[PATCH 08/13] iommu/intel-iommu: cleanup intel_{alloc,free}_coherent

Christoph Hellwig
2018-03-05T17:47:24Z

Use the dma_direct_* helpers and cleanup the code flow.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/iommu/Kconfig | 1 +
drivers/iommu/intel-iommu.c | 62 ++++++++++++---------------------------------
2 files changed, 17 insertions(+), 46 deletions(-)

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index dc7c1914645d..df171cb85822 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -143,6 +143,7 @@ config DMAR_TABLE
config INTEL_IOMMU
bool "Support for Intel IOMMU using DMA Remapping Devices"
depends on PCI_MSI && ACPI && (X86 || IA64_GENERIC)
+ select DMA_DIRECT_OPS
select IOMMU_API
select IOMMU_IOVA
select DMAR_TABLE
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index fd899b2a12bb..24d1b1b42013 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -31,6 +31,7 @@
#include <linux/pci.h>
#include <linux/dmar.h>
#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
#include <linux/mempool.h>
#include <linux/memory.h>
#include <linux/cpu.h>
@@ -3708,61 +3709,30 @@ static void *intel_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flags,
unsigned long attrs)
{
- struct page *page = NULL;
- int order;
-
- size = PAGE_ALIGN(size);
- order = get_order(size);
-
- if (!iommu_no_mapping(dev))
- flags &= ~(GFP_DMA | GFP_DMA32);
- else if (dev->coherent_dma_mask < dma_get_required_mask(dev)) {
- if (dev->coherent_dma_mask < DMA_BIT_MASK(32))
- flags |= GFP_DMA;
- else
- flags |= GFP_DMA32;
- }
+ void *vaddr;

- if (gfpflags_allow_blocking(flags)) {
- unsigned int count = size >> PAGE_SHIFT;
+ vaddr = dma_direct_alloc(dev, size, dma_handle, flags, attrs);
+ if (iommu_no_mapping(dev) || !vaddr)
+ return vaddr;

- page = dma_alloc_from_contiguous(dev, count, order, flags);
- if (page && iommu_no_mapping(dev) &&
- page_to_phys(page) + size > dev->coherent_dma_mask) {
- dma_release_from_contiguous(dev, page, count);
- page = NULL;
- }
- }
-
- if (!page)
- page = alloc_pages(flags, order);
- if (!page)
- return NULL;
- memset(page_address(page), 0, size);
-
- *dma_handle = __intel_map_single(dev, page_to_phys(page), size,
- DMA_BIDIRECTIONAL,
- dev->coherent_dma_mask);
- if (*dma_handle)
- return page_address(page);
- if (!dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT))
- __free_pages(page, order);
+ *dma_handle = __intel_map_single(dev, virt_to_phys(vaddr),
+ PAGE_ALIGN(size), DMA_BIDIRECTIONAL,
+ dev->coherent_dma_mask);
+ if (!*dma_handle)
+ goto out_free_pages;
+ return vaddr;

+out_free_pages:
+ dma_direct_free(dev, size, vaddr, *dma_handle, attrs);
return NULL;
}

static void intel_free_coherent(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle, unsigned long attrs)
{
- int order;
- struct page *page = virt_to_page(vaddr);
-
- size = PAGE_ALIGN(size);
- order = get_order(size);
-
- intel_unmap(dev, dma_handle, size);
- if (!dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT))
- __free_pages(page, order);
+ if (!iommu_no_mapping(dev))
+ intel_unmap(dev, dma_handle, PAGE_ALIGN(size));
+ dma_direct_free(dev, size, vaddr, dma_handle, attrs);
}

static void intel_unmap_sg(struct device *dev, struct scatterlist *sglist,
--
2.14.2