Skip unnecessary operations if order == 0. A little bit easier to read.
Signed-off-by: Hiroshi Doyu hdoyu@nvidia.com --- arch/arm/mm/dma-mapping.c | 9 +++++---- 1 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 70a6275..aaea5e4 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1032,11 +1032,12 @@ static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, gfp_t if (!pages[i]) goto error;
- if (order) + if (order) { split_page(pages[i], order); - j = 1 << order; - while (--j) - pages[i + j] = pages[i] + j; + j = 1 << order; + while (--j) + pages[i + j] = pages[i] + j; + }
__dma_clear_buffer(pages[i], PAGE_SIZE << order); i += 1 << order;
Signed-off-by: Hiroshi Doyu hdoyu@nvidia.com --- arch/arm/mm/dma-mapping.c | 1 - 1 files changed, 0 insertions(+), 1 deletions(-)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index aaea5e4..8cb9542 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1557,7 +1557,6 @@ static void arm_coherent_iommu_unmap_page(struct device *dev, dma_addr_t handle, { struct dma_iommu_mapping *mapping = dev->archdata.mapping; dma_addr_t iova = handle & PAGE_MASK; - struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova)); int offset = handle & ~PAGE_MASK; int len = PAGE_ALIGN(size + offset);
With many IOMMU'able devices, console gets noisy.
Tegra30 has a few dozen of IOMMU'able devices.
Signed-off-by: Hiroshi Doyu hdoyu@nvidia.com --- arch/arm/mm/dma-mapping.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 8cb9542..2621282 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1747,7 +1747,7 @@ int arm_iommu_attach_device(struct device *dev, dev->archdata.mapping = mapping; set_dma_ops(dev, &iommu_ops);
- pr_info("Attached IOMMU controller to %s device.\n", dev_name(dev)); + pr_debug("Attached IOMMU controller to %s device.\n", dev_name(dev)); return 0; }
Skip cache maint for invalid page but warn it.
Signed-off-by: Hiroshi Doyu hdoyu@nvidia.com --- arch/arm/mm/dma-mapping.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 2621282..0368702 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1589,6 +1589,9 @@ static void arm_iommu_unmap_page(struct device *dev, dma_addr_t handle, if (!iova) return;
+ if (WARN_ON(!pfn_valid(page_to_pfn(page)))) + return; + if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) __dma_page_dev_to_cpu(page, offset, size, dir);
@@ -1607,6 +1610,9 @@ static void arm_iommu_sync_single_for_cpu(struct device *dev, if (!iova) return;
+ if (WARN_ON(!pfn_valid(page_to_pfn(page)))) + return; + __dma_page_dev_to_cpu(page, offset, size, dir); }
@@ -1621,6 +1627,9 @@ static void arm_iommu_sync_single_for_device(struct device *dev, if (!iova) return;
+ if (WARN_ON(!pfn_valid(page_to_pfn(page)))) + return; + __dma_page_cpu_to_dev(page, offset, size, dir); }
Hello,
On 8/28/2012 1:43 PM, Hiroshi Doyu wrote:
Skip cache maint for invalid page but warn it.
Signed-off-by: Hiroshi Doyu hdoyu@nvidia.com
arch/arm/mm/dma-mapping.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 2621282..0368702 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1589,6 +1589,9 @@ static void arm_iommu_unmap_page(struct device *dev, dma_addr_t handle, if (!iova) return;
- if (WARN_ON(!pfn_valid(page_to_pfn(page))))
return;- if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) __dma_page_dev_to_cpu(page, offset, size, dir);
@@ -1607,6 +1610,9 @@ static void arm_iommu_sync_single_for_cpu(struct device *dev, if (!iova) return;
- if (WARN_ON(!pfn_valid(page_to_pfn(page))))
return;- __dma_page_dev_to_cpu(page, offset, size, dir); }
@@ -1621,6 +1627,9 @@ static void arm_iommu_sync_single_for_device(struct device *dev, if (!iova) return;
- if (WARN_ON(!pfn_valid(page_to_pfn(page))))
return;- __dma_page_cpu_to_dev(page, offset, size, dir); }
I really wonder what has happened in your system that you require such paranoid checks. All of the above functions are called on the scatter-list which has been first passed to dma_map_sg(). IMHO it makes much more sense to add a pfn_valid() check in dma_map_sg() and return error if the provided scatter list is not valid instead of these WARN_ONs.
Best regards
Hi Marek,
Marek Szyprowski m.szyprowski@samsung.com wrote @ Tue, 28 Aug 2012 23:58:48 +0200:
Hello,
On 8/28/2012 1:43 PM, Hiroshi Doyu wrote:
Skip cache maint for invalid page but warn it.
Signed-off-by: Hiroshi Doyu hdoyu@nvidia.com
arch/arm/mm/dma-mapping.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 2621282..0368702 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1589,6 +1589,9 @@ static void arm_iommu_unmap_page(struct device *dev, dma_addr_t handle, if (!iova) return;
- if (WARN_ON(!pfn_valid(page_to_pfn(page))))
return;- if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) __dma_page_dev_to_cpu(page, offset, size, dir);
@@ -1607,6 +1610,9 @@ static void arm_iommu_sync_single_for_cpu(struct device *dev, if (!iova) return;
- if (WARN_ON(!pfn_valid(page_to_pfn(page))))
return;- __dma_page_dev_to_cpu(page, offset, size, dir); }
@@ -1621,6 +1627,9 @@ static void arm_iommu_sync_single_for_device(struct device *dev, if (!iova) return;
- if (WARN_ON(!pfn_valid(page_to_pfn(page))))
return;- __dma_page_cpu_to_dev(page, offset, size, dir); }
I really wonder what has happened in your system that you require such paranoid checks. All of the above functions are called on the scatter-list which has been first passed to dma_map_sg(). IMHO it makes much more sense to add a pfn_valid() check in dma_map_sg() and return error if the provided scatter list is not valid instead of these WARN_ONs.
Actually one device driver hit Oops at unmap_page() since this function could be called directly from device drivers, and WARN_ON(dump_stack) helped to find out which device driver did something wrong. IIRC, the following functions can be called directly from device drivers?
static inline void dma_unmap_page(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir); static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir); static inline void dma_sync_single_for_device(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir);
linaro-mm-sig@lists.linaro.org
-
Hiroshi Doyu -
Marek Szyprowski