From patchwork Thu Aug 11 15:30:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Fabio M. De Francesco" X-Patchwork-Id: 12943576 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 CAF4AC25B06 for ; Mon, 15 Aug 2022 13:20:22 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 5156EBBA27; Mon, 15 Aug 2022 13:20:09 +0000 (UTC) Received: from mail-wr1-x435.google.com (mail-wr1-x435.google.com [IPv6:2a00:1450:4864:20::435]) by gabe.freedesktop.org (Postfix) with ESMTPS id CED8CB4352; Thu, 11 Aug 2022 15:30:51 +0000 (UTC) Received: by mail-wr1-x435.google.com with SMTP id l22so21752788wrz.7; Thu, 11 Aug 2022 08:30:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc; bh=lsxU9RpxEtZA+Mk40O6yVmrf9Fu1AMs9ElIAZHptX+c=; b=p8TKVMzq5DwZ3OnqS3RJd818yoMLzy+vFjFcKzlWiosox7p8z1M/5PW/gBrz2e7ZOq RcCm2WazhJYvmqLcaMpSIbJowOeXPTikATddJwIFDDcXMr8NuVwx2A/6WmqWRNmnnSPW kxyxTRS7cc3d9M84ZexCGh/qOj90dgR3qwfhD8P+cNePNgofGMJMpOeMNCzRj9fwiUjR gxwLTFlId5B58kby9P2uQkwS5i9TlF/0qS/Y07//QrDxQYLLlxxo8q2Bi2H14qK4iLZX RABxL/E2v0VJN6Xq/qw/FBepYmww8/tuh6n+VQg0D9qaCoReL5dJ8aBFnN8BWFtXqIYK 4nGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc; bh=lsxU9RpxEtZA+Mk40O6yVmrf9Fu1AMs9ElIAZHptX+c=; b=EI28wRVVT3aI5U0hUVb47qe9yW9db3awYEJBVq4BoiH/4VxWr9cbzQuydbBf5Rucbj z9BzlXAp1Oj6uSB0YB5I4SIg+HcgxUZGji0P28idCvII2fA5ElOE8L1tiZiCPPO80+Vp MkdLVPA8oyWAmZnbmYktHyWPRMpYIJnU0wVyueNzt16MLwlazW9z8uLR7UGzkiEw5V18 Xb/yAstoRepj11D4QrBnfGOv2mytaJZgS3XAx5uNHTg2rf9DCGLLJpSEY61zNxXiqaFq nOIVUOXeuXHY25k8BoGV3+vs2+efvLMq9AmAWCa/NWL2B4LhmUkjpPBGOMyWpfZ4NSDJ 9FiA== X-Gm-Message-State: ACgBeo23S5O3uwX2uk9ToFQ5vmXPqCM1odxUoXSP7+jnGhT6RrxQfxlZ VeFEZQI4+vOnsMKZXLNi7+A= X-Google-Smtp-Source: AA6agR6B9bizQz9J53uYxM4sZolnfx+nbRLl41mveZTi8oUUOyyvs7b1h0H6QspWO+C/SmNj2BgX/A== X-Received: by 2002:adf:ea0a:0:b0:220:6222:ee48 with SMTP id q10-20020adfea0a000000b002206222ee48mr19221413wrm.243.1660231850215; Thu, 11 Aug 2022 08:30:50 -0700 (PDT) Received: from localhost.localdomain (host-79-27-108-198.retail.telecomitalia.it. [79.27.108.198]) by smtp.gmail.com with ESMTPSA id m7-20020a056000008700b00222ed7ea203sm9805502wrx.100.2022.08.11.08.30.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Aug 2022 08:30:48 -0700 (PDT) From: "Fabio M. De Francesco" To: Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , David Airlie , Daniel Vetter , John Harrison , Matt Roper , Matthew Brost , Lucas De Marchi , Daniele Ceraolo Spurio , Matthew Auld , Ira Weiny , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Date: Thu, 11 Aug 2022 17:30:39 +0200 Message-Id: <20220811153041.12795-2-fmdefrancesco@gmail.com> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220811153041.12795-1-fmdefrancesco@gmail.com> References: <20220811153041.12795-1-fmdefrancesco@gmail.com> MIME-Version: 1.0 X-Mailman-Approved-At: Mon, 15 Aug 2022 13:18:12 +0000 Subject: [Intel-gfx] [PATCH 1/3] drm/i915: Replace kmap() with kmap_local_page() X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Fabio M. De Francesco" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" kmap() is being deprecated in favor of kmap_local_page(). There are two main problems with kmap(): (1) It comes with an overhead as mapping space is restricted and protected by a global lock for synchronization and (2) it also requires global TLB invalidation when the kmap’s pool wraps and it might block when the mapping space is fully utilized until a slot becomes available. With kmap_local_page() the mappings are per thread, CPU local, can take page faults, and can be called from any context (including interrupts). It is faster than kmap() in kernels with HIGHMEM enabled. Furthermore, the tasks can be preempted and, when they are scheduled to run again, the kernel virtual addresses are restored and are still valid. Since its use in i915_gem.c is safe everywhere, it should be preferred. Therefore, replace kmap() with kmap_local_page() in i915_gem.c Suggested-by: Ira Weiny Signed-off-by: Fabio M. De Francesco --- drivers/gpu/drm/i915/i915_gem.