diff options
Diffstat (limited to 'drivers/base/dma-coherent.c')
-rw-r--r-- | drivers/base/dma-coherent.c | 434 |
1 files changed, 0 insertions, 434 deletions
diff --git a/drivers/base/dma-coherent.c b/drivers/base/dma-coherent.c deleted file mode 100644 index 597d40893862..000000000000 --- a/drivers/base/dma-coherent.c +++ /dev/null @@ -1,434 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * Coherent per-device memory handling. - * Borrowed from i386 - */ -#include <linux/io.h> -#include <linux/slab.h> -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/dma-mapping.h> - -struct dma_coherent_mem { - void *virt_base; - dma_addr_t device_base; - unsigned long pfn_base; - int size; - int flags; - unsigned long *bitmap; - spinlock_t spinlock; - bool use_dev_dma_pfn_offset; -}; - -static struct dma_coherent_mem *dma_coherent_default_memory __ro_after_init; - -static inline struct dma_coherent_mem *dev_get_coherent_memory(struct device *dev) -{ - if (dev && dev->dma_mem) - return dev->dma_mem; - return NULL; -} - -static inline dma_addr_t dma_get_device_base(struct device *dev, - struct dma_coherent_mem * mem) -{ - if (mem->use_dev_dma_pfn_offset) - return (mem->pfn_base - dev->dma_pfn_offset) << PAGE_SHIFT; - else - return mem->device_base; -} - -static int dma_init_coherent_memory( - phys_addr_t phys_addr, dma_addr_t device_addr, size_t size, int flags, - struct dma_coherent_mem **mem) -{ - struct dma_coherent_mem *dma_mem = NULL; - void __iomem *mem_base = NULL; - int pages = size >> PAGE_SHIFT; - int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long); - int ret; - - if (!size) { - ret = -EINVAL; - goto out; - } - - mem_base = memremap(phys_addr, size, MEMREMAP_WC); - if (!mem_base) { - ret = -EINVAL; - goto out; - } - dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL); - if (!dma_mem) { - ret = -ENOMEM; - goto out; - } - dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL); - if (!dma_mem->bitmap) { - ret = -ENOMEM; - goto out; - } - - dma_mem->virt_base = mem_base; - dma_mem->device_base = device_addr; - dma_mem->pfn_base = PFN_DOWN(phys_addr); - dma_mem->size = pages; - dma_mem->flags = flags; - spin_lock_init(&dma_mem->spinlock); - - *mem = dma_mem; - return 0; - -out: - kfree(dma_mem); - if (mem_base) - memunmap(mem_base); - return ret; -} - -static void dma_release_coherent_memory(struct dma_coherent_mem *mem) -{ - if (!mem) - return; - - memunmap(mem->virt_base); - kfree(mem->bitmap); - kfree(mem); -} - -static int dma_assign_coherent_memory(struct device *dev, - struct dma_coherent_mem *mem) -{ - if (!dev) - return -ENODEV; - - if (dev->dma_mem) - return -EBUSY; - - dev->dma_mem = mem; - return 0; -} - -int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, - dma_addr_t device_addr, size_t size, int flags) -{ - struct dma_coherent_mem *mem; - int ret; - - ret = dma_init_coherent_memory(phys_addr, device_addr, size, flags, &mem); - if (ret) - return ret; - - ret = dma_assign_coherent_memory(dev, mem); - if (ret) - dma_release_coherent_memory(mem); - return ret; -} -EXPORT_SYMBOL(dma_declare_coherent_memory); - -void dma_release_declared_memory(struct device *dev) -{ - struct dma_coherent_mem *mem = dev->dma_mem; - - if (!mem) - return; - dma_release_coherent_memory(mem); - dev->dma_mem = NULL; -} -EXPORT_SYMBOL(dma_release_declared_memory); - -void *dma_mark_declared_memory_occupied(struct device *dev, - dma_addr_t device_addr, size_t size) -{ - struct dma_coherent_mem *mem = dev->dma_mem; - unsigned long flags; - int pos, err; - - size += device_addr & ~PAGE_MASK; - - if (!mem) - return ERR_PTR(-EINVAL); - - spin_lock_irqsave(&mem->spinlock, flags); - pos = PFN_DOWN(device_addr - dma_get_device_base(dev, mem)); - err = bitmap_allocate_region(mem->bitmap, pos, get_order(size)); - spin_unlock_irqrestore(&mem->spinlock, flags); - - if (err != 0) - return ERR_PTR(err); - return mem->virt_base + (pos << PAGE_SHIFT); -} -EXPORT_SYMBOL(dma_mark_declared_memory_occupied); - -static void *__dma_alloc_from_coherent(struct dma_coherent_mem *mem, - ssize_t size, dma_addr_t *dma_handle) -{ - int order = get_order(size); - unsigned long flags; - int pageno; - void *ret; - - spin_lock_irqsave(&mem->spinlock, flags); - - if (unlikely(size > (mem->size << PAGE_SHIFT))) - goto err; - - pageno = bitmap_find_free_region(mem->bitmap, mem->size, order); - if (unlikely(pageno < 0)) - goto err; - - /* - * Memory was found in the coherent area. - */ - *dma_handle = mem->device_base + (pageno << PAGE_SHIFT); - ret = mem->virt_base + (pageno << PAGE_SHIFT); - spin_unlock_irqrestore(&mem->spinlock, flags); - memset(ret, 0, size); - return ret; -err: - spin_unlock_irqrestore(&mem->spinlock, flags); - return NULL; -} - -/** - * dma_alloc_from_dev_coherent() - allocate memory from device coherent pool - * @dev: device from which we allocate memory - * @size: size of requested memory area - * @dma_handle: This will be filled with the correct dma handle - * @ret: This pointer will be filled with the virtual address - * to allocated area. - * - * This function should be only called from per-arch dma_alloc_coherent() - * to support allocation from per-device coherent memory pools. - * - * Returns 0 if dma_alloc_coherent should continue with allocating from - * generic memory areas, or !0 if dma_alloc_coherent should return @ret. - */ -int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size, - dma_addr_t *dma_handle, void **ret) -{ - struct dma_coherent_mem *mem = dev_get_coherent_memory(dev); - - if (!mem) - return 0; - - *ret = __dma_alloc_from_coherent(mem, size, dma_handle); - if (*ret) - return 1; - - /* - * In the case where the allocation can not be satisfied from the - * per-device area, try to fall back to generic memory if the - * constraints allow it. - */ - return mem->flags & DMA_MEMORY_EXCLUSIVE; -} -EXPORT_SYMBOL(dma_alloc_from_dev_coherent); - -void *dma_alloc_from_global_coherent(ssize_t size, dma_addr_t *dma_handle) -{ - if (!dma_coherent_default_memory) - return NULL; - - return __dma_alloc_from_coherent(dma_coherent_default_memory, size, - dma_handle); -} - -static int __dma_release_from_coherent(struct dma_coherent_mem *mem, - int order, void *vaddr) -{ - if (mem && vaddr >= mem->virt_base && vaddr < - (mem->virt_base + (mem->size << PAGE_SHIFT))) { - int page = (vaddr - mem->virt_base) >> PAGE_SHIFT; - unsigned long flags; - - spin_lock_irqsave(&mem->spinlock, flags); - bitmap_release_region(mem->bitmap, page, order); - spin_unlock_irqrestore(&mem->spinlock, flags); - return 1; - } - return 0; -} - -/** - * dma_release_from_dev_coherent() - free memory to device coherent memory pool - * @dev: device from which the memory was allocated - * @order: the order of pages allocated - * @vaddr: virtual address of allocated pages - * - * This checks whether the memory was allocated from the per-device - * coherent memory pool and if so, releases that memory. - * - * Returns 1 if we correctly released the memory, or 0 if the caller should - * proceed with releasing memory from generic pools. - */ -int dma_release_from_dev_coherent(struct device *dev, int order, void *vaddr) -{ - struct dma_coherent_mem *mem = dev_get_coherent_memory(dev); - - return __dma_release_from_coherent(mem, order, vaddr); -} -EXPORT_SYMBOL(dma_release_from_dev_coherent); - -int dma_release_from_global_coherent(int order, void *vaddr) -{ - if (!dma_coherent_default_memory) - return 0; - - return __dma_release_from_coherent(dma_coherent_default_memory, order, - vaddr); -} - -static int __dma_mmap_from_coherent(struct dma_coherent_mem *mem, - struct vm_area_struct *vma, void *vaddr, size_t size, int *ret) -{ - if (mem && vaddr >= mem->virt_base && vaddr + size <= - (mem->virt_base + (mem->size << PAGE_SHIFT))) { - unsigned long off = vma->vm_pgoff; - int start = (vaddr - mem->virt_base) >> PAGE_SHIFT; - int user_count = vma_pages(vma); - int