From: Christoph Hellwig <hch@lst.de>
To: Robin Murphy <robin.murphy@arm.com>
Cc: Joerg Roedel <joro@8bytes.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
iommu@lists.linux-foundation.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 14/26] iommu/dma: Refactor iommu_dma_free
Date: Mon, 22 Apr 2019 19:59:30 +0200 [thread overview]
Message-ID: <20190422175942.18788-15-hch@lst.de> (raw)
In-Reply-To: <20190422175942.18788-1-hch@lst.de>
From: Robin Murphy <robin.murphy@arm.com>
The freeing logic was made particularly horrible by part of it being
opaque to the arch wrapper, which led to a lot of convoluted repetition
to ensure each path did everything in the right order. Now that it's
all private, we can pick apart and consolidate the logically-distinct
steps of freeing the IOMMU mapping, the underlying pages, and the CPU
remap (if necessary) into something much more manageable.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[various cosmetic changes to the code flow]
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/iommu/dma-iommu.c | 75 ++++++++++++++++++---------------------
1 file changed, 35 insertions(+), 40 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 4632b9d301a1..9658c4cc3cfe 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -916,6 +916,41 @@ static void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,
__iommu_dma_unmap(dev, handle, size);
}
+static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr,
+ dma_addr_t handle, unsigned long attrs)
+{
+ size_t alloc_size = PAGE_ALIGN(size);
+ int count = alloc_size >> PAGE_SHIFT;
+ struct page *page = NULL;
+
+ __iommu_dma_unmap(dev, handle, size);
+
+ /* Non-coherent atomic allocation? Easy */
+ if (dma_free_from_pool(cpu_addr, alloc_size))
+ return;
+
+ if (is_vmalloc_addr(cpu_addr)) {
+ /*
+ * If it the address is remapped, then it's either non-coherent
+ * or highmem CMA, or an iommu_dma_alloc_remap() construction.
+ */
+ struct page **pages = __iommu_dma_get_pages(cpu_addr);
+
+ if (pages)
+ __iommu_dma_free_pages(pages, count);
+ else
+ page = vmalloc_to_page(cpu_addr);
+
+ dma_common_free_remap(cpu_addr, alloc_size, VM_USERMAP);
+ } else {
+ /* Lowmem means a coherent atomic or CMA allocation */
+ page = virt_to_page(cpu_addr);
+ }
+
+ if (page && !dma_release_from_contiguous(dev, page, count))
+ __free_pages(page, get_order(alloc_size));
+}
+
static void *iommu_dma_alloc(struct device *dev, size_t size,
dma_addr_t *handle, gfp_t gfp, unsigned long attrs)
{
@@ -985,46 +1020,6 @@ static void *iommu_dma_alloc(struct device *dev, size_t size,
return addr;
}
-static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr,
- dma_addr_t handle, unsigned long attrs)
-{
- size_t iosize = size;
-
- size = PAGE_ALIGN(size);
- /*
- * @cpu_addr will be one of 4 things depending on how it was allocated:
- * - A remapped array of pages for contiguous allocations.
- * - A remapped array of pages from iommu_dma_alloc_remap(), for all
- * non-atomic allocations.
- * - A non-cacheable alias from the atomic pool, for atomic
- * allocations by non-coherent devices.
- * - A normal lowmem address, for atomic allocations by
- * coherent devices.
- * Hence how dodgy the below logic looks...
