/*
 * Copyright (c) 2015 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 "intel_mocs.h"
#include "intel_lrc.h"
#include "intel_ringbuffer.h"

/* structures required */
struct drm_i915_mocs_entry {
        u32 control_value;
        u16 l3cc_value;
};

struct drm_i915_mocs_table {
        u32 size;
        const struct drm_i915_mocs_entry *table;
};

/* Defines for the tables (XXX_MOCS_0 - XXX_MOCS_63) */
#define LE_CACHEABILITY(value)  ((value) << 0)
#define LE_TGT_CACHE(value)     ((value) << 2)
#define LE_LRUM(value)          ((value) << 4)
#define LE_AOM(value)           ((value) << 6)
#define LE_RSC(value)           ((value) << 7)
#define LE_SCC(value)           ((value) << 8)
#define LE_PFM(value)           ((value) << 11)
#define LE_SCF(value)           ((value) << 14)

/* Defines for the tables (LNCFMOCS0 - LNCFMOCS31) - two entries per word */
#define L3_ESC(value)           ((value) << 0)
#define L3_SCC(value)           ((value) << 1)
#define L3_CACHEABILITY(value)  ((value) << 4)

/* Helper defines */
#define GEN9_NUM_MOCS_ENTRIES   62  /* 62 out of 64 - 63 & 64 are reserved. */

/* (e)LLC caching options */
#define LE_PAGETABLE            0
#define LE_UC                   1
#define LE_WT                   2
#define LE_WB                   3

/* L3 caching options */
#define L3_DIRECT               0
#define L3_UC                   1
#define L3_RESERVED             2
#define L3_WB                   3

/* Target cache */
#define LE_TC_PAGETABLE         0
#define LE_TC_LLC               1
#define LE_TC_LLC_ELLC          2
#define LE_TC_LLC_ELLC_ALT      3

/*
 * MOCS tables
 *
 * These are the MOCS tables that are programmed across all the rings.
 * The control value is programmed to all the rings that support the
 * MOCS registers. While the l3cc_values are only programmed to the
 * LNCFCMOCS0 - LNCFCMOCS32 registers.
 *
 * These tables are intended to be kept reasonably consistent across
 * platforms. However some of the fields are not applicable to all of
 * them.
 *
 * Entries not part of the following tables are undefined as far as
 * userspace is concerned and shouldn't be relied upon.  For the time
 * being they will be implicitly initialized to the strictest caching
 * configuration (uncached) to guarantee forwards compatibility with
 * userspace programs written against more recent kernels providing
 * additional MOCS entries.
 *
 * NOTE: These tables MUST start with being uncached and the length
 *       MUST be less than 63 as the last two registers are reserved
 *       by the hardware.  These tables are part of the kernel ABI and
 *       may only be updated incrementally by adding entries at the
 *       end.
 */
static const struct drm_i915_mocs_entry skylake_mocs_table[] = {
        [I915_MOCS_UNCACHED] = {
          /* 0x00000009 */
          .control_value = LE_CACHEABILITY(LE_UC) |
                           LE_TGT_CACHE(LE_TC_LLC_ELLC) |
                           LE_LRUM(0) | LE_AOM(0) | LE_RSC(0) | LE_SCC(0) |
                           LE_PFM(0) | LE_SCF(0),

          /* 0x0010 */
          .l3cc_value =    L3_ESC(0) | L3_SCC(0) | L3_CACHEABILITY(L3_UC),
        },
        [I915_MOCS_PTE] = {
          /* 0x00000038 */
          .control_value = LE_CACHEABILITY(LE_PAGETABLE) |
                           LE_TGT_CACHE(LE_TC_LLC_ELLC) |
                           LE_LRUM(3) | LE_AOM(0) | LE_RSC(0) | LE_SCC(0) |
                           LE_PFM(0) | LE_SCF(0),
          /* 0x0030 */
          .l3cc_value =    L3_ESC(0) | L3_SCC(0) | L3_CACHEABILITY(L3_WB),
        },
        [I915_MOCS_CACHED] = {
          /* 0x0000003b */
          .control_value = LE_CACHEABILITY(LE_WB) |
                           LE_TGT_CACHE(LE_TC_LLC_ELLC) |
                           LE_LRUM(3) | LE_AOM(0) | LE_RSC(0) | LE_SCC(0) |
                           LE_PFM(0) | LE_SCF(0),
          /* 0x0030 */
          .l3cc_value =   L3_ESC(0) | L3_SCC(0) | L3_CACHEABILITY(L3_WB),
        },
};

