size: Size of coherent memory to be declared
- * @flags: Flags
- *
- * Managed dma_declare_coherent_memory().
- *
- * RETURNS:
- * 0 on success, -errno on failure.
- */
-int dmam_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
-				 dma_addr_t device_addr, size_t size, int flags)
-{
-	void *res;
-	int rc;
-
-	res = devres_alloc(dmam_coherent_decl_release, 0, GFP_KERNEL);
-	if (!res)
-		return -ENOMEM;
-
-	rc = dma_declare_coherent_memory(dev, phys_addr, device_addr, size,
-					 flags);
-	if (!rc)
-		devres_add(dev, res);
-	else
-		devres_free(res);
-
-	return rc;
-}
-EXPORT_SYMBOL(dmam_declare_coherent_memory);
-
-/**
- * dmam_release_declared_memory - Managed dma_release_declared_memory().
- * @dev: Device to release declared coherent memory for
- *
- * Managed dmam_release_declared_memory().
- */
-void dmam_release_declared_memory(struct device *dev)
-{
-	WARN_ON(devres_destroy(dev, dmam_coherent_decl_release, NULL, NULL));
-}
-EXPORT_SYMBOL(dmam_release_declared_memory);
-
-#endif
-
 /*
  * Create scatter-list for the already allocated DMA buffer.
  */
 int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
-		 void *cpu_addr, dma_addr_t handle, size_t size)
+		 void *cpu_addr, dma_addr_t dma_addr, size_t size,
+		 unsigned long attrs)
 {
-	struct page *page = virt_to_page(cpu_addr);
+	struct page *page;
 	int ret;
 
-	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
-	if (unlikely(ret))
-		return ret;
+	if (!dev_is_dma_coherent(dev)) {
+		unsigned long pfn;
 
-	sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
-	return 0;
+		if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN))
+			return -ENXIO;
+
+		/* If the PFN is not valid, we do not have a struct page */
+		pfn = arch_dma_coherent_to_pfn(dev, cpu_addr, dma_addr);
+		if (!pfn_valid(pfn))
+			return -ENXIO;
+		page = pfn_to_page(pfn);
+	} else {
+		page = virt_to_page(cpu_addr);
+	}
+
+	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
+	if (!ret)
+		sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
+	return ret;
 }
-EXPORT_SYMBOL(dma_common_get_sgtable);
+
+/*
+ * The whole dma_get_sgtable() idea is fundamentally unsafe - it seems
+ * that the intention is to allow exporting memory allocated via the
+ * coherent DMA APIs through the dma_buf API, which only accepts a
+ * scattertable.  This presents a couple of problems:
+ * 1. Not all memory allocated via the coherent DMA APIs is backed by
+ *    a struct page
+ * 2. Passing coherent DMA memory into the streaming APIs is not allowed
+ *    as we will try to flush the memory through a different alias to that
+ *    actually being used (and the flushes are redundant.)
+ */
+int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt,
+		void *cpu_addr, dma_addr_t dma_addr, size_t size,
+		unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	if (dma_is_direct(ops))
+		return dma_common_get_sgtable(dev, sgt, cpu_addr, dma_addr,
+				size, attrs);
+	if (!ops->get_sgtable)
+		return -ENXIO;
+	return ops->get_sgtable(dev, sgt, cpu_addr, dma_addr, size, attrs);
+}
+EXPORT_SYMBOL(dma_get_sgtable_attrs);
+
+#ifdef CONFIG_MMU
+/*
+ * Return the page attributes used for mapping dma_alloc_* memory, either in
+ * kernel space if remapping is needed, or to userspace through dma_mmap_*.
+ */
+pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs)
+{
+	if (dev_is_dma_coherent(dev) ||
+	    (IS_ENABLED(CONFIG_DMA_NONCOHERENT_CACHE_SYNC) &&
+             (attrs & DMA_ATTR_NON_CONSISTENT)))
+		return prot;
+#ifdef CONFIG_ARCH_HAS_DMA_WRITE_COMBINE
+	if (attrs & DMA_ATTR_WRITE_COMBINE)
+		return pgprot_writecombine(prot);
+#endif
+	return pgprot_dmacoherent(prot);
+}
+#endif /* CONFIG_MMU */
 
 /*
  * Create userspace mapping for the DMA-coherent memory.
  */
 int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
-		    void *cpu_addr, dma_addr_t dma_addr, size_t size)
+		void *cpu_addr, dma_addr_t dma_addr, size_t size,
+		unsigned long attrs)
 {
-	int ret = -ENXIO;
-#ifndef CONFIG_ARCH_NO_COHERENT_DMA_MMAP
+#ifdef CONFIG_MMU
 	unsigned long user_count = vma_pages(vma);
 	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
 	unsigned long off = vma->vm_pgoff;
+	unsigned long pfn;
+	int ret = -ENXIO;
 
-	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+	vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs);
 
 	if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
 		return ret;
 
-	if (off < count && user_count <= (count - off))
-		ret = remap_pfn_range(vma, vma->vm_start,
-				      page_to_pfn(virt_to_page(cpu_addr)) + off,
-				      user_count << PAGE_SHIFT,
-				      vma->vm_page_prot);
-#endif	/* !CONFIG_ARCH_NO_COHERENT_DMA_MMAP */
+	if (off >= count || user_count > count - off)
+		return -ENXIO;
 
