[Intel-xe] [PATCH] Different platforms has different PAT encoding in PTE and PDE format, add correct PAT encoding for pre-Xe2 platforms (XELP, XEHPC, XELPG).
Matt Roper
matthew.d.roper at intel.com
Fri Aug 11 20:30:12 UTC 2023
On Wed, Aug 09, 2023 at 12:26:30PM -0600, Lucas De Marchi wrote:
>
> As Ashutosh said, please take a look on kernel documentation on how to
> write proper commit messages.
>
> https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes
>
> It's a good idea to check checkpatch on the patch before submitting too.
> Yes, sometimes we forget, but it's good to create the habit.
>
> On Wed, Aug 09, 2023 at 05:37:30PM +0530, Ravi Kumar Vodapalli wrote:
> > Bspec: 45101, 71582
> > Signed-off-by: Ravi Kumar Vodapalli <ravi.kumar.vodapalli at intel.com>
> > ---
> > drivers/gpu/drm/xe/xe_device.c | 3 ++
> > drivers/gpu/drm/xe/xe_device_types.h | 5 ++
> > drivers/gpu/drm/xe/xe_pat.c | 76 ++++++++++++++++++++++++++++
> > drivers/gpu/drm/xe/xe_pat.h | 25 +++++++++
> > drivers/gpu/drm/xe/xe_pt.c | 28 +++-------
> > drivers/gpu/drm/xe/xe_pt_types.h | 3 +-
> > 6 files changed, 119 insertions(+), 21 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> > index 766df07de979..0675a60f17f9 100644
> > --- a/drivers/gpu/drm/xe/xe_device.c
> > +++ b/drivers/gpu/drm/xe/xe_device.c
> > @@ -34,6 +34,7 @@
> > #include "xe_vm.h"
> > #include "xe_vm_madvise.h"
> > #include "xe_wait_user_fence.h"
> > +#include "xe_pat.h"
>
> all the includes are alphabetically sorted. Do not simply append here.
>
> >
> > #ifdef CONFIG_LOCKDEP
> > struct lockdep_map xe_device_mem_access_lockdep_map = {
> > @@ -292,6 +293,8 @@ int xe_device_probe(struct xe_device *xe)
> > goto err_irq_shutdown;
> > }
> >
> > + xe_pte_pat_init(xe);
> > +
> > err = xe_mmio_probe_vram(xe);
> > if (err)
> > goto err_irq_shutdown;
> > diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
> > index bfedcc7571b0..3c64834c32fc 100644
> > --- a/drivers/gpu/drm/xe/xe_device_types.h
> > +++ b/drivers/gpu/drm/xe/xe_device_types.h
> > @@ -23,6 +23,8 @@
> > #include "intel_display_device.h"
> > #endif
> >
> > +#include "xe_pt_types.h"
> > +
> > struct xe_ggtt;
> >
> > #define XE_BO_INVALID_OFFSET LONG_MAX
> > @@ -470,6 +472,9 @@ struct xe_device {
> > u32 lvds_channel_mode;
> > } params;
> > #endif
> > + const u32 *pte_pat_table;
> > + u64 (*ppgtt_pte_encode)(struct xe_device *xe, u64 pte_pat, enum xe_cache_level cache);
> > + u64 (*ppgtt_pde_encode)(struct xe_device *xe, u64 pde_pat, enum xe_cache_level cache);
>
> A few lines above we have:
>
> /* private: */
>
> #if IS_ENABLED(CONFIG_DRM_XE_DISPLAY)
> /*
> * Any fields below this point are the ones used by display. *
> They are temporarily added here so xe_device can be desguised as *
> drm_i915_private during build. After cleanup these should go away, *
> migrating to the right sub-structs */
>
>
> You need to find a proper place in the structure to add new fields. Do
> not simply append. However I'll defer to Matt Roper (Cc'ed) if xe_device
> is the correct place or if this should be on the gt level. Anyway, it
> should probably be a substruct "ops" or "funcs" for this vfunc approach.
I think it might make more sense to keep this closer to what it's
operating on, in a more object-oriented sense. Since these vfuncs are
specific to PPGTT handling, I think 'xe_vm' might be a better spot for
them than 'xe_device.' We could also drop the 'ppgtt_' prefix and
assign the function pointers inside xe_vm_create().