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 702e5b89be22..43effce60e1b 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -212,14 +212,14 @@ shmem_pread(struct page *page, int offset, int len, char __user *user_data, char *vaddr; int ret; - vaddr = kmap(page); + vaddr = kmap_local_page(page); if (needs_clflush) drm_clflush_virt_range(vaddr + offset, len); ret = __copy_to_user(user_data, vaddr + offset, len); - kunmap(page); + kunmap_local(vaddr); return ret ? -EFAULT : 0; } @@ -634,7 +634,7 @@ shmem_pwrite(struct page *page, int offset, int len, char __user *user_data, char *vaddr; int ret; - vaddr = kmap(page); + vaddr = kmap_local_page(page); if (needs_clflush_before) drm_clflush_virt_range(vaddr + offset, len); @@ -643,7 +643,7 @@ shmem_pwrite(struct page *page, int offset, int len, char __user *user_data, if (!ret && needs_clflush_after) drm_clflush_virt_range(vaddr + offset, len); - kunmap(page); + kunmap_local(vaddr); return ret ? -EFAULT : 0; } From patchwork Thu Aug 11 15:30:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Fabio M. De Francesco" X-Patchwork-Id: 12953730 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 B333CC00140 for ; Wed, 24 Aug 2022 15:26:39 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1C96F10E6B3; Wed, 24 Aug 2022 15:26:37 +0000 (UTC) Received: from mail-wr1-x435.google.com (mail-wr1-x435.google.com [IPv6:2a00:1450:4864:20::435]) by gabe.freedesktop.org (Postfix) with ESMTPS id 061D62B9EC; Thu, 11 Aug 2022 15:30:54 +0000 (UTC) Received: by mail-wr1-x435.google.com with SMTP id l22so21752936wrz.7; Thu, 11 Aug 2022 08:30:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc; bh=qZtGOXbRC+1H6SPLMpuq1SgPyHU7zMutv39GohgMBvo=; b=kHDbzD7P9eGWeR5QgJz8o1M4lnlOV+24zL4PIkoKaISN137ifaBEtwvYZGOrdPMJ1W 6cHV0oSmCKFcNNk0vpWxMajyRH6PYZfHGLxbZa6xz0nQ0PXYtFjJjeq4xbJ9n4t/PUbL m5WN1x1jV/pmiObU1mVXl4tO198NP8iOeBji/RR6eJUItHUSMiYtAhPQHerKaSrbAzxn n7RuZbkyl7A9sc/63XXdJd5sjQkdpw5IakaHG8aepNjjhcwZFSbPg1/73XwhReevGlY8 71gjrAj4jM4uDDj5iU3EAQ3hK34JOnyjeJLo0cTpTUI0OAWpe36RaEDXeM0oEZJKjmXJ UkZg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc; bh=qZtGOXbRC+1H6SPLMpuq1SgPyHU7zMutv39GohgMBvo=; b=ewRI/9KepZoL5cea8Mgc0qsMmwJo328CZD1BOLlGvw92PuswLk9mTRhG8C90GpCE6P RLP5RFK0gFCEndMcuu3TjYq2A17uEga1INam8+foqxbfV4ax3b5XK0OA5DbywpakoYtx MwQS89p2ED8cd8MX66rlZi9hHfidqlXTh+1JxM/N4hA1fiuSiCVDLOBDAl1qmVQxryNL jDGL0NSrt377Yrkk0+Q/Gz24xVIeHtomr7ZlbJQvUSKogRuhiqofJxUHLGp8z3lM6heY NxF+TtLXY09jz5nKpMrawkXN7ZYWzS27v9whi3FswTpnMmqPF61Y/S5iGkDzekcFhl/0 6eiQ== X-Gm-Message-State: ACgBeo3Bg/DznQ/eFmHXG9t1G8wv1mWfLkJk5sv8PwtiGDKKydl10MEE bS7DIO7aXe2ODgBO8alAdiKyIQvuiVjb8A== X-Google-Smtp-Source: AA6agR5a9kzgqtDr+SyVjmXoGK7TQ3C9s6/ZzMuJhHCJyK48sU4+XUw9zEtEFNtg3FIup6WEqH0qNg== X-Received: by 2002:a5d:52cb:0:b0:21a:3cc5:f5f4 with SMTP id r11-20020a5d52cb000000b0021a3cc5f5f4mr20771696wrv.367.1660231853386; Thu, 11 Aug 2022 08:30:53 -0700 (PDT) Received: from localhost.localdomain (host-79-27-108-198.retail.telecomitalia.it. [79.27.108.198]) by smtp.gmail.com with ESMTPSA id m7-20020a056000008700b00222ed7ea203sm9805502wrx.100.2022.08.11.08.30.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Aug 2022 08:30:52 -0700 (PDT) From: "Fabio M. De Francesco" To: Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , David Airlie , Daniel Vetter , John Harrison , Matt Roper , Matthew Brost , Lucas De Marchi , Daniele Ceraolo Spurio , Matthew Auld , Ira Weiny , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Date: Thu, 11 Aug 2022 17:30:40 +0200 Message-Id: <20220811153041.12795-3-fmdefrancesco@gmail.com> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220811153041.12795-1-fmdefrancesco@gmail.com> References: <20220811153041.12795-1-fmdefrancesco@gmail.com> MIME-Version: 1.0 X-Mailman-Approved-At: