From patchwork Fri Jun 15 08:26:09 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10465873 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id AD262600F4 for ; Fri, 15 Jun 2018 08:26:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 999A828C49 for ; Fri, 15 Jun 2018 08:26:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8C11E28D0A; Fri, 15 Jun 2018 08:26:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id A8D1F28C49 for ; Fri, 15 Jun 2018 08:26:32 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id EBE306EAAD; Fri, 15 Jun 2018 08:26:31 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id 71E8F6EAAD for ; Fri, 15 Jun 2018 08:26:30 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from haswell.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 12054615-1500050 for multiple; Fri, 15 Jun 2018 09:26:09 +0100 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Fri, 15 Jun 2018 09:26:10 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Fri, 15 Jun 2018 09:26:09 +0100 Message-Id: <20180615082609.9305-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180614192404.24534-2-chris@chris-wilson.co.uk> References: <20180614192404.24534-2-chris@chris-wilson.co.uk> X-Originating-IP: 78.156.65.138 X-Country: code=GB country="United Kingdom" ip=78.156.65.138 Subject: [Intel-gfx] [PATCH v4] drm/i915/gtt: Read-only pages for insert_entries on bdw+ X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP From: Jon Bloomfield Hook up the flags to allow read-only ppGTT mappings for gen8+ v2: Include a selftest to check that writes to a readonly PTE are dropped v3: Don't duplicate cpu_check() as we can just reuse it, and even worse don't wholesale copy the theory-of-operation comment from igt_ctx_exec without changing it to explain the intention behind the new test! v4: Joonas really likes magic mystery values Signed-off-by: Jon Bloomfield Signed-off-by: Chris Wilson Cc: Joonas Lahtinen Cc: Matthew Auld Reviewed-by: Joonas Lahtinen Reviewed-by: Matthew Auld --- drivers/gpu/drm/i915/i915_gem_gtt.c | 45 ++++--- drivers/gpu/drm/i915/i915_gem_gtt.h | 7 +- drivers/gpu/drm/i915/intel_ringbuffer.c | 11 +- .../gpu/drm/i915/selftests/i915_gem_context.c | 112 +++++++++++++++++- 4 files changed, 153 insertions(+), 22 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index 705cf1c04bba..deddf15db24a 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -196,7 +196,7 @@ static int ppgtt_bind_vma(struct i915_vma *vma, return err; } - /* Currently applicable only to VLV */ + /* Applicable to VLV, and gen8+ */ pte_flags = 0; if (vma->obj->gt_ro) pte_flags |= PTE_READ_ONLY; @@ -952,10 +952,11 @@ gen8_ppgtt_insert_pte_entries(struct i915_hw_ppgtt *ppgtt, struct i915_page_directory_pointer *pdp, struct sgt_dma *iter, struct gen8_insert_pte *idx, - enum i915_cache_level cache_level) + enum i915_cache_level cache_level, + u32 flags) { struct i915_page_directory *pd; - const gen8_pte_t pte_encode = gen8_pte_encode(0, cache_level, 0); + const gen8_pte_t pte_encode = gen8_pte_encode(0, cache_level, flags); gen8_pte_t *vaddr; bool ret; @@ -1006,14 +1007,14 @@ gen8_ppgtt_insert_pte_entries(struct i915_hw_ppgtt *ppgtt, static void gen8_ppgtt_insert_3lvl(struct i915_address_space *vm, struct i915_vma *vma, enum i915_cache_level cache_level, - u32 unused) + u32 flags) { struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm); struct sgt_dma iter = sgt_dma(vma); struct gen8_insert_pte idx = gen8_insert_pte(vma->node.start); gen8_ppgtt_insert_pte_entries(ppgtt, &ppgtt->pdp, &iter, &idx, - cache_level); + cache_level, flags); vma->page_sizes.gtt = I915_GTT_PAGE_SIZE; } @@ -1021,9 +1022,10 @@ static void gen8_ppgtt_insert_3lvl(struct i915_address_space *vm, static void gen8_ppgtt_insert_huge_entries(struct i915_vma *vma, struct i915_page_directory_pointer **pdps, struct sgt_dma *iter, - enum i915_cache_level cache_level) + enum i915_cache_level cache_level, + u32 flags) { - const gen8_pte_t pte_encode = gen8_pte_encode(0, cache_level, 0); + const gen8_pte_t pte_encode = gen8_pte_encode(0, cache_level, flags); u64 start = vma->node.start; dma_addr_t rem = iter->sg->length; @@ -1139,19 +1141,21 @@ static void gen8_ppgtt_insert_huge_entries(struct i915_vma *vma, static void gen8_ppgtt_insert_4lvl(struct