/*
 * Copyright © 2019 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.
 */

#include <fcntl.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <unistd.h>

#include "drmtest.h"
#include "igt_sysfs.h"
#include "intel_chipset.h"
#include "ioctl_wrappers.h"

#include "i915/gem_engine_topology.h"
/**
 * SECTION:gem_engine_topology
 * @short_description: Helpers for dealing engine topology
 * @title: GEM Engine Topology
 *
 * This helper library contains functions used for querying and dealing
 * with engines in GEM contexts.
 *
 * Combined with intel_ctx_t, these helpers give a pretty standard pattern
 * for testing every engine in a device:
 * |[<!-- language="C" -->
 *	const struct intel_execution_engine2 *e;
 *	const intel_ctx_t *ctx = intel_ctx_create_all_physical(fd);
 *
 *	igt_subtest_with_dynamic("basic") {
 *		for_each_ctx_engine(fd, ctx, e) {
 *			igt_dynamic_f("%s", e->name)
 *			run_ctx_test(fd, ctx, e);
 *		}
 *	}
 * ]|
 * This pattern works regardless of whether or not the engines topology API
 * is available and regardless of whether or not your platform supports
 * contexts.  If engines are unavailable, it falls back to a legacy context
 * and if contexts are unavailable, intel_ctx_create_all_physical() will
 * return a wrapper around ctx0.
 *
 * If, for some reason, you want to create a second identical context to
 * use with your engine iterator, duplicating the context is easy:
 * |[<!-- language="C" -->
 *	const intel_ctx_t *ctx2 = intel_ctx_create(fd, &ctx->cfg);
 * ]|
 *
 * If you want each subtest to always create its own contexts, there are
 * also iterators which work only on a context config.  As long as all
 * contexts are created from that config, or from one with an identical set
 * of engines, the iterator will be valid for those contexts.
 * |[<!-- language="C" -->
 *	const struct intel_execution_engine2 *e;
 *	intel_ctx_cfg_t cfg = intel_ctx_cfg_all_physical(fd);
 *
 *	igt_subtest_with_dynamic("basic") {
 *		for_each_ctx_cfg_engine(fd, &cfg, e) {
 *			igt_dynamic_f("%s", e->name)
 *			run_ctx_cfg_test(fd, &cfg, e);
 *		}
 *	}
 * ]|
 */

/*
 * Limit what we support for simplicity due limitation in how much we
 * can address via execbuf2.
 */
#define SIZEOF_QUERY		offsetof(struct drm_i915_query_engine_info, \
					 engines[GEM_MAX_ENGINES])

static int __gem_query(int fd, struct drm_i915_query *q)
{
	int err = 0;

	if (igt_ioctl(fd, DRM_IOCTL_I915_QUERY, q))
		err = -errno;

	errno = 0;
	return err;
}

/**
 * __gem_query_engines:
 * @fd: open i915 drm file descriptor
 * @query_engines: Returned engine query info
 * @length: Size of query_engines, including room for the engines array
 *
 * Queries the set of engines available on this device.
 */
int __gem_query_engines(int fd,
			struct drm_i915_query_engine_info *query_engines,
			int length)
{
	struct drm_i915_query_item item = { };
	struct drm_i915_query query = { };

	item.query_id = DRM_I915_QUERY_ENGINE_INFO;
	query.items_ptr = to_user_pointer(&item);
	query.num_items = 1;
	item.length = length;

	item.data_ptr = to_user_pointer(query_engines);

	return __gem_query(fd, &query);
}

static const char *class_names[] = {
	[I915_ENGINE_CLASS_RENDER]	  = "rcs",
	[I915_ENGINE_CLASS_COPY]	  = "bcs",
	[I915_ENGINE_CLASS_VIDEO]	  = "vcs",
	[I915_ENGINE_CLASS_VIDEO_ENHANCE] = "vecs",
	[I915_ENGINE_CLASS_COMPUTE]       = "ccs",
};

static void init_engine(struct intel_execution_engine2 *e2,
			uint16_t class, uint16_t instance, uint64_t flags)
{
	int ret;

	e2->class    = class;
	e2->instance = instance;

