![Alexander Duyck](/assets/img/avatar_default.png)
This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to avoid invoking cache line invalidation if the driver will just handle it via a sync_for_cpu or sync_for_device call. Link: http://lkml.kernel.org/r/20161110113513.76501.32321.stgit@ahduyck-blue-test.jf.intel.com Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Keguang Zhang <keguang.zhang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
448 lines
12 KiB
C
448 lines
12 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2000 Ani Joshi <ajoshi@unixbox.com>
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* Copyright (C) 2000, 2001, 06 Ralf Baechle <ralf@linux-mips.org>
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* swiped from i386, and cloned for MIPS by Geert, polished by Ralf.
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*/
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#include <linux/types.h>
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#include <linux/dma-mapping.h>
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#include <linux/mm.h>
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#include <linux/export.h>
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#include <linux/scatterlist.h>
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#include <linux/string.h>
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#include <linux/gfp.h>
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#include <linux/highmem.h>
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#include <linux/dma-contiguous.h>
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#include <asm/cache.h>
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#include <asm/cpu-type.h>
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#include <asm/io.h>
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#include <dma-coherence.h>
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#if defined(CONFIG_DMA_MAYBE_COHERENT) && !defined(CONFIG_DMA_PERDEV_COHERENT)
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/* User defined DMA coherency from command line. */
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enum coherent_io_user_state coherentio = IO_COHERENCE_DEFAULT;
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EXPORT_SYMBOL_GPL(coherentio);
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int hw_coherentio = 0; /* Actual hardware supported DMA coherency setting. */
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static int __init setcoherentio(char *str)
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{
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coherentio = IO_COHERENCE_ENABLED;
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pr_info("Hardware DMA cache coherency (command line)\n");
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return 0;
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}
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early_param("coherentio", setcoherentio);
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static int __init setnocoherentio(char *str)
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{
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coherentio = IO_COHERENCE_DISABLED;
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pr_info("Software DMA cache coherency (command line)\n");
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return 0;
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}
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early_param("nocoherentio", setnocoherentio);
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#endif
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static inline struct page *dma_addr_to_page(struct device *dev,
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dma_addr_t dma_addr)
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{
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return pfn_to_page(
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plat_dma_addr_to_phys(dev, dma_addr) >> PAGE_SHIFT);
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}
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/*
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* The affected CPUs below in 'cpu_needs_post_dma_flush()' can
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* speculatively fill random cachelines with stale data at any time,
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* requiring an extra flush post-DMA.
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*
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* Warning on the terminology - Linux calls an uncached area coherent;
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* MIPS terminology calls memory areas with hardware maintained coherency
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* coherent.
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*
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* Note that the R14000 and R16000 should also be checked for in this
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* condition. However this function is only called on non-I/O-coherent
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* systems and only the R10000 and R12000 are used in such systems, the
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* SGI IP28 Indigo² rsp. SGI IP32 aka O2.
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*/
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static inline int cpu_needs_post_dma_flush(struct device *dev)
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{
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return !plat_device_is_coherent(dev) &&
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(boot_cpu_type() == CPU_R10000 ||
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boot_cpu_type() == CPU_R12000 ||
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boot_cpu_type() == CPU_BMIPS5000);
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}
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static gfp_t massage_gfp_flags(const struct device *dev, gfp_t gfp)
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{
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gfp_t dma_flag;
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/* ignore region specifiers */
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gfp &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
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#ifdef CONFIG_ISA
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if (dev == NULL)
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dma_flag = __GFP_DMA;
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else
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#endif
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#if defined(CONFIG_ZONE_DMA32) && defined(CONFIG_ZONE_DMA)
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if (dev == NULL || dev->coherent_dma_mask < DMA_BIT_MASK(32))
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dma_flag = __GFP_DMA;
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else if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
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dma_flag = __GFP_DMA32;
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else
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#endif
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#if defined(CONFIG_ZONE_DMA32) && !defined(CONFIG_ZONE_DMA)
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if (dev == NULL || dev->coherent_dma_mask < DMA_BIT_MASK(64))
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dma_flag = __GFP_DMA32;
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else
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#endif
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#if defined(CONFIG_ZONE_DMA) && !defined(CONFIG_ZONE_DMA32)
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if (dev == NULL ||
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dev->coherent_dma_mask < DMA_BIT_MASK(sizeof(phys_addr_t) * 8))
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dma_flag = __GFP_DMA;
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else
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#endif
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dma_flag = 0;
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/* Don't invoke OOM killer */
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gfp |= __GFP_NORETRY;
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return gfp | dma_flag;
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}
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static void *mips_dma_alloc_noncoherent(struct device *dev, size_t size,
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dma_addr_t * dma_handle, gfp_t gfp)
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{
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void *ret;
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gfp = massage_gfp_flags(dev, gfp);
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ret = (void *) __get_free_pages(gfp, get_order(size));
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if (ret != NULL) {
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memset(ret, 0, size);
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*dma_handle = plat_map_dma_mem(dev, ret, size);
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}
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return ret;
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}
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static void *mips_dma_alloc_coherent(struct device *dev, size_t size,
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dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
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{
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void *ret;
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struct page *page = NULL;
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unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
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/*
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* XXX: seems like the coherent and non-coherent implementations could
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* be consolidated.