i915_address_space *vm, struct i915_vma *vma, enum i915_cache_level cache_level, - u32 unused) + u32 flags) { struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm); struct sgt_dma iter = sgt_dma(vma); struct i915_page_directory_pointer **pdps = ppgtt->pml4.pdps; if (vma->page_sizes.sg > I915_GTT_PAGE_SIZE) { - gen8_ppgtt_insert_huge_entries(vma, pdps, &iter, cache_level); + gen8_ppgtt_insert_huge_entries(vma, pdps, &iter, cache_level, + flags); } else { struct gen8_insert_pte idx = gen8_insert_pte(vma->node.start); while (gen8_ppgtt_insert_pte_entries(ppgtt, pdps[idx.pml4e++], - &iter, &idx, cache_level)) + &iter, &idx, cache_level, + flags)) GEM_BUG_ON(idx.pml4e >= GEN8_PML4ES_PER_PML4); vma->page_sizes.gtt = I915_GTT_PAGE_SIZE; @@ -1564,6 +1568,9 @@ static struct i915_hw_ppgtt *gen8_ppgtt_create(struct drm_i915_private *i915) 1ULL << 48 : 1ULL << 32; + /* From bdw, there is support for read-only pages in the PPGTT */ + ppgtt->vm.has_read_only = true; + /* There are only few exceptions for gen >=6. chv and bxt. * And we are not sure about the latter so play safe for now. */ @@ -2400,7 +2407,7 @@ static void gen8_ggtt_insert_page(struct i915_address_space *vm, static void gen8_ggtt_insert_entries(struct i915_address_space *vm, struct i915_vma *vma, enum i915_cache_level level, - u32 unused) + u32 flags) { struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm); struct sgt_iter sgt_iter; @@ -2408,6 +2415,9 @@ static void gen8_ggtt_insert_entries(struct i915_address_space *vm, const gen8_pte_t pte_encode = gen8_pte_encode(0, level, 0); dma_addr_t addr; + /* The GTT does not support read-only mappings */ + GEM_BUG_ON(flags & PTE_READ_ONLY); + gtt_entries = (gen8_pte_t __iomem *)ggtt->gsm; gtt_entries += vma->node.start >> PAGE_SHIFT; for_each_sgt_dma(addr, sgt_iter, vma->pages) @@ -2534,13 +2544,14 @@ struct insert_entries { struct i915_address_space *vm; struct i915_vma *vma; enum i915_cache_level level; + u32 flags; }; static int bxt_vtd_ggtt_insert_entries__cb(void *_arg) { struct insert_entries *arg = _arg; - gen8_ggtt_insert_entries(arg->vm, arg->vma, arg->level, 0); + gen8_ggtt_insert_entries(arg->vm, arg->vma, arg->level, arg->flags); bxt_vtd_ggtt_wa(arg->vm); return 0; @@ -2549,9 +2560,9 @@ static int bxt_vtd_ggtt_insert_entries__cb(void *_arg) static void bxt_vtd_ggtt_insert_entries__BKL(struct i915_address_space *vm, struct i915_vma *vma, enum i915_cache_level level, - u32 unused) + u32 flags) { - struct insert_entries arg = { vm, vma, level }; + struct insert_entries arg = { vm, vma, level, flags }; stop_machine(bxt_vtd_ggtt_insert_entries__cb, &arg, NULL); } @@ -2642,7 +2653,7 @@ static int ggtt_bind_vma(struct i915_vma *vma, struct drm_i915_gem_object *obj = vma->obj; u32 pte_flags; - /* Currently applicable only to VLV */ + /* Applicable to VLV (gen8+ do not support RO in the GGTT) */ pte_flags = 0; if (obj->gt_ro) pte_flags |= PTE_READ_ONLY; @@ -3522,6 +3533,10 @@ int i915_ggtt_init_hw(struct drm_i915_private *dev_priv) */ mutex_lock(&dev_priv->drm.struct_mutex); i915_address_space_init(&ggtt->vm, dev_priv, "[global]"); + + /* Only VLV supports read-only GGTT mappings */ + ggtt->vm.has_read_only = IS_VALLEYVIEW(dev_priv); + if (!HAS_LLC(dev_priv) && !USES_PPGTT(dev_priv)) ggtt->vm.mm.color_adjust = i915_gtt_color_adjust; mutex_unlock(&dev_priv->drm.struct_mutex); diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h index 9a4824cae68d..f1f6d7076f12 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.h +++ b/drivers/gpu/drm/i915/i915_gem_gtt.h @@ -325,7 +325,12 @@ struct i915_address_space { struct list_head unbound_list; struct pagevec free_pages; - bool pt_kmap_wc; + + /* Some systems require uncached updates of the page directories */ + bool pt_kmap_wc:1; + + /* Some systems support read-only mappings for GGTT and/or PPGTT */ + bool has_read_only:1; /* FIXME: Need a more generic return type */ gen6_pte_t (*pte_encode)(dma_addr_t addr, diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index ef3c76425843..8853a5e6d421 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -1097,6 +1097,7 @@ void intel_ring_unpin(struct intel_ring *ring) static struct i915_vma * intel_ring_create_vma(struct drm_i915_private *dev_priv, int size) { + struct