intel_mocs.c

// SPDX-License-Identifier: MIT
/*
 * Copyright © 2015 Intel Corporation
 */

#include "i915_drv.h"

#include "intel_engine.h"
#include "intel_gt.h"
#include "intel_lrc_reg.h"
#include "intel_mocs.h"
#include "intel_ring.h"

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

struct drm_i915_mocs_table {
	unsigned int size;
	unsigned int n_entries;
	const struct drm_i915_mocs_entry *table;
	u8 uc_index;
	u8 unused_entries_index;
};

/* 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)
#define LE_COS(value)		((value) << 15)
#define LE_SSE(value)		((value) << 17)

/* 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	64  /* 63-64 are reserved, but configured. */

/* (e)LLC caching options */
/*
 * Note: LE_0_PAGETABLE works only up to Gen11; for newer gens it means
 * the same as LE_UC
 */
#define LE_0_PAGETABLE		_LE_CACHEABILITY(0)
#define LE_1_UC			_LE_CACHEABILITY(1)
#define LE_2_WT			_LE_CACHEABILITY(2)
#define LE_3_WB			_LE_CACHEABILITY(3)

/* Target cache */
#define LE_TC_0_PAGETABLE	_LE_TGT_CACHE(0)
#define LE_TC_1_LLC		_LE_TGT_CACHE(1)
#define LE_TC_2_LLC_ELLC	_LE_TGT_CACHE(2)
#define LE_TC_3_LLC_ELLC_ALT	_LE_TGT_CACHE(3)

/* L3 caching options */
#define L3_0_DIRECT		_L3_CACHEABILITY(0)
#define L3_1_UC			_L3_CACHEABILITY(1)
#define L3_2_RESERVED		_L3_CACHEABILITY(2)
#define L3_3_WB			_L3_CACHEABILITY(3)

#define MOCS_ENTRY(__idx, __control_value, __l3cc_value) \
	[__idx] = { \
		.control_value = __control_value, \
		.l3cc_value = __l3cc_value, \
		.used = 1, \
	}

/*
 * 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
 * HW platforms, and for ICL+, be identical across OSes. To achieve
 * that, for Icelake and above, list of entries is published as part
 * of bspec.
 *
 * Entries not part of the following tables are undefined as far as
 * userspace is concerned and shouldn't be relied upon.  For Gen < 12
 * they will be initialized to PTE. Gen >= 12 don't have a setting for
 * PTE and those platforms except TGL/RKL will be initialized L3 WB to
 * catch accidental use of reserved and unused mocs indexes.
 *
 * The last few entries are reserved by the hardware. For ICL+ they
 * should be initialized according to bspec and never used, for older
 * platforms they should never be written to.
 *
 * NOTE1: These tables are part of bspec and defined as part of hardware
 *       interface for ICL+. For older platforms, they are part of kernel
 *       ABI. It is expected that, for specific hardware platform, existing
 *       entries will remain constant and the table will only be updated by
 *       adding new entries, filling unused positions.
 *
 * NOTE2: For GEN >= 12 except TGL and RKL, reserved and unspecified MOCS
 *       indices have been set to L3 WB. These reserved entries should never
 *       be used, they may be changed to low performant variants with better
 *       coherency in the future if more entries are needed.
 *       For TGL/RKL, all the unspecified MOCS indexes are mapped to L3 UC.
 */
#define GEN9_MOCS_ENTRIES \
	MOCS_ENTRY(I915_MOCS_UNCACHED, \
		   LE_1_UC | LE_TC_2_LLC_ELLC, \
		   L3_1_UC), \
	MOCS_ENTRY(I915_MOCS_PTE, \
		   LE_0_PAGETABLE | LE_TC_0_PAGETABLE | LE_LRUM(3), \
		   L3_3_WB)

static const struct drm_i915_mocs_entry skl_mocs_table[] = {
	GEN9_MOCS_ENTRIES,
	MOCS_ENTRY(I915_MOCS_CACHED,
		   LE_3_WB | LE_TC_2_LLC_ELLC | LE_LRUM(3),
		   L3_3_WB),

