diff mbox

irqchip/gicv3-its: Avoid cache flush beyond ITS_BASERn memory size

Message ID 1455594112-27783-1-git-send-email-shankerd@codeaurora.org (mailing list archive)
State New, archived
Headers show

Commit Message

Shanker Donthineni Feb. 16, 2016, 3:41 a.m. UTC
Function its_alloc_tables() maintains two local variables, "order" and
and "alloc_size", to hold memory size that has been allocated to
ITS_BASEn. We don't always refresh the variable alloc_size whenever
value of the variable order changes, causing the following two problems.

  - Cache flush operation with size more than required.
  - Information reported by pr_info is not correct.

Use a helper macro that converts page order to size in bytes instead of
variable "alloc_size" to fix both the problems.

Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
---
 drivers/irqchip/irq-gic-v3-its.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

Comments

Marc Zyngier Feb. 16, 2016, 8:35 a.m. UTC | #1
On Mon, 15 Feb 2016 21:41:52 -0600
Shanker Donthineni <shankerd@codeaurora.org> wrote:

> Function its_alloc_tables() maintains two local variables, "order" and
> and "alloc_size", to hold memory size that has been allocated to
> ITS_BASEn. We don't always refresh the variable alloc_size whenever
> value of the variable order changes, causing the following two problems.
> 
>   - Cache flush operation with size more than required.
>   - Information reported by pr_info is not correct.
> 
> Use a helper macro that converts page order to size in bytes instead of
> variable "alloc_size" to fix both the problems.
> 
> Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
> ---
>  drivers/irqchip/irq-gic-v3-its.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index 0a73632..6f717f7 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -78,6 +78,9 @@ struct its_node {
>  
>  #define ITS_ITT_ALIGN		SZ_256
>  
> +/* Convert page order to size in bytes */
> +#define PAGE_ORDER_TO_BYTES(o)	(PAGE_SIZE << (o))
> +

nit: PAGE_ORDER_TO_size() seems more appropriate.

>  struct event_lpi_map {
>  	unsigned long		*lpi_map;
>  	u16			*col_map;
> @@ -846,7 +849,6 @@ static int its_alloc_tables(const char *node_name, struct its_node *its)
>  		u64 type = GITS_BASER_TYPE(val);
>  		u64 entry_size = GITS_BASER_ENTRY_SIZE(val);
>  		int order = get_order(psz);
> -		int alloc_size;
>  		int alloc_pages;
>  		u64 tmp;
>  		void *base;
> @@ -878,9 +880,8 @@ static int its_alloc_tables(const char *node_name, struct its_node *its)
>  			}
>  		}
>  
> -		alloc_size = (1 << order) * PAGE_SIZE;
>  retry_alloc_baser:
> -		alloc_pages = (alloc_size / psz);
> +		alloc_pages = (PAGE_ORDER_TO_BYTES(order) / psz);
>  		if (alloc_pages > GITS_BASER_PAGES_MAX) {
>  			alloc_pages = GITS_BASER_PAGES_MAX;
>  			order = get_order(GITS_BASER_PAGES_MAX * psz);
> @@ -933,7 +934,8 @@ retry_baser:
>  			shr = tmp & GITS_BASER_SHAREABILITY_MASK;
>  			if (!shr) {
>  				cache = GITS_BASER_nC;
> -				__flush_dcache_area(base, alloc_size);
> +				__flush_dcache_area(base,
> +						    PAGE_ORDER_TO_BYTES(order));

Please keep it on the same line. It helps my random grepping...

>  			}
>  			goto retry_baser;
>  		}
> @@ -966,7 +968,7 @@ retry_baser:
>  		}
>  
>  		pr_info("ITS: allocated %d %s @%lx (psz %dK, shr %d)\n",
> -			(int)(alloc_size / entry_size),
> +			(int)(PAGE_ORDER_TO_BYTES(order) / entry_size),
>  			its_base_type_string[type],
>  			(unsigned long)virt_to_phys(base),
>  			psz / SZ_1K, (int)shr >> GITS_BASER_SHAREABILITY_SHIFT);


Otherwise looks good.

