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-rw-r--r--kernel/dma/direct.c222
1 files changed, 180 insertions, 42 deletions
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 1c35b7b945d0..87a6bc2a96c0 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -1,13 +1,16 @@
// SPDX-License-Identifier: GPL-2.0
/*
- * DMA operations that map physical memory directly without using an IOMMU or
- * flushing caches.
+ * Copyright (C) 2018 Christoph Hellwig.
+ *
+ * DMA operations that map physical memory directly without using an IOMMU.
*/
+#include <linux/bootmem.h> /* for max_pfn */
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/dma-direct.h>
#include <linux/scatterlist.h>
#include <linux/dma-contiguous.h>
+#include <linux/dma-noncoherent.h>
#include <linux/pfn.h>
#include <linux/set_memory.h>
@@ -41,40 +44,83 @@ check_addr(struct device *dev, dma_addr_t dma_addr, size_t size,
return false;
}
- if (*dev->dma_mask >= DMA_BIT_MASK(32)) {
+ if (*dev->dma_mask >= DMA_BIT_MASK(32) || dev->bus_dma_mask) {
dev_err(dev,
- "%s: overflow %pad+%zu of device mask %llx\n",
- caller, &dma_addr, size, *dev->dma_mask);
+ "%s: overflow %pad+%zu of device mask %llx bus mask %llx\n",
+ caller, &dma_addr, size,
+ *dev->dma_mask, dev->bus_dma_mask);
}
return false;
}
return true;
}
+static inline dma_addr_t phys_to_dma_direct(struct device *dev,
+ phys_addr_t phys)
+{
+ if (force_dma_unencrypted())
+ return __phys_to_dma(dev, phys);
+ return phys_to_dma(dev, phys);
+}
+
+u64 dma_direct_get_required_mask(struct device *dev)
+{
+ u64 max_dma = phys_to_dma_direct(dev, (max_pfn - 1) << PAGE_SHIFT);
+
+ if (dev->bus_dma_mask && dev->bus_dma_mask < max_dma)
+ max_dma = dev->bus_dma_mask;
+
+ return (1ULL << (fls64(max_dma) - 1)) * 2 - 1;
+}
+
+static gfp_t __dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
+ u64 *phys_mask)
+{
+ if (dev->bus_dma_mask && dev->bus_dma_mask < dma_mask)
+ dma_mask = dev->bus_dma_mask;
+
+ if (force_dma_unencrypted())
+ *phys_mask = __dma_to_phys(dev, dma_mask);
+ else
+ *phys_mask = dma_to_phys(dev, dma_mask);
+
+ /*
+ * Optimistically try the zone that the physical address mask falls
+ * into first. If that returns memory that isn't actually addressable
+ * we will fallback to the next lower zone and try again.
+ *
+ * Note that GFP_DMA32 and GFP_DMA are no ops without the corresponding
+ * zones.
+ */
+ if (*phys_mask <= DMA_BIT_MASK(ARCH_ZONE_DMA_BITS))
+ return GFP_DMA;
+ if (*phys_mask <= DMA_BIT_MASK(32))
+ return GFP_DMA32;
+ return 0;
+}
+
static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)
{
- dma_addr_t addr = force_dma_unencrypted() ?