-	return ret;
-}
-EXPORT_SYMBOL(dma_common_mmap);
+	if (!dev_is_dma_coherent(dev)) {
+		if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN))
+			return -ENXIO;
 
-#ifdef CONFIG_MMU
-static struct vm_struct *__dma_common_pages_remap(struct page **pages,
-			size_t size, unsigned long vm_flags, pgprot_t prot,
-			const void *caller)
-{
-	struct vm_struct *area;
-
-	area = get_vm_area_caller(size, vm_flags, caller);
-	if (!area)
-		return NULL;
-
-	if (map_vm_area(area, prot, pages)) {
-		vunmap(area->addr);
-		return NULL;
+		/* If the PFN is not valid, we do not have a struct page */
+		pfn = arch_dma_coherent_to_pfn(dev, cpu_addr, dma_addr);
+		if (!pfn_valid(pfn))
+			return -ENXIO;
+	} else {
+		pfn = page_to_pfn(virt_to_page(cpu_addr));
 	}
 
-	return area;
+	return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
+			user_count << PAGE_SHIFT, vma->vm_page_prot);
+#else
+	return -ENXIO;
+#endif /* CONFIG_MMU */
 }
 
-/*
- * remaps an array of PAGE_SIZE pages into another vm_area
- * Cannot be used in non-sleeping contexts
+/**
+ * dma_can_mmap - check if a given device supports dma_mmap_*
+ * @dev: device to check
+ *
+ * Returns %true if @dev supports dma_mmap_coherent() and dma_mmap_attrs() to
+ * map DMA allocations to userspace.
  */
-void *dma_common_pages_remap(struct page **pages, size_t size,
-			unsigned long vm_flags, pgprot_t prot,
-			const void *caller)
+bool dma_can_mmap(struct device *dev)
 {
-	struct vm_struct *area;
+	const struct dma_map_ops *ops = get_dma_ops(dev);
 
-	area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller);
-	if (!area)
-		return NULL;
+	if (dma_is_direct(ops)) {
+		return IS_ENABLED(CONFIG_MMU) &&
+		       (dev_is_dma_coherent(dev) ||
+			IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN));
+	}
 
-	area->pages = pages;
-
-	return area->addr;
+	return ops->mmap != NULL;
 }
+EXPORT_SYMBOL_GPL(dma_can_mmap);
 
-/*
- * remaps an allocated contiguous region into another vm_area.
- * Cannot be used in non-sleeping contexts
+/**
+ * dma_mmap_attrs - map a coherent DMA allocation into user space
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @vma: vm_area_struct describing requested user mapping
+ * @cpu_addr: kernel CPU-view address returned from dma_alloc_attrs
+ * @dma_addr: device-view address returned from dma_alloc_attrs
+ * @size: size of memory originally requested in dma_alloc_attrs
+ * @attrs: attributes of mapping properties requested in dma_alloc_attrs
+ *
+ * Map a coherent DMA buffer previously allocated by dma_alloc_attrs into user
+ * space.  The coherent DMA buffer must not be freed by the driver until the
+ * user space mapping has been released.
  */
-
-void *dma_common_contiguous_remap(struct page *page, size_t size,
-			unsigned long vm_flags,
-			pgprot_t prot, const void *caller)
+int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
+		void *cpu_addr, dma_addr_t dma_addr, size_t size,
+		unsigned long attrs)
 {
-	int i;
-	struct page **pages;
-	struct vm_struct *area;
+	const struct dma_map_ops *ops = get_dma_ops(dev);
 
-	pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL);
-	if (!pages)
-		return NULL;
-
-	for (i = 0; i < (size >> PAGE_SHIFT); i++)
-		pages[i] = nth_page(page, i);
-
-	area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller);
-
-	kfree(pages);
-
-	if (!area)
-		return NULL;
-	return area->addr;
+	if (dma_is_direct(ops))
+		return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size,
+				attrs);
+	if (!ops->mmap)
+		return -ENXIO;
+	return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
 }
+EXPORT_SYMBOL(dma_mmap_attrs);
 
-/*
- * unmaps a range previously mapped by dma_common_*_remap
- */
-void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
+u64 dma_get_required_mask(struct device *dev)
 {
-	struct vm_struct *area = find_vm_area(cpu_addr);
+	const struct dma_map_ops *ops = get_dma_ops(dev);
 
