* [PATCH v2] iova: Move fast alloc size roundup into alloc_iova_fast()
@ 2021-12-07 11:17 John Garry via iommu
2021-12-07 11:44 ` Robin Murphy
2021-12-17 8:11 ` Joerg Roedel
0 siblings, 2 replies; 3+ messages in thread
From: John Garry via iommu @ 2021-12-07 11:17 UTC (permalink / raw)
To: joro, will; +Cc: mst, jasowang, virtualization, xieyongji, iommu, robin.murphy
It really is a property of the IOVA rcache code that we need to alloc a
power-of-2 size, so relocate the functionality to resize into
alloc_iova_fast(), rather than the callsites.
Signed-off-by: John Garry <john.garry@huawei.com>
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Xie Yongji <xieyongji@bytedance.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
---
Differences to v1:
- Separate out from original series which conflicts with Robin's IOVA FQ work:
https://lore.kernel.org/linux-iommu/1632477717-5254-1-git-send-email-john.garry@huawei.com/
- Add tags - thanks!
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index b42e38a0dbe2..84dee53fe892 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -442,14 +442,6 @@ static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain,
shift = iova_shift(iovad);
iova_len = size >> shift;
- /*
- * Freeing non-power-of-two-sized allocations back into the IOVA caches
- * will come back to bite us badly, so we have to waste a bit of space
- * rounding up anything cacheable to make sure that can't happen. The
- * order of the unadjusted size will still match upon freeing.
- */
- if (iova_len < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1)))
- iova_len = roundup_pow_of_two(iova_len);
dma_limit = min_not_zero(dma_limit, dev->bus_dma_limit);
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 9e8bc802ac05..ff567cbc42f7 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -497,6 +497,15 @@ alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
unsigned long iova_pfn;
struct iova *new_iova;
+ /*
+ * Freeing non-power-of-two-sized allocations back into the IOVA caches
+ * will come back to bite us badly, so we have to waste a bit of space
+ * rounding up anything cacheable to make sure that can't happen. The
+ * order of the unadjusted size will still match upon freeing.
+ */
+ if (size < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1)))
+ size = roundup_pow_of_two(size);
+
iova_pfn = iova_rcache_get(iovad, size, limit_pfn + 1);
if (iova_pfn)
return iova_pfn;
diff --git a/drivers/vdpa/vdpa_user/iova_domain.c b/drivers/vdpa/vdpa_user/iova_domain.c
index 1daae2608860..2b1143f11d8f 100644
--- a/drivers/vdpa/vdpa_user/iova_domain.c
+++ b/drivers/vdpa/vdpa_user/iova_domain.c
@@ -292,14 +292,6 @@ vduse_domain_alloc_iova(struct iova_domain *iovad,
unsigned long iova_len = iova_align(iovad, size) >> shift;
unsigned long iova_pfn;
- /*
- * Freeing non-power-of-two-sized allocations back into the IOVA caches
- * will come back to bite us badly, so we have to waste a bit of space
- * rounding up anything cacheable to make sure that can't happen. The
- * order of the unadjusted size will still match upon freeing.
- */
- if (iova_len < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1)))
- iova_len = roundup_pow_of_two(iova_len);
iova_pfn = alloc_iova_fast(iovad, iova_len, limit >> shift, true);
return iova_pfn << shift;
--
2.26.2
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^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2] iova: Move fast alloc size roundup into alloc_iova_fast()
2021-12-07 11:17 [PATCH v2] iova: Move fast alloc size roundup into alloc_iova_fast() John Garry via iommu
@ 2021-12-07 11:44 ` Robin Murphy
2021-12-17 8:11 ` Joerg Roedel
1 sibling, 0 replies; 3+ messages in thread
From: Robin Murphy @ 2021-12-07 11:44 UTC (permalink / raw)
To: John Garry, joro, will; +Cc: xieyongji, jasowang, virtualization, iommu, mst
On 2021-12-07 11:17, John Garry wrote:
> It really is a property of the IOVA rcache code that we need to alloc a
> power-of-2 size, so relocate the functionality to resize into
> alloc_iova_fast(), rather than the callsites.
I'd still much prefer to resolve the issue that there shouldn't *be*
more than one caller in the first place, but hey.