	/*
	 * mocs:63
	 * - used by the L3 for all of its evictions.
	 *   Thus it is expected to allow LLC cacheability to enable coherent
	 *   flows to be maintained.
	 * - used to force L3 uncachable cycles.
	 *   Thus it is expected to make the surface L3 uncacheable.
	 */
	MOCS_ENTRY(63,
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3),
		   L3_1_UC)
};

/* NOTE: the LE_TGT_CACHE is not used on Broxton */
static const struct drm_i915_mocs_entry broxton_mocs_table[] = {
	GEN9_MOCS_ENTRIES,
	MOCS_ENTRY(I915_MOCS_CACHED,
		   LE_1_UC | LE_TC_2_LLC_ELLC | LE_LRUM(3),
		   L3_3_WB)
};

#define GEN11_MOCS_ENTRIES \
	/* Entries 0 and 1 are defined per-platform */ \
	/* Base - L3 + LLC */ \
	MOCS_ENTRY(2, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3), \
		   L3_3_WB), \
	/* Base - Uncached */ \
	MOCS_ENTRY(3, \
		   LE_1_UC | LE_TC_1_LLC, \
		   L3_1_UC), \
	/* Base - L3 */ \
	MOCS_ENTRY(4, \
		   LE_1_UC | LE_TC_1_LLC, \
		   L3_3_WB), \
	/* Base - LLC */ \
	MOCS_ENTRY(5, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3), \
		   L3_1_UC), \
	/* Age 0 - LLC */ \
	MOCS_ENTRY(6, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(1), \
		   L3_1_UC), \
	/* Age 0 - L3 + LLC */ \
	MOCS_ENTRY(7, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(1), \
		   L3_3_WB), \
	/* Age: Don't Chg. - LLC */ \
	MOCS_ENTRY(8, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(2), \
		   L3_1_UC), \
	/* Age: Don't Chg. - L3 + LLC */ \
	MOCS_ENTRY(9, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(2), \
		   L3_3_WB), \
	/* No AOM - LLC */ \
	MOCS_ENTRY(10, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3) | LE_AOM(1), \
		   L3_1_UC), \
	/* No AOM - L3 + LLC */ \
	MOCS_ENTRY(11, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3) | LE_AOM(1), \
		   L3_3_WB), \
	/* No AOM; Age 0 - LLC */ \
	MOCS_ENTRY(12, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(1) | LE_AOM(1), \
		   L3_1_UC), \
	/* No AOM; Age 0 - L3 + LLC */ \
	MOCS_ENTRY(13, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(1) | LE_AOM(1), \
		   L3_3_WB), \
	/* No AOM; Age:DC - LLC */ \
	MOCS_ENTRY(14, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(2) | LE_AOM(1), \
		   L3_1_UC), \
	/* No AOM; Age:DC - L3 + LLC */ \
	MOCS_ENTRY(15, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(2) | LE_AOM(1), \
		   L3_3_WB), \
	/* Self-Snoop - L3 + LLC */ \
	MOCS_ENTRY(18, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3) | LE_SSE(3), \
		   L3_3_WB), \
	/* Skip Caching - L3 + LLC(12.5%) */ \
	MOCS_ENTRY(19, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3) | LE_SCC(7), \
		   L3_3_WB), \
	/* Skip Caching - L3 + LLC(25%) */ \
	MOCS_ENTRY(20, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3) | LE_SCC(3), \
		   L3_3_WB), \
	/* Skip Caching - L3 + LLC(50%) */ \
	MOCS_ENTRY(21, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3) | LE_SCC(1), \
		   L3_3_WB), \
	/* Skip Caching - L3 + LLC(75%) */ \
	MOCS_ENTRY(22, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3) | LE_RSC(1) | LE_SCC(3), \
		   L3_3_WB), \
	/* Skip Caching - L3 + LLC(87.5%) */ \
	MOCS_ENTRY(23, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3) | LE_RSC(1) | LE_SCC(7), \
		   L3_3_WB), \
	/* HW Reserved - SW program but never use */ \
	MOCS_ENTRY(62, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3), \
		   L3_1_UC), \
	/* HW Reserved - SW program but never use */ \
	MOCS_ENTRY(63, \
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3), \
		   L3_1_UC)

