> -----Original Message----- > From: Intel-gfx <intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of Aravind > Iddamsetty > Sent: Wednesday, September 28, 2022 4:36 PM > To: intel-gfx@xxxxxxxxxxxxxxxxxxxxx > Cc: De Marchi, Lucas <lucas.demarchi@xxxxxxxxx>; dri- > devel@xxxxxxxxxxxxxxxxxxxxx > Subject: [Intel-gfx] [PATCH v4] drm/i915/mtl: enable local stolen memory > > As an integrated GPU, MTL does not have local memory and > HAS_LMEM() returns false. However the platform's stolen memory is presented > via BAR2 (i.e., the BAR we traditionally consider to be the LMEM BAR) and AFAIU BAR2 has represented stolen memory on prior generations as well. Like on ADL. Region 0: Memory at 618e000000 (64-bit, non-prefetchable) [size=16M] Region 2: Memory at 4000000000 (64-bit, prefetchable) [size=256M] Region 4: I/O ports at 4000 [size=64] May be a bit of more explanation required here for BAR2 , how is it deifferent? Br, Anshuman Gupta. > should be managed by the driver the same way that local memory is on dgpu > platforms (which includes setting the "lmem" bit on page table entries). We use > the term "local stolen memory" to refer to this model. > > BSPEC: 53098, 63830 > > v2: > 1. dropped is_dsm_invalid, updated valid_stolen_size check from Lucas (Jani, > Lucas) 2. drop lmembar_is_igpu_stolen 3. revert to referring GFXMEM_BAR as > GEN12_LMEM_BAR (Lucas) > > v3:(Jani) > 1. rename get_mtl_gms_size to mtl_get_gms_size 2. define register for MMIO > address > > v4:(Matt) > 1. Use REG_FIELD_GET to read GMS value > 2. replace the calculations with SZ_256M/SZ_8M > > Cc: Matt Roper <matthew.d.roper@xxxxxxxxx> > Cc: Lucas De Marchi <lucas.demarchi@xxxxxxxxx> > Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> > > Signed-off-by: CQ Tang <cq.tang@xxxxxxxxx> > Signed-off-by: Aravind Iddamsetty <aravind.iddamsetty@xxxxxxxxx> > Original-author: CQ Tang > --- > drivers/gpu/drm/i915/gem/i915_gem_stolen.c | 83 ++++++++++++++++++---- > drivers/gpu/drm/i915/gt/intel_ggtt.c | 2 +- > drivers/gpu/drm/i915/i915_drv.h | 3 + > drivers/gpu/drm/i915/i915_reg.h | 4 ++ > 4 files changed, 76 insertions(+), 16 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c > b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c > index c5a4035c99cd..2f8530a0ff62 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c > @@ -77,9 +77,9 @@ void i915_gem_stolen_remove_node(struct > drm_i915_private *i915, > mutex_unlock(&i915->mm.stolen_lock); > } > > -static bool valid_stolen_size(struct resource *dsm) > +static bool valid_stolen_size(struct drm_i915_private *i915, struct > +resource *dsm) > { > - return dsm->start != 0 && dsm->end > dsm->start; > + return (dsm->start != 0 || HAS_BAR2_SMEM_STOLEN(i915)) && dsm- > >end > > +dsm->start; > } > > static int adjust_stolen(struct drm_i915_private *i915, @@ -88,7 +88,7 @@ > static int adjust_stolen(struct drm_i915_private *i915, > struct i915_ggtt *ggtt = to_gt(i915)->ggtt; > struct intel_uncore *uncore = ggtt->vm.gt->uncore; > > - if (!valid_stolen_size(dsm)) > + if (!valid_stolen_size(i915, dsm)) > return -EINVAL; > > /* > @@ -135,7 +135,7 @@ static int adjust_stolen(struct drm_i915_private *i915, > } > } > > - if (!valid_stolen_size(dsm)) > + if (!valid_stolen_size(i915, dsm)) > return -EINVAL; > > return 0; > @@ -149,8 +149,11 @@ static int request_smem_stolen(struct > drm_i915_private *i915, > /* > * With stolen lmem, we don't need to request system memory for the > * address range since it's local to the gpu. > + * > + * Starting MTL, in IGFX devices the stolen memory is exposed via > + * BAR2 and shall be considered similar to stolen lmem. > */ > - if (HAS_LMEM(i915)) > + if (HAS_LMEM(i915) || HAS_BAR2_SMEM_STOLEN(i915)) > return 0; > > /* > @@ -385,8 +388,6 @@ static void icl_get_stolen_reserved(struct > drm_i915_private *i915, > > drm_dbg(&i915->drm, "GEN6_STOLEN_RESERVED = 0x%016llx\n", > reg_val); > > - *base = reg_val & GEN11_STOLEN_RESERVED_ADDR_MASK; > - > switch (reg_val & GEN8_STOLEN_RESERVED_SIZE_MASK) { > case GEN8_STOLEN_RESERVED_1M: > *size = 1024 * 1024; > @@ -404,6 +405,12 @@ static void icl_get_stolen_reserved(struct > drm_i915_private *i915, > *size = 8 * 1024 * 1024; > MISSING_CASE(reg_val & > GEN8_STOLEN_RESERVED_SIZE_MASK); > } > + > + if (HAS_BAR2_SMEM_STOLEN(i915)) > + /* the base is initialized to stolen top so subtract size to get > base */ > + *base -= *size; > + else > + *base = reg_val & GEN11_STOLEN_RESERVED_ADDR_MASK; > } > > /* > @@ -833,6 +840,29 @@ static const struct intel_memory_region_ops > i915_region_stolen_lmem_ops = { > .init_object = _i915_gem_object_stolen_init, }; > > +static int mtl_get_gms_size(struct intel_uncore *uncore) { > + u16 ggc, gms; > + > + ggc = intel_uncore_read16(uncore, GGC); > + > + /* check GGMS, should be fixed 0x3 (8MB) */ > + if ((ggc & GGMS_MASK) != GGMS_MASK) > + return -EIO; > + > + /* return valid GMS value, -EIO if invalid */ > + gms = REG_FIELD_GET(GMS_MASK, ggc); > + switch (gms) { > + case 0x0 ... 0x04: > + return gms * 32; > + case 0xf0 ... 0xfe: > + return (gms - 0xf0 + 1) * 4; > + default: > + MISSING_CASE(gms); > + return -EIO; > + } > +} > + > struct intel_memory_region * > i915_gem_stolen_lmem_setup(struct drm_i915_private *i915, u16 type, > u16 instance) > @@ -843,6 +873,7 @@ i915_gem_stolen_lmem_setup(struct drm_i915_private > *i915, u16 type, > struct intel_memory_region *mem; > resource_size_t io_start, io_size; > resource_size_t min_page_size; > + int ret; > > if (WARN_ON_ONCE(instance)) > return ERR_PTR(-ENODEV); > @@ -850,12 +881,8 @@ i915_gem_stolen_lmem_setup(struct > drm_i915_private *i915, u16 type, > if (!i915_pci_resource_valid(pdev, GEN12_LMEM_BAR)) > return ERR_PTR(-ENXIO); > > - /* Use DSM base address instead for stolen memory */ > - dsm_base = intel_uncore_read64(uncore, GEN12_DSMBASE) & > GEN12_BDSM_MASK; > - if (IS_DG1(uncore->i915)) { > + if (HAS_BAR2_SMEM_STOLEN(i915) || IS_DG1(i915)) { > lmem_size = pci_resource_len(pdev, GEN12_LMEM_BAR); > - if (WARN_ON(lmem_size < dsm_base)) > - return ERR_PTR(-ENODEV); > } else { > resource_size_t lmem_range; > > @@ -864,13 +891,39 @@ i915_gem_stolen_lmem_setup(struct > drm_i915_private *i915, u16 type, > lmem_size *= SZ_1G; > } > > - dsm_size = lmem_size - dsm_base; > - if (pci_resource_len(pdev, GEN12_LMEM_BAR) < lmem_size) { > + if (HAS_BAR2_SMEM_STOLEN(i915)) { > + /* > + * MTL dsm size is in GGC register, not the bar size. > + * also MTL uses offset to DSMBASE in ptes, so i915 > + * uses dsm_base = 0 to setup stolen region. > + */ > + ret = mtl_get_gms_size(uncore); > + if (ret < 0) { > + drm_err(&i915->drm, "invalid MTL GGC register > setting\n"); > + return ERR_PTR(ret); > + } > + > + dsm_base = 0; > + dsm_size = (resource_size_t)(ret * SZ_1M); > + > + GEM_BUG_ON(pci_resource_len(pdev, GEN12_LMEM_BAR) != > SZ_256M); > + GEM_BUG_ON((dsm_size + SZ_8M) > lmem_size); > + } else { > + /* Use DSM base address instead for stolen memory */ > + dsm_base = intel_uncore_read64(uncore, GEN12_DSMBASE); > + if (WARN_ON(lmem_size < dsm_base)) > + return ERR_PTR(-ENODEV); > + dsm_size = lmem_size - dsm_base; > + } > + > + io_size = dsm_size; > + if (pci_resource_len(pdev, GEN12_LMEM_BAR) < dsm_size) { > io_start = 0; > io_size = 0; > + } else if (HAS_BAR2_SMEM_STOLEN(i915)) { > + io_start = pci_resource_start(pdev, GEN12_LMEM_BAR) + > SZ_8M; > } else { > io_start = pci_resource_start(pdev, GEN12_LMEM_BAR) + > dsm_base; > - io_size = dsm_size; > } > > min_page_size = HAS_64K_PAGES(i915) ? I915_GTT_PAGE_SIZE_64K : > diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c > b/drivers/gpu/drm/i915/gt/intel_ggtt.c > index 30cf5c3369d9..b31fe0fb013f 100644 > --- a/drivers/gpu/drm/i915/gt/intel_ggtt.c > +++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c > @@ -931,7 +931,7 @@ static int gen8_gmch_probe(struct i915_ggtt *ggtt) > unsigned int size; > u16 snb_gmch_ctl; > > - if (!HAS_LMEM(i915)) { > + if (!HAS_LMEM(i915) && !HAS_BAR2_SMEM_STOLEN(i915)) { > if (!i915_pci_resource_valid(pdev, GTT_APERTURE_BAR)) > return -ENXIO; > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index 84a2f6b16f57..90ed8e6db2fe 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -974,6 +974,9 @@ IS_SUBPLATFORM(const struct drm_i915_private *i915, > > #define HAS_ONE_EU_PER_FUSE_BIT(i915) (INTEL_INFO(i915)- > >has_one_eu_per_fuse_bit) > > +#define HAS_BAR2_SMEM_STOLEN(i915) (!HAS_LMEM(i915) && \ > + GRAPHICS_VER_FULL(i915) >= IP_VER(12, > 70)) > + > /* intel_device_info.c */ > static inline struct intel_device_info * mkwrite_device_info(struct > drm_i915_private *dev_priv) diff --git a/drivers/gpu/drm/i915/i915_reg.h > b/drivers/gpu/drm/i915/i915_reg.h index 5003a5ffbc6a..2126e441199d 100644 > --- a/drivers/gpu/drm/i915/i915_reg.h > +++ b/drivers/gpu/drm/i915/i915_reg.h > @@ -7967,6 +7967,10 @@ enum skl_power_gate { > > _ICL_PIPE_DSS_CTL2_PB, \ > > _ICL_PIPE_DSS_CTL2_PC) > > +#define GGC _MMIO(0x108040) > +#define GMS_MASK REG_GENMASK(15, 8) > +#define GGMS_MASK REG_GENMASK(7, 6) > + > #define GEN12_GSMBASE _MMIO(0x108100) > #define GEN12_DSMBASE _MMIO(0x1080C0) > #define GEN12_BDSM_MASK REG_GENMASK64(63, 20) > -- > 2.25.1