mmu_v1.c

// SPDX-License-Identifier: GPL-2.0

/*
 * Copyright 2016-2019 HabanaLabs, Ltd.
 * All Rights Reserved.
 */

#include "../habanalabs.h"
#include "../../include/hw_ip/mmu/mmu_general.h"

#include <linux/slab.h>

#define MMU_V1_MAX_HOPS	(MMU_HOP4 + 1)

static inline u64 get_hop_pte_addr(struct hl_ctx *ctx, struct hl_mmu_properties *mmu_prop,
					u64 *hop_addr_arr, u64 virt_addr, enum mmu_hop_num hop_idx)
{
	u64 mask, shift;

	mask = mmu_prop->hop_masks[hop_idx];
	shift = mmu_prop->hop_shifts[hop_idx];
	return hop_addr_arr[hop_idx] +
			ctx->hdev->asic_prop.mmu_pte_size * ((virt_addr & mask) >> shift);
}

static int dram_default_mapping_init(struct hl_ctx *ctx)
{
	struct hl_device *hdev = ctx->hdev;
	struct asic_fixed_properties *prop = &hdev->asic_prop;
	u64 num_of_hop3, total_hops, hop0_addr, hop1_addr, hop2_addr,
		hop2_pte_addr, hop3_pte_addr, pte_val;
	int rc, i, j, hop3_allocated = 0;

	if ((!prop->dram_supports_virtual_memory) ||
			(!hdev->dram_default_page_mapping) ||
			(ctx->asid == HL_KERNEL_ASID_ID))
		return 0;

	num_of_hop3 = prop->dram_size_for_default_page_mapping;
	do_div(num_of_hop3, prop->dram_page_size);
	do_div(num_of_hop3, HOP_PTE_ENTRIES_512);

	/* add hop1 and hop2 */
	total_hops = num_of_hop3 + 2;

	ctx->dram_default_hops = kcalloc(total_hops, HL_PTE_SIZE,  GFP_KERNEL);
	if (!ctx->dram_default_hops)
		return -ENOMEM;

	hop0_addr = hl_mmu_dr_get_hop0_addr(ctx);

	hop1_addr = hl_mmu_dr_alloc_hop(ctx);
	if (hop1_addr == ULLONG_MAX) {
		dev_err(hdev->dev, "failed to alloc hop 1\n");
		rc = -ENOMEM;
		goto hop1_err;
	}

	ctx->dram_default_hops[total_hops - 1] = hop1_addr;

	hop2_addr = hl_mmu_dr_alloc_hop(ctx);
	if (hop2_addr == ULLONG_MAX) {
		dev_err(hdev->dev, "failed to alloc hop 2\n");
		rc = -ENOMEM;
		goto hop2_err;
	}

	ctx->dram_default_hops[total_hops - 2] = hop2_addr;

	for (i = 0 ; i < num_of_hop3 ; i++) {
		ctx->dram_default_hops[i] = hl_mmu_dr_alloc_hop(ctx);
		if (ctx->dram_default_hops[i] == ULLONG_MAX) {
			dev_err(hdev->dev, "failed to alloc hop 3, i: %d\n", i);
			rc = -ENOMEM;
			goto hop3_err;
		}
		hop3_allocated++;
	}

	/* need only pte 0 in hops 0 and 1 */
	pte_val = (hop1_addr & HOP_PHYS_ADDR_MASK) | PAGE_PRESENT_MASK;
	hl_mmu_dr_write_pte(ctx, hop0_addr, pte_val);

	pte_val = (hop2_addr & HOP_PHYS_ADDR_MASK) | PAGE_PRESENT_MASK;
	hl_mmu_dr_write_pte(ctx, hop1_addr, pte_val);
	hl_mmu_dr_get_pte(ctx, hop1_addr);

	hop2_pte_addr = hop2_addr;
	for (i = 0 ; i < num_of_hop3 ; i++) {
		pte_val = (ctx->dram_default_hops[i] & HOP_PHYS_ADDR_MASK) |
				PAGE_PRESENT_MASK;
		hl_mmu_dr_write_pte(ctx, hop2_pte_addr, pte_val);
		hl_mmu_dr_get_pte(ctx, hop2_addr);
		hop2_pte_addr += HL_PTE_SIZE;
	}

	pte_val = (prop->mmu_dram_default_page_addr & HOP_PHYS_ADDR_MASK) |
			LAST_MASK | PAGE_PRESENT_MASK;

	for (i = 0 ; i < num_of_hop3 ; i++) {
		hop3_pte_addr = ctx->dram_default_hops[i];
		for (j = 0 ; j < HOP_PTE_ENTRIES_512 ; j++) {
			hl_mmu_dr_write_final_pte(ctx, hop3_pte_addr, pte_val);
			hl_mmu_dr_get_pte(ctx, ctx->dram_default_hops[i]);
			hop3_pte_addr += HL_PTE_SIZE;
		}
	}

	hl_mmu_dr_flush(ctx);

	return 0;

hop3_err:
	for (i = 0 ; i < hop3_allocated ; i++)
		hl_mmu_dr_free_hop(ctx, ctx->dram_default_hops[i]);

	hl_mmu_dr_free_hop(ctx, hop2_addr);
hop2_err:
	hl_mmu_dr_free_hop(ctx, hop1_addr);
hop1_err:
	kfree(ctx->dram_default_hops);

