On Thu, Apr 28, 2022 at 01:18:42PM +0100, Tvrtko Ursulin wrote:
>
> Hi,
>
> On 28/04/2022 00:07, Matt Roper wrote:
> > Rather than storing subslice masks internally as u8[] (inside the sseu
> > structure) and u32 (everywhere else), let's move over to using an
> > intel_sseu_ss_mask_t typedef compatible with the operations in
> > linux/bitmap.h. We're soon going to start adding code for a new
> > platform where subslice masks are spread across two 32-bit registers
> > (requiring 64 bits to represent), and we expect future platforms will
> > likely take this even farther, requiring bitmask storage larger than a
> > simple u64 can hold.
>
> I won't have time to look into this in a detailed way for a few days. Until
> then a couple questions comments only.
>
> First, out of curiousity, were you able to end up with less code after your
> series? With my bitmap conversion I think actually ended up with couple KB
> smaller text which was a good sign eliminating the internal layout
> complications was a good approach.
Yeah, looks like I did:
$ size i915.ko.orig i915.ko
text data bss dec hex filename
3479050 132498 6760 3618308 373604 i915.ko.orig
3476552 132466 6760 3615778 372c22 i915.ko
>
> For your series I am not convinced by sseu->has_common_ss_eumask. Why the
> duality, just to save a few u32 at runtime?
With this flag, eu_mask is an array of GEN_MAX_HSW_SLICES *
GEN_MAX_SS_PER_HSW_SLICE (i.e., 3*6 = 18). If we store the replicated
EU masks, then we'll have 64 u16's on PVC (where we have a DSS mask
spread across two registers) and 96 u16's on a future platform that
spreads the mask across three fuse registers. 18 -> 96 (or possibly
even more farther in the future). I think we've eliminated all of the
stack allocations of sseu structures now, so it probably isn't as
important as it used to be though; I can drop it if you think the size
savings aren't worth the extra complexity.
>
> I am also not convinced with leaving the eu_mask and subslice_mask
> being manually indexed with stride, calculcated by the driver. In my
> approach I simply went with multi-dimensional arrays which I think
> ends up with simpler code.
So something like
enum {
u16 hsw[GEN_MAX_HSW_SLICES][GEN_MAX_SS_PER_HSW_SLICE];
u16 xehp[GEN_MAX_DSS];
} eu_mask;
? Or should we just skip the enum and live with allocating three times
as much space as the largest Xe_HP platform needs?
>
> For all bitmap API call sites and *pb printk format sites, I suggest not
> hard-coding the widths from SSEU defines by querying the type itsef via
> wrappers. (See my BITMAP_BITS macro and helpers which wrap it for fields.)
>
> Ie instead:
>
> bitmap_shift_left(to_mask->b, to_mask->b, offset, I915_MAX_SS_FUSE_BITS);
>
> I suggest:
>
> bitmap_zero(slices.b, BITMAP_BITS(slices.b));
>
> Also, all accesses to the bitmap type from outside intel_sse*.c|h should use
> intel_sseu wrappers and not embed knowledge of the typedef (that it has an
> member named .b etc).
>
> And finally I would also use the opportunity to clean up the pointless u8
> types for counts and such since I think they just result in worse code
> generation.
>
> You can of course counter with what you did not like in my attempt. :) I know
> I did not finish the wrappers and possibly made an overkill by converting the
> slice mask to bitmap.
These suggestions all make sense. I'll work on incorporating them into
the next version.
Matt
>
> Regards,
>
> Tvrtko
> > Signed-off-by: Matt Roper <matthew.d.ro...@intel.com>
> > ---
> > drivers/gpu/drm/i915/gem/i915_gem_context.c | 4 +-
> > drivers/gpu/drm/i915/gt/intel_engine_cs.c | 2 +-
> > drivers/gpu/drm/i915/gt/intel_gt.c | 14 +-
> > drivers/gpu/drm/i915/gt/intel_sseu.c | 197 +++++++++++--------
> > drivers/gpu/drm/i915/gt/intel_sseu.h | 48 ++---
> > drivers/gpu/drm/i915/gt/intel_sseu_debugfs.c | 28 +--
> > drivers/gpu/drm/i915/gt/intel_workarounds.c | 28 ++-
> > drivers/gpu/drm/i915/i915_getparam.c | 2 +-
> > drivers/gpu/drm/i915/i915_query.c | 8 +-
> > 9 files changed, 183 insertions(+), 148 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > index ab4c5ab28e4d..ea012ee3a8de 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > @@ -1901,7 +1901,7 @@ i915_gem_user_to_context_sseu(struct intel_gt *gt,
> > if (user->slice_mask & ~device->slice_mask)
> > return -EINVAL;
> > - if (user->subslice_mask & ~device->subslice_mask[0])
> > + if (user->subslice_mask & ~device->subslice_mask.b[0])
> > return -EINVAL;
> > if (user->max_eus_per_subslice > device->max_eus_per_subslice)
> > @@ -1915,7 +1915,7 @@ i915_gem_user_to_context_sseu(struct intel_gt *gt,
> > /* Part specific restrictions. */
> > if (GRAPHICS_VER(i915) == 11) {
> > unsigned int hw_s = hweight8(device->slice_mask);
> > - unsigned int hw_ss_per_s = hweight8(device->subslice_mask[0]);
> > + unsigned int hw_ss_per_s = hweight8(device->subslice_mask.b[0]);
> > unsigned int req_s = hweight8(context->slice_mask);
> > unsigned int req_ss = hweight8(context->subslice_mask);
> > diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> > b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> > index 14c6ddbbfde8..39c09963b3c7 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> > @@ -610,7 +610,7 @@ static void engine_mask_apply_compute_fuses(struct
> > intel_gt *gt)
> > if (GRAPHICS_VER_FULL(i915) < IP_VER(12, 50))
> > return;
> > - ccs_mask =
> > intel_slicemask_from_dssmask(intel_sseu_get_compute_subslices(&info->sseu),
> > + ccs_mask =
> > intel_slicemask_from_dssmask(info->sseu.compute_subslice_mask,
> > ss_per_ccs);
> > /*
> > * If all DSS in a quadrant are fused off, the corresponding CCS
> > diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c
> > b/drivers/gpu/drm/i915/gt/intel_gt.c
> > index 92394f13b42f..cc03512d59ba 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_gt.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_gt.c
> > @@ -133,13 +133,6 @@ static const struct intel_mmio_range
> > dg2_lncf_steering_table[] = {
> > {},
> > };
> > -static u16 slicemask(struct intel_gt *gt, int count)
> > -{
> > - u64 dss_mask = intel_sseu_get_subslices(>->info.sseu, 0);
> > -
> > - return intel_slicemask_from_dssmask(dss_mask, count);
> > -}
> > -
> > int intel_gt_init_mmio(struct intel_gt *gt)
> > {
> > struct drm_i915_private *i915 = gt->i915;
> > @@ -153,11 +146,14 @@ int intel_gt_init_mmio(struct intel_gt *gt)
> > * An mslice is unavailable only if both the meml3 for the slice is
> > * disabled *and* all of the DSS in the slice (quadrant) are disabled.