Mon, 15 Aug 2022 13:18:12 +0000 Subject: [Intel-gfx] [PATCH 2/3] drm/i915/gt: Replace kmap() with kmap_local_page() X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Fabio M. De Francesco" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" kmap() is being deprecated in favor of kmap_local_page(). There are two main problems with kmap(): (1) It comes with an overhead as mapping space is restricted and protected by a global lock for synchronization and (2) it also requires global TLB invalidation when the kmap’s pool wraps and it might block when the mapping space is fully utilized until a slot becomes available. With kmap_local_page() the mappings are per thread, CPU local, can take page faults, and can be called from any context (including interrupts). It is faster than kmap() in kernels with HIGHMEM enabled. Furthermore, the tasks can be preempted and, when they are scheduled to run again, the kernel virtual addresses are restored and are still valid. Since its use in i915/gt is safe everywhere, it should be preferred. Therefore, replace kmap() with kmap_local_page() in i915/gt Suggested-by: Ira Weiny Signed-off-by: Fabio M. De Francesco --- drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c | 4 ++-- drivers/gpu/drm/i915/gt/shmem_utils.c | 11 ++++------- 2 files changed, 6 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c b/drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c index 6ebda3d65086..21d8ce40b897 100644 --- a/drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c +++ b/drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c @@ -747,7 +747,7 @@ static void swizzle_page(struct page *page) char *vaddr; int i; - vaddr = kmap(page); + vaddr = kmap_local_page(page); for (i = 0; i < PAGE_SIZE; i += 128) { memcpy(temp, &vaddr[i], 64); @@ -755,7 +755,7 @@ static void swizzle_page(struct page *page) memcpy(&vaddr[i + 64], temp, 64); } - kunmap(page); + kunmap_local(vaddr); } /** diff --git a/drivers/gpu/drm/i915/gt/shmem_utils.c b/drivers/gpu/drm/i915/gt/shmem_utils.c index 402f085f3a02..48edbb8a33e5 100644 --- a/drivers/gpu/drm/i915/gt/shmem_utils.c +++ b/drivers/gpu/drm/i915/gt/shmem_utils.c @@ -98,22 +98,19 @@ static int __shmem_rw(struct file *file, loff_t off, unsigned int this = min_t(size_t, PAGE_SIZE - offset_in_page(off), len); struct page *page; - void *vaddr; page = shmem_read_mapping_page_gfp(file->f_mapping, pfn, GFP_KERNEL); if (IS_ERR(page)) return PTR_ERR(page); - vaddr = kmap(page); if (write) { - memcpy(vaddr + offset_in_page(off), ptr, this); + memcpy_to_page(page, offset_in_page(off), ptr, this); set_page_dirty(page); } else { - memcpy(ptr, vaddr + offset_in_page(off), this); + memcpy_from_page(ptr, page, offset_in_page(off), this); } mark_page_accessed(page); - kunmap(page); put_page(page); len -= this; @@ -140,11 +137,11 @@ int shmem_read_to_iosys_map(struct file *file, loff_t off, if (IS_ERR(page)) return PTR_ERR(page); - vaddr = kmap(page); + vaddr = kmap_local_page(page); iosys_map_memcpy_to(map, map_off, vaddr + offset_in_page(off), this); mark_page_accessed(page); - kunmap(page); + kunmap_local(vaddr); put_page(page); len -= this; From patchwork Thu Aug 11 15:30:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Fabio M. 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[79.27.108.198]) by smtp.gmail.com with ESMTPSA id m7-20020a056000008700b00222ed7ea203sm9805502wrx.100.2022.08.11.08.30.