// SPDX-License-Identifier: MIT
/*
 * Copyright © 2014-2019 Intel Corporation
 */

#include <linux/debugfs.h>
#include <linux/string_helpers.h>

#include <drm/drm_managed.h>

#include "gt/intel_gt.h"
#include "i915_drv.h"
#include "i915_irq.h"
#include "i915_memcpy.h"
#include "intel_guc_capture.h"
#include "intel_guc_log.h"
#include "intel_guc_print.h"

#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GUC)
#define GUC_LOG_DEFAULT_CRASH_BUFFER_SIZE       SZ_2M
#define GUC_LOG_DEFAULT_DEBUG_BUFFER_SIZE       SZ_16M
#define GUC_LOG_DEFAULT_CAPTURE_BUFFER_SIZE     SZ_1M
#elif IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
#define GUC_LOG_DEFAULT_CRASH_BUFFER_SIZE       SZ_1M
#define GUC_LOG_DEFAULT_DEBUG_BUFFER_SIZE       SZ_2M
#define GUC_LOG_DEFAULT_CAPTURE_BUFFER_SIZE     SZ_1M
#else
#define GUC_LOG_DEFAULT_CRASH_BUFFER_SIZE       SZ_8K
#define GUC_LOG_DEFAULT_DEBUG_BUFFER_SIZE       SZ_64K
#define GUC_LOG_DEFAULT_CAPTURE_BUFFER_SIZE     SZ_1M
#endif

static void guc_log_copy_debuglogs_for_relay(struct intel_guc_log *log);

struct guc_log_section {
        u32 max;
        u32 flag;
        u32 default_val;
        const char *name;
};

static void _guc_log_init_sizes(struct intel_guc_log *log)
{
        struct intel_guc *guc = log_to_guc(log);
        static const struct guc_log_section sections[GUC_LOG_SECTIONS_LIMIT] = {
                {
                        GUC_LOG_CRASH_MASK >> GUC_LOG_CRASH_SHIFT,
                        GUC_LOG_LOG_ALLOC_UNITS,
                        GUC_LOG_DEFAULT_CRASH_BUFFER_SIZE,
                        "crash dump"
                },
                {
                        GUC_LOG_DEBUG_MASK >> GUC_LOG_DEBUG_SHIFT,
                        GUC_LOG_LOG_ALLOC_UNITS,
                        GUC_LOG_DEFAULT_DEBUG_BUFFER_SIZE,
                        "debug",
                },
                {
                        GUC_LOG_CAPTURE_MASK >> GUC_LOG_CAPTURE_SHIFT,
                        GUC_LOG_CAPTURE_ALLOC_UNITS,
                        GUC_LOG_DEFAULT_CAPTURE_BUFFER_SIZE,
                        "capture",
                }
        };
        int i;

        for (i = 0; i < GUC_LOG_SECTIONS_LIMIT; i++)
                log->sizes[i].bytes = sections[i].default_val;

        /* If debug size > 1MB then bump default crash size to keep the same units */
        if (log->sizes[GUC_LOG_SECTIONS_DEBUG].bytes >= SZ_1M &&
            GUC_LOG_DEFAULT_CRASH_BUFFER_SIZE < SZ_1M)
                log->sizes[GUC_LOG_SECTIONS_CRASH].bytes = SZ_1M;

        /* Prepare the GuC API structure fields: */
        for (i = 0; i < GUC_LOG_SECTIONS_LIMIT; i++) {
                /* Convert to correct units */
                if ((log->sizes[i].bytes % SZ_1M) == 0) {
                        log->sizes[i].units = SZ_1M;
                        log->sizes[i].flag = sections[i].flag;
                } else {
                        log->sizes[i].units = SZ_4K;
                        log->sizes[i].flag = 0;
                }

                if (!IS_ALIGNED(log->sizes[i].bytes, log->sizes[i].units))
                        guc_err(guc, "Mis-aligned log %s size: 0x%X vs 0x%X!\n",
                                sections[i].name, log->sizes[i].bytes, log->sizes[i].units);
                log->sizes[i].count = log->sizes[i].bytes / log->sizes[i].units;

                if (!log->sizes[i].count) {
                        guc_err(guc, "Zero log %s size!\n", sections[i].name);
                } else {
                        /* Size is +1 unit */
                        log->sizes[i].count--;
                }

