Re: [PATCH 2/8] kexec_file: Generalize kexec_add_buffer.

[Dave Young]

On 06/13/16 at 04:08pm, Thiago Jung Bauermann wrote:
> Hello Dave,
> 
> Thanks for the quick review and for your comments.
> 
> I'll separate the change to add arch_walk_system_ram and the change to add 
> kexec_locate_mem_hole into different patches, and add error handling for 
> KEXEC_ON_CRASH.
> 
> Am Montag, 13 Juni 2016, 15:29:39 schrieb Dave Young:
> > On 06/12/16 at 12:10am, Thiago Jung Bauermann wrote:
> > > Allow architectures to specify different memory walking functions for
> > > kexec_add_buffer. Intel uses iomem to track reserved memory ranges,
> > > but PowerPC uses the memblock subsystem.
> > 
> > Can the crashk_res be inserted to iomem_resource so that only one
> > weak function for system ram is needed?
> 
> Sorry, it's not clear to me what you mean by inserting crashk_res into 

Hmm, I means exporting crashkernel mem to /proc/iomem like other arches
It is just oneline:
insert_resource(_resource, _res)

But your proposal below is also fine.

> iomem_resource, but I can add a bool for_crashkernel to arch_walk_system_ram 
> so that it can decide which kind of memory to traverse, so the default 
> implementation of kexec_file.c would be:
> 
> int __weak arch_walk_system_ram(bool for_crashkernel, unsigned long start,
>   unsigned long end, bool top_down,
>   void *data,
>   int (*func)(u64, u64, void *))

arch_walk_mem sounds better?

> {
>   int ret;
> 
>   if (for_crashkernel)
>   ret = walk_iomem_res_desc(crashk_res.desc,
> IORESOURCE_SYSTEM_RAM |
> IORESOURCE_BUSY,
> start, end, data, func);
>   else
>   ret = walk_system_ram_res(start, end, data, func);
> 
>   if (ret != 1) {
>   /* A suitable memory range could not be found for buffer */
>   return -EADDRNOTAVAIL;
>   }
> }
> 
> and kexec_add_buffer / kexec_locate_mem_hole would call it with:
> 
>   if (image->type == KEXEC_TYPE_CRASH)
>   ret = arch_walk_system_ram(true, crashk_res.start,
>  crashk_res.end, top_down, ,
>  locate_mem_hole_callback);
>   else
>   ret = arch_walk_system_ram(false, 0, -1, top_down, ,
>  locate_mem_hole_callback);
> 
> What do you think?

Sounds good, but for_crashkernel can be image_type instead. and
image->type can be passed to the arch_walk_mem function directly.

Thanks
Dave

Re: [PATCH 2/8] kexec_file: Generalize kexec_add_buffer.

[Dave Young]

On 06/13/16 at 04:08pm, Thiago Jung Bauermann wrote:
> Hello Dave,
> 
> Thanks for the quick review and for your comments.
> 
> I'll separate the change to add arch_walk_system_ram and the change to add 
> kexec_locate_mem_hole into different patches, and add error handling for 
> KEXEC_ON_CRASH.
> 
> Am Montag, 13 Juni 2016, 15:29:39 schrieb Dave Young:
> > On 06/12/16 at 12:10am, Thiago Jung Bauermann wrote:
> > > Allow architectures to specify different memory walking functions for
> > > kexec_add_buffer. Intel uses iomem to track reserved memory ranges,
> > > but PowerPC uses the memblock subsystem.
> > 
> > Can the crashk_res be inserted to iomem_resource so that only one
> > weak function for system ram is needed?
> 
> Sorry, it's not clear to me what you mean by inserting crashk_res into 

Hmm, I means exporting crashkernel mem to /proc/iomem like other arches
It is just oneline:
insert_resource(_resource, _res)

But your proposal below is also fine.

> iomem_resource, but I can add a bool for_crashkernel to arch_walk_system_ram 
> so that it can decide which kind of memory to traverse, so the default 
> implementation of kexec_file.c would be:
> 
> int __weak arch_walk_system_ram(bool for_crashkernel, unsigned long start,
>   unsigned long end, bool top_down,
>   void *data,
>   int (*func)(u64, u64, void *))

arch_walk_mem sounds better?

