lkml.org 
[lkml]   [2019]   [Jan]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 03/19] dma-iommu: don't use a scatterlist in iommu_dma_alloc
Date
Directly iterating over the pages makes the code a bit simpler and
prepares for the following changes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/iommu/dma-iommu.c | 40 +++++++++++++++++----------------------
1 file changed, 17 insertions(+), 23 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index d19f3d6b43c1..4f5546a103d8 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -30,6 +30,7 @@
#include <linux/mm.h>
#include <linux/pci.h>
#include <linux/scatterlist.h>
+#include <linux/highmem.h>
#include <linux/vmalloc.h>

struct iommu_dma_msi_page {
@@ -549,9 +550,9 @@ struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp,
struct iommu_dma_cookie *cookie = domain->iova_cookie;
struct iova_domain *iovad = &cookie->iovad;
struct page **pages;
- struct sg_table sgt;
dma_addr_t iova;
- unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap;
+ unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap, i;
+ size_t mapped = 0;

*handle = DMA_MAPPING_ERROR;

@@ -576,32 +577,25 @@ struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp,
if (!iova)
goto out_free_pages;

- if (sg_alloc_table_from_pages(&sgt, pages, count, 0, size, GFP_KERNEL))
- goto out_free_iova;
+ for (i = 0; i < count; i++) {
+ phys_addr_t phys = page_to_phys(pages[i]);

- if (!(prot & IOMMU_CACHE)) {
- struct sg_mapping_iter miter;
- /*
- * The CPU-centric flushing implied by SG_MITER_TO_SG isn't
- * sufficient here, so skip it by using the "wrong" direction.
- */
- sg_miter_start(&miter, sgt.sgl, sgt.orig_nents, SG_MITER_FROM_SG);
- while (sg_miter_next(&miter))
- flush_page(dev, miter.addr, page_to_phys(miter.page));
- sg_miter_stop(&miter);
- }
+ if (!(prot & IOMMU_CACHE)) {
+ void *vaddr = kmap_atomic(pages[i]);

- if (iommu_map_sg(domain, iova, sgt.sgl, sgt.orig_nents, prot)
- < size)
- goto out_free_sg;
+ flush_page(dev, vaddr, phys);
+ kunmap_atomic(vaddr);
+ }
+
+ if (iommu_map(domain, iova + mapped, phys, PAGE_SIZE, prot))
+ goto out_unmap;
+ mapped += PAGE_SIZE;
+ }

*handle = iova;
- sg_free_table(&sgt);
return pages;
-
-out_free_sg:
- sg_free_table(&sgt);
-out_free_iova:
+out_unmap:
+ iommu_unmap(domain, iova, mapped);
iommu_dma_free_iova(cookie, iova, size);
out_free_pages:
__iommu_dma_free_pages(pages, count);
--
2.20.1
\
 
 \ /
  Last update: 2019-01-14 10:44    [W:0.219 / U:2.128 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site