// SPDX-License-Identifier: MIT
/*
 * Copyright © 2022 Intel Corporation
 */

#include "gt/intel_gt.h"
#include "gt/intel_hwconfig.h"
#include "i915_drv.h"
#include "i915_memcpy.h"
#include "intel_guc_print.h"

/*
 * GuC has a blob containing hardware configuration information (HWConfig).
 * This is formatted as a simple and flexible KLV (Key/Length/Value) table.
 *
 * For example, a minimal version could be:
 *   enum device_attr {
 *     ATTR_SOME_VALUE = 0,
 *     ATTR_SOME_MASK  = 1,
 *   };
 *
 *   static const u32 hwconfig[] = {
 *     ATTR_SOME_VALUE,
 *     1,               // Value Length in DWords
 *     8,               // Value
 *
 *     ATTR_SOME_MASK,
 *     3,
 *     0x00FFFFFFFF, 0xFFFFFFFF, 0xFF000000,
 *   };
 *
 * The attribute ids are defined in a hardware spec.
 */

static int __guc_action_get_hwconfig(struct intel_guc *guc,
                                     u32 ggtt_offset, u32 ggtt_size)
{
        u32 action[] = {
                INTEL_GUC_ACTION_GET_HWCONFIG,
                lower_32_bits(ggtt_offset),
                upper_32_bits(ggtt_offset),
                ggtt_size,
        };
        int ret;

        guc_dbg(guc, "Querying HW config table: size = %d, offset = 0x%08X\n",
                ggtt_size, ggtt_offset);
        ret = intel_guc_send_mmio(guc, action, ARRAY_SIZE(action), NULL, 0);
        if (ret == -ENXIO)
                return -ENOENT;

        return ret;
}

static int guc_hwconfig_discover_size(struct intel_guc *guc, struct intel_hwconfig *hwconfig)
{
        int ret;

        /*
         * Sending a query with zero offset and size will return the
         * size of the blob.
         */
        ret = __guc_action_get_hwconfig(guc, 0, 0);
        if (ret < 0)
                return ret;

        if (ret == 0)
                return -EINVAL;

        hwconfig->size = ret;
        return 0;
}

static int guc_hwconfig_fill_buffer(struct intel_guc *guc, struct intel_hwconfig *hwconfig)
{
        struct i915_vma *vma;
        u32 ggtt_offset;
        void *vaddr;
        int ret;

        GEM_BUG_ON(!hwconfig->size);

        ret = intel_guc_allocate_and_map_vma(guc, hwconfig->size, &vma, &vaddr);
        if (ret)
                return ret;

        ggtt_offset = intel_guc_ggtt_offset(guc, vma);

        ret = __guc_action_get_hwconfig(guc, ggtt_offset, hwconfig->size);
        if (ret >= 0)
                memcpy(hwconfig->ptr, vaddr, hwconfig->size);

        i915_vma_unpin_and_release(&vma, I915_VMA_RELEASE_MAP);

        return ret;
}

static bool has_table(struct drm_i915_private *i915)
{
        if (IS_ALDERLAKE_P(i915) && !IS_ALDERLAKE_P_N(i915))
                return true;
        if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 55))
                return true;

        return false;
}

/*
 * intel_guc_hwconfig_init - Initialize the HWConfig
 *
 * Retrieve the HWConfig table from the GuC and save it locally.
 * It can then be queried on demand by other users later on.
 */
static int guc_hwconfig_init(struct intel_gt *gt)
{
        struct intel_hwconfig *hwconfig = &gt->info.hwconfig;
        struct intel_guc *guc = gt_to_guc(gt);
        int ret;

        if (!has_table(gt->i915))
                return 0;

        ret = guc_hwconfig_discover_size(guc, hwconfig);
        if (ret)
                return ret;

        hwconfig->ptr = kmalloc(hwconfig->size, GFP_KERNEL);
        if (!hwconfig->ptr) {
                hwconfig->size = 0;
                return -ENOMEM;
        }

        ret = guc_hwconfig_fill_buffer(guc, hwconfig);
        if (ret < 0) {
                intel_gt_fini_hwconfig(gt);
                return ret;
        }

        return 0;
}

/*
 * intel_gt_init_hwconfig - Initialize the HWConfig if available
 *
 * Retrieve the HWConfig table if available on the current platform.
 */
int intel_gt_init_hwconfig(struct intel_gt *gt)
{
        if (!intel_uc_uses_guc(&gt->uc))
                return 0;

        return guc_hwconfig_init(gt);
}

/*
 * intel_gt_fini_hwconfig - Finalize the HWConfig
 *
 * Free up the memory allocation holding the table.
 */
void intel_gt_fini_hwconfig(struct intel_gt *gt)
{
        struct intel_hwconfig *hwconfig = &gt->info.hwconfig;

        kfree(hwconfig->ptr);
        hwconfig->size = 0;
        hwconfig->ptr = NULL;
}