                /* Clip to field size */
                if (log->sizes[i].count > sections[i].max) {
                        guc_err(guc, "log %s size too large: %d vs %d!\n",
                                sections[i].name, log->sizes[i].count + 1, sections[i].max + 1);
                        log->sizes[i].count = sections[i].max;
                }
        }

        if (log->sizes[GUC_LOG_SECTIONS_CRASH].units != log->sizes[GUC_LOG_SECTIONS_DEBUG].units) {
                guc_err(guc, "Unit mismatch for crash and debug sections: %d vs %d!\n",
                        log->sizes[GUC_LOG_SECTIONS_CRASH].units,
                        log->sizes[GUC_LOG_SECTIONS_DEBUG].units);
                log->sizes[GUC_LOG_SECTIONS_CRASH].units = log->sizes[GUC_LOG_SECTIONS_DEBUG].units;
                log->sizes[GUC_LOG_SECTIONS_CRASH].count = 0;
        }

        log->sizes_initialised = true;
}

static void guc_log_init_sizes(struct intel_guc_log *log)
{
        if (log->sizes_initialised)
                return;

        _guc_log_init_sizes(log);
}

static u32 intel_guc_log_section_size_crash(struct intel_guc_log *log)
{
        guc_log_init_sizes(log);

        return log->sizes[GUC_LOG_SECTIONS_CRASH].bytes;
}

static u32 intel_guc_log_section_size_debug(struct intel_guc_log *log)
{
        guc_log_init_sizes(log);

        return log->sizes[GUC_LOG_SECTIONS_DEBUG].bytes;
}

u32 intel_guc_log_section_size_capture(struct intel_guc_log *log)
{
        guc_log_init_sizes(log);

        return log->sizes[GUC_LOG_SECTIONS_CAPTURE].bytes;
}

static u32 intel_guc_log_size(struct intel_guc_log *log)
{
        /*
         *  GuC Log buffer Layout:
         *
         *  NB: Ordering must follow "enum guc_log_buffer_type".
         *
         *  +===============================+ 00B
         *  |      Debug state header       |
         *  +-------------------------------+ 32B
         *  |    Crash dump state header    |
         *  +-------------------------------+ 64B
         *  |     Capture state header      |
         *  +-------------------------------+ 96B
         *  |                               |
         *  +===============================+ PAGE_SIZE (4KB)
         *  |          Debug logs           |
         *  +===============================+ + DEBUG_SIZE
         *  |        Crash Dump logs        |
         *  +===============================+ + CRASH_SIZE
         *  |         Capture logs          |
         *  +===============================+ + CAPTURE_SIZE
         */
        return PAGE_SIZE +
                intel_guc_log_section_size_crash(log) +
                intel_guc_log_section_size_debug(log) +
                intel_guc_log_section_size_capture(log);
}

/**
 * DOC: GuC firmware log
 *
 * Firmware log is enabled by setting i915.guc_log_level to the positive level.
 * Log data is printed out via reading debugfs i915_guc_log_dump. Reading from
 * i915_guc_load_status will print out firmware loading status and scratch
 * registers value.
 */

static int guc_action_flush_log_complete(struct intel_guc *guc)
{
        u32 action[] = {
                INTEL_GUC_ACTION_LOG_BUFFER_FILE_FLUSH_COMPLETE,
                GUC_DEBUG_LOG_BUFFER
        };

        return intel_guc_send_nb(guc, action, ARRAY_SIZE(action), 0);
}

static int guc_action_flush_log(struct intel_guc *guc)
{
        u32 action[] = {
                INTEL_GUC_ACTION_FORCE_LOG_BUFFER_FLUSH,
                0
        };

        return intel_guc_send(guc, action, ARRAY_SIZE(action));
}

static int guc_action_control_log(struct intel_guc *guc, bool enable,
                                  bool default_logging, u32 verbosity)
{
        u32 action[] = {
                INTEL_GUC_ACTION_UK_LOG_ENABLE_LOGGING,
                (enable ? GUC_LOG_CONTROL_LOGGING_ENABLED : 0) |
                (verbosity << GUC_LOG_CONTROL_VERBOSITY_SHIFT) |
                (default_logging ? GUC_LOG_CONTROL_DEFAULT_LOGGING : 0)
        };