> > */
> > - if (HAS_MSLICES(i915))
> > + if (HAS_MSLICES(i915)) {
> > gt->info.mslice_mask =
> > - slicemask(gt, GEN_DSS_PER_MSLICE) |
> > +
> > intel_slicemask_from_dssmask(gt->info.sseu.subslice_mask,
> > + GEN_DSS_PER_MSLICE);
> > + gt->info.mslice_mask |=
> > (intel_uncore_read(gt->uncore, GEN10_MIRROR_FUSE3) &
> > GEN12_MEML3_EN_MASK);
> > + }
> > if (IS_DG2(i915)) {
> > gt->steering_table[MSLICE] = xehpsdv_mslice_steering_table;
> > diff --git a/drivers/gpu/drm/i915/gt/intel_sseu.c
> > b/drivers/gpu/drm/i915/gt/intel_sseu.c
> > index f7ff6a9f67b0..466505d6bd18 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_sseu.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_sseu.c
> > @@ -28,56 +28,49 @@ void intel_sseu_set_info(struct sseu_dev_info *sseu, u8
> > max_slices,
> > unsigned int
> > intel_sseu_subslice_total(const struct sseu_dev_info *sseu)
> > {
> > - unsigned int i, total = 0;
> > -
> > - for (i = 0; i < ARRAY_SIZE(sseu->subslice_mask); i++)
> > - total += hweight8(sseu->subslice_mask[i]);
> > -
> > - return total;
> > + return bitmap_weight(sseu->subslice_mask.b, I915_MAX_SS_FUSE_BITS);
> > }
> > -static u32
> > -sseu_get_subslices(const struct sseu_dev_info *sseu,
> > - const u8 *subslice_mask, u8 slice)
> > +static intel_sseu_ss_mask_t
> > +get_ss_mask_for_slice(const struct sseu_dev_info *sseu,
> > + intel_sseu_ss_mask_t all_ss,
> > + int slice)
> > {
> > - int i, offset = slice * sseu->ss_stride;
> > - u32 mask = 0;
> > + intel_sseu_ss_mask_t mask = {}, slice_ss = {};
> > + int offset = slice * sseu->max_subslices;
> > GEM_BUG_ON(slice >= sseu->max_slices);
> > - for (i = 0; i < sseu->ss_stride; i++)
> > - mask |= (u32)subslice_mask[offset + i] << i * BITS_PER_BYTE;
> > + if (sseu->max_slices == 1)
> > + return all_ss;
> > - return mask;
> > -}
> > + bitmap_set(mask.b, offset, sseu->max_subslices);
> > + bitmap_and(slice_ss.b, all_ss.b, mask.b, I915_MAX_SS_FUSE_BITS);
> > + bitmap_shift_right(slice_ss.b, slice_ss.b, offset,
> > I915_MAX_SS_FUSE_BITS);
> > -u32 intel_sseu_get_subslices(const struct sseu_dev_info *sseu, u8 slice)
> > -{
> > - return sseu_get_subslices(sseu, sseu->subslice_mask, slice);
> > + return slice_ss;
> > }
> > -static u32 sseu_get_geometry_subslices(const struct sseu_dev_info *sseu)
> > +intel_sseu_ss_mask_t
> > +intel_sseu_get_subslices(const struct sseu_dev_info *sseu, u8 slice)
> > {
> > - return sseu_get_subslices(sseu, sseu->geometry_subslice_mask, 0);
> > + return get_ss_mask_for_slice(sseu, sseu->subslice_mask, slice);
> > }
> > -u32 intel_sseu_get_compute_subslices(const struct sseu_dev_info *sseu)
> > -{
> > - return sseu_get_subslices(sseu, sseu->compute_subslice_mask, 0);
> > -}
> > -
> > -void intel_sseu_set_subslices(struct sseu_dev_info *sseu, int slice,
> > - u8 *subslice_mask, u32 ss_mask)
> > -{
> > - int offset = slice * sseu->ss_stride;
> > -
> > - memcpy(&subslice_mask[offset], &ss_mask, sseu->ss_stride);
> > -}
> > -
> > -unsigned int
> > -intel_sseu_subslices_per_slice(const struct sseu_dev_info *sseu, u8 slice)
> > +/*
> > + * Set the subslice mask associated with a specific slice. Only needed on
> > + * pre-gen11 platforms that have multiple slices.
