Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 951 insertions, 0 deletions

diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c
new file mode 100644
index 000000000..11ff1ee51
--- /dev/null
+++ b/sound/core/memalloc.c
@@ -0,0 +1,951 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ *                   Takashi Iwai <tiwai@suse.de>
+ * 
+ *  Generic memory allocators
+ */
+
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/dma-mapping.h>
+#include <linux/dma-map-ops.h>
+#include <linux/genalloc.h>
+#include <linux/highmem.h>
+#include <linux/vmalloc.h>
+#ifdef CONFIG_X86
+#include <asm/set_memory.h>
+#endif
+#include <sound/memalloc.h>
+#include "memalloc_local.h"
+
+#define DEFAULT_GFP \
+	(GFP_KERNEL | \
+	 __GFP_COMP |    /* compound page lets parts be mapped */ \
+	 __GFP_RETRY_MAYFAIL | /* don't trigger OOM-killer */ \
+	 __GFP_NOWARN)   /* no stack trace print - this call is non-critical */
+
+static const struct snd_malloc_ops *snd_dma_get_ops(struct snd_dma_buffer *dmab);
+
+#ifdef CONFIG_SND_DMA_SGBUF
+static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size);
+#endif
+
+static void *__snd_dma_alloc_pages(struct snd_dma_buffer *dmab, size_t size)
+{
+	const struct snd_malloc_ops *ops = snd_dma_get_ops(dmab);
+
+	if (WARN_ON_ONCE(!ops || !ops->alloc))
+		return NULL;
+	return ops->alloc(dmab, size);
+}
+
+/**
+ * snd_dma_alloc_dir_pages - allocate the buffer area according to the given
+ *	type and direction
+ * @type: the DMA buffer type
+ * @device: the device pointer
+ * @dir: DMA direction
+ * @size: the buffer size to allocate
+ * @dmab: buffer allocation record to store the allocated data
+ *
+ * Calls the memory-allocator function for the corresponding
+ * buffer type.
+ *
+ * Return: Zero if the buffer with the given size is allocated successfully,
+ * otherwise a negative value on error.
+ */
+int snd_dma_alloc_dir_pages(int type, struct device *device,
+			    enum dma_data_direction dir, size_t size,
+			    struct snd_dma_buffer *dmab)
+{
+	if (WARN_ON(!size))
+		return -ENXIO;
+	if (WARN_ON(!dmab))
+		return -ENXIO;
+
+	size = PAGE_ALIGN(size);
+	dmab->dev.type = type;
+	dmab->dev.dev = device;
+	dmab->dev.dir = dir;
+	dmab->bytes = 0;
+	dmab->addr = 0;
+	dmab->private_data = NULL;
+	dmab->area = __snd_dma_alloc_pages(dmab, size);
+	if (!dmab->area)
+		return -ENOMEM;
+	dmab->bytes = size;
+	return 0;
+}
+EXPORT_SYMBOL(snd_dma_alloc_dir_pages);
+
+/**
+ * snd_dma_alloc_pages_fallback - allocate the buffer area according to the given type with fallback
+ * @type: the DMA buffer type
+ * @device: the device pointer
+ * @size: the buffer size to allocate
+ * @dmab: buffer allocation record to store the allocated data
+ *
+ * Calls the memory-allocator function for the corresponding
+ * buffer type.  When no space is left, this function reduces the size and
+ * tries to allocate again.  The size actually allocated is stored in
+ * res_size argument.
+ *
+ * Return: Zero if the buffer with the given size is allocated successfully,
+ * otherwise a negative value on error.
+ */
+int snd_dma_alloc_pages_fallback(int type, struct device *device, size_t size,
+				 struct snd_dma_buffer *dmab)
+{
+	int err;
+
+	while ((err = snd_dma_alloc_pages(type, device, size, dmab)) < 0) {
+		if (err != -ENOMEM)
+			return err;
+		if (size <= PAGE_SIZE)
+			return -ENOMEM;
+		size >>= 1;
+		size = PAGE_SIZE << get_order(size);
+	}
+	if (! dmab->area)
+		return -ENOMEM;
+	return 0;
+}
+EXPORT_SYMBOL(snd_dma_alloc_pages_fallback);
+
+/**
+ * snd_dma_free_pages - release the allocated buffer
+ * @dmab: the buffer allocation record to release
+ *
+ * Releases the allocated buffer via snd_dma_alloc_pages().