Matt
>
> > };
> >
> > /**
> > diff --git a/drivers/gpu/drm/xe/xe_pat.c b/drivers/gpu/drm/xe/xe_pat.c
> > index b56a65779d26..8f4c33d0f7dc 100644
> > --- a/drivers/gpu/drm/xe/xe_pat.c
> > +++ b/drivers/gpu/drm/xe/xe_pat.c
> > @@ -62,6 +62,24 @@ static const u32 mtl_pat_table[] = {
> > [4] = MTL_PAT_0_WB | MTL_3_COH_2W,
> > };
> >
> > +static const u32 xelp_pte_pat_table[] = {
> > + [XE_CACHE_NONE] = XELP_PAT_UNCACHE,
> > + [XE_CACHE_WT] = XELP_PAT_WT_CACHE,
> > + [XE_CACHE_WB] = XELP_PAT_WB_CACHE,
> > +};
> > +
> > +static const u32 xehpc_pte_pat_table[] = {
> > + [XE_CACHE_NONE] = XEHPC_PAT_CLOS0_UNCACHE,
> > + [XE_CACHE_WT] = XEHPC_PAT_CLOS0_WT_CACHE,
> > + [XE_CACHE_WB] = XEHPC_PAT_CLOS0_WB_CACHE,
> > +};
> > +
> > +static const u32 xelpg_pte_pat_table[] = {
> > + [XE_CACHE_NONE] = XELPG_PAT_UNCACHE,
> > + [XE_CACHE_WT] = XELPG_PAT_WT_CACHE,
> > + [XE_CACHE_WB] = XELPG_PAT_WB_CACHE,
> > +};
>
> you added XE_CACHE_LAST but then did nothing with that. Did you mean to
> add a static assert to make sure we don't have arrays with fewer
> elements than XE_CACHE_LAST?
>
> > +
> > static void program_pat(struct xe_gt *gt, const u32 table[], int n_entries)
> > {
> > for (int i = 0; i < n_entries; i++) {
> > @@ -111,3 +129,61 @@ void xe_pat_init(struct xe_gt *gt)
> > GRAPHICS_VER(xe), GRAPHICS_VERx100(xe) % 100);
> > }
> > }
> > +
> > +u32 xe_pat_get_index(struct xe_device *xe, enum xe_cache_level cache)
> > +{
> > + return xe->pte_pat_table[cache];
> > +}
> > +
> > +static u64 xelp_ppgtt_pde_encode_pat(struct xe_device *xe, u64 pde_pat, enum xe_cache_level cache)
> > +{
> > + u32 pat_index = xe_pat_get_index(xe, cache);
> > +
> > + pde_pat &= ~(XELP_PDE_PAT_MASK);
> > +
> > + if (pat_index & BIT(0))
> > + pde_pat |= BIT(3);
> > +
> > + if (pat_index & BIT(1))
> > + pde_pat |= BIT(4);
> > +
> > + if (pat_index & BIT(2))
> > + pde_pat |= BIT(12);
> > +
> > + return pde_pat;
> > +}
> > +
> > +static u64 xelp_ppgtt_pte_encode_pat(struct xe_device *xe, u64 pte_pat, enum xe_cache_level cache)
> > +{
> > + u32 pat_index = xe_pat_get_index(xe, cache);
> > +
> > + pte_pat &= ~(XELP_PTE_PAT_MASK);
> > +
> > + if (pat_index & BIT(0))
> > + pte_pat |= BIT(3);
> > +
> > + if (pat_index & BIT(1))
> > + pte_pat |= BIT(4);
> > +
> > + if (pat_index & BIT(2))
> > + pte_pat |= BIT(7);
> > +
> > + return pte_pat;
> > +}
> > +
> > +void xe_pte_pat_init(struct xe_device *xe)
>
> any non-static function in this file should be xe_pat_* (there a few
> exceptions, but this is usually the rule).
>
> > +{
> > + if (GRAPHICS_VERx100(xe) >= 1270) {
> > + xe->pte_pat_table = xelpg_pte_pat_table;
> > + xe->ppgtt_pte_encode = xelp_ppgtt_pte_encode_pat;
> > + xe->ppgtt_pde_encode = xelp_ppgtt_pde_encode_pat;
>
> setting those don't belong to this file. They should be in the relevant
> file that cares about ppgtt (i.e. xe_pt.c).
>
> Also you are missing the necessary changes to xe_ggtt.c that should also
> encode the bits.
>
> > + } else if (GRAPHICS_VERx100(xe) >= 1260) {
> > + xe->pte_pat_table = xehpc_pte_pat_table;
> > + xe->ppgtt_pte_encode = xelp_ppgtt_pte_encode_pat;
> > + xe->ppgtt_pde_encode = xelp_ppgtt_pde_encode_pat;
> > + } else {
> > + xe->pte_pat_table = xelp_pte_pat_table;
> > + xe->ppgtt_pte_encode = xelp_ppgtt_pte_encode_pat;
> > + xe->ppgtt_pde_encode = xelp_ppgtt_pde_encode_pat;
> > + }
> > +}
> > diff --git a/drivers/gpu/drm/xe/xe_pat.h b/drivers/gpu/drm/xe/xe_pat.h
> > index 659de4008131..1138ac78943f 100644
> > --- a/drivers/gpu/drm/xe/xe_pat.h
> > +++ b/drivers/gpu/drm/xe/xe_pat.h
> > @@ -6,8 +6,33 @@
> > #ifndef _XE_PAT_H_
> > #define _XE_PAT_H_
> >
> > +#include "xe_device_types.h"
>
> why? we don't add includes, particularly in headers, that aren't used.