Thanks,

	M.
Shanker Donthineni Feb. 16, 2016, 11:03 p.m. UTC | #2
Hi Marc,

On 02/16/2016 02:35 AM, Marc Zyngier wrote:
> On Mon, 15 Feb 2016 21:41:52 -0600
> Shanker Donthineni <shankerd@codeaurora.org> wrote:
>
>> Function its_alloc_tables() maintains two local variables, "order" and
>> and "alloc_size", to hold memory size that has been allocated to
>> ITS_BASEn. We don't always refresh the variable alloc_size whenever
>> value of the variable order changes, causing the following two problems.
>>
>>    - Cache flush operation with size more than required.
>>    - Information reported by pr_info is not correct.
>>
>> Use a helper macro that converts page order to size in bytes instead of
>> variable "alloc_size" to fix both the problems.
>>
>> Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
>> ---
>>   drivers/irqchip/irq-gic-v3-its.c | 12 +++++++-----
>>   1 file changed, 7 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
>> index 0a73632..6f717f7 100644
>> --- a/drivers/irqchip/irq-gic-v3-its.c
>> +++ b/drivers/irqchip/irq-gic-v3-its.c
>> @@ -78,6 +78,9 @@ struct its_node {
>>   
>>   #define ITS_ITT_ALIGN		SZ_256
>>   
>> +/* Convert page order to size in bytes */
>> +#define PAGE_ORDER_TO_BYTES(o)	(PAGE_SIZE << (o))
>> +
> nit: PAGE_ORDER_TO_size() seems more appropriate.
>
I will change to PAGE_ORDER_TO_SIZE in v2 patch.

>>   struct event_lpi_map {
>>   	unsigned long		*lpi_map;
>>   	u16			*col_map;
>> @@ -846,7 +849,6 @@ static int its_alloc_tables(const char *node_name, struct its_node *its)
>>   		u64 type = GITS_BASER_TYPE(val);
>>   		u64 entry_size = GITS_BASER_ENTRY_SIZE(val);
>>   		int order = get_order(psz);
>> -		int alloc_size;
>>   		int alloc_pages;
>>   		u64 tmp;
>>   		void *base;
>> @@ -878,9 +880,8 @@ static int its_alloc_tables(const char *node_name, struct its_node *its)
>>   			}
>>   		}
>>   
>> -		alloc_size = (1 << order) * PAGE_SIZE;
>>   retry_alloc_baser:
>> -		alloc_pages = (alloc_size / psz);
>> +		alloc_pages = (PAGE_ORDER_TO_BYTES(order) / psz);
>>   		if (alloc_pages > GITS_BASER_PAGES_MAX) {
>>   			alloc_pages = GITS_BASER_PAGES_MAX;
>>   			order = get_order(GITS_BASER_PAGES_MAX * psz);
>> @@ -933,7 +934,8 @@ retry_baser:
>>   			shr = tmp & GITS_BASER_SHAREABILITY_MASK;
>>   			if (!shr) {
>>   				cache = GITS_BASER_nC;
>> -				__flush_dcache_area(base, alloc_size);
>> +				__flush_dcache_area(base,
>> +						    PAGE_ORDER_TO_BYTES(order));
> Please keep it on the same line. It helps my random grepping...
Sure, I will keep it on the same line in v2 patch.

>>   			}
>>   			goto retry_baser;
>>   		}
>> @@ -966,7 +968,7 @@ retry_baser:
>>   		}
>>   
>>   		pr_info("ITS: allocated %d %s @%lx (psz %dK, shr %d)\n",
>> -			(int)(alloc_size / entry_size),
>> +			(int)(PAGE_ORDER_TO_BYTES(order) / entry_size),
>>   			its_base_type_string[type],
>>   			(unsigned long)virt_to_phys(base),
>>   			psz / SZ_1K, (int)shr >> GITS_BASER_SHAREABILITY_SHIFT);
>
> Otherwise looks good.
>
> Thanks,
>
> 	M.
Shanker Donthineni Feb. 16, 2016, 11:08 p.m. UTC | #3
Hi Marc,