+ */
+void snd_dma_free_pages(struct snd_dma_buffer *dmab)
+{
+	const struct snd_malloc_ops *ops = snd_dma_get_ops(dmab);
+
+	if (ops && ops->free)
+		ops->free(dmab);
+}
+EXPORT_SYMBOL(snd_dma_free_pages);
+
+/* called by devres */
+static void __snd_release_pages(struct device *dev, void *res)
+{
+	snd_dma_free_pages(res);
+}
+
+/**
+ * snd_devm_alloc_dir_pages - allocate the buffer and manage with devres
+ * @dev: the device pointer
+ * @type: the DMA buffer type
+ * @dir: DMA direction
+ * @size: the buffer size to allocate
+ *
+ * Allocate buffer pages depending on the given type and manage using devres.
+ * The pages will be released automatically at the device removal.
+ *
+ * Unlike snd_dma_alloc_pages(), this function requires the real device pointer,
+ * hence it can't work with SNDRV_DMA_TYPE_CONTINUOUS or
+ * SNDRV_DMA_TYPE_VMALLOC type.
+ *
+ * Return: the snd_dma_buffer object at success, or NULL if failed
+ */
+struct snd_dma_buffer *
+snd_devm_alloc_dir_pages(struct device *dev, int type,
+			 enum dma_data_direction dir, size_t size)
+{
+	struct snd_dma_buffer *dmab;
+	int err;
+
+	if (WARN_ON(type == SNDRV_DMA_TYPE_CONTINUOUS ||
+		    type == SNDRV_DMA_TYPE_VMALLOC))
+		return NULL;
+
+	dmab = devres_alloc(__snd_release_pages, sizeof(*dmab), GFP_KERNEL);
+	if (!dmab)
+		return NULL;
+
+	err = snd_dma_alloc_dir_pages(type, dev, dir, size, dmab);
+	if (err < 0) {
+		devres_free(dmab);
+		return NULL;
+	}
+
+	devres_add(dev, dmab);
+	return dmab;
+}
+EXPORT_SYMBOL_GPL(snd_devm_alloc_dir_pages);
+
+/**
+ * snd_dma_buffer_mmap - perform mmap of the given DMA buffer
+ * @dmab: buffer allocation information
+ * @area: VM area information
+ *
+ * Return: zero if successful, or a negative error code
+ */
+int snd_dma_buffer_mmap(struct snd_dma_buffer *dmab,
+			struct vm_area_struct *area)
+{
+	const struct snd_malloc_ops *ops;
+
+	if (!dmab)
+		return -ENOENT;
+	ops = snd_dma_get_ops(dmab);
+	if (ops && ops->mmap)
+		return ops->mmap(dmab, area);
+	else
+		return -ENOENT;
+}
+EXPORT_SYMBOL(snd_dma_buffer_mmap);
+
+#ifdef CONFIG_HAS_DMA
+/**
+ * snd_dma_buffer_sync - sync DMA buffer between CPU and device
+ * @dmab: buffer allocation information
+ * @mode: sync mode
+ */
+void snd_dma_buffer_sync(struct snd_dma_buffer *dmab,
+			 enum snd_dma_sync_mode mode)
+{
+	const struct snd_malloc_ops *ops;
+
+	if (!dmab || !dmab->dev.need_sync)
+		return;
+	ops = snd_dma_get_ops(dmab);
+	if (ops && ops->sync)
+		ops->sync(dmab, mode);
+}
+EXPORT_SYMBOL_GPL(snd_dma_buffer_sync);
+#endif /* CONFIG_HAS_DMA */
+
+/**
+ * snd_sgbuf_get_addr - return the physical address at the corresponding offset
+ * @dmab: buffer allocation information
+ * @offset: offset in the ring buffer
+ *
+ * Return: the physical address
+ */
+dma_addr_t snd_sgbuf_get_addr(struct snd_dma_buffer *dmab, size_t offset)
+{
+	const struct snd_malloc_ops *ops = snd_dma_get_ops(dmab);
+
+	if (ops && ops->get_addr)
+		return ops->get_addr(dmab, offset);
+	else
+		return dmab->addr + offset;
+}
+EXPORT_SYMBOL(snd_sgbuf_get_addr);
+
+/**
+ * snd_sgbuf_get_page - return the physical page at the corresponding offset
+ * @dmab: buffer allocation information
+ * @offset: offset in the ring buffer
+ *
+ * Return: the page pointer
+ */
+struct page *snd_sgbuf_get_page(struct snd_dma_buffer *dmab, size_t offset)
