[PATCH 00/06] uio: Various minor changes

[PATCH 00/06] uio: Various minor changes

[Magnus Damm]

Hi everyone,

Here comes a few UIO changes that I've had in my queue for a while.

[PATCH 01/06] uio: Use struct_uio_mem instead of index
[PATCH 02/06] uio: Pass struct uio_mem to mmap functions
[PATCH 03/06] uio: Remove vma->vm_private_data from uio_find_mem()
[PATCH 04/06] uio: Store struct uio_mem ptr in vma->vm_private_data
[PATCH 05/06] uio: Remove redundant vma->vm_flags setup code
[PATCH 06/06] uio: Support multiple UIO_MEM_LOGICAL/VIRTUAL pages

Mostly small cleanups or performance improvements, except the last one
which contains a fix for unsupported multi-page LOGICAL/VIRTUAL maps.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
---

 Documentation/DocBook/uio-howto.tmpl |    2 
 drivers/uio/uio.c                    |   91 +++++++++++++++-------------------
 include/linux/uio_driver.h           |    1 
 3 files changed, 44 insertions(+), 50 deletions(-)

[PATCH 01/06] uio: Use struct_uio_mem instead of index

[Magnus Damm]

From: Magnus Damm <damm@igel.co.jp>

This patch teaches the UIO code to make use of struct uio_mem pointers.
The code is converted from:
   index = uio_find_mem_index()
   do_something(idev->info->mem[index].member)
to
   mem = uio_find_mem()
   do_something(mem->member)

Signed-off-by: Magnus Damm <damm@igel.co.jp>
---

 drivers/uio/uio.c |   36 ++++++++++++++++++------------------
 1 file changed, 18 insertions(+), 18 deletions(-)

--- 0001/drivers/uio/uio.c
+++ work/drivers/uio/uio.c	2008-07-18 12:39:49.000000000 +0900
@@ -427,18 +427,18 @@ static ssize_t uio_read(struct file *fil
 	return retval;
 }
 
-static int uio_find_mem_index(struct vm_area_struct *vma)
+static struct uio_mem *uio_find_mem(struct vm_area_struct *vma)
 {
 	int mi;
 	struct uio_device *idev = vma->vm_private_data;
 
 	for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
 		if (idev->info->mem[mi].size == 0)
-			return -1;
+			break;
 		if (vma->vm_pgoff == mi)
-			return mi;
+			return &idev->info->mem[mi];
 	}
-	return -1;
+	return NULL;
 }
 
 static void uio_vma_open(struct vm_area_struct *vma)
@@ -456,16 +456,16 @@ static void uio_vma_close(struct vm_area
 static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	struct uio_device *idev = vma->vm_private_data;
+	struct uio_mem *imem = uio_find_mem(vma);
 	struct page *page;
 
-	int mi = uio_find_mem_index(vma);
-	if (mi < 0)
+	if (!imem)
 		return VM_FAULT_SIGBUS;
 
-	if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
-		page = virt_to_page(idev->info->mem[mi].addr);
+	if (imem->memtype == UIO_MEM_LOGICAL)
+		page = virt_to_page(imem->addr);
 	else
-		page = vmalloc_to_page((void*)idev->info->mem[mi].addr);
+		page = vmalloc_to_page((void *)imem->addr);
 	get_page(page);
 	vmf->page = page;
 	return 0;
@@ -479,9 +479,9 @@ static struct vm_operations_struct uio_v
 
 static int uio_mmap_physical(struct vm_area_struct *vma)
 {
-	struct uio_device *idev = vma->vm_private_data;
-	int mi = uio_find_mem_index(vma);
-	if (mi < 0)
+	struct uio_mem *imem = uio_find_mem(vma);
+
+	if (!imem)
 		return -EINVAL;
 
 	vma->vm_flags |= VM_IO | VM_RESERVED;
@@ -490,7 +490,7 @@ static int uio_mmap_physical(struct vm_a
 
 	return remap_pfn_range(vma,
 			       vma->vm_start,
-			       idev->info->mem[mi].addr >> PAGE_SHIFT,
+			       imem->addr >> PAGE_SHIFT,
 			       vma->vm_end - vma->vm_start,
 			       vma->vm_page_prot);
 }
@@ -507,7 +507,7 @@ static int uio_mmap(struct file *filep, 
 {
 	struct uio_listener *listener = filep->private_data;
 	struct uio_device *idev = listener->dev;
-	int mi;
+	struct uio_mem *imem;
 	unsigned long requested_pages, actual_pages;
 	int ret = 0;
 