> {
>   int ret;
> 
>   if (for_crashkernel)
>   ret = walk_iomem_res_desc(crashk_res.desc,
> IORESOURCE_SYSTEM_RAM |
> IORESOURCE_BUSY,
> start, end, data, func);
>   else
>   ret = walk_system_ram_res(start, end, data, func);
> 
>   if (ret != 1) {
>   /* A suitable memory range could not be found for buffer */
>   return -EADDRNOTAVAIL;
>   }
> }
> 
> and kexec_add_buffer / kexec_locate_mem_hole would call it with:
> 
>   if (image->type == KEXEC_TYPE_CRASH)
>   ret = arch_walk_system_ram(true, crashk_res.start,
>  crashk_res.end, top_down, ,
>  locate_mem_hole_callback);
>   else
>   ret = arch_walk_system_ram(false, 0, -1, top_down, ,
>  locate_mem_hole_callback);
> 
> What do you think?

Sounds good, but for_crashkernel can be image_type instead. and
image->type can be passed to the arch_walk_mem function directly.

Thanks
Dave

Re: [PATCH 2/8] kexec_file: Generalize kexec_add_buffer.

[Thiago Jung Bauermann]

Hi Dave,

Am Montag, 13 Juni 2016, 16:08:19 schrieb Thiago Jung Bauermann:
> Am Montag, 13 Juni 2016, 15:29:39 schrieb Dave Young:
> > On 06/12/16 at 12:10am, Thiago Jung Bauermann wrote:
> > > Allow architectures to specify different memory walking functions for
> > > kexec_add_buffer. Intel uses iomem to track reserved memory ranges,
> > > but PowerPC uses the memblock subsystem.
> > 
> > Can the crashk_res be inserted to iomem_resource so that only one
> > weak function for system ram is needed?
> 
> Sorry, it's not clear to me what you mean by inserting crashk_res into
> iomem_resource, but I can add a bool for_crashkernel to
> arch_walk_system_ram so that it can decide which kind of memory to
> traverse.

This is the patch implementing that idea. What do you think?
-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center


kexec_file: Generalize kexec_add_buffer.

Allow architectures to specify different memory walking functions for
kexec_add_buffer. Intel uses iomem to track reserved memory ranges,
but PowerPC uses the memblock subsystem.

Signed-off-by: Thiago Jung Bauermann 
Cc: Eric Biederman 
Cc: ke...@lists.infradead.org
Cc: linux-kernel@vger.kernel.org

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index e8acb2b43dd9..be18cb80c14e 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -315,6 +315,9 @@ int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr 
*ehdr,
Elf_Shdr *sechdrs, unsigned int relsec);
 int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr 
*sechdrs,
unsigned int relsec);
+int __weak arch_walk_system_ram(bool for_crashkernel, unsigned long start,
+   unsigned long end, bool top_down, void *data,
+   int (*func)(u64, u64, void *));
 void arch_kexec_protect_crashkres(void);
 void arch_kexec_unprotect_crashkres(void);
 
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index b6eec7527e9f..5d0a6a20b12b 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -428,6 +428,38 @@ static int locate_mem_hole_callback(u64 start, u64 end, 
void *arg)
return locate_mem_hole_bottom_up(start, end, kbuf);
 }
 
+/**
+ * arch_walk_system_ram - call func(data) on free memory regions
+ * @for_crashkernel:   Is this for the crash kernel?
+ * @start: Don't visit memory regions below this address.
+ * @end:   Don't visit memory regions above this address.
+ * @top_down:  Starts from the highest address?
+ * @data:  Argument to pass to @func.
+ * @func:  Function to call for each memory region.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int __weak arch_walk_system_ram(bool for_crashkernel, unsigned long start,
+   unsigned long end, bool top_down, void *data,
+   int (*func)(u64, u64, void *))
+{
+   int ret;
+
+   if (for_crashkernel)
+   ret = walk_iomem_res_desc(crashk_res.desc,
+ IORESOURCE_SYSTEM_RAM | 
IORESOURCE_BUSY,
+ start, end, data, func);
+   else
+   ret = walk_system_ram_res(start, end, data, func);
+
+   if (ret != 1) {
+   /* A suitable memory range could not be found for buffer */
+   return -EADDRNOTAVAIL;
+   }
+
+   return 0;
+}
+
 /*
  * Helper function for placing a buffer in a kexec segment. This assumes
  * that kexec_mutex is held.
@@ -473,17 +505,14 @@ int kexec_add_buffer(struct kimage *image, char *buffer, 
unsigned long bufsz,
 
/* Walk the RAM ranges and allocate a suitable range for the buffer */
if (image->type == KEXEC_TYPE_CRASH)
-   ret = walk_iomem_res_desc(crashk_res.desc,
-   IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
-   crashk_res.start, crashk_res.end, kbuf,
-   locate_mem_hole_callback);
+   ret = arch_walk_system_ram(true, crashk_res.start,
+  crashk_res.end, top_down, kbuf,
+  locate_mem_hole_callback);
else
-   ret = walk_system_ram_res(0, -1, kbuf,
- locate_mem_hole_callback);
-   if (ret != 1) {
-   /* A suitable memory range could not be found for buffer */
-   return -EADDRNOTAVAIL;
-   }
+   ret = arch_walk_system_ram(false, 0, -1, top_down, kbuf,
+  locate_mem_hole_callback);
+   if (ret)
+   return ret;
 
/* Found a suitable memory range */
ksegment = >segment[image->nr_segments];

Re: [PATCH 2/8] kexec_file: Generalize kexec_add_buffer.

