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vfio: powerpc/spapr: Move page pinning from arch code to VFIO IOMMU driver

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This moves page pinning (get_user_pages_fast()/put_page()) code out of
the platform IOMMU code and puts it to VFIO IOMMU driver where it belongs
to as the platform code does not deal with page pinning.

This makes iommu_take_ownership()/iommu_release_ownership() deal with
the IOMMU table bitmap only.

This removes page unpinning from iommu_take_ownership() as the actual
TCE table might contain garbage and doing put_page() on it is undefined
behaviour.

Besides the last part, the rest of the patch is mechanical.

Signed-off-by: Alexey Kardashevskiy <[email protected]>
[aw: for the vfio related changes]
Acked-by: Alex Williamson <[email protected]>
Reviewed-by: David Gibson <[email protected]>
Reviewed-by: Gavin Shan <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
This commit is contained in:
Alexey Kardashevskiy 2015-06-05 16:34:58 +10:00 • committed by Michael Ellerman
commit 9b14a1ff86
3 changed files with 67 additions and 72 deletions
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80
drivers/vfio/vfio_iommu_spapr_tce.c
View file

@ -147,6 +147,67 @@ static void tce_iommu_release(void *iommu_data)
kfree(container);
}
static int tce_iommu_clear(struct tce_container *container,
struct iommu_table *tbl,
unsigned long entry, unsigned long pages)
{
unsigned long oldtce;
struct page *page;
for ( ; pages; --pages, ++entry) {
oldtce = iommu_clear_tce(tbl, entry);
if (!oldtce)
continue;
page = pfn_to_page(oldtce >> PAGE_SHIFT);
WARN_ON(!page);
if (page) {
if (oldtce & TCE_PCI_WRITE)
SetPageDirty(page);
put_page(page);
}
}
return 0;
}
static long tce_iommu_build(struct tce_container *container,
struct iommu_table *tbl,
unsigned long entry, unsigned long tce, unsigned long pages)
{
long i, ret = 0;
struct page *page = NULL;
unsigned long hva;
enum dma_data_direction direction = iommu_tce_direction(tce);
for (i = 0; i < pages; ++i) {
unsigned long offset = tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK;
ret = get_user_pages_fast(tce & PAGE_MASK, 1,
direction != DMA_TO_DEVICE, &page);
if (unlikely(ret != 1)) {
ret = -EFAULT;
break;
}
hva = (unsigned long) page_address(page) + offset;
ret = iommu_tce_build(tbl, entry + i, hva, direction);
if (ret) {
put_page(page);
pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n",
__func__, entry << tbl->it_page_shift,
tce, ret);
break;
}
tce += IOMMU_PAGE_SIZE_4K;
}
if (ret)
tce_iommu_clear(container, tbl, entry, i);
return ret;
}
static long tce_iommu_ioctl(void *iommu_data,
unsigned int cmd, unsigned long arg)
{
@ -195,7 +256,7 @@ static long tce_iommu_ioctl(void *iommu_data,
case VFIO_IOMMU_MAP_DMA: {
struct vfio_iommu_type1_dma_map param;
struct iommu_table *tbl = container->tbl;
unsigned long tce, i;
unsigned long tce;
if (!tbl)
return -ENXIO;
@ -229,17 +290,9 @@ static long tce_iommu_ioctl(void *iommu_data,
if (ret)
return ret;
for (i = 0; i < (param.size >> IOMMU_PAGE_SHIFT_4K); ++i) {
ret = iommu_put_tce_user_mode(tbl,
(param.iova >> IOMMU_PAGE_SHIFT_4K) + i,
tce);
if (ret)
break;
tce += IOMMU_PAGE_SIZE_4K;
}
if (ret)
iommu_clear_tces_and_put_pages(tbl,
param.iova >> IOMMU_PAGE_SHIFT_4K, i);
ret = tce_iommu_build(container, tbl,
param.iova >> IOMMU_PAGE_SHIFT_4K,
tce, param.size >> IOMMU_PAGE_SHIFT_4K);
iommu_flush_tce(tbl);
@ -273,7 +326,7 @@ static long tce_iommu_ioctl(void *iommu_data,
if (ret)
return ret;
ret = iommu_clear_tces_and_put_pages(tbl,
ret = tce_iommu_clear(container, tbl,
param.iova >> IOMMU_PAGE_SHIFT_4K,
param.size >> IOMMU_PAGE_SHIFT_4K);
iommu_flush_tce(tbl);
@ -357,6 +410,7 @@ static void tce_iommu_detach_group(void *iommu_data,
/* pr_debug("tce_vfio: detaching group #%u from iommu %p\n",
iommu_group_id(iommu_group), iommu_group); */
container->tbl = NULL;
tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
iommu_release_ownership(tbl);
}
mutex_unlock(&container->lock);