arch/nds32/kernel/dma.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 // Copyright (C) 2005-2017 Andes Technology Corporation

 #include <linux/types.h>
 #include <linux/mm.h>
 #include <linux/string.h>
 #include <linux/dma-noncoherent.h>
 #include <linux/io.h>
 #include <linux/cache.h>
 #include <linux/highmem.h>
 #include <linux/slab.h>
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
 #include <asm/proc-fns.h>

 /*
  * This is the page table (2MB) covering uncached, DMA consistent allocations
  */
 static pte_t *consistent_pte;
 static DEFINE_RAW_SPINLOCK(consistent_lock);

 /*
  * VM region handling support.
  *
  * This should become something generic, handling VM region allocations for
  * vmalloc and similar (ioremap, module space, etc).
  *
  * I envisage vmalloc()'s supporting vm_struct becoming:
  *
  *  struct vm_struct {
  *    struct vm_region	region;
  *    unsigned long	flags;
  *    struct page	**pages;
  *    unsigned int	nr_pages;
  *    unsigned long	phys_addr;
  *  };
  *
  * get_vm_area() would then call vm_region_alloc with an appropriate
  * struct vm_region head (eg):
  *
  *  struct vm_region vmalloc_head = {
  *	.vm_list	= LIST_HEAD_INIT(vmalloc_head.vm_list),
  *	.vm_start	= VMALLOC_START,
  *	.vm_end		= VMALLOC_END,
  *  };
  *
  * However, vmalloc_head.vm_start is variable (typically, it is dependent on
  * the amount of RAM found at boot time.)  I would imagine that get_vm_area()
  * would have to initialise this each time prior to calling vm_region_alloc().
  */
 struct arch_vm_region {
 	struct list_head vm_list;
 	unsigned long vm_start;
 	unsigned long vm_end;
 	struct page *vm_pages;
 };

 static struct arch_vm_region consistent_head = {
 	.vm_list = LIST_HEAD_INIT(consistent_head.vm_list),
 	.vm_start = CONSISTENT_BASE,
 	.vm_end = CONSISTENT_END,
 };

 static struct arch_vm_region *vm_region_alloc(struct arch_vm_region *head,
 					      size_t size, int gfp)
 {
 	unsigned long addr = head->vm_start, end = head->vm_end - size;
 	unsigned long flags;
 	struct arch_vm_region *c, *new;

 	new = kmalloc(sizeof(struct arch_vm_region), gfp);
 	if (!new)
 		goto out;

 	raw_spin_lock_irqsave(&consistent_lock, flags);

 	list_for_each_entry(c, &head->vm_list, vm_list) {
 		if ((addr + size) < addr)
 			goto nospc;
 		if ((addr + size) <= c->vm_start)
 			goto found;
 		addr = c->vm_end;
 		if (addr > end)
 			goto nospc;
 	}

 found:
 	/*
 	 * Insert this entry _before_ the one we found.
 	 */
 	list_add_tail(&new->vm_list, &c->vm_list);
 	new->vm_start = addr;
 	new->vm_end = addr + size;

 	raw_spin_unlock_irqrestore(&consistent_lock, flags);
 	return new;

 nospc:
 	raw_spin_unlock_irqrestore(&consistent_lock, flags);
 	kfree(new);
 out:
 	return NULL;
 }

 static struct arch_vm_region *vm_region_find(struct arch_vm_region *head,
 					     unsigned long addr)
 {
 	struct arch_vm_region *c;

 	list_for_each_entry(c, &head->vm_list, vm_list) {
 		if (c->vm_start == addr)
 			goto out;
 	}
 	c = NULL;
 out:
 	return c;
 }

 void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
 		gfp_t gfp, unsigned long attrs)
 {
 	struct page *page;
 	struct arch_vm_region *c;
 	unsigned long order;
 	u64 mask = ~0ULL, limit;
 	pgprot_t prot = pgprot_noncached(PAGE_KERNEL);

 	if (!consistent_pte) {
 		pr_err("%s: not initialized\n", __func__);
 		dump_stack();
 		return NULL;
 	}

 	if (dev) {
 		mask = dev->coherent_dma_mask;

 		/*
 		 * Sanity check the DMA mask - it must be non-zero, and
 		 * must be able to be satisfied by a DMA allocation.
 		 */
 		if (mask == 0) {
 			dev_warn(dev, "coherent DMA mask is unset\n");
 			goto no_page;
 		}