[Thiago Jung Bauermann]

Hi Dave,

Am Montag, 13 Juni 2016, 16:08:19 schrieb Thiago Jung Bauermann:
> Am Montag, 13 Juni 2016, 15:29:39 schrieb Dave Young:
> > On 06/12/16 at 12:10am, Thiago Jung Bauermann wrote:
> > > Allow architectures to specify different memory walking functions for
> > > kexec_add_buffer. Intel uses iomem to track reserved memory ranges,
> > > but PowerPC uses the memblock subsystem.
> > 
> > Can the crashk_res be inserted to iomem_resource so that only one
> > weak function for system ram is needed?
> 
> Sorry, it's not clear to me what you mean by inserting crashk_res into
> iomem_resource, but I can add a bool for_crashkernel to
> arch_walk_system_ram so that it can decide which kind of memory to
> traverse.

This is the patch implementing that idea. What do you think?
-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center


kexec_file: Generalize kexec_add_buffer.

Allow architectures to specify different memory walking functions for
kexec_add_buffer. Intel uses iomem to track reserved memory ranges,
but PowerPC uses the memblock subsystem.

Signed-off-by: Thiago Jung Bauermann 
Cc: Eric Biederman 
Cc: ke...@lists.infradead.org
Cc: linux-kernel@vger.kernel.org

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index e8acb2b43dd9..be18cb80c14e 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -315,6 +315,9 @@ int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr 
*ehdr,
Elf_Shdr *sechdrs, unsigned int relsec);
 int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr 
*sechdrs,
unsigned int relsec);
+int __weak arch_walk_system_ram(bool for_crashkernel, unsigned long start,
+   unsigned long end, bool top_down, void *data,
+   int (*func)(u64, u64, void *));
 void arch_kexec_protect_crashkres(void);
 void arch_kexec_unprotect_crashkres(void);
 
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index b6eec7527e9f..5d0a6a20b12b 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -428,6 +428,38 @@ static int locate_mem_hole_callback(u64 start, u64 end, 
void *arg)
return locate_mem_hole_bottom_up(start, end, kbuf);
 }
 
+/**
+ * arch_walk_system_ram - call func(data) on free memory regions
+ * @for_crashkernel:   Is this for the crash kernel?
+ * @start: Don't visit memory regions below this address.
+ * @end:   Don't visit memory regions above this address.
+ * @top_down:  Starts from the highest address?
+ * @data:  Argument to pass to @func.
+ * @func:  Function to call for each memory region.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int __weak arch_walk_system_ram(bool for_crashkernel, unsigned long start,
+   unsigned long end, bool top_down, void *data,
+   int (*func)(u64, u64, void *))
+{
+   int ret;
+
+   if (for_crashkernel)
+   ret = walk_iomem_res_desc(crashk_res.desc,
+ IORESOURCE_SYSTEM_RAM | 
IORESOURCE_BUSY,
+ start, end, data, func);
+   else
+   ret = walk_system_ram_res(start, end, data, func);
+
+   if (ret != 1) {
+   /* A suitable memory range could not be found for buffer */
+   return -EADDRNOTAVAIL;
+   }
+
+   return 0;
+}
+
 /*
  * Helper function for placing a buffer in a kexec segment. This assumes
  * that kexec_mutex is held.
@@ -473,17 +505,14 @@ int kexec_add_buffer(struct kimage *image, char *buffer, 
unsigned long bufsz,
 
/* Walk the RAM ranges and allocate a suitable range for the buffer */
if (image->type == KEXEC_TYPE_CRASH)
-   ret = walk_iomem_res_desc(crashk_res.desc,
-   IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
-   crashk_res.start, crashk_res.end, kbuf,
-   locate_mem_hole_callback);
+   ret = arch_walk_system_ram(true, crashk_res.start,
+  crashk_res.end, top_down, kbuf,
+  locate_mem_hole_callback);
else
-   ret = walk_system_ram_res(0, -1, kbuf,
- locate_mem_hole_callback);
-   if (ret != 1) {
-   /* A suitable memory range could not be found for buffer */
-   return -EADDRNOTAVAIL;
-   }
+   ret = arch_walk_system_ram(false, 0, -1, top_down, kbuf,
+  locate_mem_hole_callback);
+   if (ret)
+   return ret;
 
/* Found a suitable memory range */
ksegment = >segment[image->nr_segments];

Re: [PATCH 2/8] kexec_file: Generalize kexec_add_buffer.

