Re: [PATCH v2 2/4] DMA: PL330: Change allocation method to properly free DMA descriptors
On 24 October 2012 09:40, Vinod Koul wrote:
> On Fri, 2012-10-05 at 15:47 +0530, Inderpal Singh wrote:
>> In probe, memory for multiple DMA descriptors were being allocated at once
>> and then it was being split and added into DMA pool one by one. The address
>> of this memory allocation is not being saved anywhere. To free this memory,
>> the address is required. Initially the first node of the pool will be
>> pointed by this address but as we use this pool the descs will shuffle and
>> hence we will lose the track of the address.
>>
>> This patch does following:
>>
>> 1. Allocates DMA descs one by one and then adds them to pool so that all
>>descs can be fetched and memory freed one by one. This way runtime
>>added descs can also be freed.
>> 2. Free DMA descs in case of error in probe and in module's remove function
> For probe, again you have cleaner code by using devm_kzalloc.
>
> On 1, if we use the devm_kzalloc then we don't need to allocate in
> chunks right?
>
Yes, if we use devm_kzalloc we wont have to allocate in chunks.
I will update this patch to use devm_kzalloc and send it again.
>>
>> Signed-off-by: Inderpal Singh
>> ---
>> drivers/dma/pl330.c | 35 +--
>> 1 file changed, 25 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
>> index 10c6b6a..bf71ff7 100644
>> --- a/drivers/dma/pl330.c
>> +++ b/drivers/dma/pl330.c
>> @@ -2541,20 +2541,20 @@ static int add_desc(struct dma_pl330_dmac *pdmac,
>> gfp_t flg, int count)
>> if (!pdmac)
>> return 0;
>>
>> - desc = kmalloc(count * sizeof(*desc), flg);
>> - if (!desc)
>> - return 0;
>> + for (i = 0; i < count; i++) {
>> + desc = kmalloc(sizeof(*desc), flg);
>> + if (!desc)
>> + break;
>> + _init_desc(desc);
>>
>> - spin_lock_irqsave(&pdmac->pool_lock, flags);
>> + spin_lock_irqsave(&pdmac->pool_lock, flags);
>>
>> - for (i = 0; i < count; i++) {
>> - _init_desc(&desc[i]);
>> - list_add_tail(&desc[i].node, &pdmac->desc_pool);
>> - }
>> + list_add_tail(&desc->node, &pdmac->desc_pool);
>>
>> - spin_unlock_irqrestore(&pdmac->pool_lock, flags);
>> + spin_unlock_irqrestore(&pdmac->pool_lock, flags);
>> + }
>>
>> - return count;
>> + return i;
>> }
>>
>> static struct dma_pl330_desc *
>> @@ -2857,6 +2857,7 @@ pl330_probe(struct amba_device *adev, const struct
>> amba_id *id)
>> struct dma_pl330_platdata *pdat;
>> struct dma_pl330_dmac *pdmac;
>> struct dma_pl330_chan *pch;
>> + struct dma_pl330_desc *desc;
>> struct pl330_info *pi;
>> struct dma_device *pd;
>> struct resource *res;
>> @@ -2978,6 +2979,12 @@ pl330_probe(struct amba_device *adev, const struct
>> amba_id *id)
>> probe_err5:
>> kfree(pdmac->peripherals);
>> probe_err4:
>> + while (!list_empty(&pdmac->desc_pool)) {
>> + desc = list_entry(pdmac->desc_pool.next,
>> + struct dma_pl330_desc, node);
>> + list_del(&desc->node);
>> + kfree(desc);
>> + }
>> pl330_del(pi);
>> probe_err3:
>> free_irq(irq, pi);
>> @@ -2994,6 +3001,7 @@ static int __devexit pl330_remove(struct amba_device
>> *adev)
>> {
>> struct dma_pl330_dmac *pdmac = amba_get_drvdata(adev);
>> struct dma_pl330_chan *pch, *_p;
>> + struct dma_pl330_desc *desc;
>> struct pl330_info *pi;
>> struct resource *res;
>> int irq;
>> @@ -3015,6 +3023,13 @@ static int __devexit pl330_remove(struct amba_device
>> *adev)
>> pl330_free_chan_resources(&pch->chan);
>> }
>>
>> + while (!list_empty(&pdmac->desc_pool)) {
>> + desc = list_entry(pdmac->desc_pool.next,
>> + struct dma_pl330_desc, node);
>> + list_del(&desc->node);
>> + kfree(desc);
>> + }
>> +
>> pi = &pdmac->pif;
>>
>> pl330_del(pi);
>
>
> --
> Vinod Koul
> Intel Corp.
