diff options
Diffstat (limited to 'arch/xtensa/kernel/pci-dma.c')
| -rw-r--r-- | arch/xtensa/kernel/pci-dma.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c new file mode 100644 index 000000000..1fc138b6b --- /dev/null +++ b/arch/xtensa/kernel/pci-dma.c @@ -0,0 +1,212 @@ +/* + * DMA coherent memory allocation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + * Copyright (C) 2002 - 2005 Tensilica Inc. + * Copyright (C) 2015 Cadence Design Systems Inc. + * + * Based on version for i386. + * + * Chris Zankel <chris@zankel.net> + * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com> + */ + +#include <linux/dma-contiguous.h> +#include <linux/dma-noncoherent.h> +#include <linux/dma-direct.h> +#include <linux/gfp.h> +#include <linux/highmem.h> +#include <linux/mm.h> +#include <linux/types.h> +#include <asm/cacheflush.h> +#include <asm/io.h> +#include <asm/platform.h> + +static void do_cache_op(phys_addr_t paddr, size_t size, + void (*fn)(unsigned long, unsigned long)) +{ + unsigned long off = paddr & (PAGE_SIZE - 1); + unsigned long pfn = PFN_DOWN(paddr); + struct page *page = pfn_to_page(pfn); + + if (!PageHighMem(page)) + fn((unsigned long)phys_to_virt(paddr), size); + else + while (size > 0) { + size_t sz = min_t(size_t, size, PAGE_SIZE - off); + void *vaddr = kmap_atomic(page); + + fn((unsigned long)vaddr + off, sz); + kunmap_atomic(vaddr); + off = 0; + ++page; + size -= sz; + } +} + +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_BIDIRECTIONAL: + case DMA_FROM_DEVICE: + do_cache_op(paddr, size, __invalidate_dcache_range); + break; + + case DMA_NONE: + BUG(); + break; + + default: + break; + } +} + +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_BIDIRECTIONAL: + case DMA_TO_DEVICE: + if (XCHAL_DCACHE_IS_WRITEBACK) + do_cache_op(paddr, size, __flush_dcache_range); + break; + + case DMA_NONE: + BUG(); + break; + + default: + break; + } +} + +#ifdef CONFIG_MMU +bool platform_vaddr_cached(const void *p) +{ + unsigned long addr = (unsigned long)p; + + return addr >= XCHAL_KSEG_CACHED_VADDR && + addr - XCHAL_KSEG_CACHED_VADDR < XCHAL_KSEG_SIZE; +} + +bool platform_vaddr_uncached(const void *p) +{ + unsigned long addr = (unsigned long)p; + + return addr >= XCHAL_KSEG_BYPASS_VADDR && + addr - XCHAL_KSEG_BYPASS_VADDR < XCHAL_KSEG_SIZE; +} + +void *platform_vaddr_to_uncached(void *p) +{ + return p + XCHAL_KSEG_BYPASS_VADDR - XCHAL_KSEG_CACHED_VADDR; +} + +void *platform_vaddr_to_cached(void *p) +{ + return p + XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR; +} +#else +bool __attribute__((weak)) platform_vaddr_cached(const void *p) +{ + WARN_ONCE(1, "Default %s implementation is used\n", __func__); + return true; +} + +bool __attribute__((weak)) platform_vaddr_uncached(const void *p) +{ + WARN_ONCE(1, "Default %s implementation is used\n", __func__); + return false; +} + +void __attribute__((weak)) *platform_vaddr_to_uncached(void *p) +{ + WARN_ONCE(1, "Default %s implementation is used\n", __func__); + return p; +} + +void __attribute__((weak)) *platform_vaddr_to_cached(void *p) +{ + WARN_ONCE(1, "Default %s implementation is used\n", __func__); + return p; +} +#endif + +/* + * Note: We assume that the full memory space is always mapped to 'kseg' + * Otherwise we have to use page attributes (not implemented). + */ + +void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, + gfp_t flag, unsigned long attrs) +{ + unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; + struct page *page = NULL; + + /* ignore region speicifiers */ + + flag &= ~(__GFP_DMA | __GFP_HIGHMEM); + + if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff)) + flag |= GFP_DMA; + + if (gfpflags_allow_blocking(flag)) + page = dma_alloc_from_contiguous(dev, count, get_order(size), + flag & __GFP_NOWARN); + + if (!page) + page = alloc_pages(flag, get_order(size)); + + if (!page) + return NULL; + + *handle = phys_to_dma(dev, page_to_phys(page)); + + if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) { + return page; + } + +#ifdef CONFIG_MMU + if (PageHighMem(page)) { + void *p; + + p = dma_common_contiguous_remap(page, size, VM_MAP, + pgprot_noncached(PAGE_KERNEL), + __builtin_return_address(0)); + if (!p) { + if (!dma_release_from_contiguous(dev, page, count)) + __free_pages(page, get_order(size)); + } + return p; + } +#endif + BUG_ON(!platform_vaddr_cached(page_address(page))); + __invalidate_dcache_range((unsigned long)page_address(page), size); + return platform_vaddr_to_uncached(page_address(page)); +} + +void arch_dma_free(struct device *dev, size_t size, void *vaddr, + dma_addr_t dma_handle, unsigned long attrs) +{ + unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; + struct page *page; + + if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) { + page = vaddr; + } else if (platform_vaddr_uncached(vaddr)) { + page = virt_to_page(platform_vaddr_to_cached(vaddr)); + } else { +#ifdef CONFIG_MMU + dma_common_free_remap(vaddr, size, VM_MAP); +#endif + page = pfn_to_page(PHYS_PFN(dma_to_phys(dev, dma_handle))); + } + + if (!dma_release_from_contiguous(dev, page, count)) + __free_pages(page, get_order(size)); +} |