Acked-by: Robin Murphy <robin.murphy@arm.com>
> Signed-off-by: John Garry <john.garry@huawei.com>
> Acked-by: Will Deacon <will@kernel.org>
> Reviewed-by: Xie Yongji <xieyongji@bytedance.com>
> Acked-by: Jason Wang <jasowang@redhat.com>
> Acked-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> Differences to v1:
> - Separate out from original series which conflicts with Robin's IOVA FQ work:
> https://lore.kernel.org/linux-iommu/1632477717-5254-1-git-send-email-john.garry@huawei.com/
> - Add tags - thanks!
>
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index b42e38a0dbe2..84dee53fe892 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -442,14 +442,6 @@ static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain,
>
> shift = iova_shift(iovad);
> iova_len = size >> shift;
> - /*
> - * Freeing non-power-of-two-sized allocations back into the IOVA caches
> - * will come back to bite us badly, so we have to waste a bit of space
> - * rounding up anything cacheable to make sure that can't happen. The
> - * order of the unadjusted size will still match upon freeing.
> - */
> - if (iova_len < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1)))
> - iova_len = roundup_pow_of_two(iova_len);
>
> dma_limit = min_not_zero(dma_limit, dev->bus_dma_limit);
>
> diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
> index 9e8bc802ac05..ff567cbc42f7 100644
> --- a/drivers/iommu/iova.c
> +++ b/drivers/iommu/iova.c
> @@ -497,6 +497,15 @@ alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
> unsigned long iova_pfn;
> struct iova *new_iova;
>
> + /*
> + * Freeing non-power-of-two-sized allocations back into the IOVA caches
> + * will come back to bite us badly, so we have to waste a bit of space
> + * rounding up anything cacheable to make sure that can't happen. The
> + * order of the unadjusted size will still match upon freeing.
> + */
> + if (size < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1)))
> + size = roundup_pow_of_two(size);
> +
> iova_pfn = iova_rcache_get(iovad, size, limit_pfn + 1);
> if (iova_pfn)
> return iova_pfn;
> diff --git a/drivers/vdpa/vdpa_user/iova_domain.c b/drivers/vdpa/vdpa_user/iova_domain.c
> index 1daae2608860..2b1143f11d8f 100644
> --- a/drivers/vdpa/vdpa_user/iova_domain.c
> +++ b/drivers/vdpa/vdpa_user/iova_domain.c
> @@ -292,14 +292,6 @@ vduse_domain_alloc_iova(struct iova_domain *iovad,
> unsigned long iova_len = iova_align(iovad, size) >> shift;
> unsigned long iova_pfn;
>
> - /*
> - * Freeing non-power-of-two-sized allocations back into the IOVA caches
> - * will come back to bite us badly, so we have to waste a bit of space
> - * rounding up anything cacheable to make sure that can't happen. The
> - * order of the unadjusted size will still match upon freeing.
> - */
> - if (iova_len < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1)))
> - iova_len = roundup_pow_of_two(iova_len);
> iova_pfn = alloc_iova_fast(iovad, iova_len, limit >> shift, true);
>
> return iova_pfn << shift;
>
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] iova: Move fast alloc size roundup into alloc_iova_fast()
2021-12-07 11:17 [PATCH v2] iova: Move fast alloc size roundup into alloc_iova_fast() John Garry via iommu
2021-12-07 11:44 ` Robin Murphy
@ 2021-12-17 8:11 ` Joerg Roedel
1 sibling, 0 replies; 3+ messages in thread
From: Joerg Roedel @ 2021-12-17 8:11 UTC (permalink / raw)
To: John Garry
Cc: mst, robin.murphy, jasowang, virtualization, xieyongji, iommu,
will
On Tue, Dec 07, 2021 at 07:17:26PM +0800, John Garry wrote:
> It really is a property of the IOVA rcache code that we need to alloc a
> power-of-2 size, so relocate the functionality to resize into
> alloc_iova_fast(), rather than the callsites.
>
> Signed-off-by: John Garry <john.garry@huawei.com>
> Acked-by: Will Deacon <will@kernel.org>
> Reviewed-by: Xie Yongji <xieyongji@bytedance.com>
> Acked-by: Jason Wang <jasowang@redhat.com>
> Acked-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> Differences to v1:
> - Separate out from original series which conflicts with Robin's IOVA FQ work:
> https://lore.kernel.org/linux-iommu/1632477717-5254-1-git-send-email-john.garry@huawei.com/
> - Add tags - thanks!
Applied, thanks.
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iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
^ permalink raw reply [flat|nested] 3+ messages in thread
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