Re: [PATCH v2]Resend:videobuf_dma_sg: a new implementation for mmap

2010-08-02 Thread Figo.zhang 
On Fri, 2010-07-30 at 19:39 +0800, Figo.zhang wrote:
 On Fri, 2010-07-30 at 11:31 +0200, Laurent Pinchart wrote:
  Hi,
  
  On Friday 30 July 2010 02:08:02 Figo.zhang wrote:
   a mmap issue for videobuf-dma-sg: it will alloc a new page for mmaping 
   when
   it encounter page fault at video_vm_ops-fault(). pls see
   http://www.spinics.net/lists/linux-media/msg21243.html
   
   a new implementation for mmap, it translate to vmalloc to page at
   video_vm_ops-fault().
   
   in v2, if mem-dma.vmalloc is NULL at video_vm_ops-fault(), it will alloc
   memory by vmlloc_32().
  
  You're replacing allocation in videobuf_vm_fault by allocationg in 
  videobuf_vm_fault. I don't see the point. videobuf_vm_fault needs to go 
  away 
  completely.
 in now videobuf code, the mmap alloc a new buf, the capture dma buffer
 using vmalloc() alloc buffer, how is
 relationship with them? in usrspace , the mmap region will not the
 actual capture dma data, how is work? 


hmm, I understand with some mistake before.for mmap in videobuf-sg, it
is not call vmalloc_32() to alloc memory, it call
videobuf_dma_init_user_locked()-get_user_pages(), and the end, it will
handle_mm_fault()- vm_ops-fault(). Because in mmap(), it have assigned
vaule for baddr variable.

it is too obscure for videobuf-sg, hope for videbuf2. ~~


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Re: [PATCH v2]Resend:videobuf_dma_sg: a new implementation for mmap

2010-07-30 Thread Laurent Pinchart 
Hi,

On Friday 30 July 2010 02:08:02 Figo.zhang wrote:
 a mmap issue for videobuf-dma-sg: it will alloc a new page for mmaping when
 it encounter page fault at video_vm_ops-fault(). pls see
 http://www.spinics.net/lists/linux-media/msg21243.html
 
 a new implementation for mmap, it translate to vmalloc to page at
 video_vm_ops-fault().
 
 in v2, if mem-dma.vmalloc is NULL at video_vm_ops-fault(), it will alloc
 memory by vmlloc_32().

You're replacing allocation in videobuf_vm_fault by allocationg in 
videobuf_vm_fault. I don't see the point. videobuf_vm_fault needs to go away 
completely.

This has been discussed previously: fixing videobuf is not really possible. A 
videobuf2 implementation is needed and is (slowly) being worked on. I wouldn't 
bother with this patch, just drop it.

 Signed-off-by: Figo.zhang figo1...@gmail.com
 ---
 drivers/media/video/videobuf-dma-sg.c |   50
 +++-- 1 files changed, 41 insertions(+), 9
 deletions(-)
 
 diff --git a/drivers/media/video/videobuf-dma-sg.c
 b/drivers/media/video/videobuf-dma-sg.c index 8359e6b..f7295da 100644
 --- a/drivers/media/video/videobuf-dma-sg.c
 +++ b/drivers/media/video/videobuf-dma-sg.c
 @@ -201,10 +201,11 @@ int videobuf_dma_init_kernel(struct videobuf_dmabuf
 *dma, int direction, dprintk(1, init kernel [%d pages]\n, nr_pages);
 
   dma-direction = direction;
 - dma-vmalloc = vmalloc_32(nr_pages  PAGE_SHIFT);
 - if (NULL == dma-vmalloc) {
 - dprintk(1, vmalloc_32(%d pages) failed\n, nr_pages);
 - return -ENOMEM;
 + if (!dma-vmalloc)
 + dma-vmalloc = vmalloc_32(nr_pages  PAGE_SHIFT);
 + if (NULL == dma-vmalloc) {
 + dprintk(1, vmalloc_32(%d pages) failed\n, nr_pages);
 + return -ENOMEM;
   }
 
