Re: [RFC 1/5] block/nvme: use some NVME_CAP_* macros

[Auger Eric <eric.auger@redhat.com>]

Hi Philippe,

On 10/15/20 3:36 PM, Philippe Mathieu-Daudé wrote:
> On 10/15/20 3:32 PM, Philippe Mathieu-Daudé wrote:
>> On 10/15/20 3:29 PM, Philippe Mathieu-Daudé wrote:
>>> On 10/15/20 1:52 PM, Eric Auger wrote:
>>>> let's use NVME_CAP_DSTRD, NVME_CAP_MPSMIN and NVME_CAP_TO macros
>>>>
>>>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>>>> ---
>>>>   block/nvme.c | 6 +++---
>>>>   1 file changed, 3 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/block/nvme.c b/block/nvme.c
>>>> index f4f27b6da7..e3d96f20d0 100644
>>>> --- a/block/nvme.c
>>>> +++ b/block/nvme.c
>>>> @@ -728,10 +728,10 @@ static int nvme_init(BlockDriverState *bs,
>>>> const char *device, int namespace,
>>>>           goto out;
>>>>       }
>>>> -    s->page_size = MAX(4096, 1 << (12 + ((cap >> 48) & 0xF)));
>>>> -    s->doorbell_scale = (4 << (((cap >> 32) & 0xF))) /
>>>> sizeof(uint32_t);
>>>> +    s->page_size = MAX(4096, 1 << (12 + NVME_CAP_MPSMIN(cap)));
>>>
>>> Are you suggesting commit fad1eb68862 ("block/nvme: Use register
>>> definitions from 'block/nvme.h'") is buggy?
yes I think so. Sorry I messed up my rebase and failed to grab that patch.
>>
>> Buh I wonder how we missed that :/
> 
> Since your patch doesn't apply anyway, I might fix as:
> 
>         s->page_size = 4096 << NVME_CAP_MPSMIN(cap);
1 << (12 + NVME_CAP_MPSMIN(cap)) matches the spec text so personally I
would keep that.

Thanks

Eric
> 
>>
>>>
>>>> +    s->doorbell_scale = (4 << ((NVME_CAP_DSTRD(cap)))) /
>>>> sizeof(uint32_t);
>>>>       bs->bl.opt_mem_alignment = s->page_size;
>>>> -    timeout_ms = MIN(500 * ((cap >> 24) & 0xFF), 30000);
>>>> +    timeout_ms = MIN(500 * NVME_CAP_TO(cap), 30000);
>>>>       /* Reset device to get a clean state. */
>>>>       s->regs->ctrl.cc = cpu_to_le32(le32_to_cpu(s->regs->ctrl.cc) &
>>>> 0xFE);
>>>>
>>>
>>
> 
>