count = PAGE_ALIGN(size) >> PAGE_SHIFT; - - *ret = -ENXIO; - if (off < count && user_count <= count - off) { - unsigned long pfn = mem->pfn_base + start + off; - *ret = remap_pfn_range(vma, vma->vm_start, pfn, - user_count << PAGE_SHIFT, - vma->vm_page_prot); - } - return 1; - } - return 0; -} - -/** - * dma_mmap_from_dev_coherent() - mmap memory from the device coherent pool - * @dev: device from which the memory was allocated - * @vma: vm_area for the userspace memory - * @vaddr: cpu address returned by dma_alloc_from_dev_coherent - * @size: size of the memory buffer allocated - * @ret: result from remap_pfn_range() - * - * This checks whether the memory was allocated from the per-device - * coherent memory pool and if so, maps that memory to the provided vma. - * - * Returns 1 if @vaddr belongs to the device coherent pool and the caller - * should return @ret, or 0 if they should proceed with mapping memory from - * generic areas. - */ -int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *vma, - void *vaddr, size_t size, int *ret) -{ - struct dma_coherent_mem *mem = dev_get_coherent_memory(dev); - - return __dma_mmap_from_coherent(mem, vma, vaddr, size, ret); -} -EXPORT_SYMBOL(dma_mmap_from_dev_coherent); - -int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *vaddr, - size_t size, int *ret) -{ - if (!dma_coherent_default_memory) - return 0; - - return __dma_mmap_from_coherent(dma_coherent_default_memory, vma, - vaddr, size, ret); -} - -/* - * Support for reserved memory regions defined in device tree - */ -#ifdef CONFIG_OF_RESERVED_MEM -#include <linux/of.h> -#include <linux/of_fdt.h> -#include <linux/of_reserved_mem.h> - -static struct reserved_mem *dma_reserved_default_memory __initdata; - -static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev) -{ - struct dma_coherent_mem *mem = rmem->priv; - int ret; - - if (!mem) { - ret = dma_init_coherent_memory(rmem->base, rmem->base, - rmem->size, - DMA_MEMORY_EXCLUSIVE, &mem); - if (ret) { - pr_err("Reserved memory: failed to init DMA memory pool at %pa, size %ld MiB\n", - &rmem->base, (unsigned long)rmem->size / SZ_1M); - return ret; - } - } - mem->use_dev_dma_pfn_offset = true; - rmem->priv = mem; - dma_assign_coherent_memory(dev, mem); - return 0; -} - -static void rmem_dma_device_release(struct reserved_mem *rmem, - struct device *dev) -{ - if (dev) - dev->dma_mem = NULL; -} - -static const struct reserved_mem_ops rmem_dma_ops = { - .device_init = rmem_dma_device_init, - .device_release = rmem_dma_device_release, -}; - -static int __init rmem_dma_setup(struct reserved_mem *rmem) -{ - unsigned long node = rmem->fdt_node; - - if (of_get_flat_dt_prop(node, "reusable", NULL)) - return -EINVAL; - -#ifdef CONFIG_ARM - if (!of_get_flat_dt_prop(node, "no-map", NULL)) { - pr_err("Reserved memory: regions without no-map are not yet supported\n"); - return -EINVAL; - } - - if (of_get_flat_dt_prop(node, "linux,dma-default", NULL)) { - WARN(dma_reserved_default_memory, - "Reserved memory: region for default DMA coherent area is redefined\n"); - dma_reserved_default_memory = rmem; - } -#endif - - rmem->ops = &rmem_dma_ops; - pr_info("Reserved memory: created DMA memory pool at %pa, size %ld MiB\n", - &rmem->base, (unsigned long)rmem->size / SZ_1M); - return 0; -} - -static int __init dma_init_reserved_memory(void) -{ - const struct reserved_mem_ops *ops; - int ret; - - if (!dma_reserved_default_memory) - return -ENOMEM; - - ops = dma_reserved_default_memory->ops; - - /* - * We rely on rmem_dma_device_init() does not propagate error of - * dma_assign_coherent_memory() for "NULL" device. - */ - ret = ops->device_init(dma_reserved_default_memory, NULL); - - if (!ret) { - dma_coherent_default_memory = dma_reserved_default_memory->priv; - pr_info("DMA: default coherent area is set\n"); - } - - return ret; -} - -core_initcall(dma_init_reserved_memory); - -RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup); -#endif |