- __phys_to_dma(dev, phys) : phys_to_dma(dev, phys);
- return addr + size - 1 <= dev->coherent_dma_mask;
+ return phys_to_dma_direct(dev, phys) + size - 1 <=
+ min_not_zero(dev->coherent_dma_mask, dev->bus_dma_mask);
}
-void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
- gfp_t gfp, unsigned long attrs)
+void *dma_direct_alloc_pages(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
{
unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
int page_order = get_order(size);
struct page *page = NULL;
+ u64 phys_mask;
void *ret;
+ if (attrs & DMA_ATTR_NO_WARN)
+ gfp |= __GFP_NOWARN;
+
/* we always manually zero the memory once we are done: */
gfp &= ~__GFP_ZERO;
-
- /* GFP_DMA32 and GFP_DMA are no ops without the corresponding zones: */
- if (dev->coherent_dma_mask <= DMA_BIT_MASK(ARCH_ZONE_DMA_BITS))
- gfp |= GFP_DMA;
- if (dev->coherent_dma_mask <= DMA_BIT_MASK(32) && !(gfp & GFP_DMA))
- gfp |= GFP_DMA32;
-
+ gfp |= __dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
+ &phys_mask);
again:
/* CMA can be used only in the context which permits sleeping */
if (gfpflags_allow_blocking(gfp)) {
@@ -93,15 +139,14 @@ again:
page = NULL;
if (IS_ENABLED(CONFIG_ZONE_DMA32) &&
- dev->coherent_dma_mask < DMA_BIT_MASK(64) &&
+ phys_mask < DMA_BIT_MASK(64) &&
!(gfp & (GFP_DMA32 | GFP_DMA))) {
gfp |= GFP_DMA32;
goto again;
}
if (IS_ENABLED(CONFIG_ZONE_DMA) &&
- dev->coherent_dma_mask < DMA_BIT_MASK(32) &&
- !(gfp & GFP_DMA)) {
+ phys_mask < DMA_BIT_MASK(32) && !(gfp & GFP_DMA)) {
gfp = (gfp & ~GFP_DMA32) | GFP_DMA;
goto again;
}
@@ -124,7 +169,7 @@ again:
* NOTE: this function must never look at the dma_addr argument, because we want
* to be able to use it as a helper for iommu implementations as well.
*/
-void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
+void dma_direct_free_pages(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t dma_addr, unsigned long attrs)
{
unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
@@ -136,14 +181,96 @@ void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
free_pages((unsigned long)cpu_addr, page_order);
}
+void *dma_direct_alloc(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
+{
+ if (!dev_is_dma_coherent(dev))
+ return arch_dma_alloc(dev, size, dma_handle, gfp, attrs);
+ return dma_direct_alloc_pages(dev, size, dma_handle, gfp, attrs);
+}
+
+void dma_direct_free(struct device *dev, size_t size,
+ void *cpu_addr, dma_addr_t dma_addr, unsigned long attrs)
+{
+ if (!dev_is_dma_coherent(dev))
+ arch_dma_free(dev, size, cpu_addr, dma_addr, attrs);
+ else
+ dma_direct_free_pages(dev, size, cpu_addr, dma_addr, attrs);
+}
+
+static void dma_direct_sync_single_for_device(struct device *dev,
+ dma_addr_t addr, size_t size, enum dma_data_direction dir)
+{
+ if (dev_is_dma_coherent(dev))
+ return;
+ arch_sync_dma_for_device(dev, dma_to_phys(dev, addr), size, dir);
+}
+
+static void dma_direct_sync_sg_for_device(struct device *dev,
+ struct scatterlist *sgl, int nents, enum dma_data_direction dir)
+{
+ struct scatterlist *sg;
+ int i;
+
+ if (dev_is_dma_coherent(dev))
+ return;
+
+ for_each_sg(sgl, sg, nents, i)
+ arch_sync_dma_for_device(dev, sg_phys(sg), sg->length, dir);
+}
+
+#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
+ defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
+static void dma_direct_sync_single_for_cpu(struct device *dev,
+ dma_addr_t addr, size_t size, enum dma_data_direction dir)
+{
+ if (dev_is_dma_coherent(dev))
+ return;
+ arch_sync_dma_for_cpu(dev, dma_to_phys(dev, addr), size, dir);
+ arch_sync_dma_for_cpu_all(dev);
+}
+
+static void dma_direct_sync_sg_for_cpu(struct device *dev,