> > + */
> > +static void set_subslices(struct sseu_dev_info *sseu, int slice, u32
> > ss_mask)
> > {
> > - return hweight32(intel_sseu_get_subslices(sseu, slice));
> > + intel_sseu_ss_mask_t mask = {}, newbits = {};
> > + int offset = slice * sseu->max_subslices;
> > +
> > + bitmap_set(mask.b, offset, sseu->max_subslices);
> > + bitmap_from_arr32(newbits.b, &ss_mask, 32);
> > + bitmap_shift_left(newbits.b, newbits.b, offset, I915_MAX_SS_FUSE_BITS);
> > + bitmap_replace(sseu->subslice_mask.b, sseu->subslice_mask.b,
> > + newbits.b, mask.b, I915_MAX_SS_FUSE_BITS);
> > }
> > static int sseu_eu_idx(const struct sseu_dev_info *sseu, int slice,
> > @@ -115,7 +108,7 @@ static u16 compute_eu_total(const struct sseu_dev_info
> > *sseu)
> > u16 i, total = 0;
> > if (sseu->has_common_ss_eumask)
> > - return intel_sseu_subslices_per_slice(sseu, 0) *
> > + return bitmap_weight(sseu->subslice_mask.b,
> > I915_MAX_SS_FUSE_BITS) *
> > hweight16(sseu->eu_mask[0]);
> > for (i = 0; i < ARRAY_SIZE(sseu->eu_mask); i++)
> > @@ -155,11 +148,42 @@ int intel_sseu_copy_eumask_to_user(void __user *to,
> > return copy_to_user(to, eu_mask, len);
> > }
> > -static void gen11_compute_sseu_info(struct sseu_dev_info *sseu,
> > - u32 g_ss_en, u32 c_ss_en, u16 eu_en)
> > +/**
> > + * intel_sseu_copy_ssmask_to_user - Copy subslice mask into a userspace
> > buffer
> > + * @to: Pointer to userspace buffer to copy to
> > + * @sseu: SSEU structure containing subslice mask to copy
> > + *
> > + * Copies the subslice mask to a userspace buffer in the format expected by
> > + * the query ioctl's topology queries.
> > + *
> > + * Returns the result of the copy_to_user() operation.
> > + */
> > +int intel_sseu_copy_ssmask_to_user(void __user *to,
> > + const struct sseu_dev_info *sseu)
> > {
> > - u32 valid_ss_mask = GENMASK(sseu->max_subslices - 1, 0);
> > + u8 ss_mask[GEN_SS_MASK_SIZE] = {};
> > + int len = sseu->max_slices * sseu->ss_stride;
> > + int s, ss, i;
> > + for (s = 0; s < sseu->max_slices; s++) {
> > + for (ss = 0; ss < sseu->max_subslices; ss++) {
> > + i = s * sseu->ss_stride + ss;
> > +
> > + if (!intel_sseu_has_subslice(sseu, s, ss))
> > + continue;
> > +
> > + ss_mask[i / BITS_PER_BYTE] |= BIT(i % BITS_PER_BYTE);
> > + }
> > + }
> > +
> > + return copy_to_user(to, ss_mask, len);
> > +}
> > +
> > +static void gen11_compute_sseu_info(struct sseu_dev_info *sseu,
> > + intel_sseu_ss_mask_t g_ss_en,
> > + intel_sseu_ss_mask_t c_ss_en,
> > + u16 eu_en)
> > +{
> > /* g_ss_en/c_ss_en represent entire subslice mask across all slices */
> > GEM_BUG_ON(sseu->max_slices * sseu->max_subslices >
> > sizeof(g_ss_en) * BITS_PER_BYTE);
> > @@ -174,12 +198,12 @@ static void gen11_compute_sseu_info(struct
> > sseu_dev_info *sseu,
> > * enabled subslice count for the purposes of selecting subslices to
> > * use in a particular GEM context.
> > */
> > - intel_sseu_set_subslices(sseu, 0, sseu->compute_subslice_mask,
> > - c_ss_en & valid_ss_mask);
> > - intel_sseu_set_subslices(sseu, 0, sseu->geometry_subslice_mask,
> > - g_ss_en & valid_ss_mask);
> > - intel_sseu_set_subslices(sseu, 0, sseu->subslice_mask,
> > - (g_ss_en | c_ss_en) & valid_ss_mask);
> > + bitmap_copy(sseu->compute_subslice_mask.b, c_ss_en.b,
> > I915_MAX_SS_FUSE_BITS);
> > + bitmap_copy(sseu->geometry_subslice_mask.b, g_ss_en.b,
> > I915_MAX_SS_FUSE_BITS);
> > + bitmap_or(sseu->subslice_mask.b,
> > + sseu->compute_subslice_mask.b,
> > + sseu->geometry_subslice_mask.b,
> > + I915_MAX_SS_FUSE_BITS);
> > sseu->has_common_ss_eumask = 1;
> > sseu->eu_mask[0] = eu_en;
> > @@ -191,7 +215,8 @@ static void xehp_sseu_info_init(struct intel_gt *gt)
> > {
> > struct sseu_dev_info *sseu = >->info.sseu;
> > struct intel_uncore *uncore = gt->uncore;
> > - u32 g_dss_en, c_dss_en = 0;
> > + intel_sseu_ss_mask_t g_dss_en = {}, c_dss_en = {};
> > + u32 val;
> > u16 eu_en = 0;
> > u8 eu_en_fuse;
> > int eu;
> > @@ -204,8 +229,11 @@ static void xehp_sseu_info_init(struct intel_gt *gt)
> > */
> > intel_sseu_set_info(sseu, 1, 32, 16);
> > - g_dss_en = intel_uncore_read(uncore, GEN12_GT_GEOMETRY_DSS_ENABLE);
> > - c_dss_en = intel_uncore_read(uncore, GEN12_GT_COMPUTE_DSS_ENABLE);