-	if (!area || (area->flags & vm_flags) != vm_flags) {
-		WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
+	if (dma_is_direct(ops))
+		return dma_direct_get_required_mask(dev);
+	if (ops->get_required_mask)
+		return ops->get_required_mask(dev);
+
+	/*
+	 * We require every DMA ops implementation to at least support a 32-bit
+	 * DMA mask (and use bounce buffering if that isn't supported in
+	 * hardware).  As the direct mapping code has its own routine to
+	 * actually report an optimal mask we default to 32-bit here as that
+	 * is the right thing for most IOMMUs, and at least not actively
+	 * harmful in general.
+	 */
+	return DMA_BIT_MASK(32);
+}
+EXPORT_SYMBOL_GPL(dma_get_required_mask);
+
+void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
+		gfp_t flag, unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+	void *cpu_addr;
+
+	WARN_ON_ONCE(!dev->coherent_dma_mask);
+
+	if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr))
+		return cpu_addr;
+
+	/* let the implementation decide on the zone to allocate from: */
+	flag &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
+
+	if (dma_is_direct(ops))
+		cpu_addr = dma_direct_alloc(dev, size, dma_handle, flag, attrs);
+	else if (ops->alloc)
+		cpu_addr = ops->alloc(dev, size, dma_handle, flag, attrs);
+	else
+		return NULL;
+
+	debug_dma_alloc_coherent(dev, size, *dma_handle, cpu_addr);
+	return cpu_addr;
+}
+EXPORT_SYMBOL(dma_alloc_attrs);
+
+void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
+		dma_addr_t dma_handle, unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	if (dma_release_from_dev_coherent(dev, get_order(size), cpu_addr))
 		return;
-	}
+	/*
+	 * On non-coherent platforms which implement DMA-coherent buffers via
+	 * non-cacheable remaps, ops->free() may call vunmap(). Thus getting
+	 * this far in IRQ context is a) at risk of a BUG_ON() or trying to
+	 * sleep on some machines, and b) an indication that the driver is
+	 * probably misusing the coherent API anyway.
+	 */
+	WARN_ON(irqs_disabled());
 
-	unmap_kernel_range((unsigned long)cpu_addr, PAGE_ALIGN(size));
-	vunmap(cpu_addr);
+	if (!cpu_addr)
+		return;
+
+	debug_dma_free_coherent(dev, size, cpu_addr, dma_handle);
+	if (dma_is_direct(ops))
+		dma_direct_free(dev, size, cpu_addr, dma_handle, attrs);
+	else if (ops->free)
+		ops->free(dev, size, cpu_addr, dma_handle, attrs);
 }
+EXPORT_SYMBOL(dma_free_attrs);
+
+int dma_supported(struct device *dev, u64 mask)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	if (dma_is_direct(ops))
+		return dma_direct_supported(dev, mask);
+	if (!ops->dma_supported)
+		return 1;
+	return ops->dma_supported(dev, mask);
+}
+EXPORT_SYMBOL(dma_supported);
+
+#ifdef CONFIG_ARCH_HAS_DMA_SET_MASK
+void arch_dma_set_mask(struct device *dev, u64 mask);
+#else
+#define arch_dma_set_mask(dev, mask)	do { } while (0)
 #endif
 
-/*
- * enables DMA API use for a device
- */
-int dma_configure(struct device *dev)
+int dma_set_mask(struct device *dev, u64 mask)
 {
-	if (dev->bus->dma_configure)
-		return dev->bus->dma_configure(dev);
+	/*
+	 * Truncate the mask to the actually supported dma_addr_t width to
+	 * avoid generating unsupportable addresses.
+	 */
+	mask = (dma_addr_t)mask;
+
+	if (!dev->dma_mask || !dma_supported(dev, mask))
+		return -EIO;
+
+	arch_dma_set_mask(dev, mask);
+	*dev->dma_mask = mask;
 	return 0;
 }
+EXPORT_SYMBOL(dma_set_mask);
 
-void dma_deconfigure(struct device *dev)
+#ifndef CONFIG_ARCH_HAS_DMA_SET_COHERENT_MASK
+int dma_set_coherent_mask(struct device *dev, u64 mask)
 {
-	of_dma_deconfigure(dev);
-	acpi_dma_deconfigure(dev);
+	/*
+	 * Truncate the mask to the actually supported dma_addr_t width to
+	 * avoid generating unsupportable addresses.
+	 */
+	mask = (dma_addr_t)mask;
+
+	if (!dma_supported(dev, mask))
+		return -EIO;
+
+	dev->coherent_dma_mask = mask;
+	return 0;
 }
+EXPORT_SYMBOL(dma_set_coherent_mask);
+#endif
+
+void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
+		enum dma_data_direction dir)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+
+	if (dma_is_direct(ops))
+		arch_dma_cache_sync(dev, vaddr, size, dir);
+	else if (ops->cache_sync)
+		ops->cache_sync(dev, vaddr, size, dir);
+}
+EXPORT_SYMBOL(dma_cache_sync);
+
+size_t dma_max_mapping_size(struct device *dev)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+	size_t size = SIZE_MAX;
+
+	if (dma_is_direct(ops))
+		size = dma_direct_max_mapping_size(dev);
+	else if (ops && ops->max_mapping_size)
+		size = ops->max_mapping_size(dev);
+
+	return size;
+}
+EXPORT_SYMBOL_GPL(dma_max_mapping_size);
+
+unsigned long dma_get_merge_boundary(struct device *dev)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	if (!ops || !ops->get_merge_boundary)
+		return 0;	/* can't merge */
+
+	return ops->get_merge_boundary(dev);
+}
+EXPORT_SYMBOL_GPL(dma_get_merge_boundary);