        GEM_BUG_ON(verbosity > GUC_LOG_VERBOSITY_MAX);

        return intel_guc_send(guc, action, ARRAY_SIZE(action));
}

#ifdef __linux__

/*
 * Sub buffer switch callback. Called whenever relay has to switch to a new
 * sub buffer, relay stays on the same sub buffer if 0 is returned.
 */
static int subbuf_start_callback(struct rchan_buf *buf,
                                 void *subbuf,
                                 void *prev_subbuf)
{
        /*
         * Use no-overwrite mode by default, where relay will stop accepting
         * new data if there are no empty sub buffers left.
         * There is no strict synchronization enforced by relay between Consumer
         * and Producer. In overwrite mode, there is a possibility of getting
         * inconsistent/garbled data, the producer could be writing on to the
         * same sub buffer from which Consumer is reading. This can't be avoided
         * unless Consumer is fast enough and can always run in tandem with
         * Producer.
         */
        if (relay_buf_full(buf))
                return 0;

        return 1;
}

/*
 * file_create() callback. Creates relay file in debugfs.
 */
static struct dentry *create_buf_file_callback(const char *filename,
                                               struct dentry *parent,
                                               umode_t mode,
                                               struct rchan_buf *buf,
                                               int *is_global)
{
        struct dentry *buf_file;

        /*
         * This to enable the use of a single buffer for the relay channel and
         * correspondingly have a single file exposed to User, through which
         * it can collect the logs in order without any post-processing.
         * Need to set 'is_global' even if parent is NULL for early logging.
         */
        *is_global = 1;

        if (!parent)
                return NULL;

        buf_file = debugfs_create_file(filename, mode,
                                       parent, buf, &relay_file_operations);
        if (IS_ERR(buf_file))
                return NULL;

        return buf_file;
}

/*
 * file_remove() default callback. Removes relay file in debugfs.
 */
static int remove_buf_file_callback(struct dentry *dentry)
{
        debugfs_remove(dentry);
        return 0;
}

/* relay channel callbacks */
static const struct rchan_callbacks relay_callbacks = {
        .subbuf_start = subbuf_start_callback,
        .create_buf_file = create_buf_file_callback,
        .remove_buf_file = remove_buf_file_callback,
};

#endif /* __linux__ */

static void guc_move_to_next_buf(struct intel_guc_log *log)
{
        STUB();
#ifdef notyet
        /*
         * Make sure the updates made in the sub buffer are visible when
         * Consumer sees the following update to offset inside the sub buffer.
         */
        smp_wmb();

        /* All data has been written, so now move the offset of sub buffer. */
        relay_reserve(log->relay.channel, log->vma->obj->base.size -
                                          intel_guc_log_section_size_capture(log));

        /* Switch to the next sub buffer */
        relay_flush(log->relay.channel);
#endif
}

static void *guc_get_write_buffer(struct intel_guc_log *log)
{
        STUB();
        return NULL;
#ifdef notyet
        /*
         * Just get the base address of a new sub buffer and copy data into it
         * ourselves. NULL will be returned in no-overwrite mode, if all sub
         * buffers are full. Could have used the relay_write() to indirectly
         * copy the data, but that would have been bit convoluted, as we need to
         * write to only certain locations inside a sub buffer which cannot be
         * done without using relay_reserve() along with relay_write(). So its
         * better to use relay_reserve() alone.
         */
        return relay_reserve(log->relay.channel, 0);
#endif
}

bool intel_guc_check_log_buf_overflow(struct intel_guc_log *log,
                                      enum guc_log_buffer_type type,
                                      unsigned int full_cnt)
{
        unsigned int prev_full_cnt = log->stats[type].sampled_overflow;
        bool overflow = false;