+{
+	const struct snd_malloc_ops *ops = snd_dma_get_ops(dmab);
+
+	if (ops && ops->get_page)
+		return ops->get_page(dmab, offset);
+	else
+		return virt_to_page(dmab->area + offset);
+}
+EXPORT_SYMBOL(snd_sgbuf_get_page);
+
+/**
+ * snd_sgbuf_get_chunk_size - compute the max chunk size with continuous pages
+ *	on sg-buffer
+ * @dmab: buffer allocation information
+ * @ofs: offset in the ring buffer
+ * @size: the requested size
+ *
+ * Return: the chunk size
+ */
+unsigned int snd_sgbuf_get_chunk_size(struct snd_dma_buffer *dmab,
+				      unsigned int ofs, unsigned int size)
+{
+	const struct snd_malloc_ops *ops = snd_dma_get_ops(dmab);
+
+	if (ops && ops->get_chunk_size)
+		return ops->get_chunk_size(dmab, ofs, size);
+	else
+		return size;
+}
+EXPORT_SYMBOL(snd_sgbuf_get_chunk_size);
+
+/*
+ * Continuous pages allocator
+ */
+static void *do_alloc_pages(struct device *dev, size_t size, dma_addr_t *addr,
+			    bool wc)
+{
+	void *p;
+	gfp_t gfp = GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN;
+
+ again:
+	p = alloc_pages_exact(size, gfp);
+	if (!p)
+		return NULL;
+	*addr = page_to_phys(virt_to_page(p));
+	if (!dev)
+		return p;
+	if ((*addr + size - 1) & ~dev->coherent_dma_mask) {
+		if (IS_ENABLED(CONFIG_ZONE_DMA32) && !(gfp & GFP_DMA32)) {
+			gfp |= GFP_DMA32;
+			goto again;
+		}
+		if (IS_ENABLED(CONFIG_ZONE_DMA) && !(gfp & GFP_DMA)) {
+			gfp = (gfp & ~GFP_DMA32) | GFP_DMA;
+			goto again;
+		}
+	}
+#ifdef CONFIG_X86
+	if (wc)
+		set_memory_wc((unsigned long)(p), size >> PAGE_SHIFT);
+#endif
+	return p;
+}
+
+static void do_free_pages(void *p, size_t size, bool wc)
+{
+#ifdef CONFIG_X86
+	if (wc)
+		set_memory_wb((unsigned long)(p), size >> PAGE_SHIFT);
+#endif
+	free_pages_exact(p, size);
+}
+
+
+static void *snd_dma_continuous_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	return do_alloc_pages(dmab->dev.dev, size, &dmab->addr, false);
+}
+
+static void snd_dma_continuous_free(struct snd_dma_buffer *dmab)
+{
+	do_free_pages(dmab->area, dmab->bytes, false);
+}
+
+static int snd_dma_continuous_mmap(struct snd_dma_buffer *dmab,
+				   struct vm_area_struct *area)
+{
+	return remap_pfn_range(area, area->vm_start,
+			       dmab->addr >> PAGE_SHIFT,
+			       area->vm_end - area->vm_start,
+			       area->vm_page_prot);
+}
+
+static const struct snd_malloc_ops snd_dma_continuous_ops = {
+	.alloc = snd_dma_continuous_alloc,
+	.free = snd_dma_continuous_free,
+	.mmap = snd_dma_continuous_mmap,
+};
+
+/*
+ * VMALLOC allocator
+ */
+static void *snd_dma_vmalloc_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	return vmalloc(size);
+}
+
+static void snd_dma_vmalloc_free(struct snd_dma_buffer *dmab)
+{
+	vfree(dmab->area);
+}
+
+static int snd_dma_vmalloc_mmap(struct snd_dma_buffer *dmab,
+				struct vm_area_struct *area)
+{
+	return remap_vmalloc_range(area, dmab->area, 0);
+}
+
+#define get_vmalloc_page_addr(dmab, offset) \
+	page_to_phys(vmalloc_to_page((dmab)->area + (offset)))
+
+static dma_addr_t snd_dma_vmalloc_get_addr(struct snd_dma_buffer *dmab,
+					   size_t offset)
+{
+	return get_vmalloc_page_addr(dmab, offset) + offset % PAGE_SIZE;
+}
+
+static struct page *snd_dma_vmalloc_get_page(struct snd_dma_buffer *dmab,
+					     size_t offset)
+{
+	return vmalloc_to_page(dmab->area + offset);
