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[Qemu-devel] [PATCH 03/14] sdhci: use the ldst_le_dma() API

Philippe Mathieu-Daudé posted 14 patches 8 years, 1 month ago
[Qemu-devel] [PATCH 03/14] sdhci: use the ldst_le_dma() API
Posted by Philippe Mathieu-Daudé 8 years, 1 month ago 
This makes the code slightly safer, also easier to review.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/sd/sdhci.c | 23 +++++++----------------
 1 file changed, 7 insertions(+), 16 deletions(-)

diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c
index 312b167bfa..e39623baba 100644
--- a/hw/sd/sdhci.c
+++ b/hw/sd/sdhci.c
@@ -603,14 +603,12 @@ typedef struct ADMADescr {
 
 static void get_adma_description(SDHCIState *s, ADMADescr *dscr)
 {
-    uint32_t adma1 = 0;
-    uint64_t adma2 = 0;
+    uint32_t adma1;
+    uint64_t adma2;
     hwaddr entry_addr = (hwaddr)s->admasysaddr;
     switch (SDHC_DMA_TYPE(s->hostctl)) {
     case SDHC_CTRL_ADMA2_32:
-        dma_memory_read(&address_space_memory, entry_addr, (uint8_t *)&adma2,
-                        sizeof(adma2));
-        adma2 = le64_to_cpu(adma2);
+        adma2 = ldq_le_dma(&address_space_memory, entry_addr);
         /* The spec does not specify endianness of descriptor table.
          * We currently assume that it is LE.
          */
@@ -620,9 +618,7 @@ static void get_adma_description(SDHCIState *s, ADMADescr *dscr)
         dscr->incr = 8;
         break;
     case SDHC_CTRL_ADMA1_32:
-        dma_memory_read(&address_space_memory, entry_addr, (uint8_t *)&adma1,
-                        sizeof(adma1));
-        adma1 = le32_to_cpu(adma1);
+        adma1 = ldl_le_dma(&address_space_memory, entry_addr);
         dscr->addr = (hwaddr)(adma1 & 0xFFFFF000);
         dscr->attr = (uint8_t)extract32(adma1, 0, 7);
         dscr->incr = 4;
@@ -633,14 +629,9 @@ static void get_adma_description(SDHCIState *s, ADMADescr *dscr)
         }
         break;
     case SDHC_CTRL_ADMA2_64:
-        dma_memory_read(&address_space_memory, entry_addr,
-                        (uint8_t *)(&dscr->attr), 1);
-        dma_memory_read(&address_space_memory, entry_addr + 2,
-                        (uint8_t *)(&dscr->length), 2);
-        dscr->length = le16_to_cpu(dscr->length);
-        dma_memory_read(&address_space_memory, entry_addr + 4,
-                        (uint8_t *)(&dscr->addr), 8);
-        dscr->attr = le64_to_cpu(dscr->attr);
+        dscr->attr = ldub_dma(&address_space_memory, entry_addr);
+        dscr->length = lduw_le_dma(&address_space_memory, entry_addr + 2);
+        dscr->attr = ldq_le_dma(&address_space_memory, entry_addr + 4);
         dscr->attr &= 0xfffffff8;
         dscr->incr = 12;
         break;
-- 
2.15.1
Re: [Qemu-devel] [PATCH 03/14] sdhci: use the ldst_le_dma() API
Posted by Alistair Francis 8 years, 1 month ago 
On Wed, Dec 13, 2017 at 11:58 AM, Philippe Mathieu-Daudé
<f4bug@amsat.org> wrote:
> This makes the code slightly safer, also easier to review.
>
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>  hw/sd/sdhci.c | 23 +++++++----------------
>  1 file changed, 7 insertions(+), 16 deletions(-)
>
> diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c
> index 312b167bfa..e39623baba 100644
> --- a/hw/sd/sdhci.c
> +++ b/hw/sd/sdhci.c
> @@ -603,14 +603,12 @@ typedef struct ADMADescr {
>
>  static void get_adma_description(SDHCIState *s, ADMADescr *dscr)
>  {
> -    uint32_t adma1 = 0;
> -    uint64_t adma2 = 0;
> +    uint32_t adma1;
> +    uint64_t adma2;
>      hwaddr entry_addr = (hwaddr)s->admasysaddr;
>      switch (SDHC_DMA_TYPE(s->hostctl)) {
>      case SDHC_CTRL_ADMA2_32:
> -        dma_memory_read(&address_space_memory, entry_addr, (uint8_t *)&adma2,
> -                        sizeof(adma2));
> -        adma2 = le64_to_cpu(adma2);
> +        adma2 = ldq_le_dma(&address_space_memory, entry_addr);
>          /* The spec does not specify endianness of descriptor table.
>           * We currently assume that it is LE.
>           */
> @@ -620,9 +618,7 @@ static void get_adma_description(SDHCIState *s, ADMADescr *dscr)
>          dscr->incr = 8;
>          break;
>      case SDHC_CTRL_ADMA1_32:
> -        dma_memory_read(&address_space_memory, entry_addr, (uint8_t *)&adma1,
> -                        sizeof(adma1));
> -        adma1 = le32_to_cpu(adma1);
> +        adma1 = ldl_le_dma(&address_space_memory, entry_addr);
>          dscr->addr = (hwaddr)(adma1 & 0xFFFFF000);
>          dscr->attr = (uint8_t)extract32(adma1, 0, 7);
>          dscr->incr = 4;
> @@ -633,14 +629,9 @@ static void get_adma_description(SDHCIState *s, ADMADescr *dscr)
>          }
>          break;
>      case SDHC_CTRL_ADMA2_64:
> -        dma_memory_read(&address_space_memory, entry_addr,
> -                        (uint8_t *)(&dscr->attr), 1);
> -        dma_memory_read(&address_space_memory, entry_addr + 2,
> -                        (uint8_t *)(&dscr->length), 2);
> -        dscr->length = le16_to_cpu(dscr->length);
> -        dma_memory_read(&address_space_memory, entry_addr + 4,
> -                        (uint8_t *)(&dscr->addr), 8);
> -        dscr->attr = le64_to_cpu(dscr->attr);

