[PATCH] uio: Support 36-bit physical addresses on 32-bit systems
Hans J. Koch
hjk at hansjkoch.de
Tue Oct 18 05:50:20 EST 2011
On Mon, Oct 17, 2011 at 11:23:45AM -0700, Greg KH wrote:
> 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 at 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 at freescale.com>
> > > > >> Signed-off-by: Minghuan Lian <Minghuan.Lian at freescale.com>
> > > > >> Signed-off-by: Kumar Gala <galak at kernel.crashing.org>
> > > > >
> > > > > Signed-off-by: "Hans J. Koch" <hjk at 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.
>From 30767223785a2ea412bd31a00a4534051af1f5dd Mon Sep 17 00:00:00 2001
From: Kai Jiang <Kai.Jiang at freescale.com>
Date: Fri, 14 Oct 2011 20:04:43 +0200
Subject: [PATCH] uio: Support physical addresses >32 bits on 32-bit systems
From: Kai Jiang <Kai.Jiang at 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 at freescale.com>
Signed-off-by: Minghuan Lian <Minghuan.Lian at freescale.com>
Signed-off-by: Kumar Gala <galak at kernel.crashing.org>
Signed-off-by: Hans J. Koch <hjk at hansjkoch.de>
---
Documentation/DocBook/uio-howto.tmpl | 2 +-
drivers/uio/uio.c | 7 +++----
include/linux/uio_driver.h | 7 +++++--
3 files changed, 9 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 d2efe82..dc27d89 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 +634,7 @@ 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 665517c..fd99ff9 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
@@ -31,7 +34,7 @@ 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;
--
1.7.6.3
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