> > + val = intel_uncore_read(uncore, GEN12_GT_GEOMETRY_DSS_ENABLE);
> > + bitmap_from_arr32(g_dss_en.b, &val, 32);
> > +
> > + val = intel_uncore_read(uncore, GEN12_GT_COMPUTE_DSS_ENABLE);
> > + bitmap_from_arr32(c_dss_en.b, &val, 32);
> > eu_en_fuse = intel_uncore_read(uncore, XEHP_EU_ENABLE) &
> > XEHP_EU_ENA_MASK;
> > @@ -220,7 +248,8 @@ static void gen12_sseu_info_init(struct intel_gt *gt)
> > {
> > struct sseu_dev_info *sseu = >->info.sseu;
> > struct intel_uncore *uncore = gt->uncore;
> > - u32 g_dss_en;
> > + intel_sseu_ss_mask_t g_dss_en = {}, empty_mask = {};
> > + u32 val;
> > u16 eu_en = 0;
> > u8 eu_en_fuse;
> > u8 s_en;
> > @@ -243,7 +272,8 @@ static void gen12_sseu_info_init(struct intel_gt *gt)
> > drm_dbg(>->i915->drm, "Slice mask %#x is not the expected
> > 0x1!\n",
> > s_en);
> > - g_dss_en = intel_uncore_read(uncore, GEN12_GT_GEOMETRY_DSS_ENABLE);
> > + val = intel_uncore_read(uncore, GEN12_GT_GEOMETRY_DSS_ENABLE);
> > + bitmap_from_arr32(g_dss_en.b, &val, 32);
> > /* one bit per pair of EUs */
> > eu_en_fuse = ~(intel_uncore_read(uncore, GEN11_EU_DISABLE) &
> > @@ -253,7 +283,7 @@ static void gen12_sseu_info_init(struct intel_gt *gt)
> > if (eu_en_fuse & BIT(eu))
> > eu_en |= BIT(eu * 2) | BIT(eu * 2 + 1);
> > - gen11_compute_sseu_info(sseu, g_dss_en, 0, eu_en);
> > + gen11_compute_sseu_info(sseu, g_dss_en, empty_mask, eu_en);
> > /* TGL only supports slice-level power gating */
> > sseu->has_slice_pg = 1;
> > @@ -263,7 +293,8 @@ static void gen11_sseu_info_init(struct intel_gt *gt)
> > {
> > struct sseu_dev_info *sseu = >->info.sseu;
> > struct intel_uncore *uncore = gt->uncore;
> > - u32 ss_en;
> > + intel_sseu_ss_mask_t ss_en = {}, empty_mask = {};
> > + u32 val;
> > u8 eu_en;
> > u8 s_en;
> > @@ -282,12 +313,13 @@ static void gen11_sseu_info_init(struct intel_gt *gt)
> > drm_dbg(>->i915->drm, "Slice mask %#x is not the expected
> > 0x1!\n",
> > s_en);
> > - ss_en = ~intel_uncore_read(uncore, GEN11_GT_SUBSLICE_DISABLE);
> > + val = ~intel_uncore_read(uncore, GEN11_GT_SUBSLICE_DISABLE);
> > + bitmap_from_arr32(ss_en.b, &val, 32);
> > eu_en = ~(intel_uncore_read(uncore, GEN11_EU_DISABLE) &
> > GEN11_EU_DIS_MASK);
> > - gen11_compute_sseu_info(sseu, ss_en, 0, eu_en);
> > + gen11_compute_sseu_info(sseu, ss_en, empty_mask, eu_en);
> > /* ICL has no power gating restrictions. */
> > sseu->has_slice_pg = 1;
> > @@ -328,7 +360,7 @@ static void cherryview_sseu_info_init(struct intel_gt
> > *gt)
> > sseu_set_eus(sseu, 0, 1, ~disabled_mask);
> > }
> > - intel_sseu_set_subslices(sseu, 0, sseu->subslice_mask, subslice_mask);
> > + set_subslices(sseu, 0, subslice_mask);
> > sseu->eu_total = compute_eu_total(sseu);
> > @@ -384,8 +416,7 @@ static void gen9_sseu_info_init(struct intel_gt *gt)
> > /* skip disabled slice */
> > continue;
> > - intel_sseu_set_subslices(sseu, s, sseu->subslice_mask,
> > - subslice_mask);
> > + set_subslices(sseu, s, subslice_mask);
> > eu_disable = intel_uncore_read(uncore, GEN9_EU_DISABLE(s));
> > for (ss = 0; ss < sseu->max_subslices; ss++) {
> > @@ -442,8 +473,8 @@ static void gen9_sseu_info_init(struct intel_gt *gt)
> > sseu->has_eu_pg = sseu->eu_per_subslice > 2;
> > if (IS_GEN9_LP(i915)) {
> > -#define IS_SS_DISABLED(ss) (!(sseu->subslice_mask[0] & BIT(ss)))
> > - info->has_pooled_eu = hweight8(sseu->subslice_mask[0]) == 3;
> > +#define IS_SS_DISABLED(ss) test_bit(ss, sseu->subslice_mask.b)
> > + info->has_pooled_eu = hweight8(sseu->subslice_mask.b[0]) == 3;
> > sseu->min_eu_in_pool = 0;
> > if (info->has_pooled_eu) {
> > @@ -497,8 +528,7 @@ static void bdw_sseu_info_init(struct intel_gt *gt)
> > /* skip disabled slice */
> > continue;
> > - intel_sseu_set_subslices(sseu, s, sseu->subslice_mask,
> > - subslice_mask);
> > + set_subslices(sseu, s, subslice_mask);
> > for (ss = 0; ss < sseu->max_subslices; ss++) {
> > u8 eu_disabled_mask;
> > @@ -595,8 +625,7 @@ static void hsw_sseu_info_init(struct intel_gt *gt)
> > sseu->eu_per_subslice);
> > for (s = 0; s < sseu->max_slices; s++) {
> > - intel_sseu_set_subslices(sseu, s, sseu->subslice_mask,
> > - subslice_mask);
> > + set_subslices(sseu, s, subslice_mask);
> > for (ss = 0; ss < sseu->max_subslices; ss++) {
