Revert "iommu/intel-iommu: Enable CONFIG_DMA_DIRECT_OPS=y and clean up intel_{alloc,free}_coherent()"

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 <hch@lst.de>
Reported-by: Fabio Coatti <fabio.coatti@gmail.com>
Tested-by: Fabio Coatti <fabio.coatti@gmail.com>

2 files changed, 46 insertions, 17 deletions

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index e055d228bfb9..689ffe538370 100644
--- 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 NEED_DMA_MAP_STATE
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 14e4b3722428..b344a883f116 100644
--- 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>
@@ -3713,30 +3712,61 @@ static void *intel_alloc_coherent(struct device *dev, size_t size,
                                   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;
+        size = PAGE_ALIGN(size);
+        order = get_order(size);
 
-        *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;
+        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,