>
Regards,
Inder
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Re: [PATCH v2 2/4] DMA: PL330: Change allocation method to properly free DMA descriptors
On Fri, 2012-10-05 at 15:47 +0530, Inderpal Singh wrote:
> In probe, memory for multiple DMA descriptors were being allocated at once
> and then it was being split and added into DMA pool one by one. The address
> of this memory allocation is not being saved anywhere. To free this memory,
> the address is required. Initially the first node of the pool will be
> pointed by this address but as we use this pool the descs will shuffle and
> hence we will lose the track of the address.
>
> This patch does following:
>
> 1. Allocates DMA descs one by one and then adds them to pool so that all
>descs can be fetched and memory freed one by one. This way runtime
>added descs can also be freed.
> 2. Free DMA descs in case of error in probe and in module's remove function
For probe, again you have cleaner code by using devm_kzalloc.
On 1, if we use the devm_kzalloc then we don't need to allocate in
chunks right?
>
> Signed-off-by: Inderpal Singh
> ---
> drivers/dma/pl330.c | 35 +--
> 1 file changed, 25 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> index 10c6b6a..bf71ff7 100644
> --- a/drivers/dma/pl330.c
> +++ b/drivers/dma/pl330.c
> @@ -2541,20 +2541,20 @@ static int add_desc(struct dma_pl330_dmac *pdmac,
> gfp_t flg, int count)
> if (!pdmac)
> return 0;
>
> - desc = kmalloc(count * sizeof(*desc), flg);
> - if (!desc)
> - return 0;
> + for (i = 0; i < count; i++) {
> + desc = kmalloc(sizeof(*desc), flg);
> + if (!desc)
> + break;
> + _init_desc(desc);
>
> - spin_lock_irqsave(&pdmac->pool_lock, flags);
> + spin_lock_irqsave(&pdmac->pool_lock, flags);
>
> - for (i = 0; i < count; i++) {
> - _init_desc(&desc[i]);
> - list_add_tail(&desc[i].node, &pdmac->desc_pool);
> - }
> + list_add_tail(&desc->node, &pdmac->desc_pool);
>
> - spin_unlock_irqrestore(&pdmac->pool_lock, flags);
> + spin_unlock_irqrestore(&pdmac->pool_lock, flags);
> + }
>
> - return count;
> + return i;
> }
>
> static struct dma_pl330_desc *
> @@ -2857,6 +2857,7 @@ pl330_probe(struct amba_device *adev, const struct
> amba_id *id)
> struct dma_pl330_platdata *pdat;
> struct dma_pl330_dmac *pdmac;
> struct dma_pl330_chan *pch;
> + struct dma_pl330_desc *desc;
> struct pl330_info *pi;
> struct dma_device *pd;
> struct resource *res;
> @@ -2978,6 +2979,12 @@ pl330_probe(struct amba_device *adev, const struct
> amba_id *id)
> probe_err5:
> kfree(pdmac->peripherals);
> probe_err4:
> + while (!list_empty(&pdmac->desc_pool)) {
> + desc = list_entry(pdmac->desc_pool.next,
> + struct dma_pl330_desc, node);
> + list_del(&desc->node);
> + kfree(desc);
> + }
> pl330_del(pi);
> probe_err3:
> free_irq(irq, pi);
> @@ -2994,6 +3001,7 @@ static int __devexit pl330_remove(struct amba_device
> *adev)
> {
> struct dma_pl330_dmac *pdmac = amba_get_drvdata(adev);
> struct dma_pl330_chan *pch, *_p;
> + struct dma_pl330_desc *desc;
> struct pl330_info *pi;
> struct resource *res;
> int irq;
> @@ -3015,6 +3023,13 @@ static int __devexit pl330_remove(struct amba_device
> *adev)
> pl330_free_chan_resources(&pch->chan);
> }
>
> + while (!list_empty(&pdmac->desc_pool)) {
> + desc = list_entry(pdmac->desc_pool.next,
> + struct dma_pl330_desc, node);
> + list_del(&desc->node);
> + kfree(desc);
> + }
> +
> pi = &pdmac->pif;
>
> pl330_del(pi);
--
Vinod Koul
Intel Corp.