[Thiago Jung Bauermann]

Hello Dave,

Thanks for the quick review and for your comments.

I'll separate the change to add arch_walk_system_ram and the change to add 
kexec_locate_mem_hole into different patches, and add error handling for 
KEXEC_ON_CRASH.

Am Montag, 13 Juni 2016, 15:29:39 schrieb Dave Young:
> On 06/12/16 at 12:10am, Thiago Jung Bauermann wrote:
> > Allow architectures to specify different memory walking functions for
> > kexec_add_buffer. Intel uses iomem to track reserved memory ranges,
> > but PowerPC uses the memblock subsystem.
> 
> Can the crashk_res be inserted to iomem_resource so that only one
> weak function for system ram is needed?

Sorry, it's not clear to me what you mean by inserting crashk_res into 
iomem_resource, but I can add a bool for_crashkernel to arch_walk_system_ram 
so that it can decide which kind of memory to traverse, so the default 
implementation of kexec_file.c would be:

int __weak arch_walk_system_ram(bool for_crashkernel, unsigned long start,
unsigned long end, bool top_down,
void *data,
int (*func)(u64, u64, void *))
{
int ret;

if (for_crashkernel)
ret = walk_iomem_res_desc(crashk_res.desc,
  IORESOURCE_SYSTEM_RAM |
  IORESOURCE_BUSY,
  start, end, data, func);
else
ret = walk_system_ram_res(start, end, data, func);

if (ret != 1) {
/* A suitable memory range could not be found for buffer */
return -EADDRNOTAVAIL;
}
}

and kexec_add_buffer / kexec_locate_mem_hole would call it with:

if (image->type == KEXEC_TYPE_CRASH)
ret = arch_walk_system_ram(true, crashk_res.start,
   crashk_res.end, top_down, ,
   locate_mem_hole_callback);
else
ret = arch_walk_system_ram(false, 0, -1, top_down, ,
   locate_mem_hole_callback);

What do you think?

-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH 2/8] kexec_file: Generalize kexec_add_buffer.

[Thiago Jung Bauermann]

Hello Dave,

Thanks for the quick review and for your comments.

I'll separate the change to add arch_walk_system_ram and the change to add 
kexec_locate_mem_hole into different patches, and add error handling for 
KEXEC_ON_CRASH.

Am Montag, 13 Juni 2016, 15:29:39 schrieb Dave Young:
> On 06/12/16 at 12:10am, Thiago Jung Bauermann wrote:
> > Allow architectures to specify different memory walking functions for
> > kexec_add_buffer. Intel uses iomem to track reserved memory ranges,
> > but PowerPC uses the memblock subsystem.
> 
> Can the crashk_res be inserted to iomem_resource so that only one
> weak function for system ram is needed?

Sorry, it's not clear to me what you mean by inserting crashk_res into 
iomem_resource, but I can add a bool for_crashkernel to arch_walk_system_ram 
so that it can decide which kind of memory to traverse, so the default 
implementation of kexec_file.c would be:

int __weak arch_walk_system_ram(bool for_crashkernel, unsigned long start,
unsigned long end, bool top_down,
void *data,
int (*func)(u64, u64, void *))
{
int ret;

if (for_crashkernel)
ret = walk_iomem_res_desc(crashk_res.desc,
  IORESOURCE_SYSTEM_RAM |
  IORESOURCE_BUSY,
  start, end, data, func);
else
ret = walk_system_ram_res(start, end, data, func);

if (ret != 1) {
/* A suitable memory range could not be found for buffer */
return -EADDRNOTAVAIL;
}
}

and kexec_add_buffer / kexec_locate_mem_hole would call it with:

if (image->type == KEXEC_TYPE_CRASH)
ret = arch_walk_system_ram(true, crashk_res.start,
   crashk_res.end, top_down, ,
   locate_mem_hole_callback);
else
ret = arch_walk_system_ram(false, 0, -1, top_down, ,
   locate_mem_hole_callback);

What do you think?

-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH 2/8] kexec_file: Generalize kexec_add_buffer.

[Dave Young]

On 06/12/16 at 12:10am, Thiago Jung Bauermann wrote:
> Allow architectures to specify different memory walking functions for
> kexec_add_buffer. Intel uses iomem to track reserved memory ranges,
> but PowerPC uses the memblock subsystem.