   dprintk(1, vmalloc is at addr 0x%08lx, size=%d\n,
 @@ -397,16 +398,47 @@ static void videobuf_vm_close(struct vm_area_struct
 *vma) */
  static int videobuf_vm_fault(struct vm_area_struct *vma, struct vm_fault
 *vmf) {
 - struct page *page;
 + struct page *page = NULL;
 + struct videobuf_mapping *map = vma-vm_private_data;
 + struct videobuf_queue *q = map-q;
 + struct videobuf_dma_sg_memory *mem = NULL;
 +
 + unsigned long offset;
 + unsigned long page_nr;
 + int first;
 
   dprintk(3, fault: fault @ %08lx [vma %08lx-%08lx]\n,
   (unsigned long)vmf-virtual_address,
   vma-vm_start, vma-vm_end);
 
 - page = alloc_page(GFP_USER | __GFP_DMA32);
 - if (!page)
 - return VM_FAULT_OOM;
 - clear_user_highpage(page, (unsigned long)vmf-virtual_address);
 + mutex_lock(q-vb_lock);
 + offset = (unsigned long)vmf-virtual_address - vma-vm_start;
 + page_nr = offset  PAGE_SHIFT;
 +
 + for (first = 0; first  VIDEO_MAX_FRAME; first++) {
 + if (NULL == q-bufs[first])
 + continue;
 +
 + MAGIC_CHECK(mem-magic, MAGIC_SG_MEM);
 +
 + if (q-bufs[first]-map == map)
 + break;
 + }
 +
 + mem = q-bufs[first]-priv;
 + if (!mem)
 + return VM_FAULT_SIGBUS;
 + if (!mem-dma.vmalloc) {
 + mem-dma.vmalloc = vmalloc_32(PAGE_ALIGN(q-bufs[first]-size));
 + if (NULL == mem-dma.vmalloc) {
 + dprintk(1, %s: vmalloc_32() failed\n, __func__);
 + return VM_FAULT_OOM;
 + }
 + } else
 + page = vmalloc_to_page(mem-dma.vmalloc+
 + (offset  (~PAGE_MASK)));
 + mutex_unlock(q-vb_lock);
 +
   vmf-page = page;
 
   return 0;

-- 
Regards,

Laurent Pinchart
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Re: [PATCH v2]Resend:videobuf_dma_sg: a new implementation for mmap

2010-07-30 Thread Figo.zhang 
On Fri, 2010-07-30 at 11:31 +0200, Laurent Pinchart wrote:
 Hi,
 
 On Friday 30 July 2010 02:08:02 Figo.zhang wrote:
  a mmap issue for videobuf-dma-sg: it will alloc a new page for mmaping when
  it encounter page fault at video_vm_ops-fault(). pls see
  http://www.spinics.net/lists/linux-media/msg21243.html
  
  a new implementation for mmap, it translate to vmalloc to page at
  video_vm_ops-fault().
  
  in v2, if mem-dma.vmalloc is NULL at video_vm_ops-fault(), it will alloc
  memory by vmlloc_32().
 
 You're replacing allocation in videobuf_vm_fault by allocationg in 
 videobuf_vm_fault. I don't see the point. videobuf_vm_fault needs to go away 
 completely.
in now videobuf code, the mmap alloc a new buf, the capture dma buffer
using vmalloc() alloc buffer, how is
relationship with them? in usrspace , the mmap region will not the
actual capture dma data, how is work? 

 
 This has been discussed previously: fixing videobuf is not really possible. A 
 videobuf2 implementation is needed and is (slowly) being worked on. 
hi Mauro, do you think this is a issue for videobuf-dma-sg?

 I wouldn't 
 bother with this patch, just drop it.
 
