From b5572d312d5925ff05b46c42ccbad0e945dc813c Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 7 Nov 2019 22:12:01 +0000 Subject: [PATCH] drm/i915/selftests: Mark up sole accessor to ctx->vm as being protected In the selftests, where we are accessing a private ctx from within the confines of a single test, we know that the ctx->vm pointer is static and bounded by the lifetime of the test. We can use a simple helper to provide the RCU annotations to keep sparse happy. Signed-off-by: Chris Wilson Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20191107221201.30497-1-chris@chris-wilson.co.uk --- .../gpu/drm/i915/gem/selftests/i915_gem_context.c | 24 +++++++++++++--------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c index 896f47d80a1c..9a509c18b7c7 100644 --- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c +++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c @@ -26,6 +26,12 @@ #define DW_PER_PAGE (PAGE_SIZE / sizeof(u32)) +static inline struct i915_address_space *ctx_vm(struct i915_gem_context *ctx) +{ + /* single threaded, private ctx */ + return rcu_dereference_protected(ctx->vm, true); +} + static int live_nop_switch(void *arg) { const unsigned int nctx = 1024; @@ -786,14 +792,15 @@ static int igt_shared_ctx_exec(void *arg) } mutex_lock(&ctx->mutex); - __assign_ppgtt(ctx, parent->vm); + __assign_ppgtt(ctx, ctx_vm(parent)); mutex_unlock(&ctx->mutex); ce = i915_gem_context_get_engine(ctx, engine->legacy_idx); GEM_BUG_ON(IS_ERR(ce)); if (!obj) { - obj = create_test_object(parent->vm, file, &objects); + obj = create_test_object(ctx_vm(parent), + file, &objects); if (IS_ERR(obj)) { err = PTR_ERR(obj); intel_context_put(ce); @@ -1343,14 +1350,11 @@ static int igt_ctx_readonly(void *arg) goto out_file; } - rcu_read_lock(); - vm = rcu_dereference(ctx->vm) ?: &i915->ggtt.alias->vm; + vm = ctx_vm(ctx) ?: &i915->ggtt.alias->vm; if (!vm || !vm->has_read_only) { - rcu_read_unlock(); err = 0; goto out_file; } - rcu_read_unlock(); ndwords = 0; dw = 0; @@ -1380,7 +1384,7 @@ static int igt_ctx_readonly(void *arg) pr_err("Failed to fill dword %lu [%lu/%lu] with gpu (%s) [full-ppgtt? %s], err=%d\n", ndwords, dw, max_dwords(obj), ce->engine->name, - yesno(!!rcu_access_pointer(ctx->vm)), + yesno(!!ctx_vm(ctx)), err); i915_gem_context_unlock_engines(ctx); goto out_file; @@ -1698,11 +1702,11 @@ static int igt_vm_isolation(void *arg) } /* We can only test vm isolation, if the vm are distinct */ - if (ctx_a->vm == ctx_b->vm) + if (ctx_vm(ctx_a) == ctx_vm(ctx_b)) goto out_file; - vm_total = ctx_a->vm->total; - GEM_BUG_ON(ctx_b->vm->total != vm_total); + vm_total = ctx_vm(ctx_a)->total; + GEM_BUG_ON(ctx_vm(ctx_b)->total != vm_total); vm_total -= I915_GTT_PAGE_SIZE; count = 0; -- 2.11.0