From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0B1D9C3601A for ; Tue, 1 Apr 2025 17:57:17 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 3375710E647; Tue, 1 Apr 2025 17:57:16 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="TIdpu00T"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.11]) by gabe.freedesktop.org (Postfix) with ESMTPS id 604F510E63E; Tue, 1 Apr 2025 17:57:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1743530234; x=1775066234; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=Y8po2mG+ZdaKzrhPAKY3Rl4zdUDsFxDOPIFpWcJDdv0=; b=TIdpu00T8f4RCTgE29x8sf3XHxx13w9jo5zgLGgTaMkRA2o1V17deBa7 thuxTXmmbVQ4xEe437HW8ccZZL0kdFxMT3whIEVR9lTkeSIrywSRCMJnf zmKex5Qk4gMIT/qaZ+WBR+tmX0Szp9MnPvlEw3TfpuNOJVBXaHgqe7xpf roUJfjLAZ6NGccyCCXHJH9aEqnPvPEhzZ5wmMG9RuEwI+T52gn6THscuq x0ORz3KgvW/y3j8Xgfxc6Jo2RUCYnS9D6em+312hvLIUNXLRLSZUJJ3qd UvaK8XSn9tVs66uhMwG1jEf50njKe7BImz7CCIWa5vveoCKAl/tbmX0Ry g==; X-CSE-ConnectionGUID: pSz1Q6WBQwiThhhqy6aiSA== X-CSE-MsgGUID: wj8hk7iXThu8oG+AXpTnBA== X-IronPort-AV: E=McAfee;i="6700,10204,11391"; a="55067318" X-IronPort-AV: E=Sophos;i="6.14,294,1736841600"; d="scan'208";a="55067318" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by orvoesa103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2025 10:57:14 -0700 X-CSE-ConnectionGUID: umPCKkn0S/CmVVIWh/SdPA== X-CSE-MsgGUID: MGn87gW3SuSRxx6RaXap2w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.14,294,1736841600"; d="scan'208";a="131660814" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.74]) by orviesa005.jf.intel.com with SMTP; 01 Apr 2025 10:57:09 -0700 Received: by stinkbox (sSMTP sendmail emulation); Tue, 01 Apr 2025 20:57:09 +0300 Date: Tue, 1 Apr 2025 20:57:09 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Jocelyn Falempe Cc: Jani Nikula , Rodrigo Vivi , Joonas Lahtinen , Tvrtko Ursulin , David Airlie , Simona Vetter , intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v6 4/8] drm/i915/gem: Add i915_gem_object_panic_map() Message-ID: References: <20250401125818.333033-1-jfalempe@redhat.com> <20250401125818.333033-5-jfalempe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Patchwork-Hint: comment X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Tue, Apr 01, 2025 at 08:47:50PM +0300, Ville Syrjälä wrote: > On Tue, Apr 01, 2025 at 02:51:10PM +0200, Jocelyn Falempe wrote: > > Prepare the work for drm_panic support. This is used to map the > > current framebuffer, so the CPU can overwrite it with the panic > > message. > > > > Signed-off-by: Jocelyn Falempe > > --- > > > > v5: > > * Use iosys_map for intel_bo_panic_map(). > > > > drivers/gpu/drm/i915/display/intel_bo.c | 5 ++++ > > drivers/gpu/drm/i915/display/intel_bo.h | 1 + > > drivers/gpu/drm/i915/gem/i915_gem_object.h | 2 ++ > > drivers/gpu/drm/i915/gem/i915_gem_pages.c | 29 ++++++++++++++++++++++ > > drivers/gpu/drm/xe/display/intel_bo.c | 10 ++++++++ > > 5 files changed, 47 insertions(+) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_bo.c b/drivers/gpu/drm/i915/display/intel_bo.c > > index fbd16d7b58d9..ac904e9ec7d5 100644 > > --- a/drivers/gpu/drm/i915/display/intel_bo.c > > +++ b/drivers/gpu/drm/i915/display/intel_bo.c > > @@ -57,3 +57,8 @@ void intel_bo_describe(struct seq_file *m, struct drm_gem_object *obj) > > { > > i915_debugfs_describe_obj(m, to_intel_bo(obj)); > > } > > + > > +void intel_bo_panic_map(struct drm_gem_object *obj, struct iosys_map *map) > > +{ > > + i915_gem_object_panic_map(to_intel_bo(obj), map); > > +} > > diff --git a/drivers/gpu/drm/i915/display/intel_bo.h b/drivers/gpu/drm/i915/display/intel_bo.h > > index ea7a2253aaa5..5b6c63d99786 100644 > > --- a/drivers/gpu/drm/i915/display/intel_bo.h > > +++ b/drivers/gpu/drm/i915/display/intel_bo.h > > @@ -23,5 +23,6 @@ struct intel_frontbuffer *intel_bo_set_frontbuffer(struct drm_gem_object *obj, > > struct intel_frontbuffer *front); > > > > void intel_bo_describe(struct seq_file *m, struct drm_gem_object *obj); > > +void intel_bo_panic_map(struct drm_gem_object *obj, struct iosys_map *map); > > > > #endif /* __INTEL_BO__ */ > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h > > index a5f34542135c..b16092707ea5 100644 > > --- a/drivers/gpu/drm/i915/gem/i915_gem_object.h > > +++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h > > @@ -692,6 +692,8 @@ i915_gem_object_unpin_pages(struct drm_i915_gem_object *obj) > > int __i915_gem_object_put_pages(struct drm_i915_gem_object *obj); > > int i915_gem_object_truncate(struct drm_i915_gem_object *obj); > > > > +void i915_gem_object_panic_map(struct drm_i915_gem_object *obj, struct iosys_map *map); > > + > > /** > > * i915_gem_object_pin_map - return a contiguous mapping of the entire object > > * @obj: the object to map into kernel address space > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c b/drivers/gpu/drm/i915/gem/i915_gem_pages.c > > index 8780aa243105..718bea6474d7 100644 > > --- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c > > +++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c > > @@ -355,6 +355,35 @@ static void *i915_gem_object_map_pfn(struct drm_i915_gem_object *obj, > > return vaddr ?: ERR_PTR(-ENOMEM); > > } > > > > +/* Map the current framebuffer for CPU access. Called from panic handler, so no > > + * need to pin or cleanup. > > + */ > > +void i915_gem_object_panic_map(struct drm_i915_gem_object *obj, struct iosys_map *map) > > +{ > > + enum i915_map_type has_type; > > + void *ptr; > > + > > + ptr = page_unpack_bits(obj->mm.mapping, &has_type); > > + > > + > > + if (!ptr) { > > + if (i915_gem_object_has_struct_page(obj)) > > + ptr = i915_gem_object_map_page(obj, I915_MAP_WB); > > + else > > + ptr = i915_gem_object_map_pfn(obj, I915_MAP_WB); > > WB mapping would require clflushing to make it to the display. > Is that being done somewhere? This also seems to have a bunch of race conditions: - what happens if the oops happens before the pages have even been swapped in? - what happens if the oops happens before we've committed the fb to the hardware? > > > + > > + if (IS_ERR(ptr)) > > + return; > > What happens when the mapping fails? > > > + > > + obj->mm.mapping = page_pack_bits(ptr, I915_MAP_WB); > > + } > > + > > + if (i915_gem_object_has_iomem(obj)) > > + iosys_map_set_vaddr_iomem(map, (void __iomem *) ptr); > > + else > > + iosys_map_set_vaddr(map, ptr); > > +} > > + > > /* get, pin, and map the pages of the object into kernel space */ > > void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj, > > enum i915_map_type type) > > diff --git a/drivers/gpu/drm/xe/display/intel_bo.c b/drivers/gpu/drm/xe/display/intel_bo.c > > index 27437c22bd70..c68166a64336 100644 > > --- a/drivers/gpu/drm/xe/display/intel_bo.c > > +++ b/drivers/gpu/drm/xe/display/intel_bo.c > > @@ -59,3 +59,13 @@ void intel_bo_describe(struct seq_file *m, struct drm_gem_object *obj) > > { > > /* FIXME */ > > } > > + > > +void intel_bo_panic_map(struct drm_gem_object *obj, struct iosys_map *map) > > +{ > > + struct xe_bo *bo = gem_to_xe_bo(obj); > > + int ret; > > + > > + ret = ttm_bo_vmap(&bo->ttm, map); > > + if (ret) > > + iosys_map_clear(map); > > +} > > -- > > 2.49.0 > > -- > Ville Syrjälä > Intel -- Ville Syrjälä Intel