/* NOTE: the LE_TGT_CACHE is not used on Broxton */
static const struct drm_i915_mocs_entry broxton_mocs_table[] = {
        [I915_MOCS_UNCACHED] = {
          /* 0x00000009 */
          .control_value = LE_CACHEABILITY(LE_UC) |
                           LE_TGT_CACHE(LE_TC_LLC_ELLC) |
                           LE_LRUM(0) | LE_AOM(0) | LE_RSC(0) | LE_SCC(0) |
                           LE_PFM(0) | LE_SCF(0),

          /* 0x0010 */
          .l3cc_value =    L3_ESC(0) | L3_SCC(0) | L3_CACHEABILITY(L3_UC),
        },
        [I915_MOCS_PTE] = {
          /* 0x00000038 */
          .control_value = LE_CACHEABILITY(LE_PAGETABLE) |
                           LE_TGT_CACHE(LE_TC_LLC_ELLC) |
                           LE_LRUM(3) | LE_AOM(0) | LE_RSC(0) | LE_SCC(0) |
                           LE_PFM(0) | LE_SCF(0),

          /* 0x0030 */
          .l3cc_value =    L3_ESC(0) | L3_SCC(0) | L3_CACHEABILITY(L3_WB),
        },
        [I915_MOCS_CACHED] = {
          /* 0x00000039 */
          .control_value = LE_CACHEABILITY(LE_UC) |
                           LE_TGT_CACHE(LE_TC_LLC_ELLC) |
                           LE_LRUM(3) | LE_AOM(0) | LE_RSC(0) | LE_SCC(0) |
                           LE_PFM(0) | LE_SCF(0),

          /* 0x0030 */
          .l3cc_value =    L3_ESC(0) | L3_SCC(0) | L3_CACHEABILITY(L3_WB),
        },
};

/**
 * get_mocs_settings()
 * @dev_priv:   i915 device.
 * @table:      Output table that will be made to point at appropriate
 *            MOCS values for the device.
 *
 * This function will return the values of the MOCS table that needs to
 * be programmed for the platform. It will return the values that need
 * to be programmed and if they need to be programmed.
 *
 * Return: true if there are applicable MOCS settings for the device.
 */
static bool get_mocs_settings(struct drm_i915_private *dev_priv,
                              struct drm_i915_mocs_table *table)
{
        bool result = false;

        if (IS_GEN9_BC(dev_priv) || IS_CANNONLAKE(dev_priv)) {
                table->size  = ARRAY_SIZE(skylake_mocs_table);
                table->table = skylake_mocs_table;
                result = true;
        } else if (IS_GEN9_LP(dev_priv)) {
                table->size  = ARRAY_SIZE(broxton_mocs_table);
                table->table = broxton_mocs_table;
                result = true;
        } else {
                WARN_ONCE(INTEL_INFO(dev_priv)->gen >= 9,
                          "Platform that should have a MOCS table does not.\n");
        }

        /* WaDisableSkipCaching:skl,bxt,kbl,glk */
        if (IS_GEN9(dev_priv)) {
                int i;

                for (i = 0; i < table->size; i++)
                        if (WARN_ON(table->table[i].l3cc_value &
                                    (L3_ESC(1) | L3_SCC(0x7))))
                                return false;
        }

        return result;
}

static i915_reg_t mocs_register(enum intel_engine_id engine_id, int index)
{
        switch (engine_id) {
        case RCS:
                return GEN9_GFX_MOCS(index);
        case VCS:
                return GEN9_MFX0_MOCS(index);
        case BCS:
                return GEN9_BLT_MOCS(index);
        case VECS:
                return GEN9_VEBOX_MOCS(index);
        case VCS2:
                return GEN9_MFX1_MOCS(index);
        default:
                MISSING_CASE(engine_id);
                return INVALID_MMIO_REG;
        }
}