	/* engine is a virtual engine */
	if (class == (uint16_t)I915_ENGINE_CLASS_INVALID &&
	    instance == (uint16_t)I915_ENGINE_CLASS_INVALID_VIRTUAL) {
		strcpy(e2->name, "virtual");
		e2->is_virtual = true;
		return;
	} else {
		e2->is_virtual = false;
	}

	if (class < ARRAY_SIZE(class_names)) {
		e2->flags = flags;
		ret = snprintf(e2->name, sizeof(e2->name), "%s%u",
			       class_names[class], instance);
	} else {
		igt_debug("found unknown engine (%d, %d)\n", class, instance);
		e2->flags = -1;
		ret = snprintf(e2->name, sizeof(e2->name), "c%u_%u",
			       class, instance);
	}

	igt_assert(ret < sizeof(e2->name));
}

static int __query_engine_list(int fd, struct intel_engine_data *ed)
{
	uint8_t buff[SIZEOF_QUERY] = { };
	struct drm_i915_query_engine_info *query_engine =
			(struct drm_i915_query_engine_info *) buff;
	int i, err;

	err = __gem_query_engines(fd, query_engine, SIZEOF_QUERY);
	if (err)
		return err;

	for (i = 0; i < query_engine->num_engines; i++)
		init_engine(&ed->engines[i],
			    query_engine->engines[i].engine.engine_class,
			    query_engine->engines[i].engine.engine_instance, i);

	ed->nengines = query_engine->num_engines;

	return 0;
}

struct intel_execution_engine2 *
intel_get_current_engine(struct intel_engine_data *ed)
{
	if (ed->n >= ed->nengines)
		ed->current_engine = NULL;
	else if (!ed->n)
		ed->current_engine = &ed->engines[0];

	return ed->current_engine;
}

void intel_next_engine(struct intel_engine_data *ed)
{
	if (ed->n + 1 < ed->nengines) {
		ed->n++;
		ed->current_engine = &ed->engines[ed->n];
	} else {
		ed->n = ed->nengines;
		ed->current_engine = NULL;
	}
}

struct intel_execution_engine2 *
intel_get_current_physical_engine(struct intel_engine_data *ed)
{
	struct intel_execution_engine2 *e;

	while ((e = intel_get_current_engine(ed)) && e->is_virtual)
	     intel_next_engine(ed);

	return e;
}

static struct intel_engine_data intel_engine_list_for_static(int fd)
{
	const struct intel_execution_engine2 *e2;
	struct intel_engine_data engine_data = { };

	igt_debug("using pre-allocated engine list\n");

	__for_each_static_engine(e2) {
		if (igt_only_list_subtests() ||
		    (fd < 0) ||
		    gem_has_ring(fd, e2->flags)) {
			struct intel_execution_engine2 *__e2 =
				&engine_data.engines[
				engine_data.nengines];

			strcpy(__e2->name, e2->name);
			__e2->instance   = e2->instance;
			__e2->class      = e2->class;
			__e2->flags      = e2->flags;
			__e2->is_virtual = false;

			engine_data.nengines++;
                }
	}

	return engine_data;
}

/**
 * intel_engine_list_of_physical:
 * @fd: open i915 drm file descriptor
 *
 * Returns the list of all physical engines in the device
 */
struct intel_engine_data intel_engine_list_of_physical(int fd)
{
	struct intel_engine_data engine_data = { };

	if (__query_engine_list(fd, &engine_data) == 0)
		return engine_data;

	return intel_engine_list_for_static(fd);
}

/**
 * intel_engine_list_for_ctx_cfg:
 * @fd: open i915 drm file descriptor
 * @cfg: Context config
 *
 * Returns the list of all engines in the context config
 */
struct intel_engine_data
intel_engine_list_for_ctx_cfg(int fd, const intel_ctx_cfg_t *cfg)
{
	igt_assert(cfg);
	if (fd >= 0 && cfg->num_engines) {
		struct intel_engine_data engine_data = { };
		int i;

		if (cfg->load_balance) {
			engine_data.nengines = cfg->num_engines + 1;

			init_engine(&engine_data.engines[0],
				    I915_ENGINE_CLASS_INVALID,
				    I915_ENGINE_CLASS_INVALID_NONE,
				    0);

			for (i = 0; i < cfg->num_engines; i++)
				init_engine(&engine_data.engines[i + 1],
					    cfg->engines[i].engine_class,
					    cfg->engines[i].engine_instance,
					    i + 1);
		} else {
			engine_data.nengines = cfg->num_engines;
			for (i = 0; i < cfg->num_engines; i++)
				init_engine(&engine_data.engines[i],
					    cfg->engines[i].engine_class,
					    cfg->engines[i].engine_instance,
					    i);
		}

		return engine_data;
	} else {
		/* This is a legacy context */
		return intel_engine_list_for_static(fd);
	}
}