+}
+
+static unsigned int
+snd_dma_vmalloc_get_chunk_size(struct snd_dma_buffer *dmab,
+			       unsigned int ofs, unsigned int size)
+{
+	unsigned int start, end;
+	unsigned long addr;
+
+	start = ALIGN_DOWN(ofs, PAGE_SIZE);
+	end = ofs + size - 1; /* the last byte address */
+	/* check page continuity */
+	addr = get_vmalloc_page_addr(dmab, start);
+	for (;;) {
+		start += PAGE_SIZE;
+		if (start > end)
+			break;
+		addr += PAGE_SIZE;
+		if (get_vmalloc_page_addr(dmab, start) != addr)
+			return start - ofs;
+	}
+	/* ok, all on continuous pages */
+	return size;
+}
+
+static const struct snd_malloc_ops snd_dma_vmalloc_ops = {
+	.alloc = snd_dma_vmalloc_alloc,
+	.free = snd_dma_vmalloc_free,
+	.mmap = snd_dma_vmalloc_mmap,
+	.get_addr = snd_dma_vmalloc_get_addr,
+	.get_page = snd_dma_vmalloc_get_page,
+	.get_chunk_size = snd_dma_vmalloc_get_chunk_size,
+};
+
+#ifdef CONFIG_HAS_DMA
+/*
+ * IRAM allocator
+ */
+#ifdef CONFIG_GENERIC_ALLOCATOR
+static void *snd_dma_iram_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	struct device *dev = dmab->dev.dev;
+	struct gen_pool *pool;
+	void *p;
+
+	if (dev->of_node) {
+		pool = of_gen_pool_get(dev->of_node, "iram", 0);
+		/* Assign the pool into private_data field */
+		dmab->private_data = pool;
+
+		p = gen_pool_dma_alloc_align(pool, size, &dmab->addr, PAGE_SIZE);
+		if (p)
+			return p;
+	}
+
+	/* Internal memory might have limited size and no enough space,
+	 * so if we fail to malloc, try to fetch memory traditionally.
+	 */
+	dmab->dev.type = SNDRV_DMA_TYPE_DEV;
+	return __snd_dma_alloc_pages(dmab, size);
+}
+
+static void snd_dma_iram_free(struct snd_dma_buffer *dmab)
+{
+	struct gen_pool *pool = dmab->private_data;
+
+	if (pool && dmab->area)
+		gen_pool_free(pool, (unsigned long)dmab->area, dmab->bytes);
+}
+
+static int snd_dma_iram_mmap(struct snd_dma_buffer *dmab,
+			     struct vm_area_struct *area)
+{
+	area->vm_page_prot = pgprot_writecombine(area->vm_page_prot);
+	return remap_pfn_range(area, area->vm_start,
+			       dmab->addr >> PAGE_SHIFT,
+			       area->vm_end - area->vm_start,
+			       area->vm_page_prot);
+}
+
+static const struct snd_malloc_ops snd_dma_iram_ops = {
+	.alloc = snd_dma_iram_alloc,
+	.free = snd_dma_iram_free,
+	.mmap = snd_dma_iram_mmap,
+};
+#endif /* CONFIG_GENERIC_ALLOCATOR */
+
+/*
+ * Coherent device pages allocator
+ */
+static void *snd_dma_dev_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	return dma_alloc_coherent(dmab->dev.dev, size, &dmab->addr, DEFAULT_GFP);
+}
+
+static void snd_dma_dev_free(struct snd_dma_buffer *dmab)
+{
+	dma_free_coherent(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
+}
+
+static int snd_dma_dev_mmap(struct snd_dma_buffer *dmab,
+			    struct vm_area_struct *area)
+{
+	return dma_mmap_coherent(dmab->dev.dev, area,
+				 dmab->area, dmab->addr, dmab->bytes);
+}
+
+static const struct snd_malloc_ops snd_dma_dev_ops = {
+	.alloc = snd_dma_dev_alloc,
+	.free = snd_dma_dev_free,
+	.mmap = snd_dma_dev_mmap,
+};
+
+/*
+ * Write-combined pages
+ */
+/* x86-specific allocations */
+#ifdef CONFIG_SND_DMA_SGBUF
+static void *snd_dma_wc_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	return do_alloc_pages(dmab->dev.dev, size, &dmab->addr, true);
+}
+
+static void snd_dma_wc_free(struct snd_dma_buffer *dmab)