        if (full_cnt != prev_full_cnt) {
                overflow = true;

                log->stats[type].overflow = full_cnt;
                log->stats[type].sampled_overflow += full_cnt - prev_full_cnt;

                if (full_cnt < prev_full_cnt) {
                        /* buffer_full_cnt is a 4 bit counter */
                        log->stats[type].sampled_overflow += 16;
                }

                guc_notice_ratelimited(log_to_guc(log), "log buffer overflow\n");
        }

        return overflow;
}

unsigned int intel_guc_get_log_buffer_size(struct intel_guc_log *log,
                                           enum guc_log_buffer_type type)
{
        switch (type) {
        case GUC_DEBUG_LOG_BUFFER:
                return intel_guc_log_section_size_debug(log);
        case GUC_CRASH_DUMP_LOG_BUFFER:
                return intel_guc_log_section_size_crash(log);
        case GUC_CAPTURE_LOG_BUFFER:
                return intel_guc_log_section_size_capture(log);
        default:
                MISSING_CASE(type);
        }

        return 0;
}

size_t intel_guc_get_log_buffer_offset(struct intel_guc_log *log,
                                       enum guc_log_buffer_type type)
{
        enum guc_log_buffer_type i;
        size_t offset = PAGE_SIZE;/* for the log_buffer_states */

        for (i = GUC_DEBUG_LOG_BUFFER; i < GUC_MAX_LOG_BUFFER; ++i) {
                if (i == type)
                        break;
                offset += intel_guc_get_log_buffer_size(log, i);
        }

        return offset;
}

static void _guc_log_copy_debuglogs_for_relay(struct intel_guc_log *log)
{
        struct intel_guc *guc = log_to_guc(log);
        unsigned int buffer_size, read_offset, write_offset, bytes_to_copy, full_cnt;
        struct guc_log_buffer_state *log_buf_state, *log_buf_snapshot_state;
        struct guc_log_buffer_state log_buf_state_local;
        enum guc_log_buffer_type type;
        void *src_data, *dst_data;
        bool new_overflow;

        mutex_lock(&log->relay.lock);

        if (guc_WARN_ON(guc, !intel_guc_log_relay_created(log)))
                goto out_unlock;

        /* Get the pointer to shared GuC log buffer */
        src_data = log->buf_addr;
        log_buf_state = src_data;

        /* Get the pointer to local buffer to store the logs */
        log_buf_snapshot_state = dst_data = guc_get_write_buffer(log);

        if (unlikely(!log_buf_snapshot_state)) {
                /*
                 * Used rate limited to avoid deluge of messages, logs might be
                 * getting consumed by User at a slow rate.
                 */
                guc_err_ratelimited(guc, "no sub-buffer to copy general logs\n");
                log->relay.full_count++;

                goto out_unlock;
        }

        /* Actual logs are present from the 2nd page */
        src_data += PAGE_SIZE;
        dst_data += PAGE_SIZE;

        /* For relay logging, we exclude error state capture */
        for (type = GUC_DEBUG_LOG_BUFFER; type <= GUC_CRASH_DUMP_LOG_BUFFER; type++) {
                /*
                 * Make a copy of the state structure, inside GuC log buffer
                 * (which is uncached mapped), on the stack to avoid reading
                 * from it multiple times.
                 */
                memcpy(&log_buf_state_local, log_buf_state,
                       sizeof(struct guc_log_buffer_state));
                buffer_size = intel_guc_get_log_buffer_size(log, type);
                read_offset = log_buf_state_local.read_ptr;
                write_offset = log_buf_state_local.sampled_write_ptr;
                full_cnt = log_buf_state_local.buffer_full_cnt;

                /* Bookkeeping stuff */
                log->stats[type].flush += log_buf_state_local.flush_to_file;
                new_overflow = intel_guc_check_log_buf_overflow(log, type, full_cnt);

                /* Update the state of shared log buffer */
                log_buf_state->read_ptr = write_offset;
                log_buf_state->flush_to_file = 0;
                log_buf_state++;

