--- /dev/null
+/*
+ * Copyright © 2013 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:
+ * Brad Volkin <bradley.d.volkin@intel.com>
+ *
+ */
+
+#include "i915_drv.h"
+
+/**
+ * DOC: i915 batch buffer command parser
+ *
+ * Motivation:
+ * Certain OpenGL features (e.g. transform feedback, performance monitoring)
+ * require userspace code to submit batches containing commands such as
+ * MI_LOAD_REGISTER_IMM to access various registers. Unfortunately, some
+ * generations of the hardware will noop these commands in "unsecure" batches
+ * (which includes all userspace batches submitted via i915) even though the
+ * commands may be safe and represent the intended programming model of the
+ * device.
+ *
+ * The software command parser is similar in operation to the command parsing
+ * done in hardware for unsecure batches. However, the software parser allows
+ * some operations that would be noop'd by hardware, if the parser determines
+ * the operation is safe, and submits the batch as "secure" to prevent hardware
+ * parsing.
+ *
+ * Threats:
+ * At a high level, the hardware (and software) checks attempt to prevent
+ * granting userspace undue privileges. There are three categories of privilege.
+ *
+ * First, commands which are explicitly defined as privileged or which should
+ * only be used by the kernel driver. The parser generally rejects such
+ * commands, though it may allow some from the drm master process.
+ *
+ * Second, commands which access registers. To support correct/enhanced
+ * userspace functionality, particularly certain OpenGL extensions, the parser
+ * provides a whitelist of registers which userspace may safely access (for both
+ * normal and drm master processes).
+ *
+ * Third, commands which access privileged memory (i.e. GGTT, HWS page, etc).
+ * The parser always rejects such commands.
+ *
+ * The majority of the problematic commands fall in the MI_* range, with only a
+ * few specific commands on each ring (e.g. PIPE_CONTROL and MI_FLUSH_DW).
+ *
+ * Implementation:
+ * Each ring maintains tables of commands and registers which the parser uses in
+ * scanning batch buffers submitted to that ring.
+ *
+ * Since the set of commands that the parser must check for is significantly
+ * smaller than the number of commands supported, the parser tables contain only
+ * those commands required by the parser. This generally works because command
+ * opcode ranges have standard command length encodings. So for commands that
+ * the parser does not need to check, it can easily skip them. This is
+ * implementated via a per-ring length decoding vfunc.
+ *
+ * Unfortunately, there are a number of commands that do not follow the standard
+ * length encoding for their opcode range, primarily amongst the MI_* commands.
+ * To handle this, the parser provides a way to define explicit "skip" entries
+ * in the per-ring command tables.
+ *
+ * Other command table entries map fairly directly to high level categories
+ * mentioned above: rejected, master-only, register whitelist. The parser
+ * implements a number of checks, including the privileged memory checks, via a
+ * general bitmasking mechanism.