+{
+	do_free_pages(dmab->area, dmab->bytes, true);
+}
+
+static int snd_dma_wc_mmap(struct snd_dma_buffer *dmab,
+			   struct vm_area_struct *area)
+{
+	area->vm_page_prot = pgprot_writecombine(area->vm_page_prot);
+	return snd_dma_continuous_mmap(dmab, area);
+}
+#else
+static void *snd_dma_wc_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	return dma_alloc_wc(dmab->dev.dev, size, &dmab->addr, DEFAULT_GFP);
+}
+
+static void snd_dma_wc_free(struct snd_dma_buffer *dmab)
+{
+	dma_free_wc(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
+}
+
+static int snd_dma_wc_mmap(struct snd_dma_buffer *dmab,
+			   struct vm_area_struct *area)
+{
+	return dma_mmap_wc(dmab->dev.dev, area,
+			   dmab->area, dmab->addr, dmab->bytes);
+}
+#endif /* CONFIG_SND_DMA_SGBUF */
+
+static const struct snd_malloc_ops snd_dma_wc_ops = {
+	.alloc = snd_dma_wc_alloc,
+	.free = snd_dma_wc_free,
+	.mmap = snd_dma_wc_mmap,
+};
+
+/*
+ * Non-contiguous pages allocator
+ */
+static void *snd_dma_noncontig_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	struct sg_table *sgt;
+	void *p;
+
+#ifdef CONFIG_SND_DMA_SGBUF
+	if (cpu_feature_enabled(X86_FEATURE_XENPV))
+		return snd_dma_sg_fallback_alloc(dmab, size);
+#endif
+	sgt = dma_alloc_noncontiguous(dmab->dev.dev, size, dmab->dev.dir,
+				      DEFAULT_GFP, 0);
+#ifdef CONFIG_SND_DMA_SGBUF
+	if (!sgt && !get_dma_ops(dmab->dev.dev))
+		return snd_dma_sg_fallback_alloc(dmab, size);
+#endif
+	if (!sgt)
+		return NULL;
+
+	dmab->dev.need_sync = dma_need_sync(dmab->dev.dev,
+					    sg_dma_address(sgt->sgl));
+	p = dma_vmap_noncontiguous(dmab->dev.dev, size, sgt);
+	if (p) {
+		dmab->private_data = sgt;
+		/* store the first page address for convenience */
+		dmab->addr = snd_sgbuf_get_addr(dmab, 0);
+	} else {
+		dma_free_noncontiguous(dmab->dev.dev, size, sgt, dmab->dev.dir);
+	}
+	return p;
+}
+
+static void snd_dma_noncontig_free(struct snd_dma_buffer *dmab)
+{
+	dma_vunmap_noncontiguous(dmab->dev.dev, dmab->area);
+	dma_free_noncontiguous(dmab->dev.dev, dmab->bytes, dmab->private_data,
+			       dmab->dev.dir);
+}
+
+static int snd_dma_noncontig_mmap(struct snd_dma_buffer *dmab,
+				  struct vm_area_struct *area)
+{
+	return dma_mmap_noncontiguous(dmab->dev.dev, area,
+				      dmab->bytes, dmab->private_data);
+}
+
+static void snd_dma_noncontig_sync(struct snd_dma_buffer *dmab,
+				   enum snd_dma_sync_mode mode)
+{
+	if (mode == SNDRV_DMA_SYNC_CPU) {
+		if (dmab->dev.dir == DMA_TO_DEVICE)
+			return;
+		invalidate_kernel_vmap_range(dmab->area, dmab->bytes);
+		dma_sync_sgtable_for_cpu(dmab->dev.dev, dmab->private_data,
+					 dmab->dev.dir);
+	} else {
+		if (dmab->dev.dir == DMA_FROM_DEVICE)
+			return;
+		flush_kernel_vmap_range(dmab->area, dmab->bytes);
+		dma_sync_sgtable_for_device(dmab->dev.dev, dmab->private_data,
+					    dmab->dev.dir);
+	}
+}
+
+static inline void snd_dma_noncontig_iter_set(struct snd_dma_buffer *dmab,
+					      struct sg_page_iter *piter,
+					      size_t offset)
+{
+	struct sg_table *sgt = dmab->private_data;
+
+	__sg_page_iter_start(piter, sgt->sgl, sgt->orig_nents,
+			     offset >> PAGE_SHIFT);
+}
+
+static dma_addr_t snd_dma_noncontig_get_addr(struct snd_dma_buffer *dmab,
+					     size_t offset)
+{
+	struct sg_dma_page_iter iter;