Can the crashk_res be inserted to iomem_resource so that only one
weak function for system ram is needed?

> 
> Also, factor kexec_locate_mem_hole out of kexec_add_buffer. It will be
> used by the PowerPC kexec_file_load implementation to find free memory
> for the purgatory stack.
> 
> Cc: Eric Biederman 
> Cc: ke...@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
> ---
>  include/linux/kexec.h | 10 ++
>  kernel/kexec_file.c   | 96 
> +--
>  2 files changed, 81 insertions(+), 25 deletions(-)
> 
> diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> index e8acb2b43dd9..920e2cbe5bdd 100644
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -210,6 +210,10 @@ extern asmlinkage long sys_kexec_load(unsigned long 
> entry,
>   struct kexec_segment __user *segments,
>   unsigned long flags);
>  extern int kernel_kexec(void);
> +int kexec_locate_mem_hole(struct kimage *image, unsigned long size,
> +   unsigned long align, unsigned long start,
> +   unsigned long end, bool top_down,
> +   unsigned long *addr);
>  extern int kexec_add_buffer(struct kimage *image, char *buffer,
>   unsigned long bufsz, unsigned long memsz,
>   unsigned long buf_align, unsigned long buf_min,
> @@ -315,6 +319,12 @@ int __weak arch_kexec_apply_relocations_add(const 
> Elf_Ehdr *ehdr,
>   Elf_Shdr *sechdrs, unsigned int relsec);
>  int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr 
> *sechdrs,
>   unsigned int relsec);
> +int __weak arch_walk_iomem(unsigned long desc, unsigned long start,
> +unsigned long end, bool top_down, void *data,
> +int (*func)(u64, u64, void *));
> +int __weak arch_walk_system_ram(unsigned long start, unsigned long end,
> + bool top_down, void *data,
> + int (*func)(u64, u64, void *));
>  void arch_kexec_protect_crashkres(void);
>  void arch_kexec_unprotect_crashkres(void);
>  
> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
> index b6eec7527e9f..300f71cb4f72 100644
> --- a/kernel/kexec_file.c
> +++ b/kernel/kexec_file.c
> @@ -428,6 +428,68 @@ static int locate_mem_hole_callback(u64 start, u64 end, 
> void *arg)
>   return locate_mem_hole_bottom_up(start, end, kbuf);
>  }
>  
> +int __weak arch_walk_iomem(unsigned long desc, unsigned long start,
> +unsigned long end, bool top_down, void *data,
> +int (*func)(u64, u64, void *))
> +{
> + return walk_iomem_res_desc(desc,
> +IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
> +start, end, data, func);
> +}
> +
> +int __weak arch_walk_system_ram(unsigned long start, unsigned long end,
> + bool top_down, void *data,
> + int (*func)(u64, u64, void *))
> +{
> + return walk_system_ram_res(start, end, data, func);
> +}
> +
> +/**
> + * kexec_locate_mem_hole - find free memory to load segment or use in 
> purgatory
> + * @image:   kexec image being updated.
> + * @size:Memory size.
> + * @align:   Minimum alignment needed.
> + * @start:   Minimum starting address.
> + * @end: Maximum end address.
> + * @top_down Find the highest free memory region?
> + * @addr On success, will have start address of the memory region found.
> + *
> + * Return: 0 on success, negative erro on failure.
> + */
> +int kexec_locate_mem_hole(struct kimage *image, unsigned long size,
> +   unsigned long align, unsigned long start,
> +   unsigned long end, bool top_down, unsigned long *addr)
> +{
> + int ret;
> + struct kexec_buf buf;
> +
> + memset(, 0, sizeof(struct kexec_buf));
> + buf.image = image;
> +
> + buf.memsz = size;
> + buf.buf_align = align;
> + buf.buf_min = start;
> + buf.buf_max = end;
> + buf.top_down = top_down;
> +
> + /* Walk the RAM ranges and allocate a suitable range for the buffer */
> + if (image->type == KEXEC_TYPE_CRASH)
> + ret = arch_walk_iomem(crashk_res.desc, crashk_res.start,
> +   crashk_res.end, top_down, ,
> +   locate_mem_hole_callback);
> + else
> + ret = arch_walk_system_ram(0, -1, top_down, ,
> +locate_mem_hole_callback);
> + if (ret != 1) {
> +  

Re: [PATCH 2/8] kexec_file: Generalize kexec_add_buffer.