                /* First copy the state structure in snapshot buffer */
                memcpy(log_buf_snapshot_state, &log_buf_state_local,
                       sizeof(struct guc_log_buffer_state));

                /*
                 * The write pointer could have been updated by GuC firmware,
                 * after sending the flush interrupt to Host, for consistency
                 * set write pointer value to same value of sampled_write_ptr
                 * in the snapshot buffer.
                 */
                log_buf_snapshot_state->write_ptr = write_offset;
                log_buf_snapshot_state++;

                /* Now copy the actual logs. */
                if (unlikely(new_overflow)) {
                        /* copy the whole buffer in case of overflow */
                        read_offset = 0;
                        write_offset = buffer_size;
                } else if (unlikely((read_offset > buffer_size) ||
                                    (write_offset > buffer_size))) {
                        guc_err(guc, "invalid log buffer state\n");
                        /* copy whole buffer as offsets are unreliable */
                        read_offset = 0;
                        write_offset = buffer_size;
                }

                /* Just copy the newly written data */
                if (read_offset > write_offset) {
                        i915_memcpy_from_wc(dst_data, src_data, write_offset);
                        bytes_to_copy = buffer_size - read_offset;
                } else {
                        bytes_to_copy = write_offset - read_offset;
                }
                i915_memcpy_from_wc(dst_data + read_offset,
                                    src_data + read_offset, bytes_to_copy);

                src_data += buffer_size;
                dst_data += buffer_size;
        }

        guc_move_to_next_buf(log);

out_unlock:
        mutex_unlock(&log->relay.lock);
}

static void copy_debug_logs_work(struct work_struct *work)
{
        struct intel_guc_log *log =
                container_of(work, struct intel_guc_log, relay.flush_work);

        guc_log_copy_debuglogs_for_relay(log);
}

static int guc_log_relay_map(struct intel_guc_log *log)
{
        lockdep_assert_held(&log->relay.lock);

        if (!log->vma || !log->buf_addr)
                return -ENODEV;

        /*
         * WC vmalloc mapping of log buffer pages was done at
         * GuC Log Init time, but lets keep a ref for book-keeping
         */
        i915_gem_object_get(log->vma->obj);
        log->relay.buf_in_use = true;

        return 0;
}

static void guc_log_relay_unmap(struct intel_guc_log *log)
{
        lockdep_assert_held(&log->relay.lock);

        i915_gem_object_put(log->vma->obj);
        log->relay.buf_in_use = false;
}

void intel_guc_log_init_early(struct intel_guc_log *log)
{
        struct intel_guc *guc = log_to_guc(log);
        struct drm_i915_private *i915 = guc_to_i915(guc);

        drmm_mutex_init(&i915->drm, &log->relay.lock);
        drmm_mutex_init(&i915->drm, &log->guc_lock);
        INIT_WORK(&log->relay.flush_work, copy_debug_logs_work);
        log->relay.started = false;
}

static int guc_log_relay_create(struct intel_guc_log *log)
{
        STUB();
        return -ENOSYS;
#ifdef notyet
        struct intel_guc *guc = log_to_guc(log);
        struct drm_i915_private *i915 = guc_to_i915(guc);
        struct rchan *guc_log_relay_chan;
        size_t n_subbufs, subbuf_size;
        int ret;

        lockdep_assert_held(&log->relay.lock);
        GEM_BUG_ON(!log->vma);

         /*
          * Keep the size of sub buffers same as shared log buffer
          * but GuC log-events excludes the error-state-capture logs
          */
        subbuf_size = log->vma->size - intel_guc_log_section_size_capture(log);