  Signed-off-by: Figo.zhang figo1...@gmail.com
  ---
  drivers/media/video/videobuf-dma-sg.c |   50
  +++-- 1 files changed, 41 insertions(+), 9
  deletions(-)
  
  diff --git a/drivers/media/video/videobuf-dma-sg.c
  b/drivers/media/video/videobuf-dma-sg.c index 8359e6b..f7295da 100644
  --- a/drivers/media/video/videobuf-dma-sg.c
  +++ b/drivers/media/video/videobuf-dma-sg.c
  @@ -201,10 +201,11 @@ int videobuf_dma_init_kernel(struct videobuf_dmabuf
  *dma, int direction, dprintk(1, init kernel [%d pages]\n, nr_pages);
  
  dma-direction = direction;
  -   dma-vmalloc = vmalloc_32(nr_pages  PAGE_SHIFT);
  -   if (NULL == dma-vmalloc) {
  -   dprintk(1, vmalloc_32(%d pages) failed\n, nr_pages);
  -   return -ENOMEM;
  +   if (!dma-vmalloc)
  +   dma-vmalloc = vmalloc_32(nr_pages  PAGE_SHIFT);
  +   if (NULL == dma-vmalloc) {
  +   dprintk(1, vmalloc_32(%d pages) failed\n, nr_pages);
  +   return -ENOMEM;
  }
  
  dprintk(1, vmalloc is at addr 0x%08lx, size=%d\n,
  @@ -397,16 +398,47 @@ static void videobuf_vm_close(struct vm_area_struct
  *vma) */
   static int videobuf_vm_fault(struct vm_area_struct *vma, struct vm_fault
  *vmf) {
  -   struct page *page;
  +   struct page *page = NULL;
  +   struct videobuf_mapping *map = vma-vm_private_data;
  +   struct videobuf_queue *q = map-q;
  +   struct videobuf_dma_sg_memory *mem = NULL;
  +
  +   unsigned long offset;
  +   unsigned long page_nr;
  +   int first;
  
  dprintk(3, fault: fault @ %08lx [vma %08lx-%08lx]\n,
  (unsigned long)vmf-virtual_address,
  vma-vm_start, vma-vm_end);
  
  -   page = alloc_page(GFP_USER | __GFP_DMA32);
  -   if (!page)
  -   return VM_FAULT_OOM;
  -   clear_user_highpage(page, (unsigned long)vmf-virtual_address);
  +   mutex_lock(q-vb_lock);
  +   offset = (unsigned long)vmf-virtual_address - vma-vm_start;
  +   page_nr = offset  PAGE_SHIFT;
  +
  +   for (first = 0; first  VIDEO_MAX_FRAME; first++) {
  +   if (NULL == q-bufs[first])
  +   continue;
  +
  +   MAGIC_CHECK(mem-magic, MAGIC_SG_MEM);
  +
  +   if (q-bufs[first]-map == map)
  +   break;
  +   }
  +
  +   mem = q-bufs[first]-priv;
  +   if (!mem)
  +   return VM_FAULT_SIGBUS;
  +   if (!mem-dma.vmalloc) {
  +   mem-dma.vmalloc = vmalloc_32(PAGE_ALIGN(q-bufs[first]-size));
  +   if (NULL == mem-dma.vmalloc) {
  +   dprintk(1, %s: vmalloc_32() failed\n, __func__);
  +   return VM_FAULT_OOM;
  +   }
  +   } else
  +   page = vmalloc_to_page(mem-dma.vmalloc+
  +   (offset  (~PAGE_MASK)));
  +   mutex_unlock(q-vb_lock);
  +
  vmf-page = page;
  
  return 0;
 


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Re: [PATCH v2]Resend:videobuf_dma_sg: a new implementation for mmap

2010-07-30 Thread Figo.zhang 
On Fri, 2010-07-30 at 11:31 +0200, Laurent Pinchart wrote:
 Hi,
 
 On Friday 30 July 2010 02:08:02 Figo.zhang wrote:
  a mmap issue for videobuf-dma-sg: it will alloc a new page for mmaping when
  it encounter page fault at video_vm_ops-fault(). pls see
  http://www.spinics.net/lists/linux-media/msg21243.html
  
  a new implementation for mmap, it translate to vmalloc to page at
  video_vm_ops-fault().
  
  in v2, if mem-dma.vmalloc is NULL at video_vm_ops-fault(), it will alloc
  memory by vmlloc_32().
 
