Message ID | 20240116075636.6121-5-ville.syrjala@linux.intel.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | drm/i915: (stolen) memory region related fixes | expand |
On 1/16/2024 8:56 AM, Ville Syrjala wrote: > From: Ville Syrjälä<ville.syrjala@linux.intel.com> > > On MTL accessing stolen memory via the BARs is somehow borked, > and it can hang the machine. As a workaround let's bypass the > BARs and just go straight to DSMBASE/GSMBASE instead. > > Note that on every other platform this itself would hang the > machine, but on MTL the system firmware is expected to relax > the access permission guarding stolen memory to enable this > workaround, and thus direct CPU accesses should be fine. > > The raw stolen memory areas won't be passed to VMs so we'll > need to risk using the BAR there for the initial setup. Once > command submission is up we should switch to MI_UPDATE_GTT > which at least shouldn't hang the whole machine. > > v2: Don't use direct GSM/DSM access on guests > Add w/a number > > Cc: Paz Zcharya<pazz@chromium.org> > Cc: Nirmoy Das<nirmoy.das@intel.com> > Cc: Joonas Lahtinen<joonas.lahtinen@linux.intel.com> > Reviewed-by: Andrzej Hajda<andrzej.hajda@intel.com> > Reviewed-by: Radhakrishna Sripada<radhakrishna.sripada@intel.com> > Signed-off-by: Ville Syrjälä<ville.syrjala@linux.intel.com> I think i915_run_as_guest() should work. Reviewed-by: Nirmoy Das <nirmoy.das@intel.com> > --- > drivers/gpu/drm/i915/gem/i915_gem_stolen.c | 14 +++++++++++++- > drivers/gpu/drm/i915/gt/intel_ggtt.c | 16 +++++++++++++++- > 2 files changed, 28 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c > index ee237043c302..0b429f1ecd99 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c > @@ -941,7 +941,19 @@ i915_gem_stolen_lmem_setup(struct drm_i915_private *i915, u16 type, > dsm_size = ALIGN_DOWN(lmem_size - dsm_base, SZ_1M); > } > > - if (pci_resource_len(pdev, GEN12_LMEM_BAR) < lmem_size) { > + if (IS_METEORLAKE(i915) && !i915_run_as_guest()) { > + /* > + * Wa_22018444074 > + * > + * Access via BAR can hang MTL, go directly to DSM, > + * except for VM guests which won't have access to it. > + * > + * Normally this would not work but on MTL the system firmware > + * should have relaxed the access permissions sufficiently. > + */ > + io_start = intel_uncore_read64(uncore, GEN12_DSMBASE) & GEN12_BDSM_MASK; > + io_size = dsm_size; > + } else if (pci_resource_len(pdev, GEN12_LMEM_BAR) < lmem_size) { > io_start = 0; > io_size = 0; > } else { > diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c > index 21a7e3191c18..7a716ff16070 100644 > --- a/drivers/gpu/drm/i915/gt/intel_ggtt.c > +++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c > @@ -24,6 +24,7 @@ > #include "intel_ring.h" > #include "i915_drv.h" > #include "i915_pci.h" > +#include "i915_reg.h" > #include "i915_request.h" > #include "i915_scatterlist.h" > #include "i915_utils.h" > @@ -1152,13 +1153,26 @@ static unsigned int gen6_gttadr_offset(struct drm_i915_private *i915) > static int ggtt_probe_common(struct i915_ggtt *ggtt, u64 size) > { > struct drm_i915_private *i915 = ggtt->vm.i915; > + struct intel_uncore *uncore = ggtt->vm.gt->uncore; > struct pci_dev *pdev = to_pci_dev(i915->drm.dev); > phys_addr_t phys_addr; > u32 pte_flags; > int ret; > > GEM_WARN_ON(pci_resource_len(pdev, GEN4_GTTMMADR_BAR) != gen6_gttmmadr_size(i915)); > - phys_addr = pci_resource_start(pdev, GEN4_GTTMMADR_BAR) + gen6_gttadr_offset(i915); > + /* > + * Wa_22018444074 > + * > + * Access via BAR can hang MTL, go directly to GSM, > + * except for VM guests which won't have access to it. > + * > + * Normally this would not work but on MTL the system firmware > + * should have relaxed the access permissions sufficiently. > + */ > + if (IS_METEORLAKE(i915) && !i915_run_as_guest()) > + phys_addr = intel_uncore_read64(uncore, GEN12_GSMBASE) & GEN12_BDSM_MASK; > + else > + phys_addr = pci_resource_start(pdev, GEN4_GTTMMADR_BAR) + gen6_gttadr_offset(i915); > > if (needs_wc_ggtt_mapping(i915)) > ggtt->gsm = ioremap_wc(phys_addr, size);
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c index ee237043c302..0b429f1ecd99 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c @@ -941,7 +941,19 @@ i915_gem_stolen_lmem_setup(struct drm_i915_private *i915, u16 type, dsm_size = ALIGN_DOWN(lmem_size - dsm_base, SZ_1M); } - if (pci_resource_len(pdev, GEN12_LMEM_BAR) < lmem_size) { + if (IS_METEORLAKE(i915) && !i915_run_as_guest()) { + /* + * Wa_22018444074 + * + * Access via BAR can hang MTL, go directly to DSM, + * except for VM guests which won't have access to it. + * + * Normally this would not work but on MTL the system firmware + * should have relaxed the access permissions sufficiently. + */ + io_start = intel_uncore_read64(uncore, GEN12_DSMBASE) & GEN12_BDSM_MASK; + io_size = dsm_size; + } else if (pci_resource_len(pdev, GEN12_LMEM_BAR) < lmem_size) { io_start = 0; io_size = 0; } else { diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c index 21a7e3191c18..7a716ff16070 100644 --- a/drivers/gpu/drm/i915/gt/intel_ggtt.c +++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c @@ -24,6 +24,7 @@ #include "intel_ring.h" #include "i915_drv.h" #include "i915_pci.h" +#include "i915_reg.h" #include "i915_request.h" #include "i915_scatterlist.h" #include "i915_utils.h" @@ -1152,13 +1153,26 @@ static unsigned int gen6_gttadr_offset(struct drm_i915_private *i915) static int ggtt_probe_common(struct i915_ggtt *ggtt, u64 size) { struct drm_i915_private *i915 = ggtt->vm.i915; + struct intel_uncore *uncore = ggtt->vm.gt->uncore; struct pci_dev *pdev = to_pci_dev(i915->drm.dev); phys_addr_t phys_addr; u32 pte_flags; int ret; GEM_WARN_ON(pci_resource_len(pdev, GEN4_GTTMMADR_BAR) != gen6_gttmmadr_size(i915)); - phys_addr = pci_resource_start(pdev, GEN4_GTTMMADR_BAR) + gen6_gttadr_offset(i915); + /* + * Wa_22018444074 + * + * Access via BAR can hang MTL, go directly to GSM, + * except for VM guests which won't have access to it. + * + * Normally this would not work but on MTL the system firmware + * should have relaxed the access permissions sufficiently. + */ + if (IS_METEORLAKE(i915) && !i915_run_as_guest()) + phys_addr = intel_uncore_read64(uncore, GEN12_GSMBASE) & GEN12_BDSM_MASK; + else + phys_addr = pci_resource_start(pdev, GEN4_GTTMMADR_BAR) + gen6_gttadr_offset(i915); if (needs_wc_ggtt_mapping(i915)) ggtt->gsm = ioremap_wc(phys_addr, size);