igt: Remove gen7_forcewake_mt

Having demonstrated that FORCEWAKE_MT is suspect to the same old
concurrent mmio access bug that stalks gen7, we have shown that it is
not viable for userspace to poke around inside FORCEWAKE_MT directly. As
it can not work correctly, remove the test.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

4 files changed, 0 insertions, 258 deletions

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 8472a6bf..dbc7be72 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -126,8 +126,6 @@ gem_tiled_swapping_CFLAGS = $(AM_CFLAGS) $(THREAD_CFLAGS)
 gem_tiled_swapping_LDADD = $(LDADD) -lpthread
 prime_self_import_CFLAGS = $(AM_CFLAGS) $(THREAD_CFLAGS)
 prime_self_import_LDADD = $(LDADD) -lpthread
-gen7_forcewake_mt_CFLAGS = $(AM_CFLAGS) $(THREAD_CFLAGS)
-gen7_forcewake_mt_LDADD = $(LDADD) -lpthread
 gem_userptr_blits_CFLAGS = $(AM_CFLAGS) $(THREAD_CFLAGS)
 gem_userptr_blits_LDADD = $(LDADD) -lpthread
 perf_pmu_LDADD = $(LDADD) $(top_builddir)/lib/libigt_perf.la
diff --git a/tests/Makefile.sources b/tests/Makefile.sources
index 23f859be..4a81ac4a 100644
--- a/tests/Makefile.sources
+++ b/tests/Makefile.sources
@@ -166,7 +166,6 @@ TESTS_progs = \
 	gen3_render_mixed_blits \
 	gen3_render_tiledx_blits \
 	gen3_render_tiledy_blits \
-	gen7_forcewake_mt \
 	gvt_basic \
 	kms_3d \
 	kms_addfb_basic \
diff --git a/tests/gen7_forcewake_mt.c b/tests/gen7_forcewake_mt.c
deleted file mode 100644
index 164c7fd9..00000000
--- a/tests/gen7_forcewake_mt.c
+++ /dev/null
@@ -1,254 +0,0 @@
-/*
- * Copyright © 2014 Intel Corporation
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice (including the next
- * paragraph) shall be included in all copies or substantial portions of the
- * Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
- * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
- * IN THE SOFTWARE.
- *
- * Authors:
- *    Chris Wilson <chris@chris-wilson.co.uk>
- *
- */
-
-/*
- * Testcase: Exercise a suspect workaround required for FORCEWAKE_MT
- *
- */
-
-#include "igt.h"
-#include <sys/types.h>
-#include <pthread.h>
-#include <string.h>
-
-#include "drm.h"
-
-IGT_TEST_DESCRIPTION("Exercise a suspect workaround required for"
-		     " FORCEWAKE_MT.");
-
-#define FORCEWAKE_MT 0xa188
-#define READ_ONCE(x) (*(volatile typeof(x) *)(&(x)))
-
-struct thread {
-	pthread_t thread;
-	pthread_mutex_t *lock;
-	volatile uint32_t *forcewake_mt;
-	int fd;
-	int bit;
-	bool done;
-};
-
-static const struct pci_id_match match[] = {
-	INTEL_IVB_D_IDS(NULL),
-	INTEL_IVB_M_IDS(NULL),
-
-	INTEL_HSW_IDS(NULL),
-
-	{ 0, 0, 0 },
-};
-
-static struct pci_device *__igfx_get(void)
-{
-	struct pci_device *dev;
-
-	if (pci_system_init())
-		return 0;
-
-	dev = pci_device_find_by_slot(0, 0, 2, 0);
-	if (dev == NULL || dev->vendor_id != 0x8086) {
-		struct pci_device_iterator *iter;
-
-		iter = pci_id_match_iterator_create(match);
-		if (!iter)
-			return 0;
-
-		dev = pci_device_next(iter);
-		pci_iterator_destroy(iter);
-	}
-
-	pci_device_probe(dev);
-	return dev;
-}
-
-static volatile uint32_t *igfx_mmio_forcewake_mt(void)
-{
-	struct pci_device *pci = __igfx_get();
-
-	igt_require(pci && intel_gen(pci->device_id) == 7);
-
-	intel_mmio_use_pci_bar(pci);
-
-	return (volatile uint32_t *)((char *)igt_global_mmio + FORCEWAKE_MT);
-}
-
-static void *thread(void *arg)
-{
-	static const char acquire_error[] = "acquire";
-	static const char release_error[] = "release";
-
-	struct thread *t = arg;
-	const uint32_t bit = 1 << t->bit;
-	volatile uint32_t *forcewake_mt = t->forcewake_mt;
-	void *result = NULL;
-
-	while (!result && !READ_ONCE(t->done)) {
-		/*
-		 * The HW is fubar; concurrent mmio access to even
-		 * the FORCEWAKE_MT results in a machine lockup, nullifying
-		 * the entire purpose of FORCEWAKE_MT... Sigh.
-		 */
-		pthread_mutex_lock(t->lock);
-
-		*forcewake_mt = bit << 16 | bit;