 You're replacing allocation in videobuf_vm_fault by allocationg in 
 videobuf_vm_fault. I don't see the point. videobuf_vm_fault needs to go away 
 completely.
in now videobuf code, the mmap alloc a new buf, the capture dma buffer
using vmalloc() alloc buffer, how is
relationship with them? in usrspace , the mmap region will not the
actual capture dma data, how is work? 

 
 This has been discussed previously: fixing videobuf is not really possible. A 
 videobuf2 implementation is needed and is (slowly) being worked on. 
hi Mauro, do you think this is a issue for videobuf-dma-sg?

 I wouldn't 
 bother with this patch, just drop it.
 
  Signed-off-by: Figo.zhang figo1...@gmail.com
  ---
  drivers/media/video/videobuf-dma-sg.c |   50
  +++-- 1 files changed, 41 insertions(+), 9
  deletions(-)
  
  diff --git a/drivers/media/video/videobuf-dma-sg.c
  b/drivers/media/video/videobuf-dma-sg.c index 8359e6b..f7295da 100644
  --- a/drivers/media/video/videobuf-dma-sg.c
  +++ b/drivers/media/video/videobuf-dma-sg.c
  @@ -201,10 +201,11 @@ int videobuf_dma_init_kernel(struct videobuf_dmabuf
  *dma, int direction, dprintk(1, init kernel [%d pages]\n, nr_pages);
  
  dma-direction = direction;
  -   dma-vmalloc = vmalloc_32(nr_pages  PAGE_SHIFT);
  -   if (NULL == dma-vmalloc) {
  -   dprintk(1, vmalloc_32(%d pages) failed\n, nr_pages);
  -   return -ENOMEM;
  +   if (!dma-vmalloc)
  +   dma-vmalloc = vmalloc_32(nr_pages  PAGE_SHIFT);
  +   if (NULL == dma-vmalloc) {
  +   dprintk(1, vmalloc_32(%d pages) failed\n, nr_pages);
  +   return -ENOMEM;
  }
  
  dprintk(1, vmalloc is at addr 0x%08lx, size=%d\n,
  @@ -397,16 +398,47 @@ static void videobuf_vm_close(struct vm_area_struct
  *vma) */
   static int videobuf_vm_fault(struct vm_area_struct *vma, struct vm_fault
  *vmf) {
  -   struct page *page;
  +   struct page *page = NULL;
  +   struct videobuf_mapping *map = vma-vm_private_data;
  +   struct videobuf_queue *q = map-q;
  +   struct videobuf_dma_sg_memory *mem = NULL;
  +
  +   unsigned long offset;
  +   unsigned long page_nr;
  +   int first;
  
  dprintk(3, fault: fault @ %08lx [vma %08lx-%08lx]\n,
  (unsigned long)vmf-virtual_address,
  vma-vm_start, vma-vm_end);
  
  -   page = alloc_page(GFP_USER | __GFP_DMA32);
  -   if (!page)
  -   return VM_FAULT_OOM;
  -   clear_user_highpage(page, (unsigned long)vmf-virtual_address);
  +   mutex_lock(q-vb_lock);
  +   offset = (unsigned long)vmf-virtual_address - vma-vm_start;
  +   page_nr = offset  PAGE_SHIFT;
  +
  +   for (first = 0; first  VIDEO_MAX_FRAME; first++) {
  +   if (NULL == q-bufs[first])
  +   continue;
  +
  +   MAGIC_CHECK(mem-magic, MAGIC_SG_MEM);
  +
  +   if (q-bufs[first]-map == map)
  +   break;
  +   }
  +
  +   mem = q-bufs[first]-priv;
  +   if (!mem)
  +   return VM_FAULT_SIGBUS;
  +   if (!mem-dma.vmalloc) {
  +   mem-dma.vmalloc = vmalloc_32(PAGE_ALIGN(q-bufs[first]-size));
  +   if (NULL == mem-dma.vmalloc) {
  +   dprintk(1, %s: vmalloc_32() failed\n, __func__);
  +   return VM_FAULT_OOM;
  +   }
  +   } else
  +   page = vmalloc_to_page(mem-dma.vmalloc+
  +   (offset  (~PAGE_MASK)));
  +   mutex_unlock(q-vb_lock);
  +
  vmf-page = page;
  
  return 0;
 



