From 6197cff30df44e4db85fed545fecb7df00ff8cd0 Mon Sep 17 00:00:00 2001 From: John Harrison Date: Tue, 18 Apr 2023 11:17:43 -0700 Subject: [PATCH] drm/i915: Dump error capture to kernel log This is useful for getting debug information out in certain situations, such as failing kernel selftests and CI runs that don't log error captures. It is especially useful for things like retrieving GuC logs as GuC operation can't be tracked by adding printk or ftrace entries. v2: Add CONFIG_DRM_I915_DEBUG_GEM wrapper (review feedback by Rodrigo). Signed-off-by: John Harrison Reviewed-by: Vinay Belgaumkar Link: https://patchwork.freedesktop.org/patch/msgid/20230418181744.3251240-2-John.C.Harrison@Intel.com --- drivers/gpu/drm/i915/i915_gpu_error.c | 132 ++++++++++++++++++++++++++ drivers/gpu/drm/i915/i915_gpu_error.h | 10 ++ 2 files changed, 142 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c index 566536499954..ec368e700235 100644 --- a/drivers/gpu/drm/i915/i915_gpu_error.c +++ b/drivers/gpu/drm/i915/i915_gpu_error.c @@ -2228,3 +2228,135 @@ void i915_disable_error_state(struct drm_i915_private *i915, int err) i915->gpu_error.first_error = ERR_PTR(err); spin_unlock_irq(&i915->gpu_error.lock); } + +#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM) +void intel_klog_error_capture(struct intel_gt *gt, + intel_engine_mask_t engine_mask) +{ + static int g_count; + struct drm_i915_private *i915 = gt->i915; + struct i915_gpu_coredump *error; + intel_wakeref_t wakeref; + size_t buf_size = PAGE_SIZE * 128; + size_t pos_err; + char *buf, *ptr, *next; + int l_count = g_count++; + int line = 0; + + /* Can't allocate memory during a reset */ + if (test_bit(I915_RESET_BACKOFF, >->reset.flags)) { + drm_err(>->i915->drm, "[Capture/%d.%d] Inside GT reset, skipping error capture :(\n", + l_count, line++); + return; + } + + error = READ_ONCE(i915->gpu_error.first_error); + if (error) { + drm_err(&i915->drm, "[Capture/%d.%d] Clearing existing error capture first...\n", + l_count, line++); + i915_reset_error_state(i915); + } + + with_intel_runtime_pm(&i915->runtime_pm, wakeref) + error = i915_gpu_coredump(gt, engine_mask, CORE_DUMP_FLAG_NONE); + + if (IS_ERR(error)) { + drm_err(&i915->drm, "[Capture/%d.%d] Failed to capture error capture: %ld!\n", + l_count, line++, PTR_ERR(error)); + return; + } + + buf = kvmalloc(buf_size, GFP_KERNEL); + if (!buf) { + drm_err(&i915->drm, "[Capture/%d.%d] Failed to allocate buffer for error capture!\n", + l_count, line++); + i915_gpu_coredump_put(error); + return; + } + + drm_info(&i915->drm, "[Capture/%d.%d] Dumping i915 error capture for %ps...\n", + l_count, line++, __builtin_return_address(0)); + + /* Largest string length safe to print via dmesg */ +# define MAX_CHUNK 800 + + pos_err = 0; + while (1) { + ssize_t got = i915_gpu_coredump_copy_to_buffer(error, buf, pos_err, buf_size - 1); + + if (got <= 0) + break; + + buf[got] = 0; + pos_err += got; + + ptr = buf; + while (got > 0) { + size_t count; + char tag[2]; + + next = strnchr(ptr, got, '\n'); + if (next) { + count = next - ptr; + *next = 0; + tag[0] = '>'; + tag[1] = '<'; + } else { + count = got; + tag[0] = '}'; + tag[1] = '{'; + } + + if (count > MAX_CHUNK) { + size_t pos; + char *ptr2 = ptr; + + for (pos = MAX_CHUNK; pos < count; pos += MAX_CHUNK) { + char chr = ptr[pos]; + + ptr[pos] = 0; + drm_info(&i915->drm, "[Capture/%d.%d] }%s{\n", + l_count, line++, ptr2); + ptr[pos] = chr; + ptr2 = ptr + pos; + + /* + * If spewing large amounts of data via a serial console, + * this can be a very slow process. So be friendly and try + * not to cause 'softlockup on CPU' problems. + */ + cond_resched(); + } + + if (ptr2 < (ptr + count)) + drm_info(&i915->drm, "[Capture/%d.%d] %c%s%c\n", + l_count, line++, tag[0], ptr2, tag[1]); + else if (tag[0] == '>') + drm_info(&i915->drm, "[Capture/%d.%d] ><\n", + l_count, line++); + } else { + drm_info(&i915->drm, "[Capture/%d.%d] %c%s%c\n", + l_count, line++, tag[0], ptr, tag[1]); + } + + ptr = next; + got -= count; + if (next) { + ptr++; + got--; + } + + /* As above. */ + cond_resched(); + } + + if (got) + drm_info(&i915->drm, "[Capture/%d.%d] Got %zd bytes remaining!\n", + l_count, line++, got); + } + + kvfree(buf); + + drm_info(&i915->drm, "[Capture/%d.%d] Dumped %zd bytes\n", l_count, line++, pos_err); +} +#endif diff --git a/drivers/gpu/drm/i915/i915_gpu_error.h b/drivers/gpu/drm/i915/i915_gpu_error.h index a91932cc6531..a78c061ce26f 100644 --- a/drivers/gpu/drm/i915/i915_gpu_error.h +++ b/drivers/gpu/drm/i915/i915_gpu_error.h @@ -258,6 +258,16 @@ static inline u32 i915_reset_engine_count(struct i915_gpu_error *error, #define CORE_DUMP_FLAG_NONE 0x0 #define CORE_DUMP_FLAG_IS_GUC_CAPTURE BIT(0) +#if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR) && IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM) +void intel_klog_error_capture(struct intel_gt *gt, + intel_engine_mask_t engine_mask); +#else +static inline void intel_klog_error_capture(struct intel_gt *gt, + intel_engine_mask_t engine_mask) +{ +} +#endif + #if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR) __printf(2, 3) -- 2.25.1