From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- kernel/dma/coherent.c | 403 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 403 insertions(+) create mode 100644 kernel/dma/coherent.c (limited to 'kernel/dma/coherent.c') diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c new file mode 100644 index 000000000..ff5683a57 --- /dev/null +++ b/kernel/dma/coherent.c @@ -0,0 +1,403 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Coherent per-device memory handling. + * Borrowed from i386 + */ +#include +#include +#include +#include +#include +#include + +struct dma_coherent_mem { + void *virt_base; + dma_addr_t device_base; + unsigned long pfn_base; + int size; + unsigned long *bitmap; + spinlock_t spinlock; + bool use_dev_dma_pfn_offset; +}; + +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 phys_to_dma(dev, PFN_PHYS(mem->pfn_base)); + return mem->device_base; +} + +static struct dma_coherent_mem *dma_init_coherent_memory(phys_addr_t phys_addr, + dma_addr_t device_addr, size_t size, bool use_dma_pfn_offset) +{ + struct dma_coherent_mem *dma_mem; + int pages = size >> PAGE_SHIFT; + void *mem_base; + + if (!size) + return ERR_PTR(-EINVAL); + + mem_base = memremap(phys_addr, size, MEMREMAP_WC); + if (!mem_base) + return ERR_PTR(-EINVAL); + + dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL); + if (!dma_mem) + goto out_unmap_membase; + dma_mem->bitmap = bitmap_zalloc(pages, GFP_KERNEL); + if (!dma_mem->bitmap) + goto out_free_dma_mem; + + 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->use_dev_dma_pfn_offset = use_dma_pfn_offset; + spin_lock_init(&dma_mem->spinlock); + + return dma_mem; + +out_free_dma_mem: + kfree(dma_mem); +out_unmap_membase: + memunmap(mem_base); + pr_err("Reserved memory: failed to init DMA memory pool at %pa, size %zd MiB\n", + &phys_addr, size / SZ_1M); + return ERR_PTR(-ENOMEM); +} + +static void _dma_release_coherent_memory(struct dma_coherent_mem *mem) +{ + if (!mem) + return; + + memunmap(mem->virt_base); + bitmap_free(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; +} + +/* + * Declare a region of memory to be handed out by dma_alloc_coherent() when it + * is asked for coherent memory for this device. This shall only be used + * from platform code, usually based on the device tree description. + * + * phys_addr is the CPU physical address to which the memory is currently + * assigned (this will be ioremapped so the CPU can access the region). + * + * device_addr is the DMA address the device needs to be programmed with to + * actually address this memory (this will be handed out as the dma_addr_t in + * dma_alloc_coherent()). + * + * size is the size of the area (must be a multiple of PAGE_SIZE). + * + * As a simplification for the platforms, only *one* such region of memory may + * be declared per device. + */ +int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, + dma_addr_t device_addr, size_t size) +{ + struct dma_coherent_mem *mem; + int ret; + + mem = dma_init_coherent_memory(phys_addr, device_addr, size, false); + if (IS_ERR(mem)) + return PTR_ERR(mem); + + ret = dma_assign_coherent_memory(dev, mem); + if (ret) + _dma_release_coherent_memory(mem); + return ret; +} + +void dma_release_coherent_memory(struct device *dev) +{ + if (dev) { + _dma_release_coherent_memory(dev->dma_mem); + dev->dma_mem = NULL; + } +} + +static void *__dma_alloc_from_coherent(struct device *dev, + 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 > ((dma_addr_t)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 = dma_get_device_base(dev, mem) + + ((dma_addr_t)pageno << PAGE_SHIFT); + ret = mem->virt_base + ((dma_addr_t)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(dev, mem, size, dma_handle); + return 1; +} + +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 + ((dma_addr_t)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); +} + +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 + ((dma_addr_t)mem->size << PAGE_SHIFT))) { + unsigned long off = vma->vm_pgoff; + int start = (vaddr - mem->virt_base) >> PAGE_SHIFT; + unsigned long 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); +} + +#ifdef CONFIG_DMA_GLOBAL_POOL +static struct dma_coherent_mem *dma_coherent_default_memory __ro_after_init; + +void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size, + dma_addr_t *dma_handle) +{ + if (!dma_coherent_default_memory) + return NULL; + + return __dma_alloc_from_coherent(dev, dma_coherent_default_memory, size, + dma_handle); +} + +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); +} + +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); +} + +int dma_init_global_coherent(phys_addr_t phys_addr, size_t size) +{ + struct dma_coherent_mem *mem; + + mem = dma_init_coherent_memory(phys_addr, phys_addr, size, true); + if (IS_ERR(mem)) + return PTR_ERR(mem); + dma_coherent_default_memory = mem; + pr_info("DMA: default coherent area is set\n"); + return 0; +} +#endif /* CONFIG_DMA_GLOBAL_POOL */ + +/* + * Support for reserved memory regions defined in device tree + */ +#ifdef CONFIG_OF_RESERVED_MEM +#include +#include +#include + +#ifdef CONFIG_DMA_GLOBAL_POOL +static struct reserved_mem *dma_reserved_default_memory __initdata; +#endif + +static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev) +{ + if (!rmem->priv) { + struct dma_coherent_mem *mem; + + mem = dma_init_coherent_memory(rmem->base, rmem->base, + rmem->size, true); + if (IS_ERR(mem)) + return PTR_ERR(mem); + rmem->priv = mem; + } + dma_assign_coherent_memory(dev, rmem->priv); + 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; + } +#endif + +#ifdef CONFIG_DMA_GLOBAL_POOL + 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; +} + +#ifdef CONFIG_DMA_GLOBAL_POOL +static int __init dma_init_reserved_memory(void) +{ + if (!dma_reserved_default_memory) + return -ENOMEM; + return dma_init_global_coherent(dma_reserved_default_memory->base, + dma_reserved_default_memory->size); +} +core_initcall(dma_init_reserved_memory); +#endif /* CONFIG_DMA_GLOBAL_POOL */ + +RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup); +#endif -- cgit v1.2.3