[PATCH 1/2] [Patch-next -v2] ACPI, APEI Fix the return value(==NULL) of acpi_pre_map().

[PATCH 1/2] [Patch-next -v2] ACPI, APEI Fix the return value(==NULL) of acpi_pre_map().

[Jin Dongming]

acpi_pre_map() is used for remapping the physical address of I/O, so
it should be return NULL or remapped virtual address. The problem is
that when (paddr - pg_off) equals 0, no matter whether I/O remapping is
successful or not, the function returns NULL.

In acpi_pre_map(), after the physical address is remapped sucessfully,
it will check whether the physical address has been added into acpi_iomaps
list again.
   - If the physical address has beed added into acpi_iomaps, the virtual
     address will be saved in vaddr.
   - Otherwise, NULL be saved in vaddr.

So if the physical address is the first time to be remapped, vaddr will be
NULL always.

In many cases, (paddr - pg_off) may not equal 0. So the function could work
well. In our machine, (paddr - pg_off) equals 0, so the return value of
acpi_pre_map() is NULL.

This patch fixed it and I confirmed it on x86_64 next-tree.

Signed-off-by: Jin Dongming <jin.dongming@np.css.fujitsu.com>
---
 drivers/acpi/atomicio.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/atomicio.c b/drivers/acpi/atomicio.c
index 8f8bd73..1bc2614 100644
--- a/drivers/acpi/atomicio.c
+++ b/drivers/acpi/atomicio.c
@@ -133,7 +133,7 @@ static void __iomem *acpi_pre_map(phys_addr_t paddr,
 
 	spin_lock_irqsave(&acpi_iomaps_lock, flags);
 	vaddr = __acpi_try_ioremap(paddr, size);
-	if (vaddr) {
+	if (unlikely(vaddr)) {
 		spin_unlock_irqrestore(&acpi_iomaps_lock, flags);
 		iounmap(map->vaddr);
 		kfree(map);
@@ -142,7 +142,7 @@ static void __iomem *acpi_pre_map(phys_addr_t paddr,
 	list_add_tail_rcu(&map->list, &acpi_iomaps);
 	spin_unlock_irqrestore(&acpi_iomaps_lock, flags);
 
-	return vaddr + (paddr - pg_off);
+	return map->vaddr + (paddr - pg_off);
 err_unmap:
 	iounmap(vaddr);
 	return NULL;
-- 
1.7.1.1

Re: [PATCH 1/2] [Patch-next -v2] ACPI, APEI Fix the return value(==NULL) of acpi_pre_map().

[Huang Ying]

On Wed, 2010-08-18 at 07:46 +0800, Jin Dongming wrote:
> acpi_pre_map() is used for remapping the physical address of I/O, so
> it should be return NULL or remapped virtual address. The problem is
> that when (paddr - pg_off) equals 0, no matter whether I/O remapping is
> successful or not, the function returns NULL.
> 
> In acpi_pre_map(), after the physical address is remapped sucessfully,
> it will check whether the physical address has been added into acpi_iomaps
> list again.
>    - If the physical address has beed added into acpi_iomaps, the virtual
>      address will be saved in vaddr.
>    - Otherwise, NULL be saved in vaddr.
> 
> So if the physical address is the first time to be remapped, vaddr will be
> NULL always.
> 
> In many cases, (paddr - pg_off) may not equal 0. So the function could work
> well. In our machine, (paddr - pg_off) equals 0, so the return value of
> acpi_pre_map() is NULL.
> 
> This patch fixed it and I confirmed it on x86_64 next-tree.
> 
> Signed-off-by: Jin Dongming <jin.dongming@np.css.fujitsu.com>
Acked-by: Huang Ying <ying.huang@intel.com>

Best Regards,
Huang Ying

[PATCH 1/2] [Patch-next -v2] ACPI, APEI Fix the return value(==NULL) of acpi_pre_map().

[Jin Dongming]

acpi_pre_map() is used for remapping the physical address of I/O, so
it should be return NULL or remapped virtual address. The problem is
that when (paddr - pg_off) equals 0, no matter whether I/O remapping is
successful or not, the function returns NULL.

In acpi_pre_map(), after the physical address is remapped sucessfully,
it will check whether the physical address has been added into acpi_iomaps
list again.
   - If the physical address has beed added into acpi_iomaps, the virtual
     address will be saved in vaddr.
   - Otherwise, NULL be saved in vaddr.

So if the physical address is the first time to be remapped, vaddr will be
NULL always.

In many cases, (paddr - pg_off) may not equal 0. So the function could work
well. In our machine, (paddr - pg_off) equals 0, so the return value of
acpi_pre_map() is NULL.

This patch fixed it and I confirmed it on x86_64 next-tree.