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[PATCH v2 2/4] DMA: PL330: Change allocation method to properly free DMA descriptors
In probe, memory for multiple DMA descriptors were being allocated at once
and then it was being split and added into DMA pool one by one. The address
of this memory allocation is not being saved anywhere. To free this memory,
the address is required. Initially the first node of the pool will be
pointed by this address but as we use this pool the descs will shuffle and
hence we will lose the track of the address.
This patch does following:
1. Allocates DMA descs one by one and then adds them to pool so that all
descs can be fetched and memory freed one by one. This way runtime
added descs can also be freed.
2. Free DMA descs in case of error in probe and in module's remove function
Signed-off-by: Inderpal Singh
---
drivers/dma/pl330.c | 35 +--
1 file changed, 25 insertions(+), 10 deletions(-)
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 10c6b6a..bf71ff7 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -2541,20 +2541,20 @@ static int add_desc(struct dma_pl330_dmac *pdmac, gfp_t
flg, int count)
if (!pdmac)
return 0;
- desc = kmalloc(count * sizeof(*desc), flg);
- if (!desc)
- return 0;
+ for (i = 0; i < count; i++) {
+ desc = kmalloc(sizeof(*desc), flg);
+ if (!desc)
+ break;
+ _init_desc(desc);
- spin_lock_irqsave(&pdmac->pool_lock, flags);
+ spin_lock_irqsave(&pdmac->pool_lock, flags);
- for (i = 0; i < count; i++) {
- _init_desc(&desc[i]);
- list_add_tail(&desc[i].node, &pdmac->desc_pool);
- }
+ list_add_tail(&desc->node, &pdmac->desc_pool);
- spin_unlock_irqrestore(&pdmac->pool_lock, flags);
+ spin_unlock_irqrestore(&pdmac->pool_lock, flags);
+ }
- return count;
+ return i;
}
static struct dma_pl330_desc *
@@ -2857,6 +2857,7 @@ pl330_probe(struct amba_device *adev, const struct
amba_id *id)
struct dma_pl330_platdata *pdat;
struct dma_pl330_dmac *pdmac;
struct dma_pl330_chan *pch;
+ struct dma_pl330_desc *desc;
struct pl330_info *pi;
struct dma_device *pd;
struct resource *res;
@@ -2978,6 +2979,12 @@ pl330_probe(struct amba_device *adev, const struct
amba_id *id)
probe_err5:
kfree(pdmac->peripherals);
probe_err4:
+ while (!list_empty(&pdmac->desc_pool)) {
+ desc = list_entry(pdmac->desc_pool.next,
+ struct dma_pl330_desc, node);
+ list_del(&desc->node);
+ kfree(desc);
+ }
pl330_del(pi);
probe_err3:
free_irq(irq, pi);
@@ -2994,6 +3001,7 @@ static int __devexit pl330_remove(struct amba_device
*adev)
{
struct dma_pl330_dmac *pdmac = amba_get_drvdata(adev);
struct dma_pl330_chan *pch, *_p;
+ struct dma_pl330_desc *desc;
struct pl330_info *pi;
struct resource *res;
int irq;
@@ -3015,6 +3023,13 @@ static int __devexit pl330_remove(struct amba_device
*adev)
pl330_free_chan_resources(&pch->chan);
}
+ while (!list_empty(&pdmac->desc_pool)) {
+ desc = list_entry(pdmac->desc_pool.next,
+ struct dma_pl330_desc, node);
+ list_del(&desc->node);
+ kfree(desc);
+ }
+
pi = &pdmac->pif;
pl330_del(pi);
--
1.7.9.5
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