Patchwork uio: Support 36-bit physical addresses on 32-bit systems

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Submitter Kumar Gala
Date Oct. 13, 2011, 3:50 p.m.
Message ID <1318521058-15662-1-git-send-email-galak@kernel.crashing.org>
Download mbox | patch
Permalink /patch/119561/
State Superseded
Headers show

Comments

Kumar Gala - Oct. 13, 2011, 3:50 p.m.
From: Kai Jiang <Kai.Jiang@freescale.com>

To support >32-bit physical addresses for UIO_MEM_PHYS type we need to
extend the width of 'addr' in struct uio_mem.  Numerous platforms like
embedded PPC, ARM, and X86 have support for systems with larger physical
address than logical.

Since 'addr' may contain a physical, logical, or virtual address the
easiest solution is to just change the type to 'phys_addr_t' which
should always be greater than or equal to the sizeof(void *) such that
it can properly hold any of the address types.

For physical address we can support up to a 44-bit physical address on a
typical 32-bit system as we utilize remap_pfn_range() for the mapping of
the memory region and pfn's are represnted by shifting the address by
the page size (typically 4k).

Signed-off-by: Kai Jiang <Kai.Jiang@freescale.com>
Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
---
v3:
* Updated commit message to be correct w/regards to code
* Updated comment about addr field in uio_mem
v2:
* Use phys_addr_t instead of 'unsigned long long'
* Updated DocBook detail in uio-howto.tmpl

 Documentation/DocBook/uio-howto.tmpl |    2 +-
 drivers/uio/uio.c                    |    8 ++++----
 include/linux/uio_driver.h           |    7 +++++--
 3 files changed, 10 insertions(+), 7 deletions(-)
Hans J. Koch - Oct. 14, 2011, 6:31 p.m.
On Thu, Oct 13, 2011 at 10:50:58AM -0500, Kumar Gala wrote:
> From: Kai Jiang <Kai.Jiang@freescale.com>
> 
> To support >32-bit physical addresses for UIO_MEM_PHYS type we need to
> extend the width of 'addr' in struct uio_mem.  Numerous platforms like
> embedded PPC, ARM, and X86 have support for systems with larger physical
> address than logical.
> 
> Since 'addr' may contain a physical, logical, or virtual address the
> easiest solution is to just change the type to 'phys_addr_t' which
> should always be greater than or equal to the sizeof(void *) such that
> it can properly hold any of the address types.
> 
> For physical address we can support up to a 44-bit physical address on a
> typical 32-bit system as we utilize remap_pfn_range() for the mapping of
> the memory region and pfn's are represnted by shifting the address by
> the page size (typically 4k).
> 
> Signed-off-by: Kai Jiang <Kai.Jiang@freescale.com>
> Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>
> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

Signed-off-by: "Hans J. Koch" <hjk@hansjkoch.de>

That looks good to me. There's an unnecessary cast (see below), but I fixed that
on the way.