 	}

 	/*
 	 * Sanity check the allocation size.
 	 */
 	size = PAGE_ALIGN(size);
 	limit = (mask + 1) & ~mask;
 	if ((limit && size >= limit) ||
 	    size >= (CONSISTENT_END - CONSISTENT_BASE)) {
 		pr_warn("coherent allocation too big "
 			"(requested %#x mask %#llx)\n", size, mask);
 		goto no_page;
 	}

 	order = get_order(size);

 	if (mask != 0xffffffff)
 		gfp |= GFP_DMA;

 	page = alloc_pages(gfp, order);
 	if (!page)
 		goto no_page;

 	/*
 	 * Invalidate any data that might be lurking in the
 	 * kernel direct-mapped region for device DMA.
 	 */
 	{
 		unsigned long kaddr = (unsigned long)page_address(page);
 		memset(page_address(page), 0, size);
 		cpu_dma_wbinval_range(kaddr, kaddr + size);
 	}

 	/*
 	 * Allocate a virtual address in the consistent mapping region.
 	 */
 	c = vm_region_alloc(&consistent_head, size,
 			    gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
 	if (c) {
 		pte_t *pte = consistent_pte + CONSISTENT_OFFSET(c->vm_start);
 		struct page *end = page + (1 << order);

 		c->vm_pages = page;

 		/*
 		 * Set the "dma handle"
 		 */
 		*handle = page_to_phys(page);

 		do {
 			BUG_ON(!pte_none(*pte));

 			/*
 			 * x86 does not mark the pages reserved...
 			 */
 			SetPageReserved(page);
 			set_pte(pte, mk_pte(page, prot));
 			page++;
 			pte++;
 		} while (size -= PAGE_SIZE);

 		/*
 		 * Free the otherwise unused pages.
 		 */
 		while (page < end) {
 			__free_page(page);
 			page++;
 		}

 		return (void *)c->vm_start;
 	}

 	if (page)
 		__free_pages(page, order);
 no_page:
 	*handle = ~0;
 	return NULL;
 }

 void arch_dma_free(struct device *dev, size_t size, void *cpu_addr,
 		dma_addr_t handle, unsigned long attrs)
 {
 	struct arch_vm_region *c;
 	unsigned long flags, addr;
 	pte_t *ptep;

 	size = PAGE_ALIGN(size);

 	raw_spin_lock_irqsave(&consistent_lock, flags);

 	c = vm_region_find(&consistent_head, (unsigned long)cpu_addr);
 	if (!c)
 		goto no_area;

 	if ((c->vm_end - c->vm_start) != size) {
 		pr_err("%s: freeing wrong coherent size (%ld != %d)\n",
 		       __func__, c->vm_end - c->vm_start, size);
 		dump_stack();
 		size = c->vm_end - c->vm_start;
 	}

 	ptep = consistent_pte + CONSISTENT_OFFSET(c->vm_start);
 	addr = c->vm_start;
 	do {
 		pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep);
 		unsigned long pfn;

 		ptep++;
 		addr += PAGE_SIZE;

 		if (!pte_none(pte) && pte_present(pte)) {
 			pfn = pte_pfn(pte);

 			if (pfn_valid(pfn)) {
 				struct page *page = pfn_to_page(pfn);

 				/*
 				 * x86 does not mark the pages reserved...
 				 */
 				ClearPageReserved(page);

 				__free_page(page);
 				continue;
 			}
 		}

 		pr_crit("%s: bad page in kernel page table\n", __func__);
 	} while (size -= PAGE_SIZE);

 	flush_tlb_kernel_range(c->vm_start, c->vm_end);

 	list_del(&c->vm_list);

 	raw_spin_unlock_irqrestore(&consistent_lock, flags);

 	kfree(c);
 	return;

 no_area:
 	raw_spin_unlock_irqrestore(&consistent_lock, flags);
 	pr_err("%s: trying to free invalid coherent area: %p\n",
 	       __func__, cpu_addr);
 	dump_stack();
 }