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Aug 2022 08:30:55 -0700 (PDT) From: "Fabio M. De Francesco" To: Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , David Airlie , Daniel Vetter , John Harrison , Matt Roper , Matthew Brost , Lucas De Marchi , Daniele Ceraolo Spurio , Matthew Auld , Ira Weiny , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Date: Thu, 11 Aug 2022 17:30:41 +0200 Message-Id: <20220811153041.12795-4-fmdefrancesco@gmail.com> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220811153041.12795-1-fmdefrancesco@gmail.com> References: <20220811153041.12795-1-fmdefrancesco@gmail.com> MIME-Version: 1.0 X-Mailman-Approved-At: Mon, 15 Aug 2022 13:18:12 +0000 Subject: [Intel-gfx] [PATCH 3/3] drm/i915/gem: Replace kmap() with kmap_local_page() X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Fabio M. De Francesco" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" kmap() is being deprecated in favor of kmap_local_page(). There are two main problems with kmap(): (1) It comes with an overhead as mapping space is restricted and protected by a global lock for synchronization and (2) it also requires global TLB invalidation when the kmap’s pool wraps and it might block when the mapping space is fully utilized until a slot becomes available. With kmap_local_page() the mappings are per thread, CPU local, can take page faults, and can be called from any context (including interrupts). It is faster than kmap() in kernels with HIGHMEM enabled. Furthermore, the tasks can be preempted and, when they are scheduled to run again, the kernel virtual addresses are restored and are still valid. Since its use in i915/gem is safe everywhere, it should be preferred. Therefore, replace kmap() with kmap_local_page() in i915/gem. Suggested-by: Ira Weiny Signed-off-by: Fabio M. De Francesco --- drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 6 ++---- drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c | 8 ++++---- 2 files changed, 6 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c index 4eed3dd90ba8..2bc6ab9964ff 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c @@ -640,16 +640,14 @@ i915_gem_object_create_shmem_from_data(struct drm_i915_private *dev_priv, do { unsigned int len = min_t(typeof(size), size, PAGE_SIZE); struct page *page; - void *pgdata, *vaddr; + void *pgdata; err = aops->write_begin(file, file->f_mapping, offset, len, &page, &pgdata); if (err < 0) goto fail; - vaddr = kmap(page); - memcpy(vaddr, data, len); - kunmap(page); + memcpy_to_page(page, 0, data, len); err = aops->write_end(file, file->f_mapping, offset, len, len, page, pgdata); diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c index 3ced9948a331..bb25b50b5688 100644 --- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c +++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c @@ -153,7 +153,7 @@ static int check_partial_mapping(struct drm_i915_gem_object *obj, intel_gt_flush_ggtt_writes(to_gt(i915)); p = i915_gem_object_get_page(obj, offset >> PAGE_SHIFT); - cpu = kmap(p) + offset_in_page(offset); + cpu = kmap_local_page(p) + offset_in_page(offset); drm_clflush_virt_range(cpu, sizeof(*cpu)); if (*cpu != (u32)page) { pr_err("Partial view for %lu [%u] (offset=%llu, size=%u [%llu, row size %u], fence=%d, tiling=%d, stride=%d) misalignment, expected write to page (%llu + %u [0x%llx]) of 0x%x, found 0x%x\n", @@ -171,7 +171,7 @@ static int check_partial_mapping(struct drm_i915_gem_object *obj, } *cpu = 0; drm_clflush_virt_range(cpu, sizeof(*cpu)); - kunmap(p); + kunmap_local(cpu); out: i915_gem_object_lock(obj, NULL); @@ -249,7 +249,7 @@ static int check_partial_mappings(struct drm_i915_gem_object *obj, intel_gt_flush_ggtt_writes(to_gt(i915)); p = i915_gem_object_get_page(obj, offset >> PAGE_SHIFT); - cpu = kmap(p) + offset_in_page(offset); + cpu = kmap_local_page(p) + offset_in_page(offset); drm_clflush_virt_range(cpu, sizeof(*cpu)); if (*cpu != (u32)page) { pr_err("Partial view for %lu [%u] (offset=%llu, size=%u [%llu, row size %u], fence=%d, tiling=%d, stride=%d) misalignment, expected write to page (%llu + %u [0x%llx]) of 0x%x, found 0x%x\n", @@ -267,7 +267,7 @@ static int check_partial_mappings(struct drm_i915_gem_object *obj, } *cpu = 0; drm_clflush_virt_range(cpu, sizeof(*cpu)); - kunmap(p); + kunmap_local(cpu); if (err) return err;