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Commit d5ca451c authored by Sudarshan Rajagopalan's avatar Sudarshan Rajagopalan Committed by Gerrit - the friendly Code Review server
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dma-mapping-fast: add support for atomic fastmap allocations 



Support for coherent and non-coherent atomic allocations
in fastmap.

Change-Id: I3628508a4b2af5aa82d56a4a6a6ee4cef98cd47f
Signed-off-by: default avatarSudarshan Rajagopalan <sudaraja@codeaurora.org>
parent eac6c82e

drivers/iommu/dma-mapping-fast.c

+223 −6
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <asm/cacheflush.h>

#include <asm/dma-iommu.h>

#include <linux/slab.h>

#include <linux/genalloc.h>

#include <linux/vmalloc.h>

#include <linux/pci.h>

#include <linux/dma-iommu.h>
@@ -23,6 +24,18 @@ 
#define FAST_PAGE_SIZE (1UL << FAST_PAGE_SHIFT)

#define FAST_PAGE_MASK (~(PAGE_SIZE - 1))



#define DEFAULT_DMA_COHERENT_POOL_SIZE	SZ_256K

static struct gen_pool *atomic_pool __ro_after_init;



static size_t atomic_pool_size __initdata = DEFAULT_DMA_COHERENT_POOL_SIZE;



static int __init early_coherent_pool(char *p)

{

	atomic_pool_size = memparse(p, &p);

	return 0;

}

early_param("coherent_pool", early_coherent_pool);



static pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot,

				 bool coherent)

{
@@ -33,6 +46,48 @@ static pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot, 
	return prot;

}



static void *__alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags)

{

	unsigned long val;

	void *ptr = NULL;



	if (!atomic_pool) {

		WARN(1, "coherent pool not initialised!\n");

		return NULL;

	}



	val = gen_pool_alloc(atomic_pool, size);

	if (val) {

		phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val);



		*ret_page = phys_to_page(phys);

		ptr = (void *)val;

		memset(ptr, 0, size);

	}



	return ptr;

}



static phys_addr_t __atomic_get_phys(void *addr)

{

	return gen_pool_virt_to_phys(atomic_pool, (unsigned long)addr);

}



static bool __in_atomic_pool(void *start, size_t size)

{

	return addr_in_gen_pool(atomic_pool, (unsigned long)start, size);

}



static int __free_from_pool(void *start, size_t size)

{

	if (!__in_atomic_pool(start, size))

		return 0;



	gen_pool_free(atomic_pool, (unsigned long)start, size);



	return 1;

}



static bool is_dma_coherent(struct device *dev, unsigned long attrs)

{

	bool is_coherent;
@@ -248,6 +303,69 @@ static bool __bit_is_sooner(unsigned long candidate, 
	return true;

}





static int __init atomic_pool_init(void)

{

	pgprot_t prot = __pgprot(PROT_NORMAL_NC);

	unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT;

	struct page *page;

	void *addr;

	unsigned int pool_size_order = get_order(atomic_pool_size);



	if (dev_get_cma_area(NULL))

		page = dma_alloc_from_contiguous(NULL, nr_pages,

						 pool_size_order, false);

	else

		page = alloc_pages(GFP_DMA32, pool_size_order);



	if (page) {

		int ret;

		void *page_addr = page_address(page);



		memset(page_addr, 0, atomic_pool_size);

		__dma_flush_area(page_addr, atomic_pool_size);



		atomic_pool = gen_pool_create(PAGE_SHIFT, -1);

		if (!atomic_pool)

			goto free_page;



		addr = dma_common_contiguous_remap(page, atomic_pool_size,

					VM_USERMAP, prot, atomic_pool_init);



		if (!addr)

			goto destroy_genpool;



		ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr,

					page_to_phys(page),

					atomic_pool_size, -1);

		if (ret)

			goto remove_mapping;



		gen_pool_set_algo(atomic_pool,

				  gen_pool_first_fit_order_align,

				  NULL);



		pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n",

			atomic_pool_size / 1024);

		return 0;

	}

	goto out;



remove_mapping:

	dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP, false);

destroy_genpool:

	gen_pool_destroy(atomic_pool);

	atomic_pool = NULL;

free_page:

	if (!dma_release_from_contiguous(NULL, page, nr_pages))

		__free_pages(page, pool_size_order);

out:

	pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",

		atomic_pool_size / 1024);

	return -ENOMEM;

}

arch_initcall(atomic_pool_init);



static void __fast_smmu_free_iova(struct dma_fast_smmu_mapping *mapping,

				  dma_addr_t iova, size_t size)

{
@@ -499,11 +617,57 @@ static void __fast_smmu_free_pages(struct page **pages, int count) 
{

	int i;



	if (!pages)

		return;

	for (i = 0; i < count; i++)

		__free_page(pages[i]);

	kvfree(pages);

}



static void *fast_smmu_alloc_atomic(struct dma_fast_smmu_mapping *mapping,

				    size_t size, gfp_t gfp, unsigned long attrs,

				    dma_addr_t *handle, bool coherent)

{

	void *addr;

	unsigned long flags;

	struct page *page;

	dma_addr_t dma_addr;

	int prot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);



	size = ALIGN(size, FAST_PAGE_SIZE);

	if (coherent) {

		page = alloc_pages(gfp, get_order(size));

		addr = page ? page_address(page) : NULL;