[Dave Young]

On 06/12/16 at 12:10am, Thiago Jung Bauermann wrote:
> Allow architectures to specify different memory walking functions for
> kexec_add_buffer. Intel uses iomem to track reserved memory ranges,
> but PowerPC uses the memblock subsystem.

Can the crashk_res be inserted to iomem_resource so that only one
weak function for system ram is needed?

> 
> Also, factor kexec_locate_mem_hole out of kexec_add_buffer. It will be
> used by the PowerPC kexec_file_load implementation to find free memory
> for the purgatory stack.
> 
> Cc: Eric Biederman 
> Cc: ke...@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
> ---
>  include/linux/kexec.h | 10 ++
>  kernel/kexec_file.c   | 96 
> +--
>  2 files changed, 81 insertions(+), 25 deletions(-)
> 
> diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> index e8acb2b43dd9..920e2cbe5bdd 100644
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -210,6 +210,10 @@ extern asmlinkage long sys_kexec_load(unsigned long 
> entry,
>   struct kexec_segment __user *segments,
>   unsigned long flags);
>  extern int kernel_kexec(void);
> +int kexec_locate_mem_hole(struct kimage *image, unsigned long size,
> +   unsigned long align, unsigned long start,
> +   unsigned long end, bool top_down,
> +   unsigned long *addr);
>  extern int kexec_add_buffer(struct kimage *image, char *buffer,
>   unsigned long bufsz, unsigned long memsz,
>   unsigned long buf_align, unsigned long buf_min,
> @@ -315,6 +319,12 @@ int __weak arch_kexec_apply_relocations_add(const 
> Elf_Ehdr *ehdr,
>   Elf_Shdr *sechdrs, unsigned int relsec);
>  int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr 
> *sechdrs,
>   unsigned int relsec);
> +int __weak arch_walk_iomem(unsigned long desc, unsigned long start,
> +unsigned long end, bool top_down, void *data,
> +int (*func)(u64, u64, void *));
> +int __weak arch_walk_system_ram(unsigned long start, unsigned long end,
> + bool top_down, void *data,
> + int (*func)(u64, u64, void *));
>  void arch_kexec_protect_crashkres(void);
>  void arch_kexec_unprotect_crashkres(void);
>  
> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
> index b6eec7527e9f..300f71cb4f72 100644
> --- a/kernel/kexec_file.c
> +++ b/kernel/kexec_file.c
> @@ -428,6 +428,68 @@ static int locate_mem_hole_callback(u64 start, u64 end, 
> void *arg)
>   return locate_mem_hole_bottom_up(start, end, kbuf);
>  }
>  
> +int __weak arch_walk_iomem(unsigned long desc, unsigned long start,
> +unsigned long end, bool top_down, void *data,
> +int (*func)(u64, u64, void *))
> +{
> + return walk_iomem_res_desc(desc,
> +IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
> +start, end, data, func);
> +}
> +
> +int __weak arch_walk_system_ram(unsigned long start, unsigned long end,
> + bool top_down, void *data,
> + int (*func)(u64, u64, void *))
> +{
> + return walk_system_ram_res(start, end, data, func);
> +}
> +
> +/**
> + * kexec_locate_mem_hole - find free memory to load segment or use in 
> purgatory
> + * @image:   kexec image being updated.
> + * @size:Memory size.
> + * @align:   Minimum alignment needed.
> + * @start:   Minimum starting address.
> + * @end: Maximum end address.
> + * @top_down Find the highest free memory region?
> + * @addr On success, will have start address of the memory region found.
> + *
> + * Return: 0 on success, negative erro on failure.
> + */
> +int kexec_locate_mem_hole(struct kimage *image, unsigned long size,
> +   unsigned long align, unsigned long start,
> +   unsigned long end, bool top_down, unsigned long *addr)
> +{
> + int ret;
> + struct kexec_buf buf;
> +
> + memset(, 0, sizeof(struct kexec_buf));
> + buf.image = image;
> +
> + buf.memsz = size;
> + buf.buf_align = align;
> + buf.buf_min = start;
> + buf.buf_max = end;
> + buf.top_down = top_down;
> +
> + /* Walk the RAM ranges and allocate a suitable range for the buffer */
> + if (image->type == KEXEC_TYPE_CRASH)
> + ret = arch_walk_iomem(crashk_res.desc, crashk_res.start,
> +   crashk_res.end, top_down, ,
> +   locate_mem_hole_callback);
> + else
> + ret = arch_walk_system_ram(0, -1, top_down, ,
> +locate_mem_hole_callback);
> + if (ret != 1) {
> + /* A suitable 

Re: [PATCH 2/8] kexec_file: Generalize kexec_add_buffer.