+ */
+
+static u32 gen7_render_get_cmd_length_mask(u32 cmd_header)
+{
+ u32 client = (cmd_header & INSTR_CLIENT_MASK) >> INSTR_CLIENT_SHIFT;
+ u32 subclient =
+ (cmd_header & INSTR_SUBCLIENT_MASK) >> INSTR_SUBCLIENT_SHIFT;
+
+ if (client == INSTR_MI_CLIENT)
+ return 0x3F;
+ else if (client == INSTR_RC_CLIENT) {
+ if (subclient == INSTR_MEDIA_SUBCLIENT)
+ return 0xFFFF;
+ else
+ return 0xFF;
+ }
+
+ DRM_DEBUG_DRIVER("CMD: Abnormal rcs cmd length! 0x%08X\n", cmd_header);
+ return 0;
+}
+
+static u32 gen7_bsd_get_cmd_length_mask(u32 cmd_header)
+{
+ u32 client = (cmd_header & INSTR_CLIENT_MASK) >> INSTR_CLIENT_SHIFT;
+ u32 subclient =
+ (cmd_header & INSTR_SUBCLIENT_MASK) >> INSTR_SUBCLIENT_SHIFT;
+
+ if (client == INSTR_MI_CLIENT)
+ return 0x3F;
+ else if (client == INSTR_RC_CLIENT) {
+ if (subclient == INSTR_MEDIA_SUBCLIENT)
+ return 0xFFF;
+ else
+ return 0xFF;
+ }
+
+ DRM_DEBUG_DRIVER("CMD: Abnormal bsd cmd length! 0x%08X\n", cmd_header);
+ return 0;
+}
+
+static u32 gen7_blt_get_cmd_length_mask(u32 cmd_header)
+{
+ u32 client = (cmd_header & INSTR_CLIENT_MASK) >> INSTR_CLIENT_SHIFT;
+
+ if (client == INSTR_MI_CLIENT)
+ return 0x3F;
+ else if (client == INSTR_BC_CLIENT)
+ return 0xFF;
+
+ DRM_DEBUG_DRIVER("CMD: Abnormal blt cmd length! 0x%08X\n", cmd_header);
+ return 0;
+}
+
+static void validate_cmds_sorted(struct intel_ring_buffer *ring)
+{
+ int i;
+
+ if (!ring->cmd_tables || ring->cmd_table_count == 0)
+ return;
+
+ for (i = 0; i < ring->cmd_table_count; i++) {
+ const struct drm_i915_cmd_table *table = &ring->cmd_tables[i];
+ u32 previous = 0;
+ int j;
+
+ for (j = 0; j < table->count; j++) {
+ const struct drm_i915_cmd_descriptor *desc =
+ &table->table[i];
+ u32 curr = desc->cmd.value & desc->cmd.mask;
+
+ if (curr < previous)
+ DRM_ERROR("CMD: table not sorted ring=%d table=%d entry=%d cmd=0x%08X prev=0x%08X\n",
+ ring->id, i, j, curr, previous);
+
+ previous = curr;
+ }
+ }
+}
+
+static void check_sorted(int ring_id, const u32 *reg_table, int reg_count)
+{
+ int i;
+ u32 previous = 0;
+
+ for (i = 0; i < reg_count; i++) {
+ u32 curr = reg_table[i];
+
+ if (curr < previous)
+ DRM_ERROR("CMD: table not sorted ring=%d entry=%d reg=0x%08X prev=0x%08X\n",
+ ring_id, i, curr, previous);
+
+ previous = curr;
+ }
+}
+
+static void validate_regs_sorted(struct intel_ring_buffer *ring)
+{
+ check_sorted(ring->id, ring->reg_table, ring->reg_count);
+ check_sorted(ring->id, ring->master_reg_table, ring->master_reg_count);
+}
+
+/**
+ * i915_cmd_parser_init_ring() - set cmd parser related fields for a ringbuffer
+ * @ring: the ringbuffer to initialize
+ *
+ * Optionally initializes fields related to batch buffer command parsing in the
+ * struct intel_ring_buffer based on whether the platform requires software
+ * command parsing.
+ */
+void i915_cmd_parser_init_ring(struct intel_ring_buffer *ring)
+{
+ if (!IS_GEN7(ring->dev))
+ return;
+
+ switch (ring->id) {
+ case RCS:
+ ring->get_cmd_length_mask = gen7_render_get_cmd_length_mask;
+ break;
+ case VCS:
+ ring->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
+ break;
+ case BCS:
+ ring->get_cmd_length_mask = gen7_blt_get_cmd_length_mask;
+ break;
+ case VECS:
+ /* VECS can use the same length_mask function as VCS */
+ ring->get_cmd_length_mask = gen7_bsd_get_cmd_length_mask;
+ break;
+ default:
+ DRM_ERROR("CMD: cmd_parser_init with unknown ring: %d\n",
+ ring->id);
+ BUG();
+ }
+
+ validate_cmds_sorted(ring);
+ validate_regs_sorted(ring);
+}
+
+static const struct drm_i915_cmd_descriptor*
+find_cmd_in_table(const struct drm_i915_cmd_table *table,
+ u32 cmd_header)
+{
+ int i;
+
+ for (i = 0; i < table->count; i++) {
+ const struct drm_i915_cmd_descriptor *desc = &table->table[i];
+ u32 masked_cmd = desc->cmd.mask & cmd_header;
+ u32 masked_value = desc->cmd.value & desc->cmd.mask;
+
+ if (masked_cmd == masked_value)
+ return desc;
+ }
+
+ return NULL;
+}
+
+/*
+ * Returns a pointer to a descriptor for the command specified by cmd_header.