> +        dscr->attr = ldub_dma(&address_space_memory, entry_addr);
> +        dscr->length = lduw_le_dma(&address_space_memory, entry_addr + 2);
> +        dscr->attr = ldq_le_dma(&address_space_memory, entry_addr + 4);

Why this is being overwritten?

It looks like you have dropped an addr as well.

Alistair

>          dscr->attr &= 0xfffffff8;
>          dscr->incr = 12;
>          break;
> --
> 2.15.1
>
>
Re: [Qemu-devel] [PATCH 03/14] sdhci: use the ldst_le_dma() API
Posted by Philippe Mathieu-Daudé 8 years, 1 month ago 
On Thu, Dec 14, 2017 at 2:23 PM, Alistair Francis
<alistair.francis@xilinx.com> wrote:
> On Wed, Dec 13, 2017 at 11:58 AM, Philippe Mathieu-Daudé
> <f4bug@amsat.org> wrote:
>> This makes the code slightly safer, also easier to review.
>>
>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>> ---
>>  hw/sd/sdhci.c | 23 +++++++----------------
>>  1 file changed, 7 insertions(+), 16 deletions(-)
>>
>> diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c
>> index 312b167bfa..e39623baba 100644
>> --- a/hw/sd/sdhci.c
>> +++ b/hw/sd/sdhci.c
>> @@ -603,14 +603,12 @@ typedef struct ADMADescr {
>>
>>  static void get_adma_description(SDHCIState *s, ADMADescr *dscr)
>>  {
>> -    uint32_t adma1 = 0;
>> -    uint64_t adma2 = 0;
>> +    uint32_t adma1;
>> +    uint64_t adma2;
>>      hwaddr entry_addr = (hwaddr)s->admasysaddr;
>>      switch (SDHC_DMA_TYPE(s->hostctl)) {
>>      case SDHC_CTRL_ADMA2_32:
>> -        dma_memory_read(&address_space_memory, entry_addr, (uint8_t *)&adma2,
>> -                        sizeof(adma2));
>> -        adma2 = le64_to_cpu(adma2);
>> +        adma2 = ldq_le_dma(&address_space_memory, entry_addr);
>>          /* The spec does not specify endianness of descriptor table.
>>           * We currently assume that it is LE.
>>           */
>> @@ -620,9 +618,7 @@ static void get_adma_description(SDHCIState *s, ADMADescr *dscr)
>>          dscr->incr = 8;
>>          break;
>>      case SDHC_CTRL_ADMA1_32:
>> -        dma_memory_read(&address_space_memory, entry_addr, (uint8_t *)&adma1,
>> -                        sizeof(adma1));
>> -        adma1 = le32_to_cpu(adma1);
>> +        adma1 = ldl_le_dma(&address_space_memory, entry_addr);
>>          dscr->addr = (hwaddr)(adma1 & 0xFFFFF000);
>>          dscr->attr = (uint8_t)extract32(adma1, 0, 7);
>>          dscr->incr = 4;
>> @@ -633,14 +629,9 @@ static void get_adma_description(SDHCIState *s, ADMADescr *dscr)
>>          }
>>          break;
>>      case SDHC_CTRL_ADMA2_64:
>> -        dma_memory_read(&address_space_memory, entry_addr,
>> -                        (uint8_t *)(&dscr->attr), 1);
>> -        dma_memory_read(&address_space_memory, entry_addr + 2,
>> -                        (uint8_t *)(&dscr->length), 2);
>> -        dscr->length = le16_to_cpu(dscr->length);
>> -        dma_memory_read(&address_space_memory, entry_addr + 4,
>> -                        (uint8_t *)(&dscr->addr), 8);
>> -        dscr->attr = le64_to_cpu(dscr->attr);
>
>> +        dscr->attr = ldub_dma(&address_space_memory, entry_addr);
>> +        dscr->length = lduw_le_dma(&address_space_memory, entry_addr + 2);
>> +        dscr->attr = ldq_le_dma(&address_space_memory, entry_addr + 4);
>
> Why this is being overwritten?