+
+	snd_dma_noncontig_iter_set(dmab, &iter.base, offset);
+	__sg_page_iter_dma_next(&iter);
+	return sg_page_iter_dma_address(&iter) + offset % PAGE_SIZE;
+}
+
+static struct page *snd_dma_noncontig_get_page(struct snd_dma_buffer *dmab,
+					       size_t offset)
+{
+	struct sg_page_iter iter;
+
+	snd_dma_noncontig_iter_set(dmab, &iter, offset);
+	__sg_page_iter_next(&iter);
+	return sg_page_iter_page(&iter);
+}
+
+static unsigned int
+snd_dma_noncontig_get_chunk_size(struct snd_dma_buffer *dmab,
+				 unsigned int ofs, unsigned int size)
+{
+	struct sg_dma_page_iter iter;
+	unsigned int start, end;
+	unsigned long addr;
+
+	start = ALIGN_DOWN(ofs, PAGE_SIZE);
+	end = ofs + size - 1; /* the last byte address */
+	snd_dma_noncontig_iter_set(dmab, &iter.base, start);
+	if (!__sg_page_iter_dma_next(&iter))
+		return 0;
+	/* check page continuity */
+	addr = sg_page_iter_dma_address(&iter);
+	for (;;) {
+		start += PAGE_SIZE;
+		if (start > end)
+			break;
+		addr += PAGE_SIZE;
+		if (!__sg_page_iter_dma_next(&iter) ||
+		    sg_page_iter_dma_address(&iter) != addr)
+			return start - ofs;
+	}
+	/* ok, all on continuous pages */
+	return size;
+}
+
+static const struct snd_malloc_ops snd_dma_noncontig_ops = {
+	.alloc = snd_dma_noncontig_alloc,
+	.free = snd_dma_noncontig_free,
+	.mmap = snd_dma_noncontig_mmap,
+	.sync = snd_dma_noncontig_sync,
+	.get_addr = snd_dma_noncontig_get_addr,
+	.get_page = snd_dma_noncontig_get_page,
+	.get_chunk_size = snd_dma_noncontig_get_chunk_size,
+};
+
+/* x86-specific SG-buffer with WC pages */
+#ifdef CONFIG_SND_DMA_SGBUF
+#define sg_wc_address(it) ((unsigned long)page_address(sg_page_iter_page(it)))
+
+static void *snd_dma_sg_wc_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	void *p = snd_dma_noncontig_alloc(dmab, size);
+	struct sg_table *sgt = dmab->private_data;
+	struct sg_page_iter iter;
+
+	if (!p)
+		return NULL;
+	if (dmab->dev.type != SNDRV_DMA_TYPE_DEV_WC_SG)
+		return p;
+	for_each_sgtable_page(sgt, &iter, 0)
+		set_memory_wc(sg_wc_address(&iter), 1);
+	return p;
+}
+
+static void snd_dma_sg_wc_free(struct snd_dma_buffer *dmab)
+{
+	struct sg_table *sgt = dmab->private_data;
+	struct sg_page_iter iter;
+
+	for_each_sgtable_page(sgt, &iter, 0)
+		set_memory_wb(sg_wc_address(&iter), 1);
+	snd_dma_noncontig_free(dmab);
+}
+
+static int snd_dma_sg_wc_mmap(struct snd_dma_buffer *dmab,
+			      struct vm_area_struct *area)
+{
+	area->vm_page_prot = pgprot_writecombine(area->vm_page_prot);
+	return dma_mmap_noncontiguous(dmab->dev.dev, area,
+				      dmab->bytes, dmab->private_data);
+}
+
+static const struct snd_malloc_ops snd_dma_sg_wc_ops = {
+	.alloc = snd_dma_sg_wc_alloc,
+	.free = snd_dma_sg_wc_free,
+	.mmap = snd_dma_sg_wc_mmap,
+	.sync = snd_dma_noncontig_sync,
+	.get_addr = snd_dma_noncontig_get_addr,
+	.get_page = snd_dma_noncontig_get_page,
+	.get_chunk_size = snd_dma_noncontig_get_chunk_size,
+};
+
+/* Fallback SG-buffer allocations for x86 */
+struct snd_dma_sg_fallback {
+	bool use_dma_alloc_coherent;
+	size_t count;
+	struct page **pages;
+	/* DMA address array; the first page contains #pages in ~PAGE_MASK */
+	dma_addr_t *addrs;
+};
+
+static void __snd_dma_sg_fallback_free(struct snd_dma_buffer *dmab,
+				       struct snd_dma_sg_fallback *sgbuf)
+{
+	size_t i, size;
+