> > sseu_set_eus(sseu, s, ss,
> > @@ -685,7 +714,7 @@ u32 intel_sseu_make_rpcs(struct intel_gt *gt,
> > */
> > if (GRAPHICS_VER(i915) == 11 &&
> > slices == 1 &&
> > - subslices > min_t(u8, 4, hweight8(sseu->subslice_mask[0]) / 2)) {
> > + subslices > min_t(u8, 4, hweight8(sseu->subslice_mask.b[0]) / 2)) {
> > GEM_BUG_ON(subslices & 1);
> > subslice_pg = false;
> > @@ -755,9 +784,11 @@ void intel_sseu_dump(const struct sseu_dev_info *sseu,
> > struct drm_printer *p)
> > hweight8(sseu->slice_mask), sseu->slice_mask);
> > drm_printf(p, "subslice total: %u\n", intel_sseu_subslice_total(sseu));
> > for (s = 0; s < sseu->max_slices; s++) {
> > - drm_printf(p, "slice%d: %u subslices, mask=%08x\n",
> > - s, intel_sseu_subslices_per_slice(sseu, s),
> > - intel_sseu_get_subslices(sseu, s));
> > + intel_sseu_ss_mask_t ssmask = intel_sseu_get_subslices(sseu, s);
> > +
> > + drm_printf(p, "slice%d: %u subslices, mask=%*pb\n",
> > + s, bitmap_weight(ssmask.b, I915_MAX_SS_FUSE_BITS),
> > + I915_MAX_SS_FUSE_BITS, ssmask.b);
> > }
> > drm_printf(p, "EU total: %u\n", sseu->eu_total);
> > drm_printf(p, "EU per subslice: %u\n", sseu->eu_per_subslice);
> > @@ -775,9 +806,11 @@ static void sseu_print_hsw_topology(const struct
> > sseu_dev_info *sseu,
> > int s, ss;
> > for (s = 0; s < sseu->max_slices; s++) {
> > - drm_printf(p, "slice%d: %u subslice(s) (0x%08x):\n",
> > - s, intel_sseu_subslices_per_slice(sseu, s),
> > - intel_sseu_get_subslices(sseu, s));
> > + intel_sseu_ss_mask_t ssmask = intel_sseu_get_subslices(sseu, s);
> > +
> > + drm_printf(p, "slice%d: %u subslice(s) (0x%*pb):\n",
> > + s, bitmap_weight(ssmask.b, I915_MAX_SS_FUSE_BITS),
> > + I915_MAX_SS_FUSE_BITS, ssmask.b);
> > for (ss = 0; ss < sseu->max_subslices; ss++) {
> > u16 enabled_eus = sseu_get_eus(sseu, s, ss);
> > @@ -791,16 +824,14 @@ static void sseu_print_hsw_topology(const struct
> > sseu_dev_info *sseu,
> > static void sseu_print_xehp_topology(const struct sseu_dev_info *sseu,
> > struct drm_printer *p)
> > {
> > - u32 g_dss_mask = sseu_get_geometry_subslices(sseu);
> > - u32 c_dss_mask = intel_sseu_get_compute_subslices(sseu);
> > int dss;
> > for (dss = 0; dss < sseu->max_subslices; dss++) {
> > u16 enabled_eus = sseu_get_eus(sseu, 0, dss);
> > drm_printf(p, "DSS_%02d: G:%3s C:%3s, %2u EUs (0x%04hx)\n", dss,
> > - str_yes_no(g_dss_mask & BIT(dss)),
> > - str_yes_no(c_dss_mask & BIT(dss)),
> > + str_yes_no(test_bit(dss,
> > sseu->geometry_subslice_mask.b)),
> > + str_yes_no(test_bit(dss,
> > sseu->compute_subslice_mask.b)),
> > hweight16(enabled_eus), enabled_eus);
> > }
> > }
> > @@ -818,20 +849,24 @@ void intel_sseu_print_topology(struct
> > drm_i915_private *i915,
> > }
> > }
> > -u16 intel_slicemask_from_dssmask(u64 dss_mask, int dss_per_slice)
> > +u16 intel_slicemask_from_dssmask(intel_sseu_ss_mask_t dss_mask,
> > + int dss_per_slice)
> > {
> > + intel_sseu_ss_mask_t per_slice_mask = {};
> > u16 slice_mask = 0;
> > int i;
> > - WARN_ON(sizeof(dss_mask) * 8 / dss_per_slice > 8 * sizeof(slice_mask));
> > + WARN_ON(DIV_ROUND_UP(I915_MAX_SS_FUSE_BITS, dss_per_slice) >
> > + 8 * sizeof(slice_mask));
> > - for (i = 0; dss_mask; i++) {
> > - if (dss_mask & GENMASK(dss_per_slice - 1, 0))
> > + bitmap_fill(per_slice_mask.b, dss_per_slice);
> > + for (i = 0; !bitmap_empty(dss_mask.b, I915_MAX_SS_FUSE_BITS); i++) {
> > + if (bitmap_intersects(dss_mask.b, per_slice_mask.b,
> > dss_per_slice))
> > slice_mask |= BIT(i);
> > - dss_mask >>= dss_per_slice;
> > + bitmap_shift_right(dss_mask.b, dss_mask.b, dss_per_slice,
> > + I915_MAX_SS_FUSE_BITS);
> > }
> > return slice_mask;
> > }
> > -
> > diff --git a/drivers/gpu/drm/i915/gt/intel_sseu.h
> > b/drivers/gpu/drm/i915/gt/intel_sseu.h
> > index 106726a2244e..455f085093ae 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_sseu.h
> > +++ b/drivers/gpu/drm/i915/gt/intel_sseu.h
> > @@ -52,11 +52,22 @@ struct drm_printer;
> > #define GEN_MAX_GSLICES (GEN_MAX_DSS / GEN_DSS_PER_GSLICE)
> > #define GEN_MAX_CSLICES (GEN_MAX_DSS / GEN_DSS_PER_CSLICE)
> > +/*
> > + * Maximum number of 32-bit registers used by hardware to express the
> > + * enabled/disabled subslices.