 /*
  * Initialise the consistent memory allocation.
  */
 static int __init consistent_init(void)
 {
 	pgd_t *pgd;
 	pmd_t *pmd;
 	pte_t *pte;
 	int ret = 0;

 	do {
 		pgd = pgd_offset(&init_mm, CONSISTENT_BASE);
 		pmd = pmd_alloc(&init_mm, pgd, CONSISTENT_BASE);
 		if (!pmd) {
 			pr_err("%s: no pmd tables\n", __func__);
 			ret = -ENOMEM;
 			break;
 		}
 		/* The first level mapping may be created in somewhere.
 		 * It's not necessary to warn here. */
 		/* WARN_ON(!pmd_none(*pmd)); */

 		pte = pte_alloc_kernel(pmd, CONSISTENT_BASE);
 		if (!pte) {
 			ret = -ENOMEM;
 			break;
 		}

 		consistent_pte = pte;
 	} while (0);

 	return ret;
 }

 core_initcall(consistent_init);

 static inline void cache_op(phys_addr_t paddr, size_t size,
 		void (*fn)(unsigned long start, unsigned long end))
 {
 	struct page *page = pfn_to_page(paddr >> PAGE_SHIFT);
 	unsigned offset = paddr & ~PAGE_MASK;
 	size_t left = size;
 	unsigned long start;

 	do {
 		size_t len = left;

 		if (PageHighMem(page)) {
 			void *addr;

 			if (offset + len > PAGE_SIZE) {
 				if (offset >= PAGE_SIZE) {
 					page += offset >> PAGE_SHIFT;
 					offset &= ~PAGE_MASK;
 				}
 				len = PAGE_SIZE - offset;
 			}

 			addr = kmap_atomic(page);
 			start = (unsigned long)(addr + offset);
 			fn(start, start + len);
 			kunmap_atomic(addr);
 		} else {
 			start = (unsigned long)phys_to_virt(paddr);
 			fn(start, start + size);
 		}
 		offset = 0;
 		page++;
 		left -= len;
 	} while (left);
 }

 void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
 		size_t size, enum dma_data_direction dir)
 {
 	switch (dir) {
 	case DMA_FROM_DEVICE:
 		break;
 	case DMA_TO_DEVICE:
 	case DMA_BIDIRECTIONAL:
 		cache_op(paddr, size, cpu_dma_wb_range);
 		break;
 	default:
 		BUG();
 	}
 }

 void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
 		size_t size, enum dma_data_direction dir)
 {
 	switch (dir) {
 	case DMA_TO_DEVICE:
 		break;
 	case DMA_FROM_DEVICE:
 	case DMA_BIDIRECTIONAL:
 		cache_op(paddr, size, cpu_dma_inval_range);
 		break;
 	default:
 		BUG();
 	}
 }
	// SPDX-License-Identifier: GPL-2.0
	// Copyright (C) 2005-2017 Andes Technology Corporation

	#include <linux/types.h>
	#include <linux/mm.h>
	#include <linux/string.h>
	#include <linux/dma-noncoherent.h>
	#include <linux/io.h>
	#include <linux/cache.h>
	#include <linux/highmem.h>
	#include <linux/slab.h>
	#include <asm/cacheflush.h>
	#include <asm/tlbflush.h>
	#include <asm/proc-fns.h>

	/*
	* This is the page table (2MB) covering uncached, DMA consistent allocations
	*/
	static pte_t *consistent_pte;
	static DEFINE_RAW_SPINLOCK(consistent_lock);

	/*
	* VM region handling support.
	*
	* This should become something generic, handling VM region allocations for
	* vmalloc and similar (ioremap, module space, etc).
	*
	* I envisage vmalloc()'s supporting vm_struct becoming:
	*
	* struct vm_struct {
	* struct vm_region region;
	* unsigned long flags;
	* struct page **pages;
	* unsigned int nr_pages;
	* unsigned long phys_addr;
	* };
	*
	* get_vm_area() would then call vm_region_alloc with an appropriate
	* struct vm_region head (eg):
	*
	* struct vm_region vmalloc_head = {
	* .vm_list = LIST_HEAD_INIT(vmalloc_head.vm_list),
	* .vm_start = VMALLOC_START,
	* .vm_end = VMALLOC_END,
	* };
	*
	* However, vmalloc_head.vm_start is variable (typically, it is dependent on
	* the amount of RAM found at boot time.) I would imagine that get_vm_area()
	* would have to initialise this each time prior to calling vm_region_alloc().
	*/
	struct arch_vm_region {
	struct list_head vm_list;
	unsigned long vm_start;
	unsigned long vm_end;
	struct page *vm_pages;
	};