        /*
         * Store up to 8 snapshots, which is large enough to buffer sufficient
         * boot time logs and provides enough leeway to User, in terms of
         * latency, for consuming the logs from relay. Also doesn't take
         * up too much memory.
         */
        n_subbufs = 8;

        if (!guc->dbgfs_node)
                return -ENOENT;

        guc_log_relay_chan = relay_open("guc_log",
                                        guc->dbgfs_node,
                                        subbuf_size, n_subbufs,
                                        &relay_callbacks, i915);
        if (!guc_log_relay_chan) {
                guc_err(guc, "Couldn't create relay channel for logging\n");

                ret = -ENOMEM;
                return ret;
        }

        GEM_BUG_ON(guc_log_relay_chan->subbuf_size < subbuf_size);
        log->relay.channel = guc_log_relay_chan;

        return 0;
#endif
}

static void guc_log_relay_destroy(struct intel_guc_log *log)
{
        STUB();
#ifdef notyet
        lockdep_assert_held(&log->relay.lock);

        relay_close(log->relay.channel);
        log->relay.channel = NULL;
#endif
}

static void guc_log_copy_debuglogs_for_relay(struct intel_guc_log *log)
{
        struct intel_guc *guc = log_to_guc(log);
        struct drm_i915_private *i915 = guc_to_i915(guc);
        intel_wakeref_t wakeref;

        _guc_log_copy_debuglogs_for_relay(log);

        /*
         * Generally device is expected to be active only at this
         * time, so get/put should be really quick.
         */
        with_intel_runtime_pm(&i915->runtime_pm, wakeref)
                guc_action_flush_log_complete(guc);
}

static u32 __get_default_log_level(struct intel_guc_log *log)
{
        struct intel_guc *guc = log_to_guc(log);
        struct drm_i915_private *i915 = guc_to_i915(guc);

        /* A negative value means "use platform/config default" */
        if (i915->params.guc_log_level < 0) {
                return (IS_ENABLED(CONFIG_DRM_I915_DEBUG) ||
                        IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)) ?
                        GUC_LOG_LEVEL_MAX : GUC_LOG_LEVEL_NON_VERBOSE;
        }

        if (i915->params.guc_log_level > GUC_LOG_LEVEL_MAX) {
                guc_warn(guc, "Log verbosity param out of range: %d > %d!\n",
                         i915->params.guc_log_level, GUC_LOG_LEVEL_MAX);
                return (IS_ENABLED(CONFIG_DRM_I915_DEBUG) ||
                        IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)) ?
                        GUC_LOG_LEVEL_MAX : GUC_LOG_LEVEL_DISABLED;
        }

        GEM_BUG_ON(i915->params.guc_log_level < GUC_LOG_LEVEL_DISABLED);
        GEM_BUG_ON(i915->params.guc_log_level > GUC_LOG_LEVEL_MAX);
        return i915->params.guc_log_level;
}

int intel_guc_log_create(struct intel_guc_log *log)
{
        struct intel_guc *guc = log_to_guc(log);
        struct i915_vma *vma;
        void *vaddr;
        u32 guc_log_size;
        int ret;

        GEM_BUG_ON(log->vma);

        guc_log_size = intel_guc_log_size(log);

        vma = intel_guc_allocate_vma(guc, guc_log_size);
        if (IS_ERR(vma)) {
                ret = PTR_ERR(vma);
                goto err;
        }

        log->vma = vma;
        /*
         * Create a WC (Uncached for read) vmalloc mapping up front immediate access to
         * data from memory during  critical events such as error capture
         */
        vaddr = i915_gem_object_pin_map_unlocked(log->vma->obj, I915_MAP_WC);
        if (IS_ERR(vaddr)) {
                ret = PTR_ERR(vaddr);
                i915_vma_unpin_and_release(&log->vma, 0);
                goto err;
        }
        log->buf_addr = vaddr;

        log->level = __get_default_log_level(log);
        guc_dbg(guc, "guc_log_level=%d (%s, verbose:%s, verbosity:%d)\n",
                log->level, str_enabled_disabled(log->level),
                str_yes_no(GUC_LOG_LEVEL_IS_VERBOSE(log->level)),
                GUC_LOG_LEVEL_TO_VERBOSITY(log->level));

        return 0;

err:
        guc_err(guc, "Failed to allocate or map log buffer %pe\n", ERR_PTR(ret));
        return ret;
}

void intel_guc_log_destroy(struct intel_guc_log *log)
{
        log->buf_addr = NULL;
        i915_vma_unpin_and_release(&log->vma, I915_VMA_RELEASE_MAP);
}

int intel_guc_log_set_level(struct intel_guc_log *log, u32 level)
{
        struct intel_guc *guc = log_to_guc(log);
        struct drm_i915_private *i915 = guc_to_i915(guc);
        intel_wakeref_t wakeref;
        int ret = 0;