@@ -516,12 +516,12 @@ static int uio_mmap(struct file *filep, 
 
 	vma->vm_private_data = idev;
 
-	mi = uio_find_mem_index(vma);
-	if (mi < 0)
+	imem = uio_find_mem(vma);
+	if (!imem)
 		return -EINVAL;
 
 	requested_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
-	actual_pages = (idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
+	actual_pages = (imem->size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 	if (requested_pages > actual_pages)
 		return -EINVAL;
 
@@ -530,7 +530,7 @@ static int uio_mmap(struct file *filep, 
 		return ret;
 	}
 
-	switch (idev->info->mem[mi].memtype) {
+	switch (imem->memtype) {
 		case UIO_MEM_PHYS:
 			return uio_mmap_physical(vma);
 		case UIO_MEM_LOGICAL:

[PATCH 02/06] uio: Pass struct uio_mem to mmap functions

[Magnus Damm]

From: Magnus Damm <damm@igel.co.jp>

This patch makes the UIO code pass a struct uio_mem pointer to the
mmap functions. This change allows us to remove one uio_find_mem()
call and an error check.

The error check can be removed since the struct uio_mem pointer has
already been verified in uio_mmap().

Signed-off-by: Magnus Damm <damm@igel.co.jp>
---

 drivers/uio/uio.c |   15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

--- 0002/drivers/uio/uio.c
+++ work/drivers/uio/uio.c	2008-07-18 12:40:42.000000000 +0900
@@ -477,17 +477,10 @@ static struct vm_operations_struct uio_v
 	.fault = uio_vma_fault,
 };
 
-static int uio_mmap_physical(struct vm_area_struct *vma)
+static int uio_mmap_physical(struct vm_area_struct *vma, struct uio_mem *imem)
 {
-	struct uio_mem *imem = uio_find_mem(vma);
-
-	if (!imem)
-		return -EINVAL;
-
 	vma->vm_flags |= VM_IO | VM_RESERVED;
-
 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
-
 	return remap_pfn_range(vma,
 			       vma->vm_start,
 			       imem->addr >> PAGE_SHIFT,
@@ -495,7 +488,7 @@ static int uio_mmap_physical(struct vm_a
 			       vma->vm_page_prot);
 }
 
-static int uio_mmap_logical(struct vm_area_struct *vma)
+static int uio_mmap_logical(struct vm_area_struct *vma, struct uio_mem *imem)
 {
 	vma->vm_flags |= VM_RESERVED;
 	vma->vm_ops = &uio_vm_ops;
@@ -532,10 +525,10 @@ static int uio_mmap(struct file *filep, 
 
 	switch (imem->memtype) {
 		case UIO_MEM_PHYS:
-			return uio_mmap_physical(vma);
+			return uio_mmap_physical(vma, imem);
 		case UIO_MEM_LOGICAL:
 		case UIO_MEM_VIRTUAL:
-			return uio_mmap_logical(vma);
+			return uio_mmap_logical(vma, imem);
 		default:
 			return -EINVAL;
 	}

[PATCH 03/06] uio: Remove vma->vm_private_data from uio_find_mem()

[Magnus Damm]

From: Magnus Damm <damm@igel.co.jp>

Pass along a struct uio_device pointer to uio_find_mem() so we can
remove the vma->vm_private_data usage. This allows us to store
different data in vma->vm_private_data in the future.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
---

 drivers/uio/uio.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

--- 0003/drivers/uio/uio.c
+++ work/drivers/uio/uio.c	2008-07-18 12:42:21.000000000 +0900
@@ -427,10 +427,10 @@ static ssize_t uio_read(struct file *fil
 	return retval;
 }
 
-static struct uio_mem *uio_find_mem(struct vm_area_struct *vma)
+static struct uio_mem *uio_find_mem(struct uio_device *idev,
+				    struct vm_area_struct *vma)
 {
 	int mi;
-	struct uio_device *idev = vma->vm_private_data;
 
 	for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
 		if (idev->info->mem[mi].size == 0)
@@ -456,7 +456,7 @@ static void uio_vma_close(struct vm_area
 static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	struct uio_device *idev = vma->vm_private_data;
-	struct uio_mem *imem = uio_find_mem(vma);
+	struct uio_mem *imem = uio_find_mem(idev, vma);
 	struct page *page;
 
 	if (!imem)
@@ -507,9 +507,7 @@ static int uio_mmap(struct file *filep, 
 	if (vma->vm_end < vma->vm_start)
 		return -EINVAL;
 
-	vma->vm_private_data = idev;
-
-	imem = uio_find_mem(vma);
+	imem = uio_find_mem(idev, vma);
 	if (!imem)
 		return -EINVAL;
 
