[igt-dev] [RFC 5/5] igt/lib: If mappable aperture is missing return 0 size

[Antonio Argenziano]

On 21/02/19 12:01, Chris Wilson wrote:
> Quoting Antonio Argenziano (2019-02-21 19:27:45)
>> So far the aperture size has been read directly from the bar,
>> in this patch we return zero if the mappable aperture is not available
>> as the value stored in the bar might not be accurate. The patch also adds a
>> 'require' when a call to gem_mappable_aperture_size() is made so that
>> the aperture is guaranteed to exist before checking the size.
>>
>> Cc: Katarzyna Dec <katarzyna.dec at intel.com>
>> Cc: Chris Wilson <chris at chris-wilson.co.uk>
>> Cc: Matthew Auld <matthew.auld at intel.com>
>> Signed-off-by: Antonio Argenziano <antonio.argenziano at intel.com>
>> ---
>>   lib/ioctl_wrappers.c            | 28 +++++++++++++++++++---------
>>   lib/ioctl_wrappers.h            |  2 +-
>>   tests/i915/gem_concurrent_all.c | 12 ++++++------
>>   tests/i915/gem_cpu_reloc.c      | 14 ++++++++++----
>>   tests/i915/gem_mmap.c           |  4 ++--
>>   tests/i915/gem_mmap_gtt.c       | 10 +++++-----
>>   tests/i915/gem_pwrite.c         |  4 ++--
>>   tests/i915/gem_shrink.c         |  2 +-
>>   tests/i915/i915_pm_rpm.c        |  2 +-
>>   tests/kms_flip.c                |  2 +-
>>   tests/prime_mmap.c              |  7 +++++--
>>   11 files changed, 53 insertions(+), 34 deletions(-)
>>
>> diff --git a/lib/ioctl_wrappers.c b/lib/ioctl_wrappers.c
>> index 25dd8ad3..ab7c7a5e 100644
>> --- a/lib/ioctl_wrappers.c
>> +++ b/lib/ioctl_wrappers.c
>> @@ -1440,19 +1440,14 @@ uint64_t gem_aperture_size(int fd)
>>          return aperture_size;
>>   }
>>   
>> -/**
>> - * gem_mappable_aperture_size:
>> - *
>> - * Feature test macro to query the kernel for the mappable gpu aperture size.
>> - * This is the area available for GTT memory mappings.
>> - *
>> - * Returns: The mappable gtt address space size.
>> - */
>> -uint64_t gem_mappable_aperture_size(void)
>> +static uint64_t __gem_mappable_aperture_size(int fd)
>>   {
>>          struct pci_device *pci_dev = intel_get_pci_device();
>>          int bar;
>>   
>> +       if (!gem_mmap__has_gtt(fd))
>> +               return 0; /* Aperture not available */
>> +
>>          if (intel_gen(pci_dev->device_id) < 3)
>>                  bar = 0;
> 
> I swear we made this accessible via fd so that we didn't need root to
> poke around libpciacess.

mhh, couldn't find it. Is it in some IOCTL?

Antonio

> -Chris
>