/**
 * intel_mocs_init_engine() - emit the mocs control table
 * @engine:     The engine for whom to emit the registers.
 *
 * This function simply emits a MI_LOAD_REGISTER_IMM command for the
 * given table starting at the given address.
 *
 * Return: 0 on success, otherwise the error status.
 */
int intel_mocs_init_engine(struct intel_engine_cs *engine)
{
        struct drm_i915_private *dev_priv = engine->i915;
        struct drm_i915_mocs_table table;
        unsigned int index;

        if (!get_mocs_settings(dev_priv, &table))
                return 0;

        if (WARN_ON(table.size > GEN9_NUM_MOCS_ENTRIES))
                return -ENODEV;

        for (index = 0; index < table.size; index++)
                I915_WRITE(mocs_register(engine->id, index),
                           table.table[index].control_value);

        /*
         * Ok, now set the unused entries to uncached. These entries
         * are officially undefined and no contract for the contents
         * and settings is given for these entries.
         *
         * Entry 0 in the table is uncached - so we are just writing
         * that value to all the used entries.
         */
        for (; index < GEN9_NUM_MOCS_ENTRIES; index++)
                I915_WRITE(mocs_register(engine->id, index),
                           table.table[0].control_value);

        return 0;
}

/**
 * emit_mocs_control_table() - emit the mocs control table
 * @req:        Request to set up the MOCS table for.
 * @table:      The values to program into the control regs.
 *
 * This function simply emits a MI_LOAD_REGISTER_IMM command for the
 * given table starting at the given address.
 *
 * Return: 0 on success, otherwise the error status.
 */
static int emit_mocs_control_table(struct drm_i915_gem_request *req,
                                   const struct drm_i915_mocs_table *table)
{
        enum intel_engine_id engine = req->engine->id;
        unsigned int index;
        u32 *cs;

        if (WARN_ON(table->size > GEN9_NUM_MOCS_ENTRIES))
                return -ENODEV;

        cs = intel_ring_begin(req, 2 + 2 * GEN9_NUM_MOCS_ENTRIES);
        if (IS_ERR(cs))
                return PTR_ERR(cs);

        *cs++ = MI_LOAD_REGISTER_IMM(GEN9_NUM_MOCS_ENTRIES);

        for (index = 0; index < table->size; index++) {
                *cs++ = i915_mmio_reg_offset(mocs_register(engine, index));
                *cs++ = table->table[index].control_value;
        }

        /*
         * Ok, now set the unused entries to uncached. These entries
         * are officially undefined and no contract for the contents
         * and settings is given for these entries.
         *
         * Entry 0 in the table is uncached - so we are just writing
         * that value to all the used entries.
         */
        for (; index < GEN9_NUM_MOCS_ENTRIES; index++) {
                *cs++ = i915_mmio_reg_offset(mocs_register(engine, index));
                *cs++ = table->table[0].control_value;
        }

        *cs++ = MI_NOOP;
        intel_ring_advance(req, cs);

        return 0;
}

static inline u32 l3cc_combine(const struct drm_i915_mocs_table *table,
                               u16 low,
                               u16 high)
{
        return table->table[low].l3cc_value |
               table->table[high].l3cc_value << 16;
}

/**
 * emit_mocs_l3cc_table() - emit the mocs control table
 * @req:        Request to set up the MOCS table for.
 * @table:      The values to program into the control regs.
 *
 * This function simply emits a MI_LOAD_REGISTER_IMM command for the
 * given table starting at the given address. This register set is
 * programmed in pairs.
 *
 * Return: 0 on success, otherwise the error status.
 */
static int emit_mocs_l3cc_table(struct drm_i915_gem_request *req,
                                const struct drm_i915_mocs_table *table)
{
        unsigned int i;
        u32 *cs;

        if (WARN_ON(table->size > GEN9_NUM_MOCS_ENTRIES))
                return -ENODEV;

        cs = intel_ring_begin(req, 2 + GEN9_NUM_MOCS_ENTRIES);
        if (IS_ERR(cs))
                return PTR_ERR(cs);