+	if (sgbuf->pages && sgbuf->addrs) {
+		i = 0;
+		while (i < sgbuf->count) {
+			if (!sgbuf->pages[i] || !sgbuf->addrs[i])
+				break;
+			size = sgbuf->addrs[i] & ~PAGE_MASK;
+			if (WARN_ON(!size))
+				break;
+			if (sgbuf->use_dma_alloc_coherent)
+				dma_free_coherent(dmab->dev.dev, size << PAGE_SHIFT,
+						  page_address(sgbuf->pages[i]),
+						  sgbuf->addrs[i] & PAGE_MASK);
+			else
+				do_free_pages(page_address(sgbuf->pages[i]),
+					      size << PAGE_SHIFT, false);
+			i += size;
+		}
+	}
+	kvfree(sgbuf->pages);
+	kvfree(sgbuf->addrs);
+	kfree(sgbuf);
+}
+
+static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	struct snd_dma_sg_fallback *sgbuf;
+	struct page **pagep, *curp;
+	size_t chunk, npages;
+	dma_addr_t *addrp;
+	dma_addr_t addr;
+	void *p;
+
+	/* correct the type */
+	if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_SG)
+		dmab->dev.type = SNDRV_DMA_TYPE_DEV_SG_FALLBACK;
+	else if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG)
+		dmab->dev.type = SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK;
+
+	sgbuf = kzalloc(sizeof(*sgbuf), GFP_KERNEL);
+	if (!sgbuf)
+		return NULL;
+	sgbuf->use_dma_alloc_coherent = cpu_feature_enabled(X86_FEATURE_XENPV);
+	size = PAGE_ALIGN(size);
+	sgbuf->count = size >> PAGE_SHIFT;
+	sgbuf->pages = kvcalloc(sgbuf->count, sizeof(*sgbuf->pages), GFP_KERNEL);
+	sgbuf->addrs = kvcalloc(sgbuf->count, sizeof(*sgbuf->addrs), GFP_KERNEL);
+	if (!sgbuf->pages || !sgbuf->addrs)
+		goto error;
+
+	pagep = sgbuf->pages;
+	addrp = sgbuf->addrs;
+	chunk = (PAGE_SIZE - 1) << PAGE_SHIFT; /* to fit in low bits in addrs */
+	while (size > 0) {
+		chunk = min(size, chunk);
+		if (sgbuf->use_dma_alloc_coherent)
+			p = dma_alloc_coherent(dmab->dev.dev, chunk, &addr, DEFAULT_GFP);
+		else
+			p = do_alloc_pages(dmab->dev.dev, chunk, &addr, false);
+		if (!p) {
+			if (chunk <= PAGE_SIZE)
+				goto error;
+			chunk >>= 1;
+			chunk = PAGE_SIZE << get_order(chunk);
+			continue;
+		}
+
+		size -= chunk;
+		/* fill pages */
+		npages = chunk >> PAGE_SHIFT;
+		*addrp = npages; /* store in lower bits */
+		curp = virt_to_page(p);
+		while (npages--) {
+			*pagep++ = curp++;
+			*addrp++ |= addr;
+			addr += PAGE_SIZE;
+		}
+	}
+
+	p = vmap(sgbuf->pages, sgbuf->count, VM_MAP, PAGE_KERNEL);
+	if (!p)
+		goto error;
+
+	if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK)
+		set_pages_array_wc(sgbuf->pages, sgbuf->count);
+
+	dmab->private_data = sgbuf;
+	/* store the first page address for convenience */
+	dmab->addr = sgbuf->addrs[0] & PAGE_MASK;
+	return p;
+
+ error:
+	__snd_dma_sg_fallback_free(dmab, sgbuf);
+	return NULL;
+}
+
+static void snd_dma_sg_fallback_free(struct snd_dma_buffer *dmab)
+{
+	struct snd_dma_sg_fallback *sgbuf = dmab->private_data;
+
+	if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK)
+		set_pages_array_wb(sgbuf->pages, sgbuf->count);
+	vunmap(dmab->area);
+	__snd_dma_sg_fallback_free(dmab, dmab->private_data);
+}
+
+static dma_addr_t snd_dma_sg_fallback_get_addr(struct snd_dma_buffer *dmab,
+					       size_t offset)
+{
+	struct snd_dma_sg_fallback *sgbuf = dmab->private_data;
+	size_t index = offset >> PAGE_SHIFT;
+
+	return (sgbuf->addrs[index] & PAGE_MASK) | (offset & ~PAGE_MASK);
+}
+
+static int snd_dma_sg_fallback_mmap(struct snd_dma_buffer *dmab,