@@ -523,6 +521,8 @@ static int uio_mmap(struct file *filep, 
 		return ret;
 	}
 
+	vma->vm_private_data = idev;
+
 	switch (imem->memtype) {
 		case UIO_MEM_PHYS:
 			return uio_mmap_physical(vma, imem);

[PATCH 04/06] uio: Store struct uio_mem ptr in vma->vm_private_data

[Magnus Damm]

From: Magnus Damm <damm@igel.co.jp>

Store a struct uio_mem pointer in vma->vm_private_data. This improves
performance since it allows us to remove a call to uio_find_mem()
from uio_vma_fault(). This change also moves the vma_count member from
struct uio_device to struct uio_mem.

The VM_FAULT_SIGBUS error case in uio_vma_fault() case is simply
removed since we've verified the struct uio_mem pointer earlier when
setting up the vma->vm_private_data.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
---

 drivers/uio/uio.c          |   17 ++++++-----------
 include/linux/uio_driver.h |    1 +
 2 files changed, 7 insertions(+), 11 deletions(-)

--- 0004/drivers/uio/uio.c
+++ work/drivers/uio/uio.c	2008-07-18 12:43:22.000000000 +0900
@@ -32,7 +32,6 @@ struct uio_device {
 	atomic_t		event;
 	struct fasync_struct	*async_queue;
 	wait_queue_head_t	wait;
-	int			vma_count;
 	struct uio_info		*info;
 	struct kobject		*map_dir;
 };
@@ -443,25 +442,21 @@ static struct uio_mem *uio_find_mem(stru
 
 static void uio_vma_open(struct vm_area_struct *vma)
 {
-	struct uio_device *idev = vma->vm_private_data;
-	idev->vma_count++;
+	struct uio_mem *imem = vma->vm_private_data;
+	imem->vma_count++;
 }
 
 static void uio_vma_close(struct vm_area_struct *vma)
 {
-	struct uio_device *idev = vma->vm_private_data;
-	idev->vma_count--;
+	struct uio_mem *imem = vma->vm_private_data;
+	imem->vma_count--;
 }
 
 static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
-	struct uio_device *idev = vma->vm_private_data;
-	struct uio_mem *imem = uio_find_mem(idev, vma);
+	struct uio_mem *imem = vma->vm_private_data;
 	struct page *page;
 
-	if (!imem)
-		return VM_FAULT_SIGBUS;
-
 	if (imem->memtype == UIO_MEM_LOGICAL)
 		page = virt_to_page(imem->addr);
 	else
@@ -521,7 +516,7 @@ static int uio_mmap(struct file *filep, 
 		return ret;
 	}
 
-	vma->vm_private_data = idev;
+	vma->vm_private_data = imem;
 
 	switch (imem->memtype) {
 		case UIO_MEM_PHYS:
--- 0001/include/linux/uio_driver.h
+++ work/include/linux/uio_driver.h	2008-07-18 12:43:22.000000000 +0900
@@ -34,6 +34,7 @@ struct uio_mem {
 	int			memtype;
 	void __iomem		*internal_addr;
 	struct uio_map		*map;
+	int			vma_count;
 };
 
 #define MAX_UIO_MAPS 	5

[PATCH 05/06] uio: Remove redundant vma->vm_flags setup code

[Magnus Damm]

From: Magnus Damm <damm@igel.co.jp>

Remove redundant VM_IO | VM_RESERVED setup code since remap_pfn_range()
already sets them for us.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
---

 drivers/uio/uio.c |    1 -
 1 file changed, 1 deletion(-)

--- 0005/drivers/uio/uio.c
+++ work/drivers/uio/uio.c	2008-07-18 12:44:42.000000000 +0900
@@ -474,7 +474,6 @@ static struct vm_operations_struct uio_v
 
 static int uio_mmap_physical(struct vm_area_struct *vma, struct uio_mem *imem)
 {
-	vma->vm_flags |= VM_IO | VM_RESERVED;
 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 	return remap_pfn_range(vma,
 			       vma->vm_start,

[PATCH 06/06] uio: Support multiple UIO_MEM_LOGICAL/VIRTUAL pages

[Magnus Damm]

From: Magnus Damm <damm@igel.co.jp>

This patch improves the UIO_MEM_LOGICAL and UIO_MEM_VIRTUAL page
fault code to support more than one page of data. Memory allocated
from the slab is however not supported, so a check for that is added
and the documentation gets a little update.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
---

 Documentation/DocBook/uio-howto.tmpl |    2 +-
 drivers/uio/uio.c                    |   10 ++++++++--
 2 files changed, 9 insertions(+), 3 deletions(-)