static const struct drm_i915_mocs_entry tgl_mocs_table[] = {
	/*
	 * NOTE:
	 * Reserved and unspecified MOCS indices have been set to (L3 + LCC).
	 * These reserved entries should never be used, they may be changed
	 * to low performant variants with better coherency in the future if
	 * more entries are needed. We are programming index I915_MOCS_PTE(1)
	 * only, __init_mocs_table() take care to program unused index with
	 * this entry.
	 */
	MOCS_ENTRY(I915_MOCS_PTE,
		   LE_0_PAGETABLE | LE_TC_0_PAGETABLE,
		   L3_1_UC),
	GEN11_MOCS_ENTRIES,

	/* Implicitly enable L1 - HDC:L1 + L3 + LLC */
	MOCS_ENTRY(48,
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3),
		   L3_3_WB),
	/* Implicitly enable L1 - HDC:L1 + L3 */
	MOCS_ENTRY(49,
		   LE_1_UC | LE_TC_1_LLC,
		   L3_3_WB),
	/* Implicitly enable L1 - HDC:L1 + LLC */
	MOCS_ENTRY(50,
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3),
		   L3_1_UC),
	/* Implicitly enable L1 - HDC:L1 */
	MOCS_ENTRY(51,
		   LE_1_UC | LE_TC_1_LLC,
		   L3_1_UC),
	/* HW Special Case (CCS) */
	MOCS_ENTRY(60,
		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3),
		   L3_1_UC),
	/* HW Special Case (Displayable) */
	MOCS_ENTRY(61,
		   LE_1_UC | LE_TC_1_LLC,
		   L3_3_WB),
};

static const struct drm_i915_mocs_entry icl_mocs_table[] = {
	/* Base - Uncached (Deprecated) */
	MOCS_ENTRY(I915_MOCS_UNCACHED,
		   LE_1_UC | LE_TC_1_LLC,
		   L3_1_UC),
	/* Base - L3 + LeCC:PAT (Deprecated) */
	MOCS_ENTRY(I915_MOCS_PTE,
		   LE_0_PAGETABLE | LE_TC_0_PAGETABLE,
		   L3_3_WB),

	GEN11_MOCS_ENTRIES
};

static const struct drm_i915_mocs_entry dg1_mocs_table[] = {

	/* UC */
	MOCS_ENTRY(1, 0, L3_1_UC),
	/* WB - L3 */
	MOCS_ENTRY(5, 0, L3_3_WB),
	/* WB - L3 50% */
	MOCS_ENTRY(6, 0, L3_ESC(1) | L3_SCC(1) | L3_3_WB),
	/* WB - L3 25% */
	MOCS_ENTRY(7, 0, L3_ESC(1) | L3_SCC(3) | L3_3_WB),
	/* WB - L3 12.5% */
	MOCS_ENTRY(8, 0, L3_ESC(1) | L3_SCC(7) | L3_3_WB),

