4.17-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Christoph Hellwig <h...@lst.de>

commit 7ec916f82c48dcfc115eee2e3e0e6d400e310fc5 upstream.

This commit may cause a less than required dma mask to be used for
some allocations, which apparently leads to module load failures for
iwlwifi sometimes.

This reverts commit d657c5c73ca987214a6f9436e435b34fc60f332a.

Signed-off-by: Christoph Hellwig <h...@lst.de>
Reported-by: Fabio Coatti <fabio.coa...@gmail.com>
Tested-by: Fabio Coatti <fabio.coa...@gmail.com>
Cc: "Jason A. Donenfeld" <ja...@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/iommu/Kconfig       |    1 
 drivers/iommu/intel-iommu.c |   64 ++++++++++++++++++++++++++++++++------------
 2 files changed, 47 insertions(+), 18 deletions(-)

--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -142,7 +142,6 @@ 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
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -31,7 +31,6 @@
 #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>
@@ -3709,30 +3708,61 @@ static void *intel_alloc_coherent(struct
                                  dma_addr_t *dma_handle, gfp_t flags,
                                  unsigned long attrs)
 {
-       void *vaddr;
+       struct page *page = NULL;
+       int order;
 
-       vaddr = dma_direct_alloc(dev, size, dma_handle, flags, attrs);
-       if (iommu_no_mapping(dev) || !vaddr)
-               return vaddr;
-
-       *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;
+       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;
+       }
+
+       if (gfpflags_allow_blocking(flags)) {
+               unsigned int count = size >> PAGE_SHIFT;
+
+               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);
 
-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)
 {
-       if (!iommu_no_mapping(dev))
-               intel_unmap(dev, dma_handle, PAGE_ALIGN(size));
-       dma_direct_free(dev, size, vaddr, dma_handle, 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);
 }
 
 static void intel_unmap_sg(struct device *dev, struct scatterlist *sglist,


Reply via email to