> > + */
> > +#define I915_MAX_SS_FUSE_REGS 1
> > +#define I915_MAX_SS_FUSE_BITS (I915_MAX_SS_FUSE_REGS * 32)
> > +
> > +typedef struct {
> > + unsigned long b[BITS_TO_LONGS(I915_MAX_SS_FUSE_BITS)];
> > +} intel_sseu_ss_mask_t;
> > +
> > struct sseu_dev_info {
> > u8 slice_mask;
> > - u8 subslice_mask[GEN_SS_MASK_SIZE];
> > - u8 geometry_subslice_mask[GEN_SS_MASK_SIZE];
> > - u8 compute_subslice_mask[GEN_SS_MASK_SIZE];
> > + intel_sseu_ss_mask_t subslice_mask;
> > + intel_sseu_ss_mask_t geometry_subslice_mask;
> > + intel_sseu_ss_mask_t compute_subslice_mask;
> > /*
> > * EU masks. Use has_common_ss_eumask to determine how the field
> > @@ -107,7 +118,7 @@ intel_sseu_from_device_info(const struct sseu_dev_info
> > *sseu)
> > {
> > struct intel_sseu value = {
> > .slice_mask = sseu->slice_mask,
> > - .subslice_mask = sseu->subslice_mask[0],
> > + .subslice_mask = sseu->subslice_mask.b[0],
> > .min_eus_per_subslice = sseu->max_eus_per_subslice,
> > .max_eus_per_subslice = sseu->max_eus_per_subslice,
> > };
> > @@ -119,18 +130,8 @@ static inline bool
> > intel_sseu_has_subslice(const struct sseu_dev_info *sseu, int slice,
> > int subslice)
> > {
> > - u8 mask;
> > - int ss_idx = subslice / BITS_PER_BYTE;
> > -
> > - if (slice >= sseu->max_slices ||
> > - subslice >= sseu->max_subslices)
> > - return false;
> > -
> > - GEM_BUG_ON(ss_idx >= sseu->ss_stride);
> > -
> > - mask = sseu->subslice_mask[slice * sseu->ss_stride + ss_idx];
> > -
> > - return mask & BIT(subslice % BITS_PER_BYTE);
> > + return test_bit(slice * sseu->ss_stride + subslice,
> > + sseu->subslice_mask.b);
> > }
> > void intel_sseu_set_info(struct sseu_dev_info *sseu, u8 max_slices,
> > @@ -139,15 +140,14 @@ void intel_sseu_set_info(struct sseu_dev_info *sseu,
> > u8 max_slices,
> > unsigned int
> > intel_sseu_subslice_total(const struct sseu_dev_info *sseu);
> > -unsigned int
> > -intel_sseu_subslices_per_slice(const struct sseu_dev_info *sseu, u8 slice);
> > +intel_sseu_ss_mask_t
> > +intel_sseu_get_subslices(const struct sseu_dev_info *sseu, u8 slice);
> > -u32 intel_sseu_get_subslices(const struct sseu_dev_info *sseu, u8 slice);
> > -
> > -u32 intel_sseu_get_compute_subslices(const struct sseu_dev_info *sseu);
> > +intel_sseu_ss_mask_t
> > +intel_sseu_get_compute_subslices(const struct sseu_dev_info *sseu);
> > void intel_sseu_set_subslices(struct sseu_dev_info *sseu, int slice,
> > - u8 *subslice_mask, u32 ss_mask);
> > + u32 ss_mask);
> > void intel_sseu_info_init(struct intel_gt *gt);
> > @@ -159,9 +159,11 @@ void intel_sseu_print_topology(struct drm_i915_private
> > *i915,
> > const struct sseu_dev_info *sseu,
> > struct drm_printer *p);
> > -u16 intel_slicemask_from_dssmask(u64 dss_mask, int dss_per_slice);
> > +u16 intel_slicemask_from_dssmask(intel_sseu_ss_mask_t dss_mask, int
> > dss_per_slice);
> > int intel_sseu_copy_eumask_to_user(void __user *to,
> > const struct sseu_dev_info *sseu);
> > +int intel_sseu_copy_ssmask_to_user(void __user *to,
> > + const struct sseu_dev_info *sseu);
> > #endif /* __INTEL_SSEU_H__ */
> > diff --git a/drivers/gpu/drm/i915/gt/intel_sseu_debugfs.c
> > b/drivers/gpu/drm/i915/gt/intel_sseu_debugfs.c
> > index 2d5d011e01db..1f77bd52a3a6 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_sseu_debugfs.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_sseu_debugfs.c
> > @@ -4,6 +4,7 @@
> > * Copyright © 2020 Intel Corporation
> > */
> > +#include <linux/bitmap.h>
> > #include <linux/string_helpers.h>
> > #include "i915_drv.h"
> > @@ -12,11 +13,15 @@
> > #include "intel_sseu_debugfs.h"
> > static void sseu_copy_subslices(const struct sseu_dev_info *sseu,
> > - int slice, u8 *to_mask)
> > + int slice,
> > + intel_sseu_ss_mask_t *to_mask)
> > {
> > - int offset = slice * sseu->ss_stride;
> > + int offset = slice * sseu->max_subslices;
> > - memcpy(&to_mask[offset], &sseu->subslice_mask[offset], sseu->ss_stride);
> > + bitmap_fill(to_mask->b, sseu->max_subslices);
> > + bitmap_shift_left(to_mask->b, to_mask->b, offset,
> > I915_MAX_SS_FUSE_BITS);
> > + bitmap_and(to_mask->b, to_mask->b, sseu->subslice_mask.b,