-		if (!igt_wait(*forcewake_mt & bit, 50, 1))
-			result = (void *)acquire_error;
-
-		/* Sleep to let another thread poke at a different bit */
-		pthread_mutex_unlock(t->lock);
-		usleep(1000);
-		pthread_mutex_lock(t->lock);
-
-		*forcewake_mt = bit << 16;
-		if (!igt_wait((*forcewake_mt & bit) == 0, 50, 1))
-			result = (void *)release_error;
-
-		pthread_mutex_unlock(t->lock);
-	}
-
-	return result;
-}
-
-#define MI_STORE_REGISTER_MEM                   (0x24<<23)
-
-igt_simple_main
-{
-	struct thread t[16];
-	pthread_mutex_t lock;
-	bool success = true;
-	int i;
-
-	igt_assert(pthread_mutex_init(&lock, NULL) == 0);
-
-	t[0].lock = &lock;
-	t[0].fd = drm_open_driver(DRIVER_INTEL);
-	t[0].forcewake_mt = igfx_mmio_forcewake_mt();
-	t[0].done = false;
-
-	for (i = 2; i < 16; i++) {
-		t[i] = t[0];
-		t[i].bit = i;
-		if (pthread_create(&t[i].thread, NULL, thread, &t[i])) {
-			igt_warn("Failed to create thread for BIT(%d)\n", i);
-			success = false;
-			goto error;
-		}
-	}
-
-	sleep(2);
-
-	igt_until_timeout(2) {
-		uint32_t *p;
-		struct drm_i915_gem_execbuffer2 execbuf;
-		struct drm_i915_gem_exec_object2 exec[2];
-		struct drm_i915_gem_relocation_entry reloc[2];
-		uint32_t b[] = {
-			MI_LOAD_REGISTER_IMM,
-			FORCEWAKE_MT,
-			2 << 16 | 2,
-			MI_STORE_REGISTER_MEM | 1,
-			FORCEWAKE_MT,
-			0, // to be patched
-			MI_LOAD_REGISTER_IMM,
-			FORCEWAKE_MT,
-			2 << 16,
-			MI_STORE_REGISTER_MEM | 1,
-			FORCEWAKE_MT,
-			1 * sizeof(uint32_t), // to be patched
-			MI_BATCH_BUFFER_END,
-			0
-		};
-
-		memset(exec, 0, sizeof(exec));
-		exec[1].handle = gem_create(t[0].fd, 4096);
-		exec[1].relocation_count = 2;
-		exec[1].relocs_ptr = (uintptr_t)reloc;
-		gem_write(t[0].fd, exec[1].handle, 0, b, sizeof(b));
-		exec[0].handle = gem_create(t[0].fd, 4096);
-
-		reloc[0].offset = 5 * sizeof(uint32_t);
-		reloc[0].delta = 0;
-		reloc[0].target_handle = exec[0].handle;
-		reloc[0].read_domains = I915_GEM_DOMAIN_RENDER;
-		reloc[0].write_domain = I915_GEM_DOMAIN_RENDER;
-		reloc[0].presumed_offset = 0;
-
-		reloc[1].offset = 11 * sizeof(uint32_t);
-		reloc[1].delta = 1 * sizeof(uint32_t);
-		reloc[1].target_handle = exec[0].handle;
-		reloc[1].read_domains = I915_GEM_DOMAIN_RENDER;
-		reloc[1].write_domain = I915_GEM_DOMAIN_RENDER;
-		reloc[1].presumed_offset = 0;
-
-		memset(&execbuf, 0, sizeof(execbuf));
-		execbuf.buffers_ptr = (uintptr_t)&exec;
-		execbuf.buffer_count = 2;
-		execbuf.batch_len = sizeof(b);
-		execbuf.flags = I915_EXEC_SECURE;
-
-		pthread_mutex_lock(t[0].lock);
-		gem_execbuf(t[0].fd, &execbuf);
-		gem_sync(t[0].fd, exec[1].handle);
-		pthread_mutex_unlock(t[0].lock);
-
-		p = gem_mmap__gtt(t[0].fd, exec[0].handle, 4096, PROT_READ);
-
-		igt_debug("[%d]={ %08x %08x }\n", i, p[0], p[1]);
-		if ((p[0] & 2) == 0) {
-			igt_warn("Failed to acquire forcewake BIT(1) from batch\n");
-			success = false;
-		}
-		if ((p[1] & 2)) {
-			igt_warn("Failed to release forcewake BIT(1) from batch\n");
-			success = false;
-		}
-
-		munmap(p, 4096);
-		gem_close(t[0].fd, exec[0].handle);
-		gem_close(t[0].fd, exec[1].handle);
-		if (!success)
-			break;
-
-		usleep(1000);
-	}
-
-error:
-	while (--i >= 2) {
-		void *result = (char *)"pthread_join to";
-
-		t[i].done = true;
-		pthread_join(t[i].thread, &result);
-		if (result) {
-			igt_warn("Thread BIT(%d) failed to %s forcewake\n", i, (char *)result);
-			success = false;
-		}
-	}
-
-	/* And clear all forcewake bits before disappearing */
-	*t[0].forcewake_mt = 0xfffe << 16;
-
-	igt_assert(success);
-}
diff --git a/tests/meson.build b/tests/meson.build
index 2a1e6f19..58729231 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -142,7 +142,6 @@ test_progs = [
 	'gen3_render_mixed_blits',
 	'gen3_render_tiledx_blits',
 	'gen3_render_tiledy_blits',
-	'gen7_forcewake_mt',
 	'gvt_basic',
 	'kms_3d',
 	'kms_addfb_basic',