xe_lmtt.c | Explore in Territory

// SPDX-License-Identifier: MIT
/*
 * Copyright © 2023 Intel Corporation
 */

#include <linux/align.h>

#include <drm/drm_managed.h>

#include "regs/xe_gt_regs.h"

#include "xe_assert.h"
#include "xe_bo.h"
#include "xe_lmtt.h"
#include "xe_map.h"
#include "xe_mmio.h"
#include "xe_res_cursor.h"
#include "xe_sriov.h"
#include "xe_sriov_printk.h"

/**
 * DOC: Local Memory Translation Table
 *
 * The Local Memory Translation Table (LMTT) provides additional abstraction
 * when Virtual Function (VF) is accessing device Local Memory (VRAM).
 *
 * The Root LMTT Page Directory contains one entry for each VF. Entries are
 * indexed by the function number (1-based, index 0 is unused).
 *
 * See `Two-Level LMTT Structure`_ and `Multi-Level LMTT Structure`_.
 */

#define lmtt_assert(lmtt, condition) …
#define lmtt_debug(lmtt, msg...) …

static bool xe_has_multi_level_lmtt(struct xe_device *xe)
{ … }

static struct xe_tile *lmtt_to_tile(struct xe_lmtt *lmtt)
{ … }

static struct xe_device *lmtt_to_xe(struct xe_lmtt *lmtt)
{ … }

static u64 lmtt_page_size(struct xe_lmtt *lmtt)
{ … }

static struct xe_lmtt_pt *lmtt_pt_alloc(struct xe_lmtt *lmtt, unsigned int level)
{ … }

static void lmtt_pt_free(struct xe_lmtt_pt *pt)
{ … }

static int lmtt_init_pd(struct xe_lmtt *lmtt)
{ … }

static void lmtt_fini_pd(struct xe_lmtt *lmtt)
{ … }

static void fini_lmtt(struct drm_device *drm, void *arg)
{ … }

/**
 * xe_lmtt_init - LMTT software initialization.
 * @lmtt: the &xe_lmtt to initialize
 *
 * The LMTT initialization requires two steps.
 *
 * The xe_lmtt_init() checks if LMTT is required on current device and selects
 * and initialize proper variant of the LMTT Root Directory. Currently supported
 * variants are `Two-Level LMTT Structure`_ and `Multi-Level LMTT Structure`_.
 *
 * In next step xe_lmtt_init_hw() will register this directory on the hardware.
 *
 * Notes:
 * The LMTT allocations are managed and will be implicitly released on driver unload.
 * This function shall be called only once and only when running as a PF driver.
 * Any LMTT initialization failure should block VFs enabling.
 *
 * Return: 0 on success or a negative error code on failure.
 */
int xe_lmtt_init(struct xe_lmtt *lmtt)
{ … }

static void lmtt_setup_dir_ptr(struct xe_lmtt *lmtt)
{ … }

/**
 * xe_lmtt_init_hw - Perform LMTT hardware initialization.
 * @lmtt: the &xe_lmtt to initialize
 *
 * This function is a second step of the LMTT initialization.
 * This function registers LMTT Root Directory prepared in xe_lmtt_init().
 *
 * This function shall be called after every hardware reset.
 * This function shall be called only when running as a PF driver.
 */
void xe_lmtt_init_hw(struct xe_lmtt *lmtt)
{ … }

static void lmtt_write_pte(struct xe_lmtt *lmtt, struct xe_lmtt_pt *pt,
			   u64 pte, unsigned int idx)
{ … }

static void lmtt_destroy_pt(struct xe_lmtt *lmtt, struct xe_lmtt_pt *pd)
{ … }

static void lmtt_drop_pages(struct xe_lmtt *lmtt, unsigned int vfid)
{ … }

static int __lmtt_alloc_range(struct xe_lmtt *lmtt, struct xe_lmtt_pt *pd,
			      u64 start, u64 end)
{ … }

static int lmtt_alloc_range(struct xe_lmtt *lmtt, unsigned int vfid, u64 start, u64 end)
{ … }

static struct xe_lmtt_pt *lmtt_leaf_pt(struct xe_lmtt *lmtt, unsigned int vfid, u64 addr)
{ … }

static void lmtt_insert_bo(struct xe_lmtt *lmtt, unsigned int vfid, struct xe_bo *bo, u64 start)
{ … }

/**
 * xe_lmtt_prepare_pages - Create VF's LMTT Page Tables.
 * @lmtt: the &xe_lmtt to update
 * @vfid: the VF identifier (1-based)
 * @range: top range of LMEM offset to be supported
 *
 * This function creates empty LMTT page tables for given VF to support
 * up to maximum #range LMEM offset. The LMTT page tables created by this
 * function must be released using xe_lmtt_drop_pages() function.
 *
 * Notes:
 * This function shall be called only after successful LMTT initialization.
 * See xe_lmtt_init().
 *
 * Return: 0 on success or a negative error code on failure.
 */
int xe_lmtt_prepare_pages(struct xe_lmtt *lmtt, unsigned int vfid, u64 range)
{ … }

/**
 * xe_lmtt_populate_pages - Update VF's LMTT Page Table Entries.
 * @lmtt: the &xe_lmtt to update
 * @vfid: the VF identifier (1-based)
 * @bo: the buffer object with LMEM allocation to be mapped
 * @offset: the offset at which #bo should be mapped
 *
 * This function updates VF's LMTT entries to use given buffer object as a backstore.
 *
 * Notes:
 * This function shall be called only after successful preparation of the
 * VF's LMTT Page Tables. See xe_lmtt_prepare().
 *
 * Return: 0 on success or a negative error code on failure.
 */
int xe_lmtt_populate_pages(struct xe_lmtt *lmtt, unsigned int vfid, struct xe_bo *bo, u64 offset)
{ … }

/**
 * xe_lmtt_drop_pages - Remove VF's LMTT Pages.
 * @lmtt: the &xe_lmtt to update
 * @vfid: the VF identifier (1-based)
 *
 * This function removes all LMTT Page Tables prepared by xe_lmtt_prepare_pages().
 *
 * This function shall be called only after successful LMTT initialization.
 * See xe_lmtt_init().
 */
void xe_lmtt_drop_pages(struct xe_lmtt *lmtt, unsigned int vfid)
{ … }

/**
 * xe_lmtt_estimate_pt_size - Estimate size of LMTT PT allocations.
 * @lmtt: the &xe_lmtt
 * @size: the size of the LMEM to be mapped over LMTT (including any offset)
 *
 * This function shall be called only by PF.
 *
 * Return: size of the PT allocation(s) needed to support given LMEM size.
 */
u64 xe_lmtt_estimate_pt_size(struct xe_lmtt *lmtt, u64 size)
{ … }

#if IS_BUILTIN(CONFIG_DRM_XE_KUNIT_TEST)
#include "tests/xe_lmtt_test.c"
#endif
linux/drivers/gpu/drm/xe/xe_lmtt.c