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*/
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if (attrs & DMA_ATTR_NON_CONSISTENT)
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return mips_dma_alloc_noncoherent(dev, size, dma_handle, gfp);
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gfp = massage_gfp_flags(dev, gfp);
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if (IS_ENABLED(CONFIG_DMA_CMA) && gfpflags_allow_blocking(gfp))
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page = dma_alloc_from_contiguous(dev,
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count, get_order(size));
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if (!page)
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page = alloc_pages(gfp, get_order(size));
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if (!page)
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return NULL;
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ret = page_address(page);
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memset(ret, 0, size);
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*dma_handle = plat_map_dma_mem(dev, ret, size);
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if (!plat_device_is_coherent(dev)) {
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dma_cache_wback_inv((unsigned long) ret, size);
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ret = UNCAC_ADDR(ret);
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}
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return ret;
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}
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static void mips_dma_free_noncoherent(struct device *dev, size_t size,
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void *vaddr, dma_addr_t dma_handle)
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{
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plat_unmap_dma_mem(dev, dma_handle, size, DMA_BIDIRECTIONAL);
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free_pages((unsigned long) vaddr, get_order(size));
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}
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static void mips_dma_free_coherent(struct device *dev, size_t size, void *vaddr,
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dma_addr_t dma_handle, unsigned long attrs)
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{
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unsigned long addr = (unsigned long) vaddr;
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unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
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struct page *page = NULL;
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if (attrs & DMA_ATTR_NON_CONSISTENT) {
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mips_dma_free_noncoherent(dev, size, vaddr, dma_handle);
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return;
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}
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plat_unmap_dma_mem(dev, dma_handle, size, DMA_BIDIRECTIONAL);
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if (!plat_device_is_coherent(dev))
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addr = CAC_ADDR(addr);
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page = virt_to_page((void *) addr);
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if (!dma_release_from_contiguous(dev, page, count))
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__free_pages(page, get_order(size));
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}
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static int mips_dma_mmap(struct device *dev, struct vm_area_struct *vma,
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void *cpu_addr, dma_addr_t dma_addr, size_t size,
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unsigned long attrs)
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{
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unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
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unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
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unsigned long addr = (unsigned long)cpu_addr;
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unsigned long off = vma->vm_pgoff;
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unsigned long pfn;
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int ret = -ENXIO;
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if (!plat_device_is_coherent(dev))
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addr = CAC_ADDR(addr);
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pfn = page_to_pfn(virt_to_page((void *)addr));
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if (attrs & DMA_ATTR_WRITE_COMBINE)
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vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
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else
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vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
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if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
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return ret;
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if (off < count && user_count <= (count - off)) {
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ret = remap_pfn_range(vma, vma->vm_start,
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pfn + off,
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user_count << PAGE_SHIFT,
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vma->vm_page_prot);
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}
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return ret;
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}
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static inline void __dma_sync_virtual(void *addr, size_t size,
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enum dma_data_direction direction)
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{
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switch (direction) {
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case DMA_TO_DEVICE:
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dma_cache_wback((unsigned long)addr, size);
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break;
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case DMA_FROM_DEVICE:
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dma_cache_inv((unsigned long)addr, size);
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break;
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case DMA_BIDIRECTIONAL:
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dma_cache_wback_inv((unsigned long)addr, size);
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break;
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default:
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BUG();
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}
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}
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/*
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* A single sg entry may refer to multiple physically contiguous
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* pages. But we still need to process highmem pages individually.
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* If highmem is not configured then the bulk of this loop gets
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* optimized out.
