[PATCH 3/9] drm/xe: Add functions to convert regular address to canonical address and back

[Souza, Jose]

On Mon, 2024-01-22 at 18:38 +0000, Summers, Stuart wrote:
> On Mon, 2024-01-22 at 09:04 -0800, José Roberto de Souza wrote:
> > Some instructions requires canonical address like
> > MI_BATCH_BUFFER_START(UMDs must call xe_exec with a canonical address
> > for Xe2+).
> > 
> > So here adding functions to convert regular address to canonical
> > address and back, the first user of this functions will be added
> > in the next patches.
> > 
> > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > Cc: Maarten Lankhorst <dev at lankhorst.se>
> > Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> > ---
> >  drivers/gpu/drm/xe/xe_device.c | 15 +++++++++++++++
> >  drivers/gpu/drm/xe/xe_device.h |  3 +++
> >  2 files changed, 18 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/xe/xe_device.c
> > b/drivers/gpu/drm/xe/xe_device.c
> > index ab417f4f7d2a7..b4cdcf1b2081a 100644
> > --- a/drivers/gpu/drm/xe/xe_device.c
> > +++ b/drivers/gpu/drm/xe/xe_device.c
> > @@ -727,3 +727,18 @@ void xe_device_mem_access_put(struct xe_device
> > *xe)
> >  
> >         xe_assert(xe, ref >= 0);
> >  }
> > +
> > +static inline int highest_address_bit_get(struct xe_device *xe)
> > +{
> > +       return xe->info.dma_mask_size > 48 ? 57 : 47;
> 
> Why not just xe->info.dma_mask_size - 1?

We have platforms that set dma_mask_size to 39, 46 and 52 but the canonical address boundaries is 48bit and 58bit bits.

> 
> Thanks,
> Stuart
> 
> > +}
> > +
> > +u64 xe_device_canonicalize_addr(struct xe_device *xe, u64 address)
> > +{
> > +       return sign_extend64(address, highest_address_bit_get(xe));
> > +}
> > +
> > +u64 xe_device_uncanonicalize_addr(struct xe_device *xe, u64 address)
> > +{
> > +       return address & GENMASK_ULL(highest_address_bit_get(xe), 0);
> > +}
> > diff --git a/drivers/gpu/drm/xe/xe_device.h
> > b/drivers/gpu/drm/xe/xe_device.h
> > index af8ac2e9e2709..ce20f6fe6219a 100644
> > --- a/drivers/gpu/drm/xe/xe_device.h
> > +++ b/drivers/gpu/drm/xe/xe_device.h
> > @@ -175,4 +175,7 @@ static inline bool xe_device_has_memirq(struct
> > xe_device *xe)
> >  
> >  u32 xe_device_ccs_bytes(struct xe_device *xe, u64 size);
> >  
> > +u64 xe_device_canonicalize_addr(struct xe_device *xe, u64 address);
> > +u64 xe_device_uncanonicalize_addr(struct xe_device *xe, u64
> > address);
> > +
> >  #endif
>