i915_address_space *vm = &dev_priv->ggtt.vm; struct drm_i915_gem_object *obj; struct i915_vma *vma; @@ -1106,10 +1107,14 @@ intel_ring_create_vma(struct drm_i915_private *dev_priv, int size) if (IS_ERR(obj)) return ERR_CAST(obj); - /* mark ring buffers as read-only from GPU side by default */ - obj->gt_ro = 1; + /* + * Mark ring buffers as read-only from GPU side (so no stray overwrites) + * if supported by the platform's GGTT. + */ + if (vm->has_read_only) + obj->gt_ro = 1; - vma = i915_vma_instance(obj, &dev_priv->ggtt.vm, NULL); + vma = i915_vma_instance(obj, vm, NULL); if (IS_ERR(vma)) goto err; diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/selftests/i915_gem_context.c index 836f1af8b833..6fe4682eacf3 100644 --- a/drivers/gpu/drm/i915/selftests/i915_gem_context.c +++ b/drivers/gpu/drm/i915/selftests/i915_gem_context.c @@ -23,6 +23,7 @@ */ #include "../i915_selftest.h" +#include "i915_random.h" #include "igt_flush_test.h" #include "mock_drm.h" @@ -248,9 +249,9 @@ static int cpu_check(struct drm_i915_gem_object *obj, unsigned int max) } for (; m < DW_PER_PAGE; m++) { - if (map[m] != 0xdeadbeef) { + if (map[m] != STACK_MAGIC) { pr_err("Invalid value at page %d, offset %d: found %x expected %x\n", - n, m, map[m], 0xdeadbeef); + n, m, map[m], STACK_MAGIC); err = -EINVAL; goto out_unmap; } @@ -306,7 +307,7 @@ create_test_object(struct i915_gem_context *ctx, if (err) return ERR_PTR(err); - err = cpu_fill(obj, 0xdeadbeef); + err = cpu_fill(obj, STACK_MAGIC); if (err) { pr_err("Failed to fill object with cpu, err=%d\n", err); @@ -421,6 +422,110 @@ static int igt_ctx_exec(void *arg) return err; } +static int igt_ctx_readonly(void *arg) +{ + struct drm_i915_private *i915 = arg; + struct drm_i915_gem_object *obj = NULL; + struct drm_file *file; + I915_RND_STATE(prng); + IGT_TIMEOUT(end_time); + LIST_HEAD(objects); + struct i915_gem_context *ctx; + struct i915_hw_ppgtt *ppgtt; + unsigned long ndwords, dw; + int err = -ENODEV; + + /* + * Create a few read-only objects (with the occasional writable object) + * and try to write into these object checking that the GPU discards + * any write to a read-only object. + */ + + file = mock_file(i915); + if (IS_ERR(file)) + return PTR_ERR(file); + + mutex_lock(&i915->drm.struct_mutex); + + ctx = i915_gem_create_context(i915, file->driver_priv); + if (IS_ERR(ctx)) { + err = PTR_ERR(ctx); + goto out_unlock; + } + + ppgtt = ctx->ppgtt ?: i915->mm.aliasing_ppgtt; + if (!ppgtt || !ppgtt->vm.has_read_only) { + err = 0; + goto out_unlock; + } + + ndwords = 0; + dw = 0; + while (!time_after(jiffies, end_time)) { + struct intel_engine_cs *engine; + unsigned int id; + + for_each_engine(engine, i915, id) { + if (!intel_engine_can_store_dword(engine)) + continue; + + if (!obj) { + obj = create_test_object(ctx, file, &objects); + if (IS_ERR(obj)) { + err = PTR_ERR(obj); + goto out_unlock; + } + + obj->gt_ro = prandom_u32_state(&prng); + } + + intel_runtime_pm_get(i915); + err = gpu_fill(obj, ctx, engine, dw); + intel_runtime_pm_put(i915); + if (err) { + pr_err("Failed to fill dword %lu [%lu/%lu] with gpu (%s) in ctx %u [full-ppgtt? %s], err=%d\n", + ndwords, dw, max_dwords(obj), + engine->name, ctx->hw_id, + yesno(!!ctx->ppgtt), err); + goto out_unlock; + } + + if (++dw == max_dwords(obj)) { + obj = NULL; + dw = 0; + } + ndwords++; + } + } + pr_info("Submitted %lu dwords (across %u engines)\n", + ndwords, INTEL_INFO(i915)->num_rings); + + dw = 0; + list_for_each_entry(obj, &objects, st_link) { + unsigned int rem = + min_t(unsigned int, ndwords - dw, max_dwords(obj)); + unsigned int num_writes; + + num_writes = rem; + if (obj->gt_ro) + num_writes = 0; + + err = cpu_check(obj, num_writes); + if (err) + break; + + dw += rem; + } + +out_unlock: + if (igt_flush_test(i915, I915_WAIT_LOCKED)) + err = -EIO; + mutex_unlock(&i915->drm.struct_mutex); + + mock_file_free(i915, file); + return err; +} + static __maybe_unused const char * __engine_name(struct drm_i915_private *i915, unsigned int engines) { @@ -595,6 +700,7 @@ int i915_gem_context_live_selftests(struct drm_i915_private *dev_priv) static const struct i915_subtest tests[] = { SUBTEST(igt_switch_to_kernel_context), SUBTEST(igt_ctx_exec), + SUBTEST(igt_ctx_readonly), }; bool fake_alias = false; int err;