On 02/16/2016 02:35 AM, Marc Zyngier wrote:
> On Mon, 15 Feb 2016 21:41:52 -0600
> Shanker Donthineni <shankerd@codeaurora.org> wrote:
>
>> Function its_alloc_tables() maintains two local variables, "order" and
>> and "alloc_size", to hold memory size that has been allocated to
>> ITS_BASEn. We don't always refresh the variable alloc_size whenever
>> value of the variable order changes, causing the following two problems.
>>
>>    - Cache flush operation with size more than required.
>>    - Information reported by pr_info is not correct.
>>
>> Use a helper macro that converts page order to size in bytes instead of
>> variable "alloc_size" to fix both the problems.
>>
>> Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
>> ---
>>   drivers/irqchip/irq-gic-v3-its.c | 12 +++++++-----
>>   1 file changed, 7 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
>> index 0a73632..6f717f7 100644
>> --- a/drivers/irqchip/irq-gic-v3-its.c
>> +++ b/drivers/irqchip/irq-gic-v3-its.c
>> @@ -78,6 +78,9 @@ struct its_node {
>>   
>>   #define ITS_ITT_ALIGN		SZ_256
>>   
>> +/* Convert page order to size in bytes */
>> +#define PAGE_ORDER_TO_BYTES(o)	(PAGE_SIZE << (o))
>> +
> nit: PAGE_ORDER_TO_size() seems more appropriate.
I will change to PAGE_ORDER_TO_SIZE in v2 patch.
>>   struct event_lpi_map {
>>   	unsigned long		*lpi_map;
>>   	u16			*col_map;
>> @@ -846,7 +849,6 @@ static int its_alloc_tables(const char *node_name, struct its_node *its)
>>   		u64 type = GITS_BASER_TYPE(val);
>>   		u64 entry_size = GITS_BASER_ENTRY_SIZE(val);
>>   		int order = get_order(psz);
>> -		int alloc_size;
>>   		int alloc_pages;
>>   		u64 tmp;
>>   		void *base;
>> @@ -878,9 +880,8 @@ static int its_alloc_tables(const char *node_name, struct its_node *its)
>>   			}
>>   		}
>>   
>> -		alloc_size = (1 << order) * PAGE_SIZE;
>>   retry_alloc_baser:
>> -		alloc_pages = (alloc_size / psz);
>> +		alloc_pages = (PAGE_ORDER_TO_BYTES(order) / psz);
>>   		if (alloc_pages > GITS_BASER_PAGES_MAX) {
>>   			alloc_pages = GITS_BASER_PAGES_MAX;
>>   			order = get_order(GITS_BASER_PAGES_MAX * psz);
>> @@ -933,7 +934,8 @@ retry_baser:
>>   			shr = tmp & GITS_BASER_SHAREABILITY_MASK;
>>   			if (!shr) {
>>   				cache = GITS_BASER_nC;
>> -				__flush_dcache_area(base, alloc_size);
>> +				__flush_dcache_area(base,
>> +						    PAGE_ORDER_TO_BYTES(order));
> Please keep it on the same line. It helps my random grepping...

Sure, I will keep it on the same line in v2 patch.

>>   			}
>>   			goto retry_baser;
>>   		}
>> @@ -966,7 +968,7 @@ retry_baser:
>>   		}
>>   
>>   		pr_info("ITS: allocated %d %s @%lx (psz %dK, shr %d)\n",
>> -			(int)(alloc_size / entry_size),
>> +			(int)(PAGE_ORDER_TO_BYTES(order) / entry_size),
>>   			its_base_type_string[type],
>>   			(unsigned long)virt_to_phys(base),
>>   			psz / SZ_1K, (int)shr >> GITS_BASER_SHAREABILITY_SHIFT);
>
> Otherwise looks good.
>
> Thanks,
>
> 	M.
Shanker Donthineni Feb. 16, 2016, 11:27 p.m. UTC | #4
Hi Marc,

On 02/16/2016 02:35 AM, Marc Zyngier wrote:
> On Mon, 15 Feb 2016 21:41:52 -0600
> Shanker Donthineni <shankerd@codeaurora.org> wrote:
>
>> Function its_alloc_tables() maintains two local variables, "order" and
>> and "alloc_size", to hold memory size that has been allocated to
>> ITS_BASEn. We don't always refresh the variable alloc_size whenever
>> value of the variable order changes, causing the following two problems.
>>
>>    - Cache flush operation with size more than required.
>>    - Information reported by pr_info is not correct.
>>
>> Use a helper macro that converts page order to size in bytes instead of
>> variable "alloc_size" to fix both the problems.
>>
>> Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
>> ---
>>   drivers/irqchip/irq-gic-v3-its.c | 12 +++++++-----
>>   1 file changed, 7 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
>> index 0a73632..6f717f7 100644
>> --- a/drivers/irqchip/irq-gic-v3-its.c
>> +++ b/drivers/irqchip/irq-gic-v3-its.c
>> @@ -78,6 +78,9 @@ struct its_node {
>>   
>>   #define ITS_ITT_ALIGN		SZ_256
>>   
>> +/* Convert page order to size in bytes */
>> +#define PAGE_ORDER_TO_BYTES(o)	(PAGE_SIZE << (o))
>> +
> nit: PAGE_ORDER_TO_size() seems more appropriate.

I will change to PAGE_ORDER_TO_SIZE in v2 patch.