--- 0001/Documentation/DocBook/uio-howto.tmpl
+++ work/Documentation/DocBook/uio-howto.tmpl	2008-07-18 12:45:22.000000000 +0900
@@ -376,7 +376,7 @@ Here's a description of the fields of <v
 <varname>int memtype</varname>: Required if the mapping is used. Set this to
 <varname>UIO_MEM_PHYS</varname> if you you have physical memory on your
 card to be mapped. Use <varname>UIO_MEM_LOGICAL</varname> for logical
-memory (e.g. allocated with <function>kmalloc()</function>). There's also
+memory (e.g. allocated with <function>alloc_pages()</function>). There's also
 <varname>UIO_MEM_VIRTUAL</varname> for virtual memory.
 </para></listitem>
 
--- 0006/drivers/uio/uio.c
+++ work/drivers/uio/uio.c	2008-07-18 12:49:38.000000000 +0900
@@ -455,12 +455,15 @@ static void uio_vma_close(struct vm_area
 static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	struct uio_mem *imem = vma->vm_private_data;
+	unsigned long vaddr = imem->addr;
 	struct page *page;
 
+	vaddr += (vmf->pgoff - vma->vm_pgoff) << PAGE_SHIFT;
+
 	if (imem->memtype == UIO_MEM_LOGICAL)
-		page = virt_to_page(imem->addr);
+		page = virt_to_page(vaddr);
 	else
-		page = vmalloc_to_page((void *)imem->addr);
+		page = vmalloc_to_page((void *)vaddr);
 	get_page(page);
 	vmf->page = page;
 	return 0;
@@ -521,6 +524,9 @@ static int uio_mmap(struct file *filep, 
 		case UIO_MEM_PHYS:
 			return uio_mmap_physical(vma, imem);
 		case UIO_MEM_LOGICAL:
+			if (virt_to_page(imem->addr)->flags & (1 << PG_slab))
+				return -EINVAL; /* kmalloc() not supported */
+			/* fall-through */
 		case UIO_MEM_VIRTUAL:
 			return uio_mmap_logical(vma, imem);
 		default:

Re: [PATCH 00/06] uio: Various minor changes

[Hans J. Koch]

On Fri, Jul 18, 2008 at 02:04:02PM +0900, Magnus Damm wrote:
> Hi everyone,
> 
> Here comes a few UIO changes that I've had in my queue for a while.

Hi Magnus,
thanks a lot for your patches. I'll have a look at them ASAP, but it'll
take a few days. I'm busy moving to a new house ATM...

Greg, could you help reviewing these ?

Thanks,
Hans

> 
> [PATCH 01/06] uio: Use struct_uio_mem instead of index
> [PATCH 02/06] uio: Pass struct uio_mem to mmap functions
> [PATCH 03/06] uio: Remove vma->vm_private_data from uio_find_mem()
> [PATCH 04/06] uio: Store struct uio_mem ptr in vma->vm_private_data
> [PATCH 05/06] uio: Remove redundant vma->vm_flags setup code
> [PATCH 06/06] uio: Support multiple UIO_MEM_LOGICAL/VIRTUAL pages
> 
> Mostly small cleanups or performance improvements, except the last one
> which contains a fix for unsupported multi-page LOGICAL/VIRTUAL maps.
> 
> Signed-off-by: Magnus Damm <damm@igel.co.jp>
> ---
> 
>  Documentation/DocBook/uio-howto.tmpl |    2 
>  drivers/uio/uio.c                    |   91 +++++++++++++++-------------------
>  include/linux/uio_driver.h           |    1 
>  3 files changed, 44 insertions(+), 50 deletions(-)

Re: [PATCH 00/06] uio: Various minor changes

[Magnus Damm]

Hi Hans,

On Sat, Jul 19, 2008 at 12:46 AM, Hans J. Koch <hjk@linutronix.de> wrote:
> On Fri, Jul 18, 2008 at 02:04:02PM +0900, Magnus Damm wrote:
>> Hi everyone,
>>
>> Here comes a few UIO changes that I've had in my queue for a while.
>
> Hi Magnus,
> thanks a lot for your patches. I'll have a look at them ASAP, but it'll
> take a few days. I'm busy moving to a new house ATM...

No problem. There is nothing in this series that must be included in
2.6.27 in my opinion, so take your time.

I do however wish to have the uio_pdrv_genirq driver included in
2.6.27. I've seen the uio_pdrv driver and the irqcontrol patches in
linux-2.6.git, but the uio_pdrv_genirq driver is still missing...
Should I repost?

Thanks for your help,

/ magnus