	/* HDC:L1 + L3 */
	MOCS_ENTRY(48, 0, L3_3_WB),
	/* HDC:L1 */
	MOCS_ENTRY(49, 0, L3_1_UC),

	/* HW Reserved */
	MOCS_ENTRY(60, 0, L3_1_UC),
	MOCS_ENTRY(61, 0, L3_1_UC),
	MOCS_ENTRY(62, 0, L3_1_UC),
	MOCS_ENTRY(63, 0, L3_1_UC),
};

enum {
	HAS_GLOBAL_MOCS = BIT(0),
	HAS_ENGINE_MOCS = BIT(1),
	HAS_RENDER_L3CC = BIT(2),
};

static bool has_l3cc(const struct drm_i915_private *i915)
{
	return true;
}

static bool has_global_mocs(const struct drm_i915_private *i915)
{
	return HAS_GLOBAL_MOCS_REGISTERS(i915);
}

static bool has_mocs(const struct drm_i915_private *i915)
{
	return !IS_DGFX(i915);
}

static unsigned int get_mocs_settings(const struct drm_i915_private *i915,
				      struct drm_i915_mocs_table *table)
{
	unsigned int flags;

	memset(table, 0, sizeof(struct drm_i915_mocs_table));

	table->unused_entries_index = I915_MOCS_PTE;
	if (IS_DG1(i915)) {
		table->size = ARRAY_SIZE(dg1_mocs_table);
		table->table = dg1_mocs_table;
		table->uc_index = 1;
		table->n_entries = GEN9_NUM_MOCS_ENTRIES;
		table->uc_index = 1;
		table->unused_entries_index = 5;
	} else if (GRAPHICS_VER(i915) >= 12) {
		table->size  = ARRAY_SIZE(tgl_mocs_table);
		table->table = tgl_mocs_table;
		table->n_entries = GEN9_NUM_MOCS_ENTRIES;
		table->uc_index = 3;
		/* For TGL/RKL, Can't be changed now for ABI reasons */
		if (!IS_TIGERLAKE(i915) && !IS_ROCKETLAKE(i915))
			table->unused_entries_index = 2;
	} else if (GRAPHICS_VER(i915) == 11) {
		table->size  = ARRAY_SIZE(icl_mocs_table);
		table->table = icl_mocs_table;
		table->n_entries = GEN9_NUM_MOCS_ENTRIES;
	} else if (IS_GEN9_BC(i915)) {
		table->size  = ARRAY_SIZE(skl_mocs_table);
		table->n_entries = GEN9_NUM_MOCS_ENTRIES;
		table->table = skl_mocs_table;
	} else if (IS_GEN9_LP(i915)) {
		table->size  = ARRAY_SIZE(broxton_mocs_table);
		table->n_entries = GEN9_NUM_MOCS_ENTRIES;
		table->table = broxton_mocs_table;
	} else {
		drm_WARN_ONCE(&i915->drm, GRAPHICS_VER(i915) >= 9,
			      "Platform that should have a MOCS table does not.\n");
		return 0;
	}

	if (GEM_DEBUG_WARN_ON(table->size > table->n_entries))
		return 0;

	/* WaDisableSkipCaching:skl,bxt,kbl,glk */
	if (GRAPHICS_VER(i915) == 9) {
		int i;

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

	flags = 0;
	if (has_mocs(i915)) {
		if (has_global_mocs(i915))
			flags |= HAS_GLOBAL_MOCS;
		else
			flags |= HAS_ENGINE_MOCS;
	}
	if (has_l3cc(i915))
		flags |= HAS_RENDER_L3CC;

	return flags;
}

/*
 * Get control_value from MOCS entry taking into account when it's not used
 * then if unused_entries_index is non-zero then its value will be returned
 * otherwise I915_MOCS_PTE's value is returned in this case.
 */
static u32 get_entry_control(const struct drm_i915_mocs_table *table,
			     unsigned int index)
{
	if (index < table->size && table->table[index].used)
		return table->table[index].control_value;
	return table->table[table->unused_entries_index].control_value;
}