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[PATCH v2]Resend:videobuf_dma_sg: a new implementation for mmap

2010-07-29 Thread Figo.zhang 
a mmap issue for videobuf-dma-sg: it will alloc a new page for mmaping when it 
encounter
page fault at video_vm_ops-fault(). pls see 
http://www.spinics.net/lists/linux-media/msg21243.html

a new implementation for mmap, it translate to vmalloc to page at 
video_vm_ops-fault().

in v2, if mem-dma.vmalloc is NULL at video_vm_ops-fault(), it will alloc 
memory by 
vmlloc_32().

Signed-off-by: Figo.zhang figo1...@gmail.com
---
drivers/media/video/videobuf-dma-sg.c |   50 +++--
 1 files changed, 41 insertions(+), 9 deletions(-)

diff --git a/drivers/media/video/videobuf-dma-sg.c 
b/drivers/media/video/videobuf-dma-sg.c
index 8359e6b..f7295da 100644
--- a/drivers/media/video/videobuf-dma-sg.c
+++ b/drivers/media/video/videobuf-dma-sg.c
@@ -201,10 +201,11 @@ int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, 
int direction,
dprintk(1, init kernel [%d pages]\n, nr_pages);
 
dma-direction = direction;
-   dma-vmalloc = vmalloc_32(nr_pages  PAGE_SHIFT);
-   if (NULL == dma-vmalloc) {
-   dprintk(1, vmalloc_32(%d pages) failed\n, nr_pages);
-   return -ENOMEM;
+   if (!dma-vmalloc)
+   dma-vmalloc = vmalloc_32(nr_pages  PAGE_SHIFT);
+   if (NULL == dma-vmalloc) {
+   dprintk(1, vmalloc_32(%d pages) failed\n, nr_pages);
+   return -ENOMEM;
}
 
dprintk(1, vmalloc is at addr 0x%08lx, size=%d\n,
@@ -397,16 +398,47 @@ static void videobuf_vm_close(struct vm_area_struct *vma)
  */
 static int videobuf_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
-   struct page *page;
+   struct page *page = NULL;
+   struct videobuf_mapping *map = vma-vm_private_data;
+   struct videobuf_queue *q = map-q;
+   struct videobuf_dma_sg_memory *mem = NULL;
+
+   unsigned long offset;
+   unsigned long page_nr;
+   int first;
 
dprintk(3, fault: fault @ %08lx [vma %08lx-%08lx]\n,
(unsigned long)vmf-virtual_address,
vma-vm_start, vma-vm_end);
 
-   page = alloc_page(GFP_USER | __GFP_DMA32);
-   if (!page)
-   return VM_FAULT_OOM;
-   clear_user_highpage(page, (unsigned long)vmf-virtual_address);
+   mutex_lock(q-vb_lock);
+   offset = (unsigned long)vmf-virtual_address - vma-vm_start;
+   page_nr = offset  PAGE_SHIFT;
+
+   for (first = 0; first  VIDEO_MAX_FRAME; first++) {
+   if (NULL == q-bufs[first])
+   continue;
+
+   MAGIC_CHECK(mem-magic, MAGIC_SG_MEM);
+
+   if (q-bufs[first]-map == map)
+   break;
+   }
+
+   mem = q-bufs[first]-priv;
+   if (!mem)
+   return VM_FAULT_SIGBUS;
+   if (!mem-dma.vmalloc) {
+   mem-dma.vmalloc = vmalloc_32(PAGE_ALIGN(q-bufs[first]-size));
+   if (NULL == mem-dma.vmalloc) {
+   dprintk(1, %s: vmalloc_32() failed\n, __func__);
+   return VM_FAULT_OOM;
+   }
+   } else
+   page = vmalloc_to_page(mem-dma.vmalloc+
+   (offset  (~PAGE_MASK)));
+   mutex_unlock(q-vb_lock);
+
vmf-page = page;
 
return 0;


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