[Dave Young]

On 06/12/16 at 12:10am, Thiago Jung Bauermann wrote:
> Allow architectures to specify different memory walking functions for
> kexec_add_buffer. Intel uses iomem to track reserved memory ranges,
> but PowerPC uses the memblock subsystem.
> 
> Also, factor kexec_locate_mem_hole out of kexec_add_buffer. It will be
> used by the PowerPC kexec_file_load implementation to find free memory
> for the purgatory stack.

Split factoring locate hole function to another patch will be clearer.

> 
> Cc: Eric Biederman 
> Cc: ke...@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
> ---
>  include/linux/kexec.h | 10 ++
>  kernel/kexec_file.c   | 96 
> +--
>  2 files changed, 81 insertions(+), 25 deletions(-)
> 
> diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> index e8acb2b43dd9..920e2cbe5bdd 100644
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -210,6 +210,10 @@ extern asmlinkage long sys_kexec_load(unsigned long 
> entry,
>   struct kexec_segment __user *segments,
>   unsigned long flags);
>  extern int kernel_kexec(void);
> +int kexec_locate_mem_hole(struct kimage *image, unsigned long size,
> +   unsigned long align, unsigned long start,
> +   unsigned long end, bool top_down,
> +   unsigned long *addr);
>  extern int kexec_add_buffer(struct kimage *image, char *buffer,
>   unsigned long bufsz, unsigned long memsz,
>   unsigned long buf_align, unsigned long buf_min,
> @@ -315,6 +319,12 @@ int __weak arch_kexec_apply_relocations_add(const 
> Elf_Ehdr *ehdr,
>   Elf_Shdr *sechdrs, unsigned int relsec);
>  int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr 
> *sechdrs,
>   unsigned int relsec);
> +int __weak arch_walk_iomem(unsigned long desc, unsigned long start,
> +unsigned long end, bool top_down, void *data,
> +int (*func)(u64, u64, void *));
> +int __weak arch_walk_system_ram(unsigned long start, unsigned long end,
> + bool top_down, void *data,
> + int (*func)(u64, u64, void *));
>  void arch_kexec_protect_crashkres(void);
>  void arch_kexec_unprotect_crashkres(void);
>  
> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
> index b6eec7527e9f..300f71cb4f72 100644
> --- a/kernel/kexec_file.c
> +++ b/kernel/kexec_file.c
> @@ -428,6 +428,68 @@ static int locate_mem_hole_callback(u64 start, u64 end, 
> void *arg)
>   return locate_mem_hole_bottom_up(start, end, kbuf);
>  }
>  
> +int __weak arch_walk_iomem(unsigned long desc, unsigned long start,
> +unsigned long end, bool top_down, void *data,
> +int (*func)(u64, u64, void *))
> +{
> + return walk_iomem_res_desc(desc,
> +IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
> +start, end, data, func);
> +}
> +
> +int __weak arch_walk_system_ram(unsigned long start, unsigned long end,
> + bool top_down, void *data,
> + int (*func)(u64, u64, void *))
> +{
> + return walk_system_ram_res(start, end, data, func);
> +}
> +
> +/**
> + * kexec_locate_mem_hole - find free memory to load segment or use in 
> purgatory
> + * @image:   kexec image being updated.
> + * @size:Memory size.
> + * @align:   Minimum alignment needed.
> + * @start:   Minimum starting address.
> + * @end: Maximum end address.
> + * @top_down Find the highest free memory region?
> + * @addr On success, will have start address of the memory region found.
> + *
> + * Return: 0 on success, negative erro on failure.
> + */
> +int kexec_locate_mem_hole(struct kimage *image, unsigned long size,
> +   unsigned long align, unsigned long start,
> +   unsigned long end, bool top_down, unsigned long *addr)
> +{
> + int ret;
> + struct kexec_buf buf;
> +
> + memset(, 0, sizeof(struct kexec_buf));
> + buf.image = image;
> +
> + buf.memsz = size;
> + buf.buf_align = align;
> + buf.buf_min = start;
> + buf.buf_max = end;
> + buf.top_down = top_down;
> +
> + /* Walk the RAM ranges and allocate a suitable range for the buffer */
> + if (image->type == KEXEC_TYPE_CRASH)
> + ret = arch_walk_iomem(crashk_res.desc, crashk_res.start,
> +   crashk_res.end, top_down, ,
> +   locate_mem_hole_callback);
> + else
> + ret = arch_walk_system_ram(0, -1, top_down, ,
> +locate_mem_hole_callback);
> + if (ret != 1) {
> + /* A suitable memory range 

Re: [PATCH 2/8] kexec_file: Generalize kexec_add_buffer.