Greg, please pull this from branch uio-for-gregkh from

git://hansjkoch.de/git/linux-hjk

Thanks,
Hans

> ---
> v3:
> * Updated commit message to be correct w/regards to code
> * Updated comment about addr field in uio_mem
> v2:
> * Use phys_addr_t instead of 'unsigned long long'
> * Updated DocBook detail in uio-howto.tmpl
> 
>  Documentation/DocBook/uio-howto.tmpl |    2 +-
>  drivers/uio/uio.c                    |    8 ++++----
>  include/linux/uio_driver.h           |    7 +++++--
>  3 files changed, 10 insertions(+), 7 deletions(-)
> 
> diff --git a/Documentation/DocBook/uio-howto.tmpl b/Documentation/DocBook/uio-howto.tmpl
> index 7c4b514d..54883de 100644
> --- a/Documentation/DocBook/uio-howto.tmpl
> +++ b/Documentation/DocBook/uio-howto.tmpl
> @@ -529,7 +529,7 @@ memory (e.g. allocated with <function>kmalloc()</function>). There's also
>  </para></listitem>
>  
>  <listitem><para>
> -<varname>unsigned long addr</varname>: Required if the mapping is used.
> +<varname>phys_addr_t addr</varname>: Required if the mapping is used.
>  Fill in the address of your memory block. This address is the one that
>  appears in sysfs.
>  </para></listitem>
> diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
> index 88f4444..43b7096 100644
> --- a/drivers/uio/uio.c
> +++ b/drivers/uio/uio.c
> @@ -69,7 +69,7 @@ static ssize_t map_name_show(struct uio_mem *mem, char *buf)
>  
>  static ssize_t map_addr_show(struct uio_mem *mem, char *buf)
>  {
> -	return sprintf(buf, "0x%lx\n", mem->addr);
> +	return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr);
>  }
>  
>  static ssize_t map_size_show(struct uio_mem *mem, char *buf)
> @@ -79,7 +79,7 @@ static ssize_t map_size_show(struct uio_mem *mem, char *buf)
>  
>  static ssize_t map_offset_show(struct uio_mem *mem, char *buf)
>  {
> -	return sprintf(buf, "0x%lx\n", mem->addr & ~PAGE_MASK);
> +	return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr & ~PAGE_MASK);
>  }
>  
>  struct map_sysfs_entry {
> @@ -634,8 +634,8 @@ static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
>  	if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
>  		page = virt_to_page(idev->info->mem[mi].addr + offset);
>  	else
> -		page = vmalloc_to_page((void *)idev->info->mem[mi].addr
> -							+ offset);
> +		page = vmalloc_to_page((void *)(unsigned long)

(void *) is enough, the (unsigned long) is not needed.

> +				idev->info->mem[mi].addr + offset);
>  	get_page(page);
>  	vmf->page = page;
>  	return 0;
> diff --git a/include/linux/uio_driver.h b/include/linux/uio_driver.h
> index 4c618cd..ad16aa9 100644
> --- a/include/linux/uio_driver.h
> +++ b/include/linux/uio_driver.h
> @@ -23,7 +23,10 @@ struct uio_map;
>  /**
>   * struct uio_mem - description of a UIO memory region
>   * @name:		name of the memory region for identification
> - * @addr:		address of the device's memory
> + * @addr:		address of the device's memory (phys_addr is used since
> + * 			addr can be logical, virtual, or physical & phys_addr_t
> + * 			should always be large enough to handle any of the
> + * 			address types)
>   * @size:		size of IO
>   * @memtype:		type of memory addr points to
>   * @internal_addr:	ioremap-ped version of addr, for driver internal use
> @@ -32,7 +35,7 @@ struct uio_map;
>   */
>  struct uio_mem {
>  	const char		*name;
> -	unsigned long		addr;
> +	phys_addr_t		addr;
>  	unsigned long		size;
>  	int			memtype;
>  	void __iomem		*internal_addr;
> -- 
> 1.7.3.4
> 
>
gregkh@suse.de - Oct. 14, 2011, 6:36 p.m.
On Fri, Oct 14, 2011 at 08:31:45PM +0200, Hans J. Koch wrote:
> On Thu, Oct 13, 2011 at 10:50:58AM -0500, Kumar Gala wrote:
> > From: Kai Jiang <Kai.Jiang@freescale.com>
> > 
> > To support >32-bit physical addresses for UIO_MEM_PHYS type we need to
> > extend the width of 'addr' in struct uio_mem.  Numerous platforms like
> > embedded PPC, ARM, and X86 have support for systems with larger physical
> > address than logical.
> > 
> > Since 'addr' may contain a physical, logical, or virtual address the
> > easiest solution is to just change the type to 'phys_addr_t' which
> > should always be greater than or equal to the sizeof(void *) such that
> > it can properly hold any of the address types.
> > 
> > For physical address we can support up to a 44-bit physical address on a
> > typical 32-bit system as we utilize remap_pfn_range() for the mapping of
> > the memory region and pfn's are represnted by shifting the address by
> > the page size (typically 4k).
> > 
> > Signed-off-by: Kai Jiang <Kai.Jiang@freescale.com>
> > Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>
> > Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
> 
> Signed-off-by: "Hans J. Koch" <hjk@hansjkoch.de>
> 
> That looks good to me. There's an unnecessary cast (see below), but I fixed that
> on the way.
> 
> Greg, please pull this from branch uio-for-gregkh from
> 
> git://hansjkoch.de/git/linux-hjk

