[PATCH] Make IOMMU code safe for > 132 GB of memory

[PATCH] Make IOMMU code safe for > 132 GB of memory

[Michael Ellerman]

Currently the IOMMU code allocates one page for the segment table, that
isn't safe if we have more than 132 GB of RAM.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
---
 arch/powerpc/platforms/cell/iommu.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c
index 7f45d59..eb2a94b 100644
--- a/arch/powerpc/platforms/cell/iommu.c
+++ b/arch/powerpc/platforms/cell/iommu.c
@@ -310,8 +310,8 @@ static void cell_iommu_setup_hardware(struct cbe_iommu *iommu, unsigned long siz
 {
 	struct page *page;
 	int ret, i;
-	unsigned long reg, segments, pages_per_segment, ptab_size, n_pte_pages;
-	unsigned long xlate_base;
+	unsigned long reg, segments, pages_per_segment, ptab_size, stab_size,
+		      n_pte_pages, xlate_base;
 	unsigned int virq;
 
 	if (cell_iommu_find_ioc(iommu->nid, &xlate_base))
@@ -328,7 +328,8 @@ static void cell_iommu_setup_hardware(struct cbe_iommu *iommu, unsigned long siz
 			__FUNCTION__, iommu->nid, segments, pages_per_segment);
 
 	/* set up the segment table */
-	page = alloc_pages_node(iommu->nid, GFP_KERNEL, 0);
+	stab_size = segments * sizeof(unsigned long);
+	page = alloc_pages_node(iommu->nid, GFP_KERNEL, get_order(stab_size));
 	BUG_ON(!page);
 	iommu->stab = page_address(page);
 	clear_page(iommu->stab);
-- 
1.5.2.rc1.1884.g59b20

Re: [PATCH] Make IOMMU code safe for > 132 GB of memory

[Jeremy Kerr]

> Currently the IOMMU code allocates one page for the segment table,
> that isn't safe if we have more than 132 GB of RAM.
>
> Signed-off-by: Michael Ellerman <michael@ellerman.id.au>

Acked-by: Jeremy Kerr <jk@ozlabs.org>

Can I have a Cell machine with > 132GB of RAM? :D


Jeremy

Re: [PATCH] Make IOMMU code safe for > 132 GB of memory

[Michael Ellerman]

[-- Attachment #1: Type: text/plain, Size: 709 bytes --]

On Tue, 2008-01-22 at 14:20 +1100, Jeremy Kerr wrote:
> > Currently the IOMMU code allocates one page for the segment table,
> > that isn't safe if we have more than 132 GB of RAM.
> >
> > Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
> 
> Acked-by: Jeremy Kerr <jk@ozlabs.org>
> 
> Can I have a Cell machine with > 132GB of RAM? :D

I have one under my desk, but I need it to warm my feet, otherwise I
could give it to you.

cheers

-- 
Michael Ellerman
OzLabs, IBM Australia Development Lab

wwweb: http://michael.ellerman.id.au
phone: +61 2 6212 1183 (tie line 70 21183)

We do not inherit the earth from our ancestors,
we borrow it from our children. - S.M.A.R.T Person

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 189 bytes --]