Do you mean 'rewritten'?

> It looks like you have dropped an addr as well.

Which addr? The diff is a bit compressed, if you separate it is more obvious:

 -        dma_memory_read(&address_space_memory, entry_addr,
 -                        (uint8_t *)(&dscr->attr), 1);
 +        dscr->attr = ldub_dma(&address_space_memory, entry_addr);


 -        dma_memory_read(&address_space_memory, entry_addr + 2,
 -                        (uint8_t *)(&dscr->length), 2);
 -        dscr->length = le16_to_cpu(dscr->length);
 +        dscr->length = lduw_le_dma(&address_space_memory, entry_addr + 2);


 -        dma_memory_read(&address_space_memory, entry_addr + 4,
 -                        (uint8_t *)(&dscr->addr), 8);
 -        dscr->attr = le64_to_cpu(dscr->attr);
 +        dscr->attr = ldq_le_dma(&address_space_memory, entry_addr + 4);

The API is detailled in this file: docs/devel/loads-stores.rst

I decided to rewrite this code with this API because it looks easier
to understand (maybe once you read the API doc), so easier to review
:)
Re: [Qemu-devel] [PATCH 03/14] sdhci: use the ldst_le_dma() API
Posted by Alistair Francis 8 years, 1 month ago 
On Thu, Dec 14, 2017 at 3:21 PM, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
> On Thu, Dec 14, 2017 at 2:23 PM, Alistair Francis
> <alistair.francis@xilinx.com> wrote:
>> On Wed, Dec 13, 2017 at 11:58 AM, Philippe Mathieu-Daudé
>> <f4bug@amsat.org> wrote:
>>> This makes the code slightly safer, also easier to review.
>>>
>>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>>> ---
>>>  hw/sd/sdhci.c | 23 +++++++----------------
>>>  1 file changed, 7 insertions(+), 16 deletions(-)
>>>
>>> diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c
>>> index 312b167bfa..e39623baba 100644
>>> --- a/hw/sd/sdhci.c
>>> +++ b/hw/sd/sdhci.c
>>> @@ -603,14 +603,12 @@ typedef struct ADMADescr {
>>>
>>>  static void get_adma_description(SDHCIState *s, ADMADescr *dscr)
>>>  {
>>> -    uint32_t adma1 = 0;
>>> -    uint64_t adma2 = 0;
>>> +    uint32_t adma1;
>>> +    uint64_t adma2;
>>>      hwaddr entry_addr = (hwaddr)s->admasysaddr;
>>>      switch (SDHC_DMA_TYPE(s->hostctl)) {
>>>      case SDHC_CTRL_ADMA2_32:
>>> -        dma_memory_read(&address_space_memory, entry_addr, (uint8_t *)&adma2,
>>> -                        sizeof(adma2));
>>> -        adma2 = le64_to_cpu(adma2);
>>> +        adma2 = ldq_le_dma(&address_space_memory, entry_addr);
>>>          /* The spec does not specify endianness of descriptor table.
>>>           * We currently assume that it is LE.
>>>           */
>>> @@ -620,9 +618,7 @@ static void get_adma_description(SDHCIState *s, ADMADescr *dscr)
>>>          dscr->incr = 8;
>>>          break;
>>>      case SDHC_CTRL_ADMA1_32:
>>> -        dma_memory_read(&address_space_memory, entry_addr, (uint8_t *)&adma1,
>>> -                        sizeof(adma1));
>>> -        adma1 = le32_to_cpu(adma1);
>>> +        adma1 = ldl_le_dma(&address_space_memory, entry_addr);
>>>          dscr->addr = (hwaddr)(adma1 & 0xFFFFF000);
>>>          dscr->attr = (uint8_t)extract32(adma1, 0, 7);