Care to send it as an email?  I can apply it easier that way as I have
limited internet access while on the road.

greg k-h
Kumar Gala - Oct. 17, 2011, 4 p.m.
On Oct 14, 2011, at 1:31 PM, Hans J. Koch wrote:

> On Thu, Oct 13, 2011 at 10:50:58AM -0500, Kumar Gala wrote:
>> From: Kai Jiang <Kai.Jiang@freescale.com>
>> 
>> To support >32-bit physical addresses for UIO_MEM_PHYS type we need to
>> extend the width of 'addr' in struct uio_mem.  Numerous platforms like
>> embedded PPC, ARM, and X86 have support for systems with larger physical
>> address than logical.
>> 
>> Since 'addr' may contain a physical, logical, or virtual address the
>> easiest solution is to just change the type to 'phys_addr_t' which
>> should always be greater than or equal to the sizeof(void *) such that
>> it can properly hold any of the address types.
>> 
>> For physical address we can support up to a 44-bit physical address on a
>> typical 32-bit system as we utilize remap_pfn_range() for the mapping of
>> the memory region and pfn's are represnted by shifting the address by
>> the page size (typically 4k).
>> 
>> Signed-off-by: Kai Jiang <Kai.Jiang@freescale.com>
>> Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>
>> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
> 
> Signed-off-by: "Hans J. Koch" <hjk@hansjkoch.de>
> 
> That looks good to me. There's an unnecessary cast (see below), but I fixed that
> on the way.
> 
> Greg, please pull this from branch uio-for-gregkh from
> 
> git://hansjkoch.de/git/linux-hjk
> 
> Thanks,
> Hans

I think removing that cast is wrong:

drivers/uio/uio.c: In function 'uio_vma_fault':
drivers/uio/uio.c:637:26: warning: cast to pointer from integer of different size

- k
Hans J. Koch - Oct. 17, 2011, 5:18 p.m.
On Mon, Oct 17, 2011 at 11:00:55AM -0500, Kumar Gala wrote:
> 
> On Oct 14, 2011, at 1:31 PM, Hans J. Koch wrote:
> 
> > On Thu, Oct 13, 2011 at 10:50:58AM -0500, Kumar Gala wrote:
> >> From: Kai Jiang <Kai.Jiang@freescale.com>
> >> 
> >> To support >32-bit physical addresses for UIO_MEM_PHYS type we need to
> >> extend the width of 'addr' in struct uio_mem.  Numerous platforms like
> >> embedded PPC, ARM, and X86 have support for systems with larger physical
> >> address than logical.
> >> 
> >> Since 'addr' may contain a physical, logical, or virtual address the
> >> easiest solution is to just change the type to 'phys_addr_t' which
> >> should always be greater than or equal to the sizeof(void *) such that
> >> it can properly hold any of the address types.
> >> 
> >> For physical address we can support up to a 44-bit physical address on a
> >> typical 32-bit system as we utilize remap_pfn_range() for the mapping of
> >> the memory region and pfn's are represnted by shifting the address by
> >> the page size (typically 4k).
> >> 
> >> Signed-off-by: Kai Jiang <Kai.Jiang@freescale.com>
> >> Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>
> >> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
> > 
> > Signed-off-by: "Hans J. Koch" <hjk@hansjkoch.de>
> > 
> > That looks good to me. There's an unnecessary cast (see below), but I fixed that
> > on the way.
> > 
> > Greg, please pull this from branch uio-for-gregkh from
> > 
> > git://hansjkoch.de/git/linux-hjk
> > 
> > Thanks,
> > Hans
> 
> I think removing that cast is wrong:
> 
> drivers/uio/uio.c: In function 'uio_vma_fault':
> drivers/uio/uio.c:637:26: warning: cast to pointer from integer of different size

Hmm, on what platform did you see this? I tested on 32bit-x86 and didn't get
any warnings.