+ *
+ * The caller must supply space for a default descriptor via the default_desc
+ * parameter. If no descriptor for the specified command exists in the ring's
+ * command parser tables, this function fills in default_desc based on the
+ * ring's default length encoding and returns default_desc.
+ */
+static const struct drm_i915_cmd_descriptor*
+find_cmd(struct intel_ring_buffer *ring,
+ u32 cmd_header,
+ struct drm_i915_cmd_descriptor *default_desc)
+{
+ u32 mask;
+ int i;
+
+ for (i = 0; i < ring->cmd_table_count; i++) {
+ const struct drm_i915_cmd_descriptor *desc;
+
+ desc = find_cmd_in_table(&ring->cmd_tables[i], cmd_header);
+ if (desc)
+ return desc;
+ }
+
+ mask = ring->get_cmd_length_mask(cmd_header);
+ if (!mask)
+ return NULL;
+
+ BUG_ON(!default_desc);
+ default_desc->flags = CMD_DESC_SKIP;
+ default_desc->length.mask = mask;
+
+ return default_desc;
+}
+
+static bool valid_reg(const u32 *table, int count, u32 addr)
+{
+ if (table && count != 0) {
+ int i;
+
+ for (i = 0; i < count; i++) {
+ if (table[i] == addr)
+ return true;
+ }
+ }
+
+ return false;
+}
+
+static u32 *vmap_batch(struct drm_i915_gem_object *obj)
+{
+ int i;
+ void *addr = NULL;
+ struct sg_page_iter sg_iter;
+ struct page **pages;
+
+ pages = drm_malloc_ab(obj->base.size >> PAGE_SHIFT, sizeof(*pages));
+ if (pages == NULL) {
+ DRM_DEBUG_DRIVER("Failed to get space for pages\n");
+ goto finish;
+ }
+
+ i = 0;
+ for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0) {
+ pages[i] = sg_page_iter_page(&sg_iter);
+ i++;
+ }
+
+ addr = vmap(pages, i, 0, PAGE_KERNEL);
+ if (addr == NULL) {
+ DRM_DEBUG_DRIVER("Failed to vmap pages\n");
+ goto finish;
+ }
+
+finish:
+ if (pages)
+ drm_free_large(pages);
+ return (u32*)addr;
+}
+
+/**
+ * i915_needs_cmd_parser() - should a given ring use software command parsing?
+ * @ring: the ring in question
+ *
+ * Only certain platforms require software batch buffer command parsing, and
+ * only when enabled via module paramter.
+ *
+ * Return: true if the ring requires software command parsing
+ */
+bool i915_needs_cmd_parser(struct intel_ring_buffer *ring)
+{
+ /* No command tables indicates a platform without parsing */
+ if (!ring->cmd_tables)
+ return false;
+
+ return (i915.enable_cmd_parser == 1);
+}
+
+#define LENGTH_BIAS 2
+
+/**
+ * i915_parse_cmds() - parse a submitted batch buffer for privilege violations
+ * @ring: the ring on which the batch is to execute
+ * @batch_obj: the batch buffer in question
+ * @batch_start_offset: byte offset in the batch at which execution starts
+ * @is_master: is the submitting process the drm master?
+ *
+ * Parses the specified batch buffer looking for privilege violations as
+ * described in the overview.