> > I915_MAX_SS_FUSE_BITS);
> > + bitmap_shift_right(to_mask->b, to_mask->b, offset,
> > I915_MAX_SS_FUSE_BITS);
> > }
> > static void cherryview_sseu_device_status(struct intel_gt *gt,
> > @@ -41,7 +46,7 @@ static void cherryview_sseu_device_status(struct intel_gt
> > *gt,
> > continue;
> > sseu->slice_mask = BIT(0);
> > - sseu->subslice_mask[0] |= BIT(ss);
> > + set_bit(0, sseu->subslice_mask.b);
> > eu_cnt = ((sig1[ss] & CHV_EU08_PG_ENABLE) ? 0 : 2) +
> > ((sig1[ss] & CHV_EU19_PG_ENABLE) ? 0 : 2) +
> > ((sig1[ss] & CHV_EU210_PG_ENABLE) ? 0 : 2) +
> > @@ -92,7 +97,7 @@ static void gen11_sseu_device_status(struct intel_gt *gt,
> > continue;
> > sseu->slice_mask |= BIT(s);
> > - sseu_copy_subslices(&info->sseu, s, sseu->subslice_mask);
> > + sseu_copy_subslices(&info->sseu, s, &sseu->subslice_mask);
> > for (ss = 0; ss < info->sseu.max_subslices; ss++) {
> > unsigned int eu_cnt;
> > @@ -148,20 +153,17 @@ static void gen9_sseu_device_status(struct intel_gt
> > *gt,
> > if (IS_GEN9_BC(gt->i915))
> > sseu_copy_subslices(&info->sseu, s,
> > - sseu->subslice_mask);
> > + &sseu->subslice_mask);
> > for (ss = 0; ss < info->sseu.max_subslices; ss++) {
> > unsigned int eu_cnt;
> > - u8 ss_idx = s * info->sseu.ss_stride +
> > - ss / BITS_PER_BYTE;
> > if (IS_GEN9_LP(gt->i915)) {
> > if (!(s_reg[s] & (GEN9_PGCTL_SS_ACK(ss))))
> > /* skip disabled subslice */
> > continue;
> > - sseu->subslice_mask[ss_idx] |=
> > - BIT(ss % BITS_PER_BYTE);
> > + set_bit(ss, sseu->subslice_mask.b);
> > }
> > eu_cnt = eu_reg[2 * s + ss / 2] & eu_mask[ss % 2];
> > @@ -189,7 +191,7 @@ static void bdw_sseu_device_status(struct intel_gt *gt,
> > sseu->eu_per_subslice = info->sseu.eu_per_subslice;
> > for (s = 0; s < fls(sseu->slice_mask); s++)
> > sseu_copy_subslices(&info->sseu, s,
> > - sseu->subslice_mask);
> > + &sseu->subslice_mask);
> > sseu->eu_total = sseu->eu_per_subslice *
> > intel_sseu_subslice_total(sseu);
> > @@ -217,8 +219,10 @@ static void i915_print_sseu_info(struct seq_file *m,
> > seq_printf(m, " %s Subslice Total: %u\n", type,
> > intel_sseu_subslice_total(sseu));
> > for (s = 0; s < fls(sseu->slice_mask); s++) {
> > + intel_sseu_ss_mask_t ssmask = intel_sseu_get_subslices(sseu, s);
> > +
> > seq_printf(m, " %s Slice%i subslices: %u\n", type,
> > - s, intel_sseu_subslices_per_slice(sseu, s));
> > + s, bitmap_weight(ssmask.b, I915_MAX_SS_FUSE_BITS));
> > }
> > seq_printf(m, " %s EU Total: %u\n", type,
> > sseu->eu_total);
> > diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c
> > b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> > index a05c4b99b3fb..5db492072f99 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> > @@ -931,6 +931,7 @@ static void
> > gen9_wa_init_mcr(struct drm_i915_private *i915, struct i915_wa_list *wal)
> > {
> > const struct sseu_dev_info *sseu = &to_gt(i915)->info.sseu;
> > + intel_sseu_ss_mask_t ssmask;
> > unsigned int slice, subslice;
> > u32 mcr, mcr_mask;
> > @@ -948,9 +949,9 @@ gen9_wa_init_mcr(struct drm_i915_private *i915, struct
> > i915_wa_list *wal)
> > * on s/ss combo, the read should be done with read_subslice_reg.
> > */
> > slice = ffs(sseu->slice_mask) - 1;
> > - GEM_BUG_ON(slice >= ARRAY_SIZE(sseu->subslice_mask));
> > - subslice = ffs(intel_sseu_get_subslices(sseu, slice));
> > - GEM_BUG_ON(!subslice);
> > + ssmask = intel_sseu_get_subslices(sseu, slice);
> > + subslice = find_first_bit(ssmask.b, I915_MAX_SS_FUSE_BITS);
> > + GEM_BUG_ON(subslice == I915_MAX_SS_FUSE_BITS);
> > subslice--;
> > /*
> > @@ -1087,11 +1088,10 @@ static void
> > icl_wa_init_mcr(struct intel_gt *gt, struct i915_wa_list *wal)
> > {
> > const struct sseu_dev_info *sseu = >->info.sseu;
> > - unsigned int slice, subslice;
> > + unsigned int subslice;
> > GEM_BUG_ON(GRAPHICS_VER(gt->i915) < 11);
> > GEM_BUG_ON(hweight8(sseu->slice_mask) > 1);
> > - slice = 0;
> > /*
> > * Although a platform may have subslices, we need to always steer
> > @@ -1102,7 +1102,7 @@ icl_wa_init_mcr(struct intel_gt *gt, struct
> > i915_wa_list *wal)
> > * one of the higher subslices, we run the risk of reading back 0's or
> > * random garbage.