	} else

		addr = __alloc_from_pool(size, &page, gfp);

	if (!addr)

		return NULL;



	spin_lock_irqsave(&mapping->lock, flags);

	dma_addr = __fast_smmu_alloc_iova(mapping, attrs, size);

	if (dma_addr == DMA_ERROR_CODE) {

		dev_err(mapping->dev, "no iova\n");

		spin_unlock_irqrestore(&mapping->lock, flags);

		goto out_free_page;

	}

	if (unlikely(av8l_fast_map_public(mapping->pgtbl_ops, dma_addr,

					  page_to_phys(page), size, prot))) {

		dev_err(mapping->dev, "no map public\n");

		goto out_free_iova;

	}

	spin_unlock_irqrestore(&mapping->lock, flags);

	*handle = dma_addr;

	return addr;



out_free_iova:

	__fast_smmu_free_iova(mapping, dma_addr, size);

	spin_unlock_irqrestore(&mapping->lock, flags);

out_free_page:

	coherent ? __free_pages(page, get_order(size)) :

		   __free_from_pool(addr, size);

	return NULL;

}



static struct page **__fast_smmu_alloc_pages(unsigned int count, gfp_t gfp)

{

	struct page **pages;
@@ -559,6 +723,11 @@ static void *fast_smmu_alloc(struct device *dev, size_t size, 


	*handle = DMA_ERROR_CODE;



	if (!gfpflags_allow_blocking(gfp)) {

		return fast_smmu_alloc_atomic(mapping, size, gfp, attrs, handle,

					      is_coherent);

	}



	pages = __fast_smmu_alloc_pages(count, gfp);

	if (!pages) {

		dev_err(dev, "no pages\n");
@@ -638,23 +807,55 @@ static void fast_smmu_free(struct device *dev, size_t size, 
{

	struct dma_fast_smmu_mapping *mapping = dev_get_mapping(dev);

	struct vm_struct *area;

	struct page **pages;

	struct page **pages = NULL;

	size_t count = ALIGN(size, SZ_4K) >> FAST_PAGE_SHIFT;

	unsigned long flags;



	size = ALIGN(size, SZ_4K);



	if (__in_atomic_pool(vaddr, size) || !is_vmalloc_addr(vaddr))

		goto no_remap;



	area = find_vm_area(vaddr);

	if (WARN_ON_ONCE(!area))

		return;



	pages = area->pages;

	dma_common_free_remap(vaddr, size, VM_USERMAP, false);

no_remap:

	spin_lock_irqsave(&mapping->lock, flags);

	av8l_fast_unmap_public(mapping->pgtbl_ops, dma_handle, size);

	__fast_smmu_free_iova(mapping, dma_handle, size);

	spin_unlock_irqrestore(&mapping->lock, flags);

	if (__in_atomic_pool(vaddr, size))

		__free_from_pool(vaddr, size);

	else if (is_vmalloc_addr(vaddr))

		__fast_smmu_free_pages(pages, count);

	else

		__free_pages(virt_to_page(vaddr), get_order(size));

}



static int __vma_remap_range(struct vm_area_struct *vma, void *cpu_addr,

			     size_t size)

{

	int ret = -ENXIO;

	unsigned long nr_vma_pages = vma_pages(vma);

	unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;

	unsigned long off = vma->vm_pgoff;

	unsigned long pfn;



	if (__in_atomic_pool(cpu_addr, size))

		pfn = __atomic_get_phys(cpu_addr) >> PAGE_SHIFT;

	else

		pfn = page_to_pfn(virt_to_page(cpu_addr));



	if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {

		ret = remap_pfn_range(vma, vma->vm_start, pfn + off,

				      vma->vm_end - vma->vm_start,

				      vma->vm_page_prot);

	}



	return ret;

}



static int fast_smmu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
@@ -669,6 +870,10 @@ static int fast_smmu_mmap_attrs(struct device *dev, struct vm_area_struct *vma, 


	vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot,

					     coherent);



	if (__in_atomic_pool(cpu_addr, size) || !is_vmalloc_addr(cpu_addr))

		return __vma_remap_range(vma, cpu_addr, size);



	area = find_vm_area(cpu_addr);

	if (!area)

		return -EINVAL;
@@ -691,13 +896,25 @@ static int fast_smmu_get_sgtable(struct device *dev, struct sg_table *sgt, 
{

	unsigned int n_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;

	struct vm_struct *area;

	struct page *page = NULL;

	int ret = -ENXIO;



	area = find_vm_area(cpu_addr);

	if (!area || !area->pages)

		return -EINVAL;

	if (area && area->pages)

		return sg_alloc_table_from_pages(sgt, area->pages, n_pages, 0,

						 size, GFP_KERNEL);

	else if (!is_vmalloc_addr(cpu_addr))

		page = virt_to_page(cpu_addr);

	else if (__in_atomic_pool(cpu_addr, size))

		page = phys_to_page(__atomic_get_phys(cpu_addr));



	if (page) {

		ret = sg_alloc_table(sgt, 1, GFP_KERNEL);

		if (!ret)

			sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);

	}



	return sg_alloc_table_from_pages(sgt, area->pages, n_pages, 0, size,

					GFP_KERNEL);

	return ret;

}



static dma_addr_t fast_smmu_dma_map_resource(