+ *
+ * Return: non-zero if the parser finds violations or otherwise fails
+ */
+int i915_parse_cmds(struct intel_ring_buffer *ring,
+ struct drm_i915_gem_object *batch_obj,
+ u32 batch_start_offset,
+ bool is_master)
+{
+ int ret = 0;
+ u32 *cmd, *batch_base, *batch_end;
+ struct drm_i915_cmd_descriptor default_desc = { 0 };
+ int needs_clflush = 0;
+
+ ret = i915_gem_obj_prepare_shmem_read(batch_obj, &needs_clflush);
+ if (ret) {
+ DRM_DEBUG_DRIVER("CMD: failed to prep read\n");
+ return ret;
+ }
+
+ batch_base = vmap_batch(batch_obj);
+ if (!batch_base) {
+ DRM_DEBUG_DRIVER("CMD: Failed to vmap batch\n");
+ i915_gem_object_unpin_pages(batch_obj);
+ return -ENOMEM;
+ }
+
+ if (needs_clflush)
+ drm_clflush_virt_range((char *)batch_base, batch_obj->base.size);
+
+ cmd = batch_base + (batch_start_offset / sizeof(*cmd));
+ batch_end = cmd + (batch_obj->base.size / sizeof(*batch_end));
+
+ while (cmd < batch_end) {
+ const struct drm_i915_cmd_descriptor *desc;
+ u32 length;
+
+ if (*cmd == MI_BATCH_BUFFER_END)
+ break;
+
+ desc = find_cmd(ring, *cmd, &default_desc);
+ if (!desc) {
+ DRM_DEBUG_DRIVER("CMD: Unrecognized command: 0x%08X\n",
+ *cmd);
+ ret = -EINVAL;
+ break;
+ }
+
+ if (desc->flags & CMD_DESC_FIXED)
+ length = desc->length.fixed;
+ else
+ length = ((*cmd & desc->length.mask) + LENGTH_BIAS);
+
+ if ((batch_end - cmd) < length) {
+ DRM_DEBUG_DRIVER("CMD: Command length exceeds batch length: 0x%08X length=%d batchlen=%ld\n",
+ *cmd,
+ length,
+ batch_end - cmd);
+ ret = -EINVAL;
+ break;
+ }
+
+ if (desc->flags & CMD_DESC_REJECT) {
+ DRM_DEBUG_DRIVER("CMD: Rejected command: 0x%08X\n", *cmd);
+ ret = -EINVAL;
+ break;
+ }
+
+ if ((desc->flags & CMD_DESC_MASTER) && !is_master) {
+ DRM_DEBUG_DRIVER("CMD: Rejected master-only command: 0x%08X\n",
+ *cmd);
+ ret = -EINVAL;
+ break;
+ }
+
+ if (desc->flags & CMD_DESC_REGISTER) {
+ u32 reg_addr = cmd[desc->reg.offset] & desc->reg.mask;
+
+ if (!valid_reg(ring->reg_table,
+ ring->reg_count, reg_addr)) {
+ if (!is_master ||
+ !valid_reg(ring->master_reg_table,
+ ring->master_reg_count,
+ reg_addr)) {
+ DRM_DEBUG_DRIVER("CMD: Rejected register 0x%08X in command: 0x%08X (ring=%d)\n",
+ reg_addr,
+ *cmd,
+ ring->id);
+ ret = -EINVAL;
+ break;
+ }
+ }
+ }
+
+ if (desc->flags & CMD_DESC_BITMASK) {
+ int i;
+
+ for (i = 0; i < MAX_CMD_DESC_BITMASKS; i++) {
+ u32 dword;
+
+ if (desc->bits[i].mask == 0)
+ break;
+
+ dword = cmd[desc->bits[i].offset] &
+ desc->bits[i].mask;
+
+ if (dword != desc->bits[i].expected) {
+ DRM_DEBUG_DRIVER("CMD: Rejected command 0x%08X for bitmask 0x%08X (exp=0x%08X act=0x%08X) (ring=%d)\n",
+ *cmd,
+ desc->bits[i].mask,
+ desc->bits[i].expected,
+ dword, ring->id);
+ ret = -EINVAL;
+ break;
+ }
+ }
+
+ if (ret)
+ break;
+ }
+
+ cmd += length;
+ }
+
+ if (cmd >= batch_end) {
+ DRM_DEBUG_DRIVER("CMD: Got to the end of the buffer w/o a BBE cmd!\n");
+ ret = -EINVAL;
+ }
+
+ vunmap(batch_base);
+
+ i915_gem_object_unpin_pages(batch_obj);
+
+ return ret;
+}
atomic_t rps_wait_boost;
};
+/*
+ * A command that requires special handling by the command parser.