/**
 * gem_has_engine_topology:
 * @fd: open i915 drm file descriptor
 *
 * Queries whether the engine topology API is supported or not.  Every
 * kernel that has the global engines query should have the
 * CONTEXT_PARAM_ENGINES and vice versa so this one check can be used for
 * either.
 *
 * Returns: Engine topology API availability.
 */
bool gem_has_engine_topology(int fd)
{
	struct intel_engine_data ed;
	return !__query_engine_list(fd, &ed);
}

struct intel_execution_engine2 gem_eb_flags_to_engine(unsigned int flags)
{
	const unsigned int ring = flags & (I915_EXEC_RING_MASK | 3 << 13);
	struct intel_execution_engine2 e2__ = {
		.class = -1,
		.instance = -1,
		.flags = -1,
	};

	if (ring == I915_EXEC_DEFAULT) {
		e2__.flags = I915_EXEC_DEFAULT;
		strcpy(e2__.name, "default");
	} else {
		const struct intel_execution_engine2 *e2;

		__for_each_static_engine(e2) {
			if (e2->flags == ring)
				return *e2;
		}

		strcpy(e2__.name, "invalid");
	}

	return e2__;
}

bool gem_engine_is_equal(const struct intel_execution_engine2 *e1,
			 const struct intel_execution_engine2 *e2)
{
	return e1->class == e2->class && e1->instance == e2->instance;
}

static int reopen(int dir, int mode)
{
	char buf[128];
	int fd;

	snprintf(buf, sizeof(buf), "/proc/self/fd/%d", dir);
	fd = open(buf, mode);
	close(dir);

	return fd;
}

static int __open_primary(int dir)
{
	int fd, major, minor;
	char target[1024];
	char device[1024];
	char buf[1024];
	int len;

	fd = openat(dir, "dev", O_RDONLY);
	if (fd < 0)
		return dir;

	len = read(fd, buf, sizeof(buf) - 1);
	close(fd);
	if (len <= 0)
		return dir;
	buf[len] = '\0';

	sscanf(buf, "%d:%d", &major, &minor);
	if (minor < 64)
		return dir;

	if (readlinkat(dir, "device", target, sizeof(target)) < 0)
		return dir;

	fd = openat(dir, "..", O_RDONLY);
	if (fd < 0)
		return dir;

	close(dir);
	for (minor = 0; minor < 64; minor++) {
		sprintf(buf, "/sys/dev/char/%d:%d", major, minor);
		dir = openat(fd, buf, O_RDONLY);
		if (dir < 0)
			break;

		if (readlinkat(dir, "device", device, sizeof(device)) > 0 &&
		    !strcmp(device, target))
			break;

		close(dir);
		dir = -1;
	}
	close(fd);

	return dir;
}

static FILE *__open_attr(int dir, const char *mode, ...)
{
	const char *path;
	FILE *file;
	va_list ap;

	/* The attributes are not to be found on render nodes */
	dir = __open_primary(dir);

	va_start(ap, mode);
	while (dir >= 0 && (path = va_arg(ap, const char *))) {
		int fd;

		fd = openat(dir, path, O_RDONLY);
		close(dir);

		dir = fd;
	}
	va_end(ap);

	if (*mode != 'r') /* clumsy, but fun */
		dir = reopen(dir, O_RDWR);

	file = fdopen(dir, mode);
	if (!file) {
		close(dir);
		return NULL;
	}

	return file;
}

int gem_engine_property_scanf(int i915, const char *engine, const char *attr,
			      const char *fmt, ...)
{
	FILE *file;
	va_list ap;
	int ret;

	file = __open_attr(igt_sysfs_open(i915), "r",
			   "engine", engine, attr, NULL);
	if (!file)
		return -1;

	va_start(ap, fmt);
	ret = vfscanf(file, fmt, ap);
	va_end(ap);

	fclose(file);
	return ret;
}

int gem_engine_property_printf(int i915, const char *engine, const char *attr,
			       const char *fmt, ...)
{
	FILE *file;
	va_list ap;
	int ret;

	file = __open_attr(igt_sysfs_open(i915), "w",
			   "engine", engine, attr, NULL);
	if (!file)
		return -1;

	va_start(ap, fmt);
	ret = vfprintf(file, fmt, ap);
	va_end(ap);

	fclose(file);
	return ret;
}

/* Ensure fast hang detection */
void gem_engine_properties_configure(int fd, struct gem_engine_properties *params)
{
	int ret;
	struct gem_engine_properties write = *params;