> > */
> > - subslice = __ffs(intel_sseu_get_subslices(sseu, slice));
> > + subslice = find_first_bit(sseu->subslice_mask.b, I915_MAX_SS_FUSE_BITS);
> > /*
> > * If the subslice we picked above also steers us to a valid L3 bank,
> > @@ -1112,7 +1112,7 @@ icl_wa_init_mcr(struct intel_gt *gt, struct
> > i915_wa_list *wal)
> > if (gt->info.l3bank_mask & BIT(subslice))
> > gt->steering_table[L3BANK] = NULL;
> > - __add_mcr_wa(gt, wal, slice, subslice);
> > + __add_mcr_wa(gt, wal, 0, subslice);
> > }
> > static void
> > @@ -1120,7 +1120,6 @@ xehp_init_mcr(struct intel_gt *gt, struct
> > i915_wa_list *wal)
> > {
> > const struct sseu_dev_info *sseu = >->info.sseu;
> > unsigned long slice, subslice = 0, slice_mask = 0;
> > - u64 dss_mask = 0;
> > u32 lncf_mask = 0;
> > int i;
> > @@ -1151,8 +1150,8 @@ xehp_init_mcr(struct intel_gt *gt, struct
> > i915_wa_list *wal)
> > */
> > /* Find the potential gslice candidates */
> > - dss_mask = intel_sseu_get_subslices(sseu, 0);
> > - slice_mask = intel_slicemask_from_dssmask(dss_mask, GEN_DSS_PER_GSLICE);
> > + slice_mask = intel_slicemask_from_dssmask(sseu->subslice_mask,
> > + GEN_DSS_PER_GSLICE);
> > /*
> > * Find the potential LNCF candidates. Either LNCF within a valid
> > @@ -1177,9 +1176,9 @@ xehp_init_mcr(struct intel_gt *gt, struct
> > i915_wa_list *wal)
> > }
> > slice = __ffs(slice_mask);
> > - subslice = __ffs(dss_mask >> (slice * GEN_DSS_PER_GSLICE));
> > + subslice = find_next_bit(sseu->subslice_mask.b, I915_MAX_SS_FUSE_BITS,
> > + slice * GEN_DSS_PER_GSLICE);
> > WARN_ON(subslice > GEN_DSS_PER_GSLICE);
> > - WARN_ON(dss_mask >> (slice * GEN_DSS_PER_GSLICE) == 0);
> > __add_mcr_wa(gt, wal, slice, subslice);
> > @@ -2012,9 +2011,8 @@ engine_fake_wa_init(struct intel_engine_cs *engine,
> > struct i915_wa_list *wal)
> > static bool needs_wa_1308578152(struct intel_engine_cs *engine)
> > {
> > - u64 dss_mask = intel_sseu_get_subslices(&engine->gt->info.sseu, 0);
> > -
> > - return (dss_mask & GENMASK(GEN_DSS_PER_GSLICE - 1, 0)) == 0;
> > + return find_first_bit(engine->gt->info.sseu.subslice_mask.b,
> > + I915_MAX_SS_FUSE_BITS) >= GEN_DSS_PER_GSLICE;
> > }
> > static void
> > diff --git a/drivers/gpu/drm/i915/i915_getparam.c
> > b/drivers/gpu/drm/i915/i915_getparam.c
> > index ac9767c56619..349d496d164a 100644
> > --- a/drivers/gpu/drm/i915/i915_getparam.c
> > +++ b/drivers/gpu/drm/i915/i915_getparam.c
> > @@ -162,7 +162,7 @@ int i915_getparam_ioctl(struct drm_device *dev, void
> > *data,
> > return -EINVAL;
> > /* Only copy bits from the first slice */
> > - memcpy(&value, sseu->subslice_mask,
> > + memcpy(&value, sseu->subslice_mask.b,
> > min(sseu->ss_stride, (u8)sizeof(value)));
> > if (!value)
> > return -ENODEV;
> > diff --git a/drivers/gpu/drm/i915/i915_query.c
> > b/drivers/gpu/drm/i915/i915_query.c
> > index 16f43bf32a05..9afa6d1eaf95 100644
> > --- a/drivers/gpu/drm/i915/i915_query.c
> > +++ b/drivers/gpu/drm/i915/i915_query.c
> > @@ -31,7 +31,7 @@ static int copy_query_item(void *query_hdr, size_t
> > query_sz,
> > static int fill_topology_info(const struct sseu_dev_info *sseu,
> > struct drm_i915_query_item *query_item,
> > - const u8 *subslice_mask)
> > + intel_sseu_ss_mask_t subslice_mask)
> > {
> > struct drm_i915_query_topology_info topo;
> > u32 slice_length, subslice_length, eu_length, total_length;
> > @@ -71,9 +71,9 @@ static int fill_topology_info(const struct sseu_dev_info
> > *sseu,
> > &sseu->slice_mask, slice_length))
> > return -EFAULT;
> > - if (copy_to_user(u64_to_user_ptr(query_item->data_ptr +
> > - sizeof(topo) + slice_length),
> > - subslice_mask, subslice_length))
> > + if (intel_sseu_copy_ssmask_to_user(u64_to_user_ptr(query_item->data_ptr
> > +
> > + sizeof(topo) +
> > slice_length),
> > + sseu))
> > return -EFAULT;
> > if (intel_sseu_copy_eumask_to_user(u64_to_user_ptr(query_item->data_ptr
> > +
--
Matt Roper
Graphics Software Engineer
VTT-OSGC Platform Enablement
Intel Corporation
(916) 356-2795