        BUILD_BUG_ON(GUC_LOG_VERBOSITY_MIN != 0);
        GEM_BUG_ON(!log->vma);

        /*
         * GuC is recognizing log levels starting from 0 to max, we're using 0
         * as indication that logging should be disabled.
         */
        if (level < GUC_LOG_LEVEL_DISABLED || level > GUC_LOG_LEVEL_MAX)
                return -EINVAL;

        mutex_lock(&log->guc_lock);

        if (log->level == level)
                goto out_unlock;

        with_intel_runtime_pm(&i915->runtime_pm, wakeref)
                ret = guc_action_control_log(guc,
                                             GUC_LOG_LEVEL_IS_VERBOSE(level),
                                             GUC_LOG_LEVEL_IS_ENABLED(level),
                                             GUC_LOG_LEVEL_TO_VERBOSITY(level));
        if (ret) {
                guc_dbg(guc, "guc_log_control action failed %pe\n", ERR_PTR(ret));
                goto out_unlock;
        }

        log->level = level;

out_unlock:
        mutex_unlock(&log->guc_lock);

        return ret;
}

bool intel_guc_log_relay_created(const struct intel_guc_log *log)
{
        return log->buf_addr;
}

int intel_guc_log_relay_open(struct intel_guc_log *log)
{
        int ret;

        if (!log->vma)
                return -ENODEV;

        mutex_lock(&log->relay.lock);

        if (intel_guc_log_relay_created(log)) {
                ret = -EEXIST;
                goto out_unlock;
        }

        /*
         * We require SSE 4.1 for fast reads from the GuC log buffer and
         * it should be present on the chipsets supporting GuC based
         * submissions.
         */
        if (!i915_has_memcpy_from_wc()) {
                ret = -ENXIO;
                goto out_unlock;
        }

        ret = guc_log_relay_create(log);
        if (ret)
                goto out_unlock;

        ret = guc_log_relay_map(log);
        if (ret)
                goto out_relay;

        mutex_unlock(&log->relay.lock);

        return 0;

out_relay:
        guc_log_relay_destroy(log);
out_unlock:
        mutex_unlock(&log->relay.lock);

        return ret;
}

int intel_guc_log_relay_start(struct intel_guc_log *log)
{
        if (log->relay.started)
                return -EEXIST;

        /*
         * When GuC is logging without us relaying to userspace, we're ignoring
         * the flush notification. This means that we need to unconditionally
         * flush on relay enabling, since GuC only notifies us once.
         */
        queue_work(system_highpri_wq, &log->relay.flush_work);

        log->relay.started = true;

        return 0;
}

void intel_guc_log_relay_flush(struct intel_guc_log *log)
{
        struct intel_guc *guc = log_to_guc(log);
        intel_wakeref_t wakeref;

        if (!log->relay.started)
                return;

        /*
         * Before initiating the forceful flush, wait for any pending/ongoing
         * flush to complete otherwise forceful flush may not actually happen.
         */
        flush_work(&log->relay.flush_work);

        with_intel_runtime_pm(guc_to_gt(guc)->uncore->rpm, wakeref)
                guc_action_flush_log(guc);

        /* GuC would have updated log buffer by now, so copy it */
        guc_log_copy_debuglogs_for_relay(log);
}