        *cs++ = MI_LOAD_REGISTER_IMM(GEN9_NUM_MOCS_ENTRIES / 2);

        for (i = 0; i < table->size/2; i++) {
                *cs++ = i915_mmio_reg_offset(GEN9_LNCFCMOCS(i));
                *cs++ = l3cc_combine(table, 2 * i, 2 * i + 1);
        }

        if (table->size & 0x01) {
                /* Odd table size - 1 left over */
                *cs++ = i915_mmio_reg_offset(GEN9_LNCFCMOCS(i));
                *cs++ = l3cc_combine(table, 2 * i, 0);
                i++;
        }

        /*
         * Now set the rest of the table to uncached - use entry 0 as
         * this will be uncached. Leave the last pair uninitialised as
         * they are reserved by the hardware.
         */
        for (; i < GEN9_NUM_MOCS_ENTRIES / 2; i++) {
                *cs++ = i915_mmio_reg_offset(GEN9_LNCFCMOCS(i));
                *cs++ = l3cc_combine(table, 0, 0);
        }

        *cs++ = MI_NOOP;
        intel_ring_advance(req, cs);

        return 0;
}

/**
 * intel_mocs_init_l3cc_table() - program the mocs control table
 * @dev_priv:      i915 device private
 *
 * This function simply programs the mocs registers for the given table
 * starting at the given address. This register set is  programmed in pairs.
 *
 * These registers may get programmed more than once, it is simpler to
 * re-program 32 registers than maintain the state of when they were programmed.
 * We are always reprogramming with the same values and this only on context
 * start.
 *
 * Return: Nothing.
 */
void intel_mocs_init_l3cc_table(struct drm_i915_private *dev_priv)
{
        struct drm_i915_mocs_table table;
        unsigned int i;

        if (!get_mocs_settings(dev_priv, &table))
                return;

        for (i = 0; i < table.size/2; i++)
                I915_WRITE(GEN9_LNCFCMOCS(i), l3cc_combine(&table, 2*i, 2*i+1));

        /* Odd table size - 1 left over */
        if (table.size & 0x01) {
                I915_WRITE(GEN9_LNCFCMOCS(i), l3cc_combine(&table, 2*i, 0));
                i++;
        }

        /*
         * Now set the rest of the table to uncached - use entry 0 as
         * this will be uncached. Leave the last pair as initialised as
         * they are reserved by the hardware.
         */
        for (; i < (GEN9_NUM_MOCS_ENTRIES / 2); i++)
                I915_WRITE(GEN9_LNCFCMOCS(i), l3cc_combine(&table, 0, 0));
}

/**
 * intel_rcs_context_init_mocs() - program the MOCS register.
 * @req:        Request to set up the MOCS tables for.
 *
 * This function will emit a batch buffer with the values required for
 * programming the MOCS register values for all the currently supported
 * rings.
 *
 * These registers are partially stored in the RCS context, so they are
 * emitted at the same time so that when a context is created these registers
 * are set up. These registers have to be emitted into the start of the
 * context as setting the ELSP will re-init some of these registers back
 * to the hw values.
 *
 * Return: 0 on success, otherwise the error status.
 */
int intel_rcs_context_init_mocs(struct drm_i915_gem_request *req)
{
        struct drm_i915_mocs_table t;
        int ret;

        if (get_mocs_settings(req->i915, &t)) {
                /* Program the RCS control registers */
                ret = emit_mocs_control_table(req, &t);
                if (ret)
                        return ret;

                /* Now program the l3cc registers */
                ret = emit_mocs_l3cc_table(req, &t);
                if (ret)
                        return ret;
        }

        return 0;
}