	ret = gem_engine_property_scanf(fd, write.engine->name,
					"heartbeat_interval_ms",
					"%d", &params->heartbeat_interval);
	igt_assert_eq(ret, 1);

	ret = gem_engine_property_printf(fd, write.engine->name,
					 "heartbeat_interval_ms", "%d",
					 write.heartbeat_interval);
	igt_assert_lt(0, ret);

	if (gem_scheduler_has_preemption(fd)) {
		ret = gem_engine_property_scanf(fd, write.engine->name,
						"preempt_timeout_ms",
						"%d", &params->preempt_timeout);
		igt_assert_eq(ret, 1);

		ret = gem_engine_property_printf(fd, write.engine->name,
						 "preempt_timeout_ms", "%d",
						 write.preempt_timeout);
		igt_assert_lt(0, ret);
	}
}

void gem_engine_properties_restore(int fd, const struct gem_engine_properties *saved)
{
	int ret;

	ret = gem_engine_property_printf(fd, saved->engine->name,
					 "heartbeat_interval_ms", "%d",
					 saved->heartbeat_interval);
	igt_assert_lt(0, ret);

	if (gem_scheduler_has_preemption(fd)) {
		ret = gem_engine_property_printf(fd, saved->engine->name,
						 "preempt_timeout_ms", "%d",
						 saved->preempt_timeout);
		igt_assert_lt(0, ret);
	}
}

static bool
__gem_engine_has_capability(int i915, const char *engine,
			    const char *attr, const char *cap)
{
	char buf[4096] = {};
	FILE *file;

	file = __open_attr(igt_sysfs_open(i915), "r",
			   "engine", engine, attr, NULL);
	if (!file)
		return NULL;

	fread(buf, 1, sizeof(buf) - 1, file);
	fclose(file);

	return strstr(buf, cap);
}

bool gem_engine_has_capability(int i915, const char *engine, const char *cap)
{
	return __gem_engine_has_capability(i915, engine, "capabilities", cap);
}

bool gem_engine_has_known_capability(int i915, const char *engine, const char *cap)
{
	return __gem_engine_has_capability(i915, engine, "known_capabilities", cap);
}

bool gem_engine_can_block_copy(int i915, const struct intel_execution_engine2 *engine)
{
	if (engine->class != I915_ENGINE_CLASS_COPY)
		return false;

	if (!gem_engine_has_known_capability(i915, engine->name, "block_copy"))
		return intel_gen(intel_get_drm_devid(i915)) >= 12;

	return gem_engine_has_capability(i915, engine->name, "block_copy");
}

uint32_t gem_engine_mmio_base(int i915, const char *engine)
{
	unsigned int mmio = 0;

	if (gem_engine_property_scanf(i915, engine, "mmio_base",
				      "%x", &mmio) < 0) {
		int gen = intel_gen(intel_get_drm_devid(i915));

		/* The layout of xcs1+ is unreliable -- hence the property! */
		if (!strcmp(engine, "rcs0")) {
			mmio = 0x2000;
		} else if (!strcmp(engine, "bcs0")) {
			mmio = 0x22000;
		} else if (!strcmp(engine, "vcs0")) {
			if (gen < 6)
				mmio = 0x4000;
			else if (gen < 11)
				mmio = 0x12000;
			else
				mmio = 0x1c0000;
		} else if (!strcmp(engine, "vecs0")) {
			if (gen < 11)
				mmio = 0x1a000;
			else
				mmio = 0x1c8000;
		}
	}

	return mmio;
}

void dyn_sysfs_engines(int i915, int engines, const char *file,
		       void (*test)(int, int))
{
	char buf[512];
	int len;

	lseek(engines, 0, SEEK_SET);
	while ((len = syscall(SYS_getdents64, engines, buf, sizeof(buf))) > 0) {
		void *ptr = buf;

		while (len) {
			struct linux_dirent64 {
				ino64_t        d_ino;
				off64_t        d_off;
				unsigned short d_reclen;
				unsigned char  d_type;
				char           d_name[];
			} *de = ptr;
			char *name;
			int engine;

			ptr += de->d_reclen;
			len -= de->d_reclen;

			engine = openat(engines, de->d_name, O_RDONLY);
			name = igt_sysfs_get(engine, "name");
			if (!name) {
				close(engine);
				continue;
			}

			igt_dynamic(name) {
				if (file) {
					struct stat st;

					igt_require(fstatat(engine, file, &st, 0) == 0);
				}

				errno = 0; /* start afresh */
				test(i915, engine);
			}

			close(engine);
		}
	}
}