[PATCH 8/9] dspbridge: add map support for big buffers

From: Fernando Guzman Lugo
Date: Wed Jun 30 2010 - 20:11:57 EST


due to a restriction in scatter gather lists, it can
not be created a list for a buffer bigger than 1MB.
This patch is spliting big mappings into 1MB mappings.

Signed-off-by: Fernando Guzman Lugo <x0095840@xxxxxx>
---
arch/arm/plat-omap/include/dspbridge/dsp-mmu.h | 2 +-
drivers/dsp/bridge/core/dsp-mmu.c | 55 ++++++++++++++---------
drivers/dsp/bridge/rmgr/proc.c | 3 +-
3 files changed, 36 insertions(+), 24 deletions(-)

diff --git a/arch/arm/plat-omap/include/dspbridge/dsp-mmu.h b/arch/arm/plat-omap/include/dspbridge/dsp-mmu.h
index 266f38b..2e4bf6a 100644
--- a/arch/arm/plat-omap/include/dspbridge/dsp-mmu.h
+++ b/arch/arm/plat-omap/include/dspbridge/dsp-mmu.h
@@ -85,6 +85,6 @@ int user_to_dsp_map(struct iommu *mmu, u32 uva, u32 da, u32 size,
* This function unmaps a user space buffer into DSP virtual address.
*
*/
-int user_to_dsp_unmap(struct iommu *mmu, u32 da);
+int user_to_dsp_unmap(struct iommu *mmu, u32 da, unsigned size);

#endif
diff --git a/drivers/dsp/bridge/core/dsp-mmu.c b/drivers/dsp/bridge/core/dsp-mmu.c
index e8da327..9a46206 100644
--- a/drivers/dsp/bridge/core/dsp-mmu.c
+++ b/drivers/dsp/bridge/core/dsp-mmu.c
@@ -133,7 +133,7 @@ int user_to_dsp_map(struct iommu *mmu, u32 uva, u32 da, u32 size,
struct page **usr_pgs)
{
int res, w;
- unsigned pages, i;
+ unsigned pages, i, j = 0;
struct vm_area_struct *vma;
struct mm_struct *mm = current->mm;
struct sg_table *sgt;
@@ -162,24 +162,31 @@ int user_to_dsp_map(struct iommu *mmu, u32 uva, u32 da, u32 size,
if (res < 0)
return res;

- sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
+ while (pages) {
+ sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);

- if (!sgt)
- return -ENOMEM;
+ if (!sgt)
+ return -ENOMEM;

- res = sg_alloc_table(sgt, pages, GFP_KERNEL);
+ res = sg_alloc_table(sgt,
+ min((unsigned)SG_MAX_SINGLE_ALLOC, pages), GFP_KERNEL);
+ pages -= min((unsigned)SG_MAX_SINGLE_ALLOC, pages);

- if (res < 0)
- goto err_sg;
+ if (res < 0)
+ goto err_sg;
+
+ for_each_sg(sgt->sgl, sg, sgt->nents, i)
+ sg_set_page(sg, usr_pgs[j++], PAGE_SIZE, 0);

- for_each_sg(sgt->sgl, sg, sgt->nents, i)
- sg_set_page(sg, usr_pgs[i], PAGE_SIZE, 0);
+ da = iommu_vmap(mmu, da, sgt, IOVMF_ENDIAN_LITTLE |
+ IOVMF_ELSZ_32);

- da = iommu_vmap(mmu, da, sgt, IOVMF_ENDIAN_LITTLE | IOVMF_ELSZ_32);
+ if (IS_ERR_VALUE(da)) {
+ res = (int)da;
+ goto err_map;
+ }

- if (IS_ERR_VALUE(da)) {
- res = (int)da;
- goto err_map;
+ da += SG_MAX_SINGLE_ALLOC * PAGE_SIZE;
}
return 0;

@@ -198,21 +205,25 @@ err_sg:
* This function unmaps a user space buffer into DSP virtual address.
*
*/
-int user_to_dsp_unmap(struct iommu *mmu, u32 da)
+int user_to_dsp_unmap(struct iommu *mmu, u32 da, unsigned size)
{
unsigned i;
struct sg_table *sgt;
struct scatterlist *sg;
+ const unsigned max_sz = SG_MAX_SINGLE_ALLOC * PAGE_SIZE;

- sgt = iommu_vunmap(mmu, da);
- if (!sgt)
- return -EFAULT;
-
- for_each_sg(sgt->sgl, sg, sgt->nents, i)
- put_page(sg_page(sg));
+ while (size) {
+ size -= min(max_sz, size);
+ sgt = iommu_vunmap(mmu, da);
+ if (!sgt)
+ return -EFAULT;

- sg_free_table(sgt);
- kfree(sgt);
+ for_each_sg(sgt->sgl, sg, sgt->nents, i)
+ put_page(sg_page(sg));

+ sg_free_table(sgt);
+ kfree(sgt);
+ da += max_sz;
+ }
return 0;
}
diff --git a/drivers/dsp/bridge/rmgr/proc.c b/drivers/dsp/bridge/rmgr/proc.c
index 4f10a41..997918e 100644
--- a/drivers/dsp/bridge/rmgr/proc.c
+++ b/drivers/dsp/bridge/rmgr/proc.c
@@ -1713,7 +1713,8 @@ int proc_un_map(void *hprocessor, void *map_addr,
/* Remove mapping from the page tables. */
if (DSP_SUCCEEDED(status)) {
status = user_to_dsp_unmap(
- p_proc_object->hbridge_context->dsp_mmu, va_align);
+ p_proc_object->hbridge_context->dsp_mmu,
+ va_align, size_align);
}

mutex_unlock(&proc_lock);
--
1.6.3.3

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