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*/
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static inline void __dma_sync(struct page *page,
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unsigned long offset, size_t size, enum dma_data_direction direction)
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{
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size_t left = size;
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do {
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size_t len = left;
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if (PageHighMem(page)) {
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void *addr;
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if (offset + len > PAGE_SIZE) {
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if (offset >= PAGE_SIZE) {
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page += offset >> PAGE_SHIFT;
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offset &= ~PAGE_MASK;
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}
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len = PAGE_SIZE - offset;
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}
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addr = kmap_atomic(page);
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__dma_sync_virtual(addr + offset, len, direction);
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kunmap_atomic(addr);
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} else
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__dma_sync_virtual(page_address(page) + offset,
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size, direction);
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offset = 0;
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page++;
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left -= len;
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} while (left);
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}
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static void mips_dma_unmap_page(struct device *dev, dma_addr_t dma_addr,
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size_t size, enum dma_data_direction direction, unsigned long attrs)
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{
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if (cpu_needs_post_dma_flush(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
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__dma_sync(dma_addr_to_page(dev, dma_addr),
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dma_addr & ~PAGE_MASK, size, direction);
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plat_post_dma_flush(dev);
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plat_unmap_dma_mem(dev, dma_addr, size, direction);
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}
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static int mips_dma_map_sg(struct device *dev, struct scatterlist *sglist,
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int nents, enum dma_data_direction direction, unsigned long attrs)
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{
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int i;
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struct scatterlist *sg;
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for_each_sg(sglist, sg, nents, i) {
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if (!plat_device_is_coherent(dev) &&
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!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
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__dma_sync(sg_page(sg), sg->offset, sg->length,
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direction);
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#ifdef CONFIG_NEED_SG_DMA_LENGTH
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sg->dma_length = sg->length;
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#endif
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sg->dma_address = plat_map_dma_mem_page(dev, sg_page(sg)) +
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sg->offset;
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}
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return nents;
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}
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static dma_addr_t mips_dma_map_page(struct device *dev, struct page *page,
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unsigned long offset, size_t size, enum dma_data_direction direction,
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unsigned long attrs)
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{
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if (!plat_device_is_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
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__dma_sync(page, offset, size, direction);
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return plat_map_dma_mem_page(dev, page) + offset;
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}
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static void mips_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
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int nhwentries, enum dma_data_direction direction,
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unsigned long attrs)
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{
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int i;
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struct scatterlist *sg;
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for_each_sg(sglist, sg, nhwentries, i) {
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if (!plat_device_is_coherent(dev) &&
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!(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
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direction != DMA_TO_DEVICE)
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__dma_sync(sg_page(sg), sg->offset, sg->length,
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direction);
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plat_unmap_dma_mem(dev, sg->dma_address, sg->length, direction);
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}
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}
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static void mips_dma_sync_single_for_cpu(struct device *dev,
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dma_addr_t dma_handle, size_t size, enum dma_data_direction direction)
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{
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if (cpu_needs_post_dma_flush(dev))
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__dma_sync(dma_addr_to_page(dev, dma_handle),
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dma_handle & ~PAGE_MASK, size, direction);
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plat_post_dma_flush(dev);
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}
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static void mips_dma_sync_single_for_device(struct device *dev,
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dma_addr_t dma_handle, size_t size, enum dma_data_direction direction)
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{
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if (!plat_device_is_coherent(dev))
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__dma_sync(dma_addr_to_page(dev, dma_handle),
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dma_handle & ~PAGE_MASK, size, direction);
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}
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static void mips_dma_sync_sg_for_cpu(struct device *dev,
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struct scatterlist *sglist, int nelems,
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enum dma_data_direction direction)
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{
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int i;
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struct scatterlist *sg;
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if (cpu_needs_post_dma_flush(dev)) {
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for_each_sg(sglist, sg, nelems, i) {
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__dma_sync(sg_page(sg), sg->offset, sg->length,
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direction);
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}
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}
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plat_post_dma_flush(dev);
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}
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static void mips_dma_sync_sg_for_device(struct device *dev,
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struct scatterlist *sglist, int nelems,
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enum dma_data_direction direction)
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{
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int i;
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struct scatterlist *sg;
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if (!plat_device_is_coherent(dev)) {
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for_each_sg(sglist, sg, nelems, i) {
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__dma_sync(sg_page(sg), sg->offset, sg->length,
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direction);
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}
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}
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}
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int mips_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
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{
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return 0;
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}
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int mips_dma_supported(struct device *dev, u64 mask)
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{
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return plat_dma_supported(dev, mask);
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}
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void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
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enum dma_data_direction direction)
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{
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BUG_ON(direction == DMA_NONE);
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if (!plat_device_is_coherent(dev))
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__dma_sync_virtual(vaddr, size, direction);
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}
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EXPORT_SYMBOL(dma_cache_sync);
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static struct dma_map_ops mips_default_dma_map_ops = {
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.alloc = mips_dma_alloc_coherent,
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.free = mips_dma_free_coherent,
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.mmap = mips_dma_mmap,
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.map_page = mips_dma_map_page,
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.unmap_page = mips_dma_unmap_page,
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.map_sg = mips_dma_map_sg,
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.unmap_sg = mips_dma_unmap_sg,
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.sync_single_for_cpu = mips_dma_sync_single_for_cpu,
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.sync_single_for_device = mips_dma_sync_single_for_device,
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.sync_sg_for_cpu = mips_dma_sync_sg_for_cpu,
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.sync_sg_for_device = mips_dma_sync_sg_for_device,
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.mapping_error = mips_dma_mapping_error,
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.dma_supported = mips_dma_supported
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};
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struct dma_map_ops *mips_dma_map_ops = &mips_default_dma_map_ops;
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EXPORT_SYMBOL(mips_dma_map_ops);
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#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
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static int __init mips_dma_init(void)
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{
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dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
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return 0;
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}
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fs_initcall(mips_dma_init);
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