Register GT0_PERF_LIMIT_REASONS (0x1381a8) is available only for Gen11+. Therefore ensure perf_limit_reasons sysfs/debugfs files are created only for Gen11+. Otherwise on Gen < 5 accessing these files results in the following oops:
<1> [88.829420] BUG: unable to handle page fault for address: ffffc90000bb81a8 <1> [88.829438] #PF: supervisor read access in kernel mode <1> [88.829447] #PF: error_code(0x0000) - not-present page Bspec: 20008 Bug: https://gitlab.freedesktop.org/drm/intel/-/issues/6863 Fixes: fe5979665f64 ("drm/i915/debugfs: Add perf_limit_reasons in debugfs") Fixes: fa68bff7cf27 ("drm/i915/gt: Add sysfs throttle frequency interfaces") Signed-off-by: Ashutosh Dixit <ashutosh.di...@intel.com> --- drivers/gpu/drm/i915/gt/intel_gt.c | 4 ++++ drivers/gpu/drm/i915/gt/intel_gt_pm_debugfs.c | 10 +++++++++- drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c | 15 +++++++++++---- 3 files changed, 24 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c index 5ddae95d4886..b367cfff48d5 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt.c +++ b/drivers/gpu/drm/i915/gt/intel_gt.c @@ -233,6 +233,10 @@ static void gen6_clear_engine_error_register(struct intel_engine_cs *engine) i915_reg_t intel_gt_perf_limit_reasons_reg(struct intel_gt *gt) { + /* GT0_PERF_LIMIT_REASONS is available only for Gen11+ */ + if (GRAPHICS_VER(gt->i915) < 11) + return INVALID_MMIO_REG; + return gt->type == GT_MEDIA ? MTL_MEDIA_PERF_LIMIT_REASONS : GT0_PERF_LIMIT_REASONS; } diff --git a/drivers/gpu/drm/i915/gt/intel_gt_pm_debugfs.c b/drivers/gpu/drm/i915/gt/intel_gt_pm_debugfs.c index 68310881a793..10f680dbd7b6 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt_pm_debugfs.c +++ b/drivers/gpu/drm/i915/gt/intel_gt_pm_debugfs.c @@ -682,6 +682,14 @@ static int perf_limit_reasons_clear(void *data, u64 val) return 0; } + +static bool perf_limit_reasons_eval(void *data) +{ + struct intel_gt *gt = data; + + return i915_mmio_reg_valid(intel_gt_perf_limit_reasons_reg(gt)); +} + DEFINE_SIMPLE_ATTRIBUTE(perf_limit_reasons_fops, perf_limit_reasons_get, perf_limit_reasons_clear, "%llu\n"); @@ -694,7 +702,7 @@ void intel_gt_pm_debugfs_register(struct intel_gt *gt, struct dentry *root) { "forcewake_user", &forcewake_user_fops, NULL}, { "llc", &llc_fops, llc_eval }, { "rps_boost", &rps_boost_fops, rps_eval }, - { "perf_limit_reasons", &perf_limit_reasons_fops, NULL }, + { "perf_limit_reasons", &perf_limit_reasons_fops, perf_limit_reasons_eval }, }; intel_gt_debugfs_register_files(root, files, ARRAY_SIZE(files), gt); diff --git a/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c b/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c index 54deae45d81f..904160952369 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c +++ b/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c @@ -545,8 +545,7 @@ static INTEL_GT_RPS_BOOL_ATTR_RO(throttle_reason_ratl, RATL_MASK); static INTEL_GT_RPS_BOOL_ATTR_RO(throttle_reason_vr_thermalert, VR_THERMALERT_MASK); static INTEL_GT_RPS_BOOL_ATTR_RO(throttle_reason_vr_tdc, VR_TDC_MASK); -static const struct attribute *freq_attrs[] = { - &dev_attr_punit_req_freq_mhz.attr, +static const struct attribute *throttle_reason_attrs[] = { &attr_throttle_reason_status.attr, &attr_throttle_reason_pl1.attr, &attr_throttle_reason_pl2.attr, @@ -791,12 +790,20 @@ void intel_gt_sysfs_pm_init(struct intel_gt *gt, struct kobject *kobj) if (!is_object_gt(kobj)) return; - ret = sysfs_create_files(kobj, freq_attrs); + ret = sysfs_create_file(kobj, &dev_attr_punit_req_freq_mhz.attr); if (ret) drm_warn(>->i915->drm, - "failed to create gt%u throttle sysfs files (%pe)", + "failed to create gt%u punit_req_freq_mhz sysfs (%pe)", gt->info.id, ERR_PTR(ret)); + if (i915_mmio_reg_valid(intel_gt_perf_limit_reasons_reg(gt))) { + ret = sysfs_create_files(kobj, throttle_reason_attrs); + if (ret) + drm_warn(>->i915->drm, + "failed to create gt%u throttle sysfs files (%pe)", + gt->info.id, ERR_PTR(ret)); + } + if (HAS_MEDIA_RATIO_MODE(gt->i915) && intel_uc_uses_guc_slpc(>->uc)) { ret = sysfs_create_files(kobj, media_perf_power_attrs); if (ret) -- 2.34.1