+				    struct vm_area_struct *area)
+{
+	struct snd_dma_sg_fallback *sgbuf = dmab->private_data;
+
+	if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK)
+		area->vm_page_prot = pgprot_writecombine(area->vm_page_prot);
+	return vm_map_pages(area, sgbuf->pages, sgbuf->count);
+}
+
+static const struct snd_malloc_ops snd_dma_sg_fallback_ops = {
+	.alloc = snd_dma_sg_fallback_alloc,
+	.free = snd_dma_sg_fallback_free,
+	.mmap = snd_dma_sg_fallback_mmap,
+	.get_addr = snd_dma_sg_fallback_get_addr,
+	/* reuse vmalloc helpers */
+	.get_page = snd_dma_vmalloc_get_page,
+	.get_chunk_size = snd_dma_vmalloc_get_chunk_size,
+};
+#endif /* CONFIG_SND_DMA_SGBUF */
+
+/*
+ * Non-coherent pages allocator
+ */
+static void *snd_dma_noncoherent_alloc(struct snd_dma_buffer *dmab, size_t size)
+{
+	void *p;
+
+	p = dma_alloc_noncoherent(dmab->dev.dev, size, &dmab->addr,
+				  dmab->dev.dir, DEFAULT_GFP);
+	if (p)
+		dmab->dev.need_sync = dma_need_sync(dmab->dev.dev, dmab->addr);
+	return p;
+}
+
+static void snd_dma_noncoherent_free(struct snd_dma_buffer *dmab)
+{
+	dma_free_noncoherent(dmab->dev.dev, dmab->bytes, dmab->area,
+			     dmab->addr, dmab->dev.dir);
+}
+
+static int snd_dma_noncoherent_mmap(struct snd_dma_buffer *dmab,
+				    struct vm_area_struct *area)
+{
+	area->vm_page_prot = vm_get_page_prot(area->vm_flags);
+	return dma_mmap_pages(dmab->dev.dev, area,
+			      area->vm_end - area->vm_start,
+			      virt_to_page(dmab->area));
+}
+
+static void snd_dma_noncoherent_sync(struct snd_dma_buffer *dmab,
+				     enum snd_dma_sync_mode mode)
+{
+	if (mode == SNDRV_DMA_SYNC_CPU) {
+		if (dmab->dev.dir != DMA_TO_DEVICE)
+			dma_sync_single_for_cpu(dmab->dev.dev, dmab->addr,
+						dmab->bytes, dmab->dev.dir);
+	} else {
+		if (dmab->dev.dir != DMA_FROM_DEVICE)
+			dma_sync_single_for_device(dmab->dev.dev, dmab->addr,
+						   dmab->bytes, dmab->dev.dir);
+	}
+}
+
+static const struct snd_malloc_ops snd_dma_noncoherent_ops = {
+	.alloc = snd_dma_noncoherent_alloc,
+	.free = snd_dma_noncoherent_free,
+	.mmap = snd_dma_noncoherent_mmap,
+	.sync = snd_dma_noncoherent_sync,
+};
+
+#endif /* CONFIG_HAS_DMA */
+
+/*
+ * Entry points
+ */
+static const struct snd_malloc_ops *snd_dma_ops[] = {
+	[SNDRV_DMA_TYPE_CONTINUOUS] = &snd_dma_continuous_ops,
+	[SNDRV_DMA_TYPE_VMALLOC] = &snd_dma_vmalloc_ops,
+#ifdef CONFIG_HAS_DMA
+	[SNDRV_DMA_TYPE_DEV] = &snd_dma_dev_ops,
+	[SNDRV_DMA_TYPE_DEV_WC] = &snd_dma_wc_ops,
+	[SNDRV_DMA_TYPE_NONCONTIG] = &snd_dma_noncontig_ops,
+	[SNDRV_DMA_TYPE_NONCOHERENT] = &snd_dma_noncoherent_ops,
+#ifdef CONFIG_SND_DMA_SGBUF
+	[SNDRV_DMA_TYPE_DEV_WC_SG] = &snd_dma_sg_wc_ops,
+#endif
+#ifdef CONFIG_GENERIC_ALLOCATOR
+	[SNDRV_DMA_TYPE_DEV_IRAM] = &snd_dma_iram_ops,
+#endif /* CONFIG_GENERIC_ALLOCATOR */
+#ifdef CONFIG_SND_DMA_SGBUF
+	[SNDRV_DMA_TYPE_DEV_SG_FALLBACK] = &snd_dma_sg_fallback_ops,
+	[SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK] = &snd_dma_sg_fallback_ops,
+#endif
+#endif /* CONFIG_HAS_DMA */
+};
+
+static const struct snd_malloc_ops *snd_dma_get_ops(struct snd_dma_buffer *dmab)
+{
+	if (WARN_ON_ONCE(!dmab))
+		return NULL;
+	if (WARN_ON_ONCE(dmab->dev.type <= SNDRV_DMA_TYPE_UNKNOWN ||
+			 dmab->dev.type >= ARRAY_SIZE(snd_dma_ops)))
+		return NULL;
+	return snd_dma_ops[dmab->dev.type];
+}