[PATCH -mm 07/11] sparc64: make iommu respect the segment size limits

FUJITA Tomonori
2007-10-24T10:49:09Z

This patch makes iommu respect segment size limits when merging sg
lists.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
---
arch/sparc64/kernel/iommu.c | 2 +-
arch/sparc64/kernel/iommu_common.c | 8 ++++++--
arch/sparc64/kernel/iommu_common.h | 3 ++-
arch/sparc64/kernel/pci_sun4v.c | 2 +-
4 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/arch/sparc64/kernel/iommu.c b/arch/sparc64/kernel/iommu.c
index 070a484..4b9115a 100644
--- a/arch/sparc64/kernel/iommu.c
+++ b/arch/sparc64/kernel/iommu.c
@@ -580,7 +580,7 @@ static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,

/* Step 1: Prepare scatter list. */

- npages = prepare_sg(sglist, nelems);
+ npages = prepare_sg(dev, sglist, nelems);

/* Step 2: Allocate a cluster and context, if necessary. */

diff --git a/arch/sparc64/kernel/iommu_common.c b/arch/sparc64/kernel/iommu_common.c
index b70324e..62c3218 100644
--- a/arch/sparc64/kernel/iommu_common.c
+++ b/arch/sparc64/kernel/iommu_common.c
@@ -4,6 +4,7 @@
* Copyright (C) 1999 David S. Miller (davem@redhat.com)
*/

+#include <linux/dma-mapping.h>
#include "iommu_common.h"

/* You are _strongly_ advised to enable the following debugging code
@@ -201,21 +202,24 @@ void verify_sglist(struct scatterlist *sglist, int nents, iopte_t *iopte, int np
}
#endif

-unsigned long prepare_sg(struct scatterlist *sg, int nents)
+unsigned long prepare_sg(struct device *dev, struct scatterlist *sg, int nents)
{
struct scatterlist *dma_sg = sg;
unsigned long prev;
u32 dent_addr, dent_len;
+ unsigned int max_seg_size;

prev = (unsigned long) sg_virt(sg);
prev += (unsigned long) (dent_len = sg->length);
dent_addr = (u32) ((unsigned long)(sg_virt(sg)) & (IO_PAGE_SIZE - 1UL));
+ max_seg_size = dma_get_max_seg_size(dev);
while (--nents) {
unsigned long addr;

sg = sg_next(sg);
addr = (unsigned long) sg_virt(sg);
- if (! VCONTIG(prev, addr)) {
+ if (! VCONTIG(prev, addr) ||
+ dent_len + sg->length > max_seg_size) {
dma_sg->dma_address = dent_addr;
dma_sg->dma_length = dent_len;
dma_sg = sg_next(dma_sg);
diff --git a/arch/sparc64/kernel/iommu_common.h b/arch/sparc64/kernel/iommu_common.h
index 75b5a58..a90d046 100644
--- a/arch/sparc64/kernel/iommu_common.h
+++ b/arch/sparc64/kernel/iommu_common.h
@@ -9,6 +9,7 @@
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/scatterlist.h>
+#include <linux/device.h>

#include <asm/iommu.h>
#include <asm/scatterlist.h>
@@ -46,4 +47,4 @@ extern void verify_sglist(struct scatterlist *sg, int nents, iopte_t *iopte, int
#define VCONTIG(__X, __Y) (((__X) == (__Y)) || \
(((__X) | (__Y)) << (64UL - PAGE_SHIFT)) == 0UL)

-extern unsigned long prepare_sg(struct scatterlist *sg, int nents);
+extern unsigned long prepare_sg(struct device *dev, struct scatterlist *sg, int nents);
diff --git a/arch/sparc64/kernel/pci_sun4v.c b/arch/sparc64/kernel/pci_sun4v.c
index 8c4875b..cc03021 100644
--- a/arch/sparc64/kernel/pci_sun4v.c
+++ b/arch/sparc64/kernel/pci_sun4v.c
@@ -490,7 +490,7 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist,
goto bad;

/* Step 1: Prepare scatter list. */
- npages = prepare_sg(sglist, nelems);
+ npages = prepare_sg(dev, sglist, nelems);

/* Step 2: Allocate a cluster and context, if necessary. */
spin_lock_irqsave(&iommu->lock, flags);
--
1.5.2.4