#define for_each_mocs(mocs, t, i) \
	for (i = 0; \
	     i < (t)->n_entries ? (mocs = get_entry_control((t), i)), 1 : 0;\
	     i++)

static void __init_mocs_table(struct intel_uncore *uncore,
			      const struct drm_i915_mocs_table *table,
			      u32 addr)
{
	unsigned int i;
	u32 mocs;

	drm_WARN_ONCE(&uncore->i915->drm, !table->unused_entries_index,
		      "Unused entries index should have been defined\n");
	for_each_mocs(mocs, table, i)
		intel_uncore_write_fw(uncore, _MMIO(addr + i * 4), mocs);
}

static u32 mocs_offset(const struct intel_engine_cs *engine)
{
	static const u32 offset[] = {
		[RCS0]  =  __GEN9_RCS0_MOCS0,
		[VCS0]  =  __GEN9_VCS0_MOCS0,
		[VCS1]  =  __GEN9_VCS1_MOCS0,
		[VECS0] =  __GEN9_VECS0_MOCS0,
		[BCS0]  =  __GEN9_BCS0_MOCS0,
		[VCS2]  = __GEN11_VCS2_MOCS0,
	};

	GEM_BUG_ON(engine->id >= ARRAY_SIZE(offset));
	return offset[engine->id];
}

static void init_mocs_table(struct intel_engine_cs *engine,
			    const struct drm_i915_mocs_table *table)
{
	__init_mocs_table(engine->uncore, table, mocs_offset(engine));
}

/*
 * Get l3cc_value from MOCS entry taking into account when it's not used
 * then if unused_entries_index is not zero then its value will be returned
 * otherwise I915_MOCS_PTE's value is returned in this case.
 */
static u16 get_entry_l3cc(const struct drm_i915_mocs_table *table,
			  unsigned int index)
{
	if (index < table->size && table->table[index].used)
		return table->table[index].l3cc_value;
	return table->table[table->unused_entries_index].l3cc_value;
}

static u32 l3cc_combine(u16 low, u16 high)
{
	return low | (u32)high << 16;
}

#define for_each_l3cc(l3cc, t, i) \
	for (i = 0; \
	     i < ((t)->n_entries + 1) / 2 ? \
	     (l3cc = l3cc_combine(get_entry_l3cc((t), 2 * i), \
				  get_entry_l3cc((t), 2 * i + 1))), 1 : \
	     0; \
	     i++)

static void init_l3cc_table(struct intel_engine_cs *engine,
			    const struct drm_i915_mocs_table *table)
{
	struct intel_uncore *uncore = engine->uncore;
	unsigned int i;
	u32 l3cc;

	for_each_l3cc(l3cc, table, i)
		intel_uncore_write_fw(uncore, GEN9_LNCFCMOCS(i), l3cc);
}

void intel_mocs_init_engine(struct intel_engine_cs *engine)
{
	struct drm_i915_mocs_table table;
	unsigned int flags;

	/* Called under a blanket forcewake */
	assert_forcewakes_active(engine->uncore, FORCEWAKE_ALL);

	flags = get_mocs_settings(engine->i915, &table);
	if (!flags)
		return;

	/* Platforms with global MOCS do not need per-engine initialization. */
	if (flags & HAS_ENGINE_MOCS)
		init_mocs_table(engine, &table);

	if (flags & HAS_RENDER_L3CC && engine->class == RENDER_CLASS)
		init_l3cc_table(engine, &table);
}

static u32 global_mocs_offset(void)
{
	return i915_mmio_reg_offset(GEN12_GLOBAL_MOCS(0));
}

void set_mocs_index(struct intel_gt *gt)
{
	struct drm_i915_mocs_table table;

	get_mocs_settings(gt->i915, &table);
	gt->mocs.uc_index = table.uc_index;
}

void intel_mocs_init(struct intel_gt *gt)
{
	struct drm_i915_mocs_table table;
	unsigned int flags;

	/*
	 * LLC and eDRAM control values are not applicable to dgfx
	 */
	flags = get_mocs_settings(gt->i915, &table);
	if (flags & HAS_GLOBAL_MOCS)
		__init_mocs_table(gt->uncore, &table, global_mocs_offset());
}

#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
#include "selftest_mocs.c"
#endif