>
> > +
> > +#define XELP_PTE_PAT_MASK (BIT_ULL(7) | BIT_ULL(4) | BIT_ULL(3))
> > +#define XELP_PDE_PAT_MASK (BIT_ULL(12) | BIT_ULL(4) | BIT_ULL(3))
> > +#define XELP_PAT_WB_CACHE 0
> > +#define XELP_PAT_WC_CACHE 1
> > +#define XELP_PAT_WT_CACHE 2
> > +#define XELP_PAT_UNCACHE 3
> > +
> > +#define XEHPC_PAT_CLOS0_UNCACHE 0
> > +#define XEHPC_PAT_CLOS0_WC_CACHE 1
> > +#define XEHPC_PAT_CLOS0_WT_CACHE 2
> > +#define XEHPC_PAT_CLOS0_WB_CACHE 3
> > +#define XEHPC_PAT_CLOS1_WT_CACHE 4
> > +#define XEHPC_PAT_CLOS1_WB_CACHE 5
> > +#define XEHPC_PAT_CLOS2_WT_CACHE 6
> > +#define XEHPC_PAT_CLOS2_WB_CACHE 7
> > +
> > +#define XELPG_PAT_WB_CACHE 0
> > +#define XELPG_PAT_WT_CACHE 1
> > +#define XELPG_PAT_UNCACHE 2
> > +#define XELPG_PAT_1_WAY_WB_CACHE 3
> > +#define XELPG_PAT_2_WAY_WB_CACHE 4
>
> only define what you use.
>
> > +
> > struct xe_gt;
> >
> > void xe_pat_init(struct xe_gt *gt);
> > +void xe_pte_pat_init(struct xe_device *xe);
> >
> > #endif
> > diff --git a/drivers/gpu/drm/xe/xe_pt.c b/drivers/gpu/drm/xe/xe_pt.c
> > index 5709518e314b..eccb0942ff46 100644
> > --- a/drivers/gpu/drm/xe/xe_pt.c
> > +++ b/drivers/gpu/drm/xe/xe_pt.c
> > @@ -58,19 +58,16 @@ static struct xe_pt *xe_pt_entry(struct xe_pt_dir *pt_dir, unsigned int index)
> > * Return: An encoded page directory entry. No errors.
> > */
> > u64 xe_pde_encode(struct xe_bo *bo, u64 bo_offset,
> > - const enum xe_cache_level level)
> > + const enum xe_cache_level cache)
> > {
> > u64 pde;
> > + struct xe_vm *vm = bo->vm;
> > + struct xe_device *xe = vm->xe;
> >
> > pde = xe_bo_addr(bo, bo_offset, XE_PAGE_SIZE);
> > pde |= XE_PAGE_PRESENT | XE_PAGE_RW;
> >
> > - /* FIXME: I don't think the PPAT handling is correct for MTL */
> > -
> > - if (level != XE_CACHE_NONE)
> > - pde |= PPAT_CACHED_PDE;
> > - else
> > - pde |= PPAT_UNCACHED;
> > + pde = xe->ppgtt_pde_encode(xe, pde, cache);
> >
> > return pde;
> > }
> > @@ -78,6 +75,9 @@ u64 xe_pde_encode(struct xe_bo *bo, u64 bo_offset,
> > static u64 __pte_encode(u64 pte, enum xe_cache_level cache,
> > struct xe_vma *vma, u32 pt_level)
> > {
> > + struct xe_vm *vm = xe_vma_vm(vma);
> > + struct xe_device *xe = vm->xe;
> > +
> > pte |= XE_PAGE_PRESENT | XE_PAGE_RW;
> >
> > if (unlikely(vma && xe_vma_read_only(vma)))
> > @@ -86,19 +86,7 @@ static u64 __pte_encode(u64 pte, enum xe_cache_level cache,
> > if (unlikely(vma && xe_vma_is_null(vma)))
> > pte |= XE_PTE_NULL;
> >
> > - /* FIXME: I don't think the PPAT handling is correct for MTL */
> > -
> > - switch (cache) {
> > - case XE_CACHE_NONE:
> > - pte |= PPAT_UNCACHED;
> > - break;
> > - case XE_CACHE_WT:
> > - pte |= PPAT_DISPLAY_ELLC;
> > - break;
> > - default:
> > - pte |= PPAT_CACHED;
> > - break;
> > - }
> > + pte = xe->ppgtt_pte_encode(xe, pte, cache);
> >
> > if (pt_level == 1)
> > pte |= XE_PDE_PS_2M;
> > diff --git a/drivers/gpu/drm/xe/xe_pt_types.h b/drivers/gpu/drm/xe/xe_pt_types.h
> > index 2ed64c0a4485..2a94ecbaa844 100644
> > --- a/drivers/gpu/drm/xe/xe_pt_types.h
> > +++ b/drivers/gpu/drm/xe/xe_pt_types.h
> > @@ -9,9 +9,10 @@
> > #include "xe_pt_walk.h"
> >
> > enum xe_cache_level {
> > - XE_CACHE_NONE,
> > + XE_CACHE_NONE = 0,
> > XE_CACHE_WT,
> > XE_CACHE_WB,
> > + XE_CACHE_LAST,
>
> I can't make sense of these changes here
>
> Lucas De Marchi
>
> > };
> >
> > #define XE_VM_MAX_LEVEL 4
> > --
> > 2.25.1
> >
--
Matt Roper
Graphics Software Engineer
Linux GPU Platform Enablement
Intel Corporation
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