	static struct arch_vm_region consistent_head = {
	.vm_list = LIST_HEAD_INIT(consistent_head.vm_list),
	.vm_start = CONSISTENT_BASE,
	.vm_end = CONSISTENT_END,
	};

	static struct arch_vm_region vm_region_alloc(struct arch_vm_region head,
	size_t size, int gfp)
	{
	unsigned long addr = head->vm_start, end = head->vm_end - size;
	unsigned long flags;
	struct arch_vm_region c, new;

	new = kmalloc(sizeof(struct arch_vm_region), gfp);
	if (!new)
	goto out;

	raw_spin_lock_irqsave(&consistent_lock, flags);

	list_for_each_entry(c, &head->vm_list, vm_list) {
	if ((addr + size) < addr)
	goto nospc;
	if ((addr + size) <= c->vm_start)
	goto found;
	addr = c->vm_end;
	if (addr > end)
	goto nospc;
	}

	found:
	/*
	* Insert this entry _before_ the one we found.
	*/
	list_add_tail(&new->vm_list, &c->vm_list);
	new->vm_start = addr;
	new->vm_end = addr + size;

	raw_spin_unlock_irqrestore(&consistent_lock, flags);
	return new;

	nospc:
	raw_spin_unlock_irqrestore(&consistent_lock, flags);
	kfree(new);
	out:
	return NULL;
	}

	static struct arch_vm_region vm_region_find(struct arch_vm_region head,
	unsigned long addr)
	{
	struct arch_vm_region *c;

	list_for_each_entry(c, &head->vm_list, vm_list) {
	if (c->vm_start == addr)
	goto out;
	}
	c = NULL;
	out:
	return c;
	}

	void arch_dma_alloc(struct device dev, size_t size, dma_addr_t *handle,
	gfp_t gfp, unsigned long attrs)
	{
	struct page *page;
	struct arch_vm_region *c;
	unsigned long order;
	u64 mask = ~0ULL, limit;
	pgprot_t prot = pgprot_noncached(PAGE_KERNEL);

	if (!consistent_pte) {
	pr_err("%s: not initialized\n", __func__);
	dump_stack();
	return NULL;
	}

	if (dev) {
	mask = dev->coherent_dma_mask;

	/*
	* Sanity check the DMA mask - it must be non-zero, and
	* must be able to be satisfied by a DMA allocation.
	*/
	if (mask == 0) {
	dev_warn(dev, "coherent DMA mask is unset\n");
	goto no_page;
	}

	}

	/*
	* Sanity check the allocation size.
	*/
	size = PAGE_ALIGN(size);
	limit = (mask + 1) & ~mask;
	if ((limit && size >= limit) \|\|
	size >= (CONSISTENT_END - CONSISTENT_BASE)) {
	pr_warn("coherent allocation too big "
	"(requested %#x mask %#llx)\n", size, mask);
	goto no_page;
	}

	order = get_order(size);

	if (mask != 0xffffffff)
	gfp \|= GFP_DMA;

	page = alloc_pages(gfp, order);
	if (!page)
	goto no_page;

	/*
	* Invalidate any data that might be lurking in the
	* kernel direct-mapped region for device DMA.
	*/
	{
	unsigned long kaddr = (unsigned long)page_address(page);
	memset(page_address(page), 0, size);
	cpu_dma_wbinval_range(kaddr, kaddr + size);
	}

	/*
	* Allocate a virtual address in the consistent mapping region.
	*/
	c = vm_region_alloc(&consistent_head, size,
	gfp & ~(__GFP_DMA \| __GFP_HIGHMEM));
	if (c) {
	pte_t *pte = consistent_pte + CONSISTENT_OFFSET(c->vm_start);
	struct page *end = page + (1 << order);

	c->vm_pages = page;

	/*
	* Set the "dma handle"
	*/
	*handle = page_to_phys(page);

	do {
	BUG_ON(!pte_none(*pte));

	/*
	* x86 does not mark the pages reserved...
	*/
	SetPageReserved(page);
	set_pte(pte, mk_pte(page, prot));
	page++;
	pte++;
	} while (size -= PAGE_SIZE);

