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-rw-r--r--arch/tile/kernel/pci-dma.c182
1 files changed, 143 insertions, 39 deletions
diff --git a/arch/tile/kernel/pci-dma.c b/arch/tile/kernel/pci-dma.c
index b3ed19f8779..9814d7082f2 100644
--- a/arch/tile/kernel/pci-dma.c
+++ b/arch/tile/kernel/pci-dma.c
@@ -22,9 +22,15 @@
/* Generic DMA mapping functions: */
/*
- * Allocate what Linux calls "coherent" memory, which for us just
- * means uncached.
+ * Allocate what Linux calls "coherent" memory. On TILEPro this is
+ * uncached memory; on TILE-Gx it is hash-for-home memory.
*/
+#ifdef __tilepro__
+#define PAGE_HOME_DMA PAGE_HOME_UNCACHED
+#else
+#define PAGE_HOME_DMA PAGE_HOME_HASH
+#endif
+
void *dma_alloc_coherent(struct device *dev,
size_t size,
dma_addr_t *dma_handle,
@@ -48,13 +54,13 @@ void *dma_alloc_coherent(struct device *dev,
if (dma_mask <= DMA_BIT_MASK(32))
node = 0;
- pg = homecache_alloc_pages_node(node, gfp, order, PAGE_HOME_UNCACHED);
+ pg = homecache_alloc_pages_node(node, gfp, order, PAGE_HOME_DMA);
if (pg == NULL)
return NULL;
addr = page_to_phys(pg);
if (addr + size > dma_mask) {
- homecache_free_pages(addr, order);
+ __homecache_free_pages(pg, order);
return NULL;
}
@@ -87,22 +93,110 @@ EXPORT_SYMBOL(dma_free_coherent);
* can count on nothing having been touched.
*/
-/* Flush a PA range from cache page by page. */
-static void __dma_map_pa_range(dma_addr_t dma_addr, size_t size)
+/* Set up a single page for DMA access. */
+static void __dma_prep_page(struct page *page, unsigned long offset,
+ size_t size, enum dma_data_direction direction)
{
- struct page *page = pfn_to_page(PFN_DOWN(dma_addr));
- size_t bytesleft = PAGE_SIZE - (dma_addr & (PAGE_SIZE - 1));
+ /*
+ * Flush the page from cache if necessary.
+ * On tilegx, data is delivered to hash-for-home L3; on tilepro,
+ * data is delivered direct to memory.
+ *
+ * NOTE: If we were just doing DMA_TO_DEVICE we could optimize
+ * this to be a "flush" not a "finv" and keep some of the
+ * state in cache across the DMA operation, but it doesn't seem
+ * worth creating the necessary flush_buffer_xxx() infrastructure.
+ */
+ int home = page_home(page);
+ switch (home) {
+ case PAGE_HOME_HASH:
+#ifdef __tilegx__
+ return;
+#endif
+ break;
+ case PAGE_HOME_UNCACHED:
+#ifdef __tilepro__
+ return;
+#endif
+ break;
+ case PAGE_HOME_IMMUTABLE:
+ /* Should be going to the device only. */
+ BUG_ON(direction == DMA_FROM_DEVICE ||
+ direction == DMA_BIDIRECTIONAL);
+ return;
+ case PAGE_HOME_INCOHERENT:
+ /* Incoherent anyway, so no need to work hard here. */
+ return;
+ default:
+ BUG_ON(home < 0 || home >= NR_CPUS);
+ break;
+ }
+ homecache_finv_page(page);
+
+#ifdef DEBUG_ALIGNMENT
+ /* Warn if the region isn't cacheline aligned. */
+ if (offset & (L2_CACHE_BYTES - 1) || (size & (L2_CACHE_BYTES - 1)))
+ pr_warn("Unaligned DMA to non-hfh memory: PA %#llx/%#lx\n",
+ PFN_PHYS(page_to_pfn(page)) + offset, size);
+#endif
+}
- while ((ssize_t)size > 0) {
- /* Flush the page. */
- homecache_flush_cache(page++, 0);
+/* Make the page ready to be read by the core. */
+static void __dma_complete_page(struct page *page, unsigned long offset,
+ size_t size, enum dma_data_direction direction)
+{
+#ifdef __tilegx__
+ switch (page_home(page)) {
+ case PAGE_HOME_HASH:
+ /* I/O device delivered data the way the cpu wanted it. */
+ break;
+ case PAGE_HOME_INCOHERENT:
+ /* Incoherent anyway, so no need to work hard here. */
+ break;
+ case PAGE_HOME_IMMUTABLE:
+ /* Extra read-only copies are not a problem. */
+ break;
+ default:
+ /* Flush the bogus hash-for-home I/O entries to memory. */
+ homecache_finv_map_page(page, PAGE_HOME_HASH);
+ break;
+ }
+#endif
+}
- /* Figure out if we need to continue on the next page. */
- size -= bytesleft;
- bytesleft = PAGE_SIZE;
+static void __dma_prep_pa_range(dma_addr_t dma_addr, size_t size,
+ enum dma_data_direction direction)
+{
+ struct page *page = pfn_to_page(PFN_DOWN(dma_addr));
+ unsigned long offset = dma_addr & (PAGE_SIZE - 1);
+ size_t bytes = min(size, (size_t)(PAGE_SIZE - offset));
+
+ while (size != 0) {
+ __dma_prep_page(page, offset, bytes, direction);
+ size -= bytes;
+ ++page;
+ offset = 0;
+ bytes = min((size_t)PAGE_SIZE, size);
+ }
+}
+
+static void __dma_complete_pa_range(dma_addr_t dma_addr, size_t size,
+ enum dma_data_direction direction)
+{
+ struct page *page = pfn_to_page(PFN_DOWN(dma_addr));
+ unsigned long offset = dma_addr & (PAGE_SIZE - 1);
+ size_t bytes = min(size, (size_t)(PAGE_SIZE - offset));
+
+ while (size != 0) {
+ __dma_complete_page(page, offset, bytes, direction);
+ size -= bytes;
+ ++page;
+ offset = 0;
+ bytes = min((size_t)PAGE_SIZE, size);
}
}
+
/*
* dma_map_single can be passed any memory address, and there appear
* to be no alignment constraints.
