On 18 September 2015 at 16:59, Dan Williams <dan.j.williams(a)intel.com> wrote:
On Fri, Sep 18, 2015 at 4:42 PM, Tyler Baker
<tyler.baker(a)linaro.org> wrote:
> Hi,
>
> On 25 August 2015 at 18:27, Dan Williams <dan.j.williams(a)intel.com> wrote:
>> From: Christoph Hellwig <hch(a)lst.de>
>>
>> Three architectures already define these, and we'll need them genericly
>> soon.
>>
>> Signed-off-by: Christoph Hellwig <hch(a)lst.de>
>> Signed-off-by: Dan Williams <dan.j.williams(a)intel.com>
>> ---
>> arch/arm/include/asm/memory.h | 6 ------
>> arch/arm64/include/asm/memory.h | 6 ------
>> arch/unicore32/include/asm/memory.h | 6 ------
>> include/asm-generic/memory_model.h | 6 ++++++
>> 4 files changed, 6 insertions(+), 18 deletions(-)
>>
>> diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
>> index b7f6fb462ea0..98d58bb04ac5 100644
>> --- a/arch/arm/include/asm/memory.h
>> +++ b/arch/arm/include/asm/memory.h
>> @@ -119,12 +119,6 @@
>> #endif
>>
>> /*
>> - * Convert a physical address to a Page Frame Number and back
>> - */
>> -#define __phys_to_pfn(paddr) ((unsigned long)((paddr) >>
PAGE_SHIFT))
>> -#define __pfn_to_phys(pfn) ((phys_addr_t)(pfn) << PAGE_SHIFT)
>> -
>> -/*
>> * Convert a page to/from a physical address
>> */
>> #define page_to_phys(page) (__pfn_to_phys(page_to_pfn(page)))
>> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
>> index f800d45ea226..d808bb688751 100644
>> --- a/arch/arm64/include/asm/memory.h
>> +++ b/arch/arm64/include/asm/memory.h
>> @@ -81,12 +81,6 @@
>> #define __phys_to_virt(x) ((unsigned long)((x) - PHYS_OFFSET +
PAGE_OFFSET))
>>
>> /*
>> - * Convert a physical address to a Page Frame Number and back
>> - */
>> -#define __phys_to_pfn(paddr) ((unsigned long)((paddr) >>
PAGE_SHIFT))
>> -#define __pfn_to_phys(pfn) ((phys_addr_t)(pfn) << PAGE_SHIFT)
>> -
>> -/*
>> * Convert a page to/from a physical address
>> */
>> #define page_to_phys(page) (__pfn_to_phys(page_to_pfn(page)))
>> diff --git a/arch/unicore32/include/asm/memory.h
b/arch/unicore32/include/asm/memory.h
>> index debafc40200a..3bb0a29fd2d7 100644
>> --- a/arch/unicore32/include/asm/memory.h
>> +++ b/arch/unicore32/include/asm/memory.h
>> @@ -61,12 +61,6 @@
>> #endif
>>
>> /*
>> - * Convert a physical address to a Page Frame Number and back
>> - */
>> -#define __phys_to_pfn(paddr) ((paddr) >> PAGE_SHIFT)
>> -#define __pfn_to_phys(pfn) ((pfn) << PAGE_SHIFT)
>> -
>> -/*
>> * Convert a page to/from a physical address
>> */
>> #define page_to_phys(page) (__pfn_to_phys(page_to_pfn(page)))
>> diff --git a/include/asm-generic/memory_model.h
b/include/asm-generic/memory_model.h
>> index 14909b0b9cae..f20f407ce45d 100644
>> --- a/include/asm-generic/memory_model.h
>> +++ b/include/asm-generic/memory_model.h
>> @@ -69,6 +69,12 @@
>> })
>> #endif /* CONFIG_FLATMEM/DISCONTIGMEM/SPARSEMEM */
>>
>> +/*
>> + * Convert a physical address to a Page Frame Number and back
>> + */
>> +#define __phys_to_pfn(paddr) ((unsigned long)((paddr) >>
PAGE_SHIFT))
>> +#define __pfn_to_phys(pfn) ((pfn) << PAGE_SHIFT)
>
> The
kernelci.org bot has been reporting complete boot failures[1] on
> ARM platforms with more than 4GB of memory and LPAE enabled. I've
> bisected[2] the failures down to this commit, and reverting it on top
> of the latest mainline resolves the boot issue. I took a closer look
> at this patch and noticed the cast to phys_addr_t was dropped in the
> generic function. Adding this to the new generic function solves the
> boot issue I'm reporting.
>
> diff --git a/include/asm-generic/memory_model.h
> b/include/asm-generic/memory_model.h
> index f20f407..db9f5c7 100644
> --- a/include/asm-generic/memory_model.h
> +++ b/include/asm-generic/memory_model.h
> @@ -73,7 +73,7 @@
> * Convert a physical address to a Page Frame Number and back
> */
> #define __phys_to_pfn(paddr) ((unsigned long)((paddr) >>
PAGE_SHIFT))
> -#define __pfn_to_phys(pfn) ((pfn) << PAGE_SHIFT)
> +#define __pfn_to_phys(pfn) ((phys_addr_t)(pfn) << PAGE_SHIFT)
>
> #define page_to_pfn __page_to_pfn
> #define pfn_to_page __pfn_to_page
>
> If this fix is valid, I can send a formal patch or it can be squashed
> into the original commit.
This fix is valid, but I wonder if it should just use the existing
PFN_PHYS() definition in include/linux/pfn.h?
Good suggestion, seems like the rational thing to do. FWIW, I gave the
patch below a spin through the
kernelci.org build/boot ci loop[1]. All
went well, no new regressions were detected.
From: Tyler Baker <tyler.baker(a)linaro.org>
Date: Fri, 18 Sep 2015 17:56:26 -0700
Subject: [PATCH] mm: fix type cast in __pfn_to_phys()
The various definitions of __pfn_to_phys() have been consolidated to
use a generic macro in include/asm-generic/memory_model.h. This hit
mainline in the form of 012dcef3f058 "mm: move __phys_to_pfn and
__pfn_to_phys to asm/generic/memory_model.h". When the generic macro
was implemented the type cast to phys_addr_t was dropped which caused
boot regressions on ARM platforms with more than 4GB of memory and
LPAE enabled.
It was suggested to use PFN_PHYS() defined in include/linux/pfn.h
as provides the correct logic and avoids further duplication.
Reported-by:
kernelci.org bot <bot(a)kernelci.org>
Suggested-by: Dan Williams <dan.j.williams(a)intel.com>
Signed-off-by: Tyler Baker <tyler.baker(a)linaro.org>
---
include/asm-generic/memory_model.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/asm-generic/memory_model.h
b/include/asm-generic/memory_model.h
index f20f407..4b4b056 100644
--- a/include/asm-generic/memory_model.h
+++ b/include/asm-generic/memory_model.h
@@ -73,7 +73,7 @@
* Convert a physical address to a Page Frame Number and back
*/
#define __phys_to_pfn(paddr) ((unsigned long)((paddr) >> PAGE_SHIFT))
-#define __pfn_to_phys(pfn) ((pfn) << PAGE_SHIFT)
+#define __pfn_to_phys(pfn) PFN_PHYS(pfn)
#define page_to_pfn __page_to_pfn
#define pfn_to_page __pfn_to_page
--
2.1.4
Cheers,
Tyler
[1]
http://kernelci.org/boot/all/job/tbaker/kernel/v4.3-rc1-221-ge75368554bf8/