	/*
	* Free the otherwise unused pages.
	*/
	while (page < end) {
	__free_page(page);
	page++;
	}

	return (void *)c->vm_start;
	}

	if (page)
	__free_pages(page, order);
	no_page:
	*handle = ~0;
	return NULL;
	}

	void arch_dma_free(struct device dev, size_t size, void cpu_addr,
	dma_addr_t handle, unsigned long attrs)
	{
	struct arch_vm_region *c;
	unsigned long flags, addr;
	pte_t *ptep;

	size = PAGE_ALIGN(size);

	raw_spin_lock_irqsave(&consistent_lock, flags);

	c = vm_region_find(&consistent_head, (unsigned long)cpu_addr);
	if (!c)
	goto no_area;

	if ((c->vm_end - c->vm_start) != size) {
	pr_err("%s: freeing wrong coherent size (%ld != %d)\n",
	__func__, c->vm_end - c->vm_start, size);
	dump_stack();
	size = c->vm_end - c->vm_start;
	}

	ptep = consistent_pte + CONSISTENT_OFFSET(c->vm_start);
	addr = c->vm_start;
	do {
	pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep);
	unsigned long pfn;

	ptep++;
	addr += PAGE_SIZE;

	if (!pte_none(pte) && pte_present(pte)) {
	pfn = pte_pfn(pte);

	if (pfn_valid(pfn)) {
	struct page *page = pfn_to_page(pfn);

	/*
	* x86 does not mark the pages reserved...
	*/
	ClearPageReserved(page);

	__free_page(page);
	continue;
	}
	}

	pr_crit("%s: bad page in kernel page table\n", __func__);
	} while (size -= PAGE_SIZE);

	flush_tlb_kernel_range(c->vm_start, c->vm_end);

	list_del(&c->vm_list);

	raw_spin_unlock_irqrestore(&consistent_lock, flags);

	kfree(c);
	return;

	no_area:
	raw_spin_unlock_irqrestore(&consistent_lock, flags);
	pr_err("%s: trying to free invalid coherent area: %p\n",
	__func__, cpu_addr);
	dump_stack();
	}

	/*
	* Initialise the consistent memory allocation.
	*/
	static int __init consistent_init(void)
	{
	pgd_t *pgd;
	pmd_t *pmd;
	pte_t *pte;
	int ret = 0;

	do {
	pgd = pgd_offset(&init_mm, CONSISTENT_BASE);
	pmd = pmd_alloc(&init_mm, pgd, CONSISTENT_BASE);
	if (!pmd) {
	pr_err("%s: no pmd tables\n", __func__);
	ret = -ENOMEM;
	break;
	}
	/* The first level mapping may be created in somewhere.
	* It's not necessary to warn here. */
	/* WARN_ON(!pmd_none(pmd)); /

	pte = pte_alloc_kernel(pmd, CONSISTENT_BASE);
	if (!pte) {
	ret = -ENOMEM;
	break;
	}

	consistent_pte = pte;
	} while (0);

	return ret;
	}

	core_initcall(consistent_init);

	static inline void cache_op(phys_addr_t paddr, size_t size,
	void (*fn)(unsigned long start, unsigned long end))
	{
	struct page *page = pfn_to_page(paddr >> PAGE_SHIFT);
	unsigned offset = paddr & ~PAGE_MASK;
	size_t left = size;
	unsigned long start;

	do {
	size_t len = left;

	if (PageHighMem(page)) {
	void *addr;

	if (offset + len > PAGE_SIZE) {
	if (offset >= PAGE_SIZE) {
	page += offset >> PAGE_SHIFT;
	offset &= ~PAGE_MASK;
	}
	len = PAGE_SIZE - offset;
	}

	addr = kmap_atomic(page);
	start = (unsigned long)(addr + offset);
	fn(start, start + len);
	kunmap_atomic(addr);
	} else {
	start = (unsigned long)phys_to_virt(paddr);
	fn(start, start + size);
	}
	offset = 0;
	page++;
	left -= len;
	} while (left);
	}

	void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
	size_t size, enum dma_data_direction dir)
	{
	switch (dir) {
	case DMA_FROM_DEVICE:
	break;
	case DMA_TO_DEVICE:
	case DMA_BIDIRECTIONAL:
	cache_op(paddr, size, cpu_dma_wb_range);
	break;
	default:
	BUG();
	}
	}

	void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
	size_t size, enum dma_data_direction dir)
	{
	switch (dir) {
	case DMA_TO_DEVICE:
	break;
	case DMA_FROM_DEVICE:
	case DMA_BIDIRECTIONAL:
	cache_op(paddr, size, cpu_dma_inval_range);
	break;
	default:
	BUG();
	}
	}