@@ -111,28 +205,29 @@ static void __dma_map_pa_range(dma_addr_t dma_addr, size_t size)
* line with some other data that has been touched in the meantime.
*/
dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
- enum dma_data_direction direction)
+ enum dma_data_direction direction)
{
dma_addr_t dma_addr = __pa(ptr);
BUG_ON(!valid_dma_direction(direction));
WARN_ON(size == 0);
- __dma_map_pa_range(dma_addr, size);
+ __dma_prep_pa_range(dma_addr, size, direction);
return dma_addr;
}
EXPORT_SYMBOL(dma_map_single);
void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
- enum dma_data_direction direction)
+ enum dma_data_direction direction)
{
BUG_ON(!valid_dma_direction(direction));
+ __dma_complete_pa_range(dma_addr, size, direction);
}
EXPORT_SYMBOL(dma_unmap_single);
int dma_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
- enum dma_data_direction direction)
+ enum dma_data_direction direction)
{
struct scatterlist *sg;
int i;
@@ -143,17 +238,25 @@ int dma_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
for_each_sg(sglist, sg, nents, i) {
sg->dma_address = sg_phys(sg);
- __dma_map_pa_range(sg->dma_address, sg->length);
+ __dma_prep_pa_range(sg->dma_address, sg->length, direction);
}
return nents;
}
EXPORT_SYMBOL(dma_map_sg);
-void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
- enum dma_data_direction direction)
+void dma_unmap_sg(struct device *dev, struct scatterlist *sglist, int nents,
+ enum dma_data_direction direction)
{
+ struct scatterlist *sg;
+ int i;
+
BUG_ON(!valid_dma_direction(direction));
+ for_each_sg(sglist, sg, nents, i) {
+ sg->dma_address = sg_phys(sg);
+ __dma_complete_pa_range(sg->dma_address, sg->length,
+ direction);
+ }
}
EXPORT_SYMBOL(dma_unmap_sg);
@@ -164,16 +267,17 @@ dma_addr_t dma_map_page(struct device *dev, struct page *page,
BUG_ON(!valid_dma_direction(direction));
BUG_ON(offset + size > PAGE_SIZE);
- homecache_flush_cache(page, 0);
-
+ __dma_prep_page(page, offset, size, direction);
return page_to_pa(page) + offset;
}
EXPORT_SYMBOL(dma_map_page);
void dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
- enum dma_data_direction direction)
+ enum dma_data_direction direction)
{
BUG_ON(!valid_dma_direction(direction));
+ __dma_complete_page(pfn_to_page(PFN_DOWN(dma_address)),
+ dma_address & PAGE_OFFSET, size, direction);
}
EXPORT_SYMBOL(dma_unmap_page);
@@ -181,33 +285,33 @@ void dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
size_t size, enum dma_data_direction direction)
{
BUG_ON(!valid_dma_direction(direction));
+ __dma_complete_pa_range(dma_handle, size, direction);
}
EXPORT_SYMBOL(dma_sync_single_for_cpu);
void dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle,
size_t size, enum dma_data_direction direction)
{
- unsigned long start = PFN_DOWN(dma_handle);
- unsigned long end = PFN_DOWN(dma_handle + size - 1);
- unsigned long i;
-
- BUG_ON(!valid_dma_direction(direction));
- for (i = start; i <= end; ++i)
- homecache_flush_cache(pfn_to_page(i), 0);
+ __dma_prep_pa_range(dma_handle, size, direction);
}
EXPORT_SYMBOL(dma_sync_single_for_device);
-void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems,
- enum dma_data_direction direction)
+void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sglist,
+ int nelems, enum dma_data_direction direction)
{
+ struct scatterlist *sg;
+ int i;
+
BUG_ON(!valid_dma_direction(direction));
- WARN_ON(nelems == 0 || sg[0].length == 0);
+ WARN_ON(nelems == 0 || sglist->length == 0);
+
+ for_each_sg(sglist, sg, nelems, i) {
+ dma_sync_single_for_cpu(dev, sg->dma_address,
+ sg_dma_len(sg), direction);
+ }
}
EXPORT_SYMBOL(dma_sync_sg_for_cpu);
-/*
- * Flush and invalidate cache for scatterlist.
- */
void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sglist,
int nelems, enum dma_data_direction direction)
{
@@ -242,8 +346,8 @@ void dma_sync_single_range_for_device(struct device *dev,
EXPORT_SYMBOL(dma_sync_single_range_for_device);
/*
- * dma_alloc_noncoherent() returns non-cacheable memory, so there's no
- * need to do any flushing here.
+ * dma_alloc_noncoherent() is #defined to return coherent memory,
+ * so there's no need to do any flushing here.
*/
void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
enum dma_data_direction direction)