Hans
Hans J. Koch - Oct. 17, 2011, 6:03 p.m.
On Mon, Oct 17, 2011 at 07:18:59PM +0200, Hans J. Koch wrote:
> On Mon, Oct 17, 2011 at 11:00:55AM -0500, Kumar Gala wrote:
> > 
> > On Oct 14, 2011, at 1:31 PM, Hans J. Koch wrote:
> > 
> > > On Thu, Oct 13, 2011 at 10:50:58AM -0500, Kumar Gala wrote:
> > >> From: Kai Jiang <Kai.Jiang@freescale.com>
> > >> 
> > >> To support >32-bit physical addresses for UIO_MEM_PHYS type we need to
> > >> extend the width of 'addr' in struct uio_mem.  Numerous platforms like
> > >> embedded PPC, ARM, and X86 have support for systems with larger physical
> > >> address than logical.
> > >> 
> > >> Since 'addr' may contain a physical, logical, or virtual address the
> > >> easiest solution is to just change the type to 'phys_addr_t' which
> > >> should always be greater than or equal to the sizeof(void *) such that
> > >> it can properly hold any of the address types.
> > >> 
> > >> For physical address we can support up to a 44-bit physical address on a
> > >> typical 32-bit system as we utilize remap_pfn_range() for the mapping of
> > >> the memory region and pfn's are represnted by shifting the address by
> > >> the page size (typically 4k).
> > >> 
> > >> Signed-off-by: Kai Jiang <Kai.Jiang@freescale.com>
> > >> Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>
> > >> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
> > > 
> > > Signed-off-by: "Hans J. Koch" <hjk@hansjkoch.de>
> > > 
> > > That looks good to me. There's an unnecessary cast (see below), but I fixed that
> > > on the way.
> > > 
> > > Greg, please pull this from branch uio-for-gregkh from
> > > 
> > > git://hansjkoch.de/git/linux-hjk
> > > 
> > > Thanks,
> > > Hans
> > 
> > I think removing that cast is wrong:
> > 
> > drivers/uio/uio.c: In function 'uio_vma_fault':
> > drivers/uio/uio.c:637:26: warning: cast to pointer from integer of different size
> 
> Hmm, on what platform did you see this? I tested on 32bit-x86 and didn't get
> any warnings.

OK, you're right. I turned on CONFIG_HIGHMEM64G and got that warning. Damned x86...

Greg, can you fix it, or should I send the patch again?

Thanks,
Hans
gregkh@suse.de - Oct. 17, 2011, 6:23 p.m.
On Mon, Oct 17, 2011 at 08:03:51PM +0200, Hans J. Koch wrote:
> On Mon, Oct 17, 2011 at 07:18:59PM +0200, Hans J. Koch wrote:
> > On Mon, Oct 17, 2011 at 11:00:55AM -0500, Kumar Gala wrote:
> > > 
> > > On Oct 14, 2011, at 1:31 PM, Hans J. Koch wrote:
> > > 
> > > > On Thu, Oct 13, 2011 at 10:50:58AM -0500, Kumar Gala wrote:
> > > >> From: Kai Jiang <Kai.Jiang@freescale.com>
> > > >> 
> > > >> To support >32-bit physical addresses for UIO_MEM_PHYS type we need to
> > > >> extend the width of 'addr' in struct uio_mem.  Numerous platforms like
> > > >> embedded PPC, ARM, and X86 have support for systems with larger physical
> > > >> address than logical.
> > > >> 
> > > >> Since 'addr' may contain a physical, logical, or virtual address the
> > > >> easiest solution is to just change the type to 'phys_addr_t' which
> > > >> should always be greater than or equal to the sizeof(void *) such that
> > > >> it can properly hold any of the address types.
> > > >> 
> > > >> For physical address we can support up to a 44-bit physical address on a
> > > >> typical 32-bit system as we utilize remap_pfn_range() for the mapping of
> > > >> the memory region and pfn's are represnted by shifting the address by
> > > >> the page size (typically 4k).
> > > >> 
> > > >> Signed-off-by: Kai Jiang <Kai.Jiang@freescale.com>
> > > >> Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>
> > > >> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
> > > > 
> > > > Signed-off-by: "Hans J. Koch" <hjk@hansjkoch.de>
> > > > 
> > > > That looks good to me. There's an unnecessary cast (see below), but I fixed that
> > > > on the way.
> > > > 
> > > > Greg, please pull this from branch uio-for-gregkh from
> > > > 
> > > > git://hansjkoch.de/git/linux-hjk
> > > > 
> > > > Thanks,
> > > > Hans
> > > 
> > > I think removing that cast is wrong:
> > > 
> > > drivers/uio/uio.c: In function 'uio_vma_fault':
> > > drivers/uio/uio.c:637:26: warning: cast to pointer from integer of different size
> > 
> > Hmm, on what platform did you see this? I tested on 32bit-x86 and didn't get
> > any warnings.
> 
> OK, you're right. I turned on CONFIG_HIGHMEM64G and got that warning. Damned x86...
> 
> Greg, can you fix it, or should I send the patch again?