Signed-off-by: Jin Dongming <jin.dongming@np.css.fujitsu.com>
---
 drivers/acpi/atomicio.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/atomicio.c b/drivers/acpi/atomicio.c
index 8f8bd73..1bc2614 100644
--- a/drivers/acpi/atomicio.c
+++ b/drivers/acpi/atomicio.c
@@ -133,7 +133,7 @@ static void __iomem *acpi_pre_map(phys_addr_t paddr,
 
 	spin_lock_irqsave(&acpi_iomaps_lock, flags);
 	vaddr = __acpi_try_ioremap(paddr, size);
-	if (vaddr) {
+	if (unlikely(vaddr)) {
 		spin_unlock_irqrestore(&acpi_iomaps_lock, flags);
 		iounmap(map->vaddr);
 		kfree(map);
@@ -142,7 +142,7 @@ static void __iomem *acpi_pre_map(phys_addr_t paddr,
 	list_add_tail_rcu(&map->list, &acpi_iomaps);
 	spin_unlock_irqrestore(&acpi_iomaps_lock, flags);
 
-	return vaddr + (paddr - pg_off);
+	return map->vaddr + (paddr - pg_off);
 err_unmap:
 	iounmap(vaddr);
 	return NULL;
-- 1.7.1.1 

Re: [PATCH 1/2] [Patch-next -v2] ACPI, APEI Fix the return value(==NULL) of acpi_pre_map().

[Huang Ying]

On Thu, 2010-09-02 at 10:31 +0800, Jin Dongming wrote:
> acpi_pre_map() is used for remapping the physical address of I/O, so
> it should be return NULL or remapped virtual address. The problem is
> that when (paddr - pg_off) equals 0, no matter whether I/O remapping is
> successful or not, the function returns NULL.
> 
> In acpi_pre_map(), after the physical address is remapped sucessfully,
> it will check whether the physical address has been added into acpi_iomaps
> list again.
>    - If the physical address has beed added into acpi_iomaps, the virtual
>      address will be saved in vaddr.
>    - Otherwise, NULL be saved in vaddr.
> 
> So if the physical address is the first time to be remapped, vaddr will be
> NULL always.
> 
> In many cases, (paddr - pg_off) may not equal 0. So the function could work
> well. In our machine, (paddr - pg_off) equals 0, so the return value of
> acpi_pre_map() is NULL.
> 
> This patch fixed it and I confirmed it on x86_64 next-tree.
> 
> Signed-off-by: Jin Dongming <jin.dongming@np.css.fujitsu.com>
Acked-by: Huang Ying <ying.huang@intel.com>

Best Regards,
Huang Ying

Re: [PATCH 1/2] [Patch-next -v2] ACPI, APEI Fix the return value(==NULL) of acpi_pre_map().

[Jin Dongming]

Hi, All,

I am very sorry for my miss. Please cancel these two patches. I will send the
new patches.

Best Regards,
Jin Dongming.

(2010/09/02 11:31), Jin Dongming wrote:
> acpi_pre_map() is used for remapping the physical address of I/O, so
> it should be return NULL or remapped virtual address. The problem is
> that when (paddr - pg_off) equals 0, no matter whether I/O remapping is
> successful or not, the function returns NULL.
> 
> In acpi_pre_map(), after the physical address is remapped sucessfully,
> it will check whether the physical address has been added into acpi_iomaps
> list again.
>    - If the physical address has beed added into acpi_iomaps, the virtual
>      address will be saved in vaddr.
>    - Otherwise, NULL be saved in vaddr.
> 
> So if the physical address is the first time to be remapped, vaddr will be
> NULL always.
> 
> In many cases, (paddr - pg_off) may not equal 0. So the function could work
> well. In our machine, (paddr - pg_off) equals 0, so the return value of
> acpi_pre_map() is NULL.
> 
> This patch fixed it and I confirmed it on x86_64 next-tree.
> 
> Signed-off-by: Jin Dongming <jin.dongming@np.css.fujitsu.com>
> ---
>  drivers/acpi/atomicio.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/acpi/atomicio.c b/drivers/acpi/atomicio.c
> index 8f8bd73..1bc2614 100644
> --- a/drivers/acpi/atomicio.c
> +++ b/drivers/acpi/atomicio.c
> @@ -133,7 +133,7 @@ static void __iomem *acpi_pre_map(phys_addr_t paddr,
>  
>  	spin_lock_irqsave(&acpi_iomaps_lock, flags);
>  	vaddr = __acpi_try_ioremap(paddr, size);
> -	if (vaddr) {
> +	if (unlikely(vaddr)) {
>  		spin_unlock_irqrestore(&acpi_iomaps_lock, flags);
>  		iounmap(map->vaddr);
>  		kfree(map);
> @@ -142,7 +142,7 @@ static void __iomem *acpi_pre_map(phys_addr_t paddr,
>  	list_add_tail_rcu(&map->list, &acpi_iomaps);
>  	spin_unlock_irqrestore(&acpi_iomaps_lock, flags);
>  
> -	return vaddr + (paddr - pg_off);
> +	return map->vaddr + (paddr - pg_off);
>  err_unmap:
>  	iounmap(vaddr);
>  	return NULL;
> -- 1.7.1.1 
> 
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