2009-03-31 00:51:52

by Jeremy Fitzhardinge

Subject: [PATCH] swiotlb: use swiotlb_alloc_boot to allocate emergency pool

Impact: bugfix

Also fix xen_swiotlb_fixup() to deal with sub-slab-sized allocations.

Signed-off-by: Jeremy Fitzhardinge <[email protected]>

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 0de836d..e8df499 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -202,7 +202,8 @@ swiotlb_init_with_default_size(size_t default_size)
/*
* Get the overflow emergency buffer
*/
- io_tlb_overflow_buffer = alloc_bootmem_low(io_tlb_overflow);
+ io_tlb_overflow_buffer = swiotlb_alloc_boot(io_tlb_overflow,
+ io_tlb_overflow >> IO_TLB_SHIFT);
if (!io_tlb_overflow_buffer)
panic("Cannot allocate SWIOTLB overflow buffer!\n");

diff --git a/drivers/pci/xen-iommu.c b/drivers/pci/xen-iommu.c
index 9ce1599..5775691 100644
--- a/drivers/pci/xen-iommu.c
+++ b/drivers/pci/xen-iommu.c
@@ -47,16 +47,22 @@ void xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs)
buf, size);

dma_bits = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT) + PAGE_SHIFT;
- for (i = 0; i < nslabs; i += IO_TLB_SEGSIZE) {
+
+ i = 0;
+ do {
+ int slabs = min(nslabs - i, (unsigned long)IO_TLB_SEGSIZE);
+
do {
rc = xen_create_contiguous_region(
(unsigned long)buf + (i << IO_TLB_SHIFT),
- get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT),
+ get_order(slabs << IO_TLB_SHIFT),
dma_bits);
} while (rc && dma_bits++ < max_dma_bits);
if (rc)
panic(KERN_ERR "xen_create_contiguous_region failed\n");
- }
+
+ i += slabs;
+ } while(i < nslabs);
}

int xen_wants_swiotlb(void)

2009-03-31 08:36:58

by FUJITA Tomonori

Subject: Re: [PATCH] swiotlb: use swiotlb_alloc_boot to allocate emergency pool

On Mon, 30 Mar 2009 17:51:34 -0700
Jeremy Fitzhardinge <[email protected]> wrote:

> Impact: bugfix
>
> Also fix xen_swiotlb_fixup() to deal with sub-slab-sized allocations.
>
> Signed-off-by: Jeremy Fitzhardinge <[email protected]>
>
> diff --git a/lib/swiotlb.c b/lib/swiotlb.c
> index 0de836d..e8df499 100644
> --- a/lib/swiotlb.c
> +++ b/lib/swiotlb.c
> @@ -202,7 +202,8 @@ swiotlb_init_with_default_size(size_t default_size)
> /*
> * Get the overflow emergency buffer
> */
> - io_tlb_overflow_buffer = alloc_bootmem_low(io_tlb_overflow);
> + io_tlb_overflow_buffer = swiotlb_alloc_boot(io_tlb_overflow,
> + io_tlb_overflow >> IO_TLB_SHIFT);
> if (!io_tlb_overflow_buffer)
> panic("Cannot allocate SWIOTLB overflow buffer!\n");
>
> diff --git a/drivers/pci/xen-iommu.c b/drivers/pci/xen-iommu.c
> index 9ce1599..5775691 100644
> --- a/drivers/pci/xen-iommu.c
> +++ b/drivers/pci/xen-iommu.c
> @@ -47,16 +47,22 @@ void xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs)
> buf, size);
>
> dma_bits = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT) + PAGE_SHIFT;
> - for (i = 0; i < nslabs; i += IO_TLB_SEGSIZE) {
> +
> + i = 0;
> + do {
> + int slabs = min(nslabs - i, (unsigned long)IO_TLB_SEGSIZE);
> +
> do {
> rc = xen_create_contiguous_region(
> (unsigned long)buf + (i << IO_TLB_SHIFT),
> - get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT),
> + get_order(slabs << IO_TLB_SHIFT),
> dma_bits);
> } while (rc && dma_bits++ < max_dma_bits);
> if (rc)
> panic(KERN_ERR "xen_create_contiguous_region failed\n");
> - }
> +
> + i += slabs;
> + } while(i < nslabs);
> }
>
> int xen_wants_swiotlb(void)

This is a patch for a tree for dom0? I have no idea what xen-iommu.c
is doing (I don't know if dom0 support will be merged into mainline or
not). But the change to lib/swiotlb.c is fine by me.

2009-03-31 14:25:06

by Jeremy Fitzhardinge

Subject: Re: [PATCH] swiotlb: use swiotlb_alloc_boot to allocate emergency pool

FUJITA Tomonori wrote:
> This is a patch for a tree for dom0? I have no idea what xen-iommu.c
> is doing (I don't know if dom0 support will be merged into mainline or
> not). But the change to lib/swiotlb.c is fine by me.
>

Yes, sorry, I was just asking about the lib/swiotlb.c change.

Thanks,
J