+ */
+struct drm_i915_cmd_descriptor {
+ /*
+ * Flags describing how the command parser processes the command.
+ *
+ * CMD_DESC_FIXED: The command has a fixed length if this is set,
+ * a length mask if not set
+ * CMD_DESC_SKIP: The command is allowed but does not follow the
+ * standard length encoding for the opcode range in
+ * which it falls
+ * CMD_DESC_REJECT: The command is never allowed
+ * CMD_DESC_REGISTER: The command should be checked against the
+ * register whitelist for the appropriate ring
+ * CMD_DESC_MASTER: The command is allowed if the submitting process
+ * is the DRM master
+ */
+ u32 flags;
+#define CMD_DESC_FIXED (1<<0)
+#define CMD_DESC_SKIP (1<<1)
+#define CMD_DESC_REJECT (1<<2)
+#define CMD_DESC_REGISTER (1<<3)
+#define CMD_DESC_BITMASK (1<<4)
+#define CMD_DESC_MASTER (1<<5)
+
+ /*
+ * The command's unique identification bits and the bitmask to get them.
+ * This isn't strictly the opcode field as defined in the spec and may
+ * also include type, subtype, and/or subop fields.
+ */
+ struct {
+ u32 value;
+ u32 mask;
+ } cmd;
+
+ /*
+ * The command's length. The command is either fixed length (i.e. does
+ * not include a length field) or has a length field mask. The flag
+ * CMD_DESC_FIXED indicates a fixed length. Otherwise, the command has
+ * a length mask. All command entries in a command table must include
+ * length information.
+ */
+ union {
+ u32 fixed;
+ u32 mask;
+ } length;
+
+ /*
+ * Describes where to find a register address in the command to check
+ * against the ring's register whitelist. Only valid if flags has the
+ * CMD_DESC_REGISTER bit set.
+ */
+ struct {
+ u32 offset;
+ u32 mask;
+ } reg;
+
+#define MAX_CMD_DESC_BITMASKS 3
+ /*
+ * Describes command checks where a particular dword is masked and
+ * compared against an expected value. If the command does not match
+ * the expected value, the parser rejects it. Only valid if flags has
+ * the CMD_DESC_BITMASK bit set. Only entries where mask is non-zero
+ * are valid.
+ */
+ struct {
+ u32 offset;
+ u32 mask;
+ u32 expected;
+ } bits[MAX_CMD_DESC_BITMASKS];
+};
+
+/*
+ * A table of commands requiring special handling by the command parser.
+ *
+ * Each ring has an array of tables. Each table consists of an array of command
+ * descriptors, which must be sorted with command opcodes in ascending order.
+ */
+struct drm_i915_cmd_table {
+ const struct drm_i915_cmd_descriptor *table;
+ int count;
+};
+
#define INTEL_INFO(dev) (&to_i915(dev)->info)
#define IS_I830(dev) ((dev)->pdev->device == 0x3577)
int enable_pc8;
int pc8_timeout;
int invert_brightness;
+ int enable_cmd_parser;
/* leave bools at the end to not create holes */
bool enable_hangcheck;
bool fastboot;
void i915_get_extra_instdone(struct drm_device *dev, uint32_t *instdone);
const char *i915_cache_level_str(int type);
+/* i915_cmd_parser.c */
+void i915_cmd_parser_init_ring(struct intel_ring_buffer *ring);
+bool i915_needs_cmd_parser(struct intel_ring_buffer *ring);
+int i915_parse_cmds(struct intel_ring_buffer *ring,
+ struct drm_i915_gem_object *batch_obj,
+ u32 batch_start_offset,
+ bool is_master);
+
/* i915_suspend.c */
extern int i915_save_state(struct drm_device *dev);
extern int i915_restore_state(struct drm_device *dev);
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