From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DCEC5BA49 for ; Tue, 7 Mar 2023 18:43:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2C06EC433EF; Tue, 7 Mar 2023 18:43:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678214625; bh=dYwR5rcLIabzIirgUlRVhd2HlYqELRPof6l9xWUaAIg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ccmssKBTW4UubDRMyHCBfg584AmHjsQSjGmrSH7Jj4j01P+rTKeuGYKPktJelAPNP bPkjl2uFCqbeXk/Kl3HK65taQwgC+bJkUZVqhYOZEFj2RhTOu9B9q0/zvMFKWqKmjY vKmn3mIQOF+PLfwuEnsjzNVxBSvsaKPhc9zeYudA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, John Harrison , Chris Wilson , Joonas Lahtinen , Jani Nikula , Rodrigo Vivi , Tvrtko Ursulin , intel-gfx@lists.freedesktop.org, =?UTF-8?q?Jouni=20H=C3=B6gander?= , Daniele Ceraolo Spurio , Jani Nikula Subject: [PATCH 6.1 882/885] drm/i915: Dont use BAR mappings for ring buffers with LLC Date: Tue, 7 Mar 2023 18:03:36 +0100 Message-Id: <20230307170040.101657104@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170001.594919529@linuxfoundation.org> References: <20230307170001.594919529@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: John Harrison commit 85636167e3206c3fbd52254fc432991cc4e90194 upstream. Direction from hardware is that ring buffers should never be mapped via the BAR on systems with LLC. There are too many caching pitfalls due to the way BAR accesses are routed. So it is safest to just not use it. Signed-off-by: John Harrison Fixes: 9d80841ea4c9 ("drm/i915: Allow ringbuffers to be bound anywhere") Cc: Chris Wilson Cc: Joonas Lahtinen Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Tvrtko Ursulin Cc: intel-gfx@lists.freedesktop.org Cc: # v4.9+ Tested-by: Jouni Högander Reviewed-by: Daniele Ceraolo Spurio Link: https://patchwork.freedesktop.org/patch/msgid/20230216011101.1909009-3-John.C.Harrison@Intel.com (cherry picked from commit 65c08339db1ada87afd6cfe7db8e60bb4851d919) Signed-off-by: Jani Nikula Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/gt/intel_ring.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/i915/gt/intel_ring.c +++ b/drivers/gpu/drm/i915/gt/intel_ring.c @@ -53,7 +53,7 @@ int intel_ring_pin(struct intel_ring *ri if (unlikely(ret)) goto err_unpin; - if (i915_vma_is_map_and_fenceable(vma)) { + if (i915_vma_is_map_and_fenceable(vma) && !HAS_LLC(vma->vm->i915)) { addr = (void __force *)i915_vma_pin_iomap(vma); } else { int type = i915_coherent_map_type(vma->vm->i915, vma->obj, false); @@ -98,7 +98,7 @@ void intel_ring_unpin(struct intel_ring return; i915_vma_unset_ggtt_write(vma); - if (i915_vma_is_map_and_fenceable(vma)) + if (i915_vma_is_map_and_fenceable(vma) && !HAS_LLC(vma->vm->i915)) i915_vma_unpin_iomap(vma); else i915_gem_object_unpin_map(vma->obj);