+ struct scatterlist *sgl, int nents, enum dma_data_direction dir)
+{
+ struct scatterlist *sg;
+ int i;
+
+ if (dev_is_dma_coherent(dev))
+ return;
+
+ for_each_sg(sgl, sg, nents, i)
+ arch_sync_dma_for_cpu(dev, sg_phys(sg), sg->length, dir);
+ arch_sync_dma_for_cpu_all(dev);
+}
+
+static void dma_direct_unmap_page(struct device *dev, dma_addr_t addr,
+ size_t size, enum dma_data_direction dir, unsigned long attrs)
+{
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ dma_direct_sync_single_for_cpu(dev, addr, size, dir);
+}
+
+static void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl,
+ int nents, enum dma_data_direction dir, unsigned long attrs)
+{
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ dma_direct_sync_sg_for_cpu(dev, sgl, nents, dir);
+}
+#endif
+
dma_addr_t dma_direct_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size, enum dma_data_direction dir,
unsigned long attrs)
{
- dma_addr_t dma_addr = phys_to_dma(dev, page_to_phys(page)) + offset;
+ phys_addr_t phys = page_to_phys(page) + offset;
+ dma_addr_t dma_addr = phys_to_dma(dev, phys);
if (!check_addr(dev, dma_addr, size, __func__))
return DIRECT_MAPPING_ERROR;
+
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ dma_direct_sync_single_for_device(dev, dma_addr, size, dir);
return dma_addr;
}
@@ -162,31 +289,29 @@ int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
sg_dma_len(sg) = sg->length;
}
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ dma_direct_sync_sg_for_device(dev, sgl, nents, dir);
return nents;
}
+/*
+ * Because 32-bit DMA masks are so common we expect every architecture to be
+ * able to satisfy them - either by not supporting more physical memory, or by
+ * providing a ZONE_DMA32. If neither is the case, the architecture needs to
+ * use an IOMMU instead of the direct mapping.
+ */
int dma_direct_supported(struct device *dev, u64 mask)
{
-#ifdef CONFIG_ZONE_DMA
- if (mask < DMA_BIT_MASK(ARCH_ZONE_DMA_BITS))
- return 0;
-#else
- /*
- * Because 32-bit DMA masks are so common we expect every architecture
- * to be able to satisfy them - either by not supporting more physical
- * memory, or by providing a ZONE_DMA32. If neither is the case, the
- * architecture needs to use an IOMMU instead of the direct mapping.
- */
- if (mask < DMA_BIT_MASK(32))
- return 0;
-#endif
- /*
- * Upstream PCI/PCIe bridges or SoC interconnects may not carry
- * as many DMA address bits as the device itself supports.
- */
- if (dev->bus_dma_mask && mask > dev->bus_dma_mask)
- return 0;
- return 1;
+ u64 min_mask;
+
+ if (IS_ENABLED(CONFIG_ZONE_DMA))
+ min_mask = DMA_BIT_MASK(ARCH_ZONE_DMA_BITS);
+ else
+ min_mask = DMA_BIT_MASK(32);
+
+ min_mask = min_t(u64, min_mask, (max_pfn - 1) << PAGE_SHIFT);
+
+ return mask >= phys_to_dma(dev, min_mask);
}
int dma_direct_mapping_error(struct device *dev, dma_addr_t dma_addr)
@@ -199,7 +324,20 @@ const struct dma_map_ops dma_direct_ops = {
.free = dma_direct_free,
.map_page = dma_direct_map_page,
.map_sg = dma_direct_map_sg,
+#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE)
+ .sync_single_for_device = dma_direct_sync_single_for_device,
+ .sync_sg_for_device = dma_direct_sync_sg_for_device,
+#endif
+#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
+ defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
+ .sync_single_for_cpu = dma_direct_sync_single_for_cpu,
+ .sync_sg_for_cpu = dma_direct_sync_sg_for_cpu,
+ .unmap_page = dma_direct_unmap_page,
+ .unmap_sg = dma_direct_unmap_sg,
+#endif
+ .get_required_mask = dma_direct_get_required_mask,
.dma_supported = dma_direct_supported,
.mapping_error = dma_direct_mapping_error,
+ .cache_sync = arch_dma_cache_sync,
};
EXPORT_SYMBOL(dma_direct_ops);