/*
 * Stops the relay log. Called from intel_guc_log_relay_close(), so no
 * possibility of race with start/flush since relay_write cannot race
 * relay_close.
 */
static void guc_log_relay_stop(struct intel_guc_log *log)
{
        struct intel_guc *guc = log_to_guc(log);
        struct drm_i915_private *i915 = guc_to_i915(guc);

        if (!log->relay.started)
                return;

        intel_synchronize_irq(i915);

        flush_work(&log->relay.flush_work);

        log->relay.started = false;
}

void intel_guc_log_relay_close(struct intel_guc_log *log)
{
        guc_log_relay_stop(log);

        mutex_lock(&log->relay.lock);
        GEM_BUG_ON(!intel_guc_log_relay_created(log));
        guc_log_relay_unmap(log);
        guc_log_relay_destroy(log);
        mutex_unlock(&log->relay.lock);
}

void intel_guc_log_handle_flush_event(struct intel_guc_log *log)
{
        if (log->relay.started)
                queue_work(system_highpri_wq, &log->relay.flush_work);
}

static const char *
stringify_guc_log_type(enum guc_log_buffer_type type)
{
        switch (type) {
        case GUC_DEBUG_LOG_BUFFER:
                return "DEBUG";
        case GUC_CRASH_DUMP_LOG_BUFFER:
                return "CRASH";
        case GUC_CAPTURE_LOG_BUFFER:
                return "CAPTURE";
        default:
                MISSING_CASE(type);
        }

        return "";
}

/**
 * intel_guc_log_info - dump information about GuC log relay
 * @log: the GuC log
 * @p: the &drm_printer
 *
 * Pretty printer for GuC log info
 */
void intel_guc_log_info(struct intel_guc_log *log, struct drm_printer *p)
{
        enum guc_log_buffer_type type;

        if (!intel_guc_log_relay_created(log)) {
                drm_puts(p, "GuC log relay not created\n");
                return;
        }

        drm_puts(p, "GuC logging stats:\n");

        drm_printf(p, "\tRelay full count: %u\n", log->relay.full_count);

        for (type = GUC_DEBUG_LOG_BUFFER; type < GUC_MAX_LOG_BUFFER; type++) {
                drm_printf(p, "\t%s:\tflush count %10u, overflow count %10u\n",
                           stringify_guc_log_type(type),
                           log->stats[type].flush,
                           log->stats[type].sampled_overflow);
        }
}

/**
 * intel_guc_log_dump - dump the contents of the GuC log
 * @log: the GuC log
 * @p: the &drm_printer
 * @dump_load_err: dump the log saved on GuC load error
 *
 * Pretty printer for the GuC log
 */
int intel_guc_log_dump(struct intel_guc_log *log, struct drm_printer *p,
                       bool dump_load_err)
{
        struct intel_guc *guc = log_to_guc(log);
        struct intel_uc *uc = container_of(guc, struct intel_uc, guc);
        struct drm_i915_gem_object *obj = NULL;
        void *map;
        u32 *page;
        int i, j;

        if (!intel_guc_is_supported(guc))
                return -ENODEV;

        if (dump_load_err)
                obj = uc->load_err_log;
        else if (guc->log.vma)
                obj = guc->log.vma->obj;

        if (!obj)
                return 0;

        page = (u32 *)__get_free_page(GFP_KERNEL);
        if (!page)
                return -ENOMEM;

        intel_guc_dump_time_info(guc, p);

        map = i915_gem_object_pin_map_unlocked(obj, I915_MAP_WC);
        if (IS_ERR(map)) {
                guc_dbg(guc, "Failed to pin log object: %pe\n", map);
                drm_puts(p, "(log data unaccessible)\n");
                free_page((unsigned long)page);
                return PTR_ERR(map);
        }

        for (i = 0; i < obj->base.size; i += PAGE_SIZE) {
                if (!i915_memcpy_from_wc(page, map + i, PAGE_SIZE))
                        memcpy(page, map + i, PAGE_SIZE);

                for (j = 0; j < PAGE_SIZE / sizeof(u32); j += 4)
                        drm_printf(p, "0x%08x 0x%08x 0x%08x 0x%08x\n",
                                   *(page + j + 0), *(page + j + 1),
                                   *(page + j + 2), *(page + j + 3));
        }

        drm_puts(p, "\n");

        i915_gem_object_unpin_map(obj);
        free_page((unsigned long)page);

        return 0;
}