[Dave Young]

On 06/12/16 at 12:10am, Thiago Jung Bauermann wrote:
> Allow architectures to specify different memory walking functions for
> kexec_add_buffer. Intel uses iomem to track reserved memory ranges,
> but PowerPC uses the memblock subsystem.
> 
> Also, factor kexec_locate_mem_hole out of kexec_add_buffer. It will be
> used by the PowerPC kexec_file_load implementation to find free memory
> for the purgatory stack.

Split factoring locate hole function to another patch will be clearer.

> 
> Cc: Eric Biederman 
> Cc: ke...@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
> ---
>  include/linux/kexec.h | 10 ++
>  kernel/kexec_file.c   | 96 
> +--
>  2 files changed, 81 insertions(+), 25 deletions(-)
> 
> diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> index e8acb2b43dd9..920e2cbe5bdd 100644
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -210,6 +210,10 @@ extern asmlinkage long sys_kexec_load(unsigned long 
> entry,
>   struct kexec_segment __user *segments,
>   unsigned long flags);
>  extern int kernel_kexec(void);
> +int kexec_locate_mem_hole(struct kimage *image, unsigned long size,
> +   unsigned long align, unsigned long start,
> +   unsigned long end, bool top_down,
> +   unsigned long *addr);
>  extern int kexec_add_buffer(struct kimage *image, char *buffer,
>   unsigned long bufsz, unsigned long memsz,
>   unsigned long buf_align, unsigned long buf_min,
> @@ -315,6 +319,12 @@ int __weak arch_kexec_apply_relocations_add(const 
> Elf_Ehdr *ehdr,
>   Elf_Shdr *sechdrs, unsigned int relsec);
>  int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr 
> *sechdrs,
>   unsigned int relsec);
> +int __weak arch_walk_iomem(unsigned long desc, unsigned long start,
> +unsigned long end, bool top_down, void *data,
> +int (*func)(u64, u64, void *));
> +int __weak arch_walk_system_ram(unsigned long start, unsigned long end,
> + bool top_down, void *data,
> + int (*func)(u64, u64, void *));
>  void arch_kexec_protect_crashkres(void);
>  void arch_kexec_unprotect_crashkres(void);
>  
> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
> index b6eec7527e9f..300f71cb4f72 100644
> --- a/kernel/kexec_file.c
> +++ b/kernel/kexec_file.c
> @@ -428,6 +428,68 @@ static int locate_mem_hole_callback(u64 start, u64 end, 
> void *arg)
>   return locate_mem_hole_bottom_up(start, end, kbuf);
>  }
>  
> +int __weak arch_walk_iomem(unsigned long desc, unsigned long start,
> +unsigned long end, bool top_down, void *data,
> +int (*func)(u64, u64, void *))
> +{
> + return walk_iomem_res_desc(desc,
> +IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
> +start, end, data, func);
> +}
> +
> +int __weak arch_walk_system_ram(unsigned long start, unsigned long end,
> + bool top_down, void *data,
> + int (*func)(u64, u64, void *))
> +{
> + return walk_system_ram_res(start, end, data, func);
> +}
> +
> +/**
> + * kexec_locate_mem_hole - find free memory to load segment or use in 
> purgatory
> + * @image:   kexec image being updated.
> + * @size:Memory size.
> + * @align:   Minimum alignment needed.
> + * @start:   Minimum starting address.
> + * @end: Maximum end address.
> + * @top_down Find the highest free memory region?
> + * @addr On success, will have start address of the memory region found.
> + *
> + * Return: 0 on success, negative erro on failure.
> + */
> +int kexec_locate_mem_hole(struct kimage *image, unsigned long size,
> +   unsigned long align, unsigned long start,
> +   unsigned long end, bool top_down, unsigned long *addr)
> +{
> + int ret;
> + struct kexec_buf buf;
> +
> + memset(, 0, sizeof(struct kexec_buf));
> + buf.image = image;
> +
> + buf.memsz = size;
> + buf.buf_align = align;
> + buf.buf_min = start;
> + buf.buf_max = end;
> + buf.top_down = top_down;
> +
> + /* Walk the RAM ranges and allocate a suitable range for the buffer */
> + if (image->type == KEXEC_TYPE_CRASH)
> + ret = arch_walk_iomem(crashk_res.desc, crashk_res.start,
> +   crashk_res.end, top_down, ,
> +   locate_mem_hole_callback);
> + else
> + ret = arch_walk_system_ram(0, -1, top_down, ,
> +locate_mem_hole_callback);
> + if (ret != 1) {
> + /* A suitable memory range could not be found for