Please send it again.

Patch

diff --git a/Documentation/DocBook/uio-howto.tmpl b/Documentation/DocBook/uio-howto.tmpl
index 7c4b514d..54883de 100644
--- a/Documentation/DocBook/uio-howto.tmpl
+++ b/Documentation/DocBook/uio-howto.tmpl
@@ -529,7 +529,7 @@  memory (e.g. allocated with <function>kmalloc()</function>). There's also
 </para></listitem>
 
 <listitem><para>
-<varname>unsigned long addr</varname>: Required if the mapping is used.
+<varname>phys_addr_t addr</varname>: Required if the mapping is used.
 Fill in the address of your memory block. This address is the one that
 appears in sysfs.
 </para></listitem>
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 88f4444..43b7096 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -69,7 +69,7 @@  static ssize_t map_name_show(struct uio_mem *mem, char *buf)
 
 static ssize_t map_addr_show(struct uio_mem *mem, char *buf)
 {
-	return sprintf(buf, "0x%lx\n", mem->addr);
+	return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr);
 }
 
 static ssize_t map_size_show(struct uio_mem *mem, char *buf)
@@ -79,7 +79,7 @@  static ssize_t map_size_show(struct uio_mem *mem, char *buf)
 
 static ssize_t map_offset_show(struct uio_mem *mem, char *buf)
 {
-	return sprintf(buf, "0x%lx\n", mem->addr & ~PAGE_MASK);
+	return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr & ~PAGE_MASK);
 }
 
 struct map_sysfs_entry {
@@ -634,8 +634,8 @@  static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
 		page = virt_to_page(idev->info->mem[mi].addr + offset);
 	else
-		page = vmalloc_to_page((void *)idev->info->mem[mi].addr
-							+ offset);
+		page = vmalloc_to_page((void *)(unsigned long)
+				idev->info->mem[mi].addr + offset);
 	get_page(page);
 	vmf->page = page;
 	return 0;
diff --git a/include/linux/uio_driver.h b/include/linux/uio_driver.h
index 4c618cd..ad16aa9 100644
--- a/include/linux/uio_driver.h
+++ b/include/linux/uio_driver.h
@@ -23,7 +23,10 @@  struct uio_map;
 /**
  * struct uio_mem - description of a UIO memory region
  * @name:		name of the memory region for identification
- * @addr:		address of the device's memory
+ * @addr:		address of the device's memory (phys_addr is used since
+ * 			addr can be logical, virtual, or physical & phys_addr_t
+ * 			should always be large enough to handle any of the
+ * 			address types)
  * @size:		size of IO
  * @memtype:		type of memory addr points to
  * @internal_addr:	ioremap-ped version of addr, for driver internal use
@@ -32,7 +35,7 @@  struct uio_map;
  */
 struct uio_mem {
 	const char		*name;
-	unsigned long		addr;
+	phys_addr_t		addr;
 	unsigned long		size;
 	int			memtype;
 	void __iomem		*internal_addr;