	return rc;
}

static void dram_default_mapping_fini(struct hl_ctx *ctx)
{
	struct hl_device *hdev = ctx->hdev;
	struct asic_fixed_properties *prop = &hdev->asic_prop;
	u64 num_of_hop3, total_hops, hop0_addr, hop1_addr, hop2_addr,
		hop2_pte_addr, hop3_pte_addr;
	int i, j;

	if ((!prop->dram_supports_virtual_memory) ||
			(!hdev->dram_default_page_mapping) ||
			(ctx->asid == HL_KERNEL_ASID_ID))
		return;

	num_of_hop3 = prop->dram_size_for_default_page_mapping;
	do_div(num_of_hop3, prop->dram_page_size);
	do_div(num_of_hop3, HOP_PTE_ENTRIES_512);

	hop0_addr = hl_mmu_dr_get_hop0_addr(ctx);
	/* add hop1 and hop2 */
	total_hops = num_of_hop3 + 2;
	hop1_addr = ctx->dram_default_hops[total_hops - 1];
	hop2_addr = ctx->dram_default_hops[total_hops - 2];

	for (i = 0 ; i < num_of_hop3 ; i++) {
		hop3_pte_addr = ctx->dram_default_hops[i];
		for (j = 0 ; j < HOP_PTE_ENTRIES_512 ; j++) {
			hl_mmu_dr_clear_pte(ctx, hop3_pte_addr);
			hl_mmu_dr_put_pte(ctx, ctx->dram_default_hops[i]);
			hop3_pte_addr += HL_PTE_SIZE;
		}
	}

	hop2_pte_addr = hop2_addr;
	for (i = 0 ; i < num_of_hop3 ; i++) {
		hl_mmu_dr_clear_pte(ctx, hop2_pte_addr);
		hl_mmu_dr_put_pte(ctx, hop2_addr);
		hop2_pte_addr += HL_PTE_SIZE;
	}

	hl_mmu_dr_clear_pte(ctx, hop1_addr);
	hl_mmu_dr_put_pte(ctx, hop1_addr);
	hl_mmu_dr_clear_pte(ctx, hop0_addr);

	kfree(ctx->dram_default_hops);

	hl_mmu_dr_flush(ctx);
}

/**
 * hl_mmu_v1_ctx_init() - initialize a context for using the MMU module.
 * @ctx: pointer to the context structure to initialize.
 *
 * Initialize a mutex to protect the concurrent mapping flow, a hash to hold all
 * page tables hops related to this context.
 * Return: 0 on success, non-zero otherwise.
 */
static int hl_mmu_v1_ctx_init(struct hl_ctx *ctx)
{
	hash_init(ctx->mmu_shadow_hash);
	return dram_default_mapping_init(ctx);
}

/*
 * hl_mmu_ctx_fini - disable a ctx from using the mmu module
 *
 * @ctx: pointer to the context structure
 *
 * This function does the following:
 * - Free any pgts which were not freed yet
 * - Free the mutex
 * - Free DRAM default page mapping hops
 */
static void hl_mmu_v1_ctx_fini(struct hl_ctx *ctx)
{
	struct hl_device *hdev = ctx->hdev;
	struct pgt_info *pgt_info;
	struct hlist_node *tmp;
	int i;

	dram_default_mapping_fini(ctx);

	if (!hash_empty(ctx->mmu_shadow_hash))
		dev_err(hdev->dev, "ctx %d is freed while it has pgts in use\n",
			ctx->asid);

	hash_for_each_safe(ctx->mmu_shadow_hash, i, tmp, pgt_info, node) {
		dev_err_ratelimited(hdev->dev,
			"pgt_info of addr 0x%llx of asid %d was not destroyed, num_ptes: %d\n",
			pgt_info->phys_addr, ctx->asid, pgt_info->num_of_ptes);
		hl_mmu_dr_free_pgt_node(ctx, pgt_info);
	}
}

static int hl_mmu_v1_unmap(struct hl_ctx *ctx,
				u64 virt_addr, bool is_dram_addr)
{
	u64 hop_addr[MMU_V1_MAX_HOPS] = {0}, hop_pte_addr[MMU_V1_MAX_HOPS] = {0}, curr_pte = 0;
	struct hl_device *hdev = ctx->hdev;
	struct asic_fixed_properties *prop = &hdev->asic_prop;
	struct hl_mmu_properties *mmu_prop;
	bool is_huge, clear_hop3 = true;
	int hop_idx;

	/* shifts and masks are the same in PMMU and HPMMU, use one of them */
	mmu_prop = is_dram_addr ? &prop->dmmu : &prop->pmmu;

	for (hop_idx = MMU_HOP0; hop_idx < MMU_HOP4; hop_idx++) {
		if (hop_idx == MMU_HOP0) {
			hop_addr[hop_idx] = hl_mmu_dr_get_hop0_addr(ctx);
		} else {
			hop_addr[hop_idx] = hl_mmu_get_next_hop_addr(ctx, curr_pte);
			if (hop_addr[hop_idx] == ULLONG_MAX)
				goto not_mapped;
		}

		hop_pte_addr[hop_idx] =
				get_hop_pte_addr(ctx, mmu_prop, hop_addr, virt_addr, hop_idx);

		curr_pte = *(u64 *) (uintptr_t) hop_pte_addr[hop_idx];
	}

	is_huge = curr_pte & mmu_prop->last_mask;

	if (is_dram_addr && !is_huge) {
		dev_err(hdev->dev, "DRAM unmapping should use huge pages only\n");
		return -EFAULT;
	}

	if (!is_huge) {
		hop