>>>          dscr->incr = 4;
>>> @@ -633,14 +629,9 @@ static void get_adma_description(SDHCIState *s, ADMADescr *dscr)
>>>          }
>>>          break;
>>>      case SDHC_CTRL_ADMA2_64:
>>> -        dma_memory_read(&address_space_memory, entry_addr,
>>> -                        (uint8_t *)(&dscr->attr), 1);
>>> -        dma_memory_read(&address_space_memory, entry_addr + 2,
>>> -                        (uint8_t *)(&dscr->length), 2);
>>> -        dscr->length = le16_to_cpu(dscr->length);
>>> -        dma_memory_read(&address_space_memory, entry_addr + 4,
>>> -                        (uint8_t *)(&dscr->addr), 8);
>>> -        dscr->attr = le64_to_cpu(dscr->attr);
>>
>>> +        dscr->attr = ldub_dma(&address_space_memory, entry_addr);
>>> +        dscr->length = lduw_le_dma(&address_space_memory, entry_addr + 2);
>>> +        dscr->attr = ldq_le_dma(&address_space_memory, entry_addr + 4);
>>
>> Why this is being overwritten?
>
> Do you mean 'rewritten'?
>
>> It looks like you have dropped an addr as well.
>
> Which addr? The diff is a bit compressed, if you separate it is more obvious:
>
>  -        dma_memory_read(&address_space_memory, entry_addr,
>  -                        (uint8_t *)(&dscr->attr), 1);
>  +        dscr->attr = ldub_dma(&address_space_memory, entry_addr);

This is rewritten later, why bother setting this here?

>
>
>  -        dma_memory_read(&address_space_memory, entry_addr + 2,
>  -                        (uint8_t *)(&dscr->length), 2);
>  -        dscr->length = le16_to_cpu(dscr->length);
>  +        dscr->length = lduw_le_dma(&address_space_memory, entry_addr + 2);
>
>
>  -        dma_memory_read(&address_space_memory, entry_addr + 4,
>  -                        (uint8_t *)(&dscr->addr), 8);

What about dscr->addr which is set here?

Alistair

>  -        dscr->attr = le64_to_cpu(dscr->attr);
>  +        dscr->attr = ldq_le_dma(&address_space_memory, entry_addr + 4);
>
> The API is detailled in this file: docs/devel/loads-stores.rst
>
> I decided to rewrite this code with this API because it looks easier
> to understand (maybe once you read the API doc), so easier to review
> :)
>
Re: [Qemu-devel] [PATCH 03/14] sdhci: use the ldst_le_dma() API
Posted by Philippe Mathieu-Daudé 8 years, 1 month ago 
> This is rewritten later, why bother setting this here?
>
>>
>>
>>  -        dma_memory_read(&address_space_memory, entry_addr + 2,
>>  -                        (uint8_t *)(&dscr->length), 2);
>>  -        dscr->length = le16_to_cpu(dscr->length);
>>  +        dscr->length = lduw_le_dma(&address_space_memory, entry_addr + 2);
>>
>>
>>  -        dma_memory_read(&address_space_memory, entry_addr + 4,
>>  -                        (uint8_t *)(&dscr->addr), 8);
>
> What about dscr->addr which is set here?

Oops. I'll drop this patch.

>>  -        dscr->attr = le64_to_cpu(dscr->attr);
>>  +        dscr->attr = ldq_le_dma(&address_space_memory, entry_addr + 4);
>>
>> The API is detailled in this file: docs/devel/loads-stores.rst

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