- */
- if (dma_in_atomic_pool(cpu_addr, size)) {
- __iommu_dma_unmap(dev, handle, iosize);
- dma_free_from_pool(cpu_addr, size);
- } else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
- struct page *page = vmalloc_to_page(cpu_addr);
-
- __iommu_dma_unmap(dev, handle, iosize);
- dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
- dma_common_free_remap(cpu_addr, size, VM_USERMAP);
- } else if (is_vmalloc_addr(cpu_addr)){
- struct page **pages = __iommu_dma_get_pages(cpu_addr);
-
- if (WARN_ON(!pages))
- return;
- __iommu_dma_unmap(dev, handle, iosize);
- __iommu_dma_free_pages(pages, size >> PAGE_SHIFT);
- dma_common_free_remap(cpu_addr, size, VM_USERMAP);
- } else {
- __iommu_dma_unmap(dev, handle, iosize);
- __free_pages(virt_to_page(cpu_addr), get_order(size));
- }
-}
-
static int __iommu_dma_mmap_pfn(struct vm_area_struct *vma,
unsigned long pfn, size_t size)
{
--
2.20.1
next prev parent reply other threads:[~2019-04-22 18:00 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-22 17:59 implement generic dma_map_ops for IOMMUs v3 Christoph Hellwig
2019-04-22 17:59 ` [PATCH 01/26] arm64/iommu: handle non-remapped addresses in ->mmap and ->get_sgtable Christoph Hellwig
2019-04-22 17:59 ` [PATCH 02/26] arm64/iommu: improve mmap bounds checking Christoph Hellwig
2019-04-29 12:35 ` Robin Murphy
2019-04-29 19:01 ` Christoph Hellwig
2019-04-30 11:38 ` Robin Murphy
2019-04-22 17:59 ` [PATCH 03/26] dma-mapping: add a Kconfig symbol to indicated arch_dma_prep_coherent presence Christoph Hellwig
2019-04-22 17:59 ` [PATCH 04/26] iommu/dma: Cleanup dma-iommu.h Christoph Hellwig
2019-04-22 17:59 ` [PATCH 05/26] iommu/dma: Remove the flush_page callback Christoph Hellwig
2019-04-22 17:59 ` [PATCH 06/26] iommu/dma: Use for_each_sg in iommu_dma_alloc Christoph Hellwig
2019-04-22 17:59 ` [PATCH 07/26] iommu/dma: move the arm64 wrappers to common code Christoph Hellwig
2019-04-29 12:56 ` Robin Murphy
2019-06-03 19:47 ` Jon Hunter
2019-06-04 6:05 ` Christoph Hellwig
2019-06-04 11:35 ` Jon Hunter
2019-04-22 17:59 ` [PATCH 08/26] iommu/dma: Move __iommu_dma_map Christoph Hellwig
2019-04-22 17:59 ` [PATCH 09/26] iommu/dma: Move domain lookup into __iommu_dma_{map,unmap} Christoph Hellwig
2019-04-22 17:59 ` [PATCH 10/26] iommu/dma: Squash __iommu_dma_{map,unmap}_page helpers Christoph Hellwig
2019-04-22 17:59 ` [PATCH 11/26] iommu/dma: Factor out remapped pages lookup Christoph Hellwig
2019-04-29 13:05 ` Robin Murphy
2019-04-29 19:10 ` Christoph Hellwig
2019-04-22 17:59 ` [PATCH 12/26] iommu/dma: Refactor the page array remapping allocator Christoph Hellwig
2019-04-29 13:10 ` Robin Murphy
2019-04-22 17:59 ` [PATCH 13/26] iommu/dma: Remove __iommu_dma_free Christoph Hellwig
2019-04-29 13:18 ` Robin Murphy
2019-04-22 17:59 ` Christoph Hellwig [this message]
2019-04-29 13:59 ` [PATCH 14/26] iommu/dma: Refactor iommu_dma_free Robin Murphy
2019-04-29 19:03 ` Christoph Hellwig
2019-04-29 19:16 ` Christoph Hellwig
2019-04-22 17:59 ` [PATCH 15/26] iommu/dma: Refactor iommu_dma_alloc Christoph Hellwig
2019-04-22 17:59 ` [PATCH 16/26] iommu/dma: Don't remap CMA unnecessarily Christoph Hellwig
2019-04-22 17:59 ` [PATCH 17/26] iommu/dma: Merge the CMA and alloc_pages allocation paths Christoph Hellwig
2019-04-22 17:59 ` [PATCH 18/26] iommu/dma: Split iommu_dma_free Christoph Hellwig
2019-04-22 17:59 ` [PATCH 19/26] iommu/dma: Cleanup variable naming in iommu_dma_alloc Christoph Hellwig
2019-04-29 14:11 ` Robin Murphy
2019-04-22 17:59 ` [PATCH 20/26] iommu/dma: Refactor iommu_dma_alloc, part 2 Christoph Hellwig
2019-04-29 14:45 ` Robin Murphy
2019-04-22 17:59 ` [PATCH 21/26] iommu/dma: Refactor iommu_dma_get_sgtable Christoph Hellwig
2019-04-29 14:08 ` Robin Murphy
2019-04-22 17:59 ` [PATCH 22/26] iommu/dma: Refactor iommu_dma_mmap Christoph Hellwig
2019-04-29 14:04 ` Robin Murphy
2019-04-22 17:59 ` [PATCH 23/26] iommu/dma: Don't depend on CONFIG_DMA_DIRECT_REMAP Christoph Hellwig
2019-04-29 14:46 ` Robin Murphy
2019-04-22 17:59 ` [PATCH 24/26] iommu/dma: Switch copyright boilerplace to SPDX Christoph Hellwig
2019-04-22 17:59 ` [PATCH 25/26] arm64: switch copyright boilerplace to SPDX in dma-mapping.c Christoph Hellwig
2019-04-22 17:59 ` [PATCH 26/26] arm64: trim includes " Christoph Hellwig
2019-04-29 15:00 ` Robin Murphy
2019-04-29 15:03 ` implement generic dma_map_ops for IOMMUs v3 Robin Murphy
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