>>   struct event_lpi_map {
>>   	unsigned long		*lpi_map;
>>   	u16			*col_map;
>> @@ -846,7 +849,6 @@ static int its_alloc_tables(const char *node_name, struct its_node *its)
>>   		u64 type = GITS_BASER_TYPE(val);
>>   		u64 entry_size = GITS_BASER_ENTRY_SIZE(val);
>>   		int order = get_order(psz);
>> -		int alloc_size;
>>   		int alloc_pages;
>>   		u64 tmp;
>>   		void *base;
>> @@ -878,9 +880,8 @@ static int its_alloc_tables(const char *node_name, struct its_node *its)
>>   			}
>>   		}
>>   
>> -		alloc_size = (1 << order) * PAGE_SIZE;
>>   retry_alloc_baser:
>> -		alloc_pages = (alloc_size / psz);
>> +		alloc_pages = (PAGE_ORDER_TO_BYTES(order) / psz);
>>   		if (alloc_pages > GITS_BASER_PAGES_MAX) {
>>   			alloc_pages = GITS_BASER_PAGES_MAX;
>>   			order = get_order(GITS_BASER_PAGES_MAX * psz);
>> @@ -933,7 +934,8 @@ retry_baser:
>>   			shr = tmp & GITS_BASER_SHAREABILITY_MASK;
>>   			if (!shr) {
>>   				cache = GITS_BASER_nC;
>> -				__flush_dcache_area(base, alloc_size);
>> +				__flush_dcache_area(base,
>> +						    PAGE_ORDER_TO_BYTES(order));
> Please keep it on the same line. It helps my random grepping...

Sure, I will keep it on the same line in v2 patch.

>>   			}
>>   			goto retry_baser;
>>   		}
>> @@ -966,7 +968,7 @@ retry_baser:
>>   		}
>>   
>>   		pr_info("ITS: allocated %d %s @%lx (psz %dK, shr %d)\n",
>> -			(int)(alloc_size / entry_size),
>> +			(int)(PAGE_ORDER_TO_BYTES(order) / entry_size),
>>   			its_base_type_string[type],
>>   			(unsigned long)virt_to_phys(base),
>>   			psz / SZ_1K, (int)shr >> GITS_BASER_SHAREABILITY_SHIFT);
>
> Otherwise looks good.
>
> Thanks,
>
> 	M.
diff mbox

Patch

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 0a73632..6f717f7 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -78,6 +78,9 @@  struct its_node {
 
 #define ITS_ITT_ALIGN		SZ_256
 
+/* Convert page order to size in bytes */
+#define PAGE_ORDER_TO_BYTES(o)	(PAGE_SIZE << (o))
+
 struct event_lpi_map {
 	unsigned long		*lpi_map;
 	u16			*col_map;
@@ -846,7 +849,6 @@  static int its_alloc_tables(const char *node_name, struct its_node *its)
 		u64 type = GITS_BASER_TYPE(val);
 		u64 entry_size = GITS_BASER_ENTRY_SIZE(val);
 		int order = get_order(psz);
-		int alloc_size;
 		int alloc_pages;
 		u64 tmp;
 		void *base;
@@ -878,9 +880,8 @@  static int its_alloc_tables(const char *node_name, struct its_node *its)
 			}
 		}
 
-		alloc_size = (1 << order) * PAGE_SIZE;
 retry_alloc_baser:
-		alloc_pages = (alloc_size / psz);
+		alloc_pages = (PAGE_ORDER_TO_BYTES(order) / psz);
 		if (alloc_pages > GITS_BASER_PAGES_MAX) {
 			alloc_pages = GITS_BASER_PAGES_MAX;
 			order = get_order(GITS_BASER_PAGES_MAX * psz);
@@ -933,7 +934,8 @@  retry_baser:
 			shr = tmp & GITS_BASER_SHAREABILITY_MASK;
 			if (!shr) {
 				cache = GITS_BASER_nC;
-				__flush_dcache_area(base, alloc_size);
+				__flush_dcache_area(base,
+						    PAGE_ORDER_TO_BYTES(order));
 			}
 			goto retry_baser;
 		}
@@ -966,7 +968,7 @@  retry_baser:
 		}
 
 		pr_info("ITS: allocated %d %s @%lx (psz %dK, shr %d)\n",
-			(int)(alloc_size / entry_size),
+			(int)(PAGE_ORDER_TO_BYTES(order) / entry_size),
 			its_base_type_string[type],
 			(unsigned long)virt_to_phys(base),
 			psz / SZ_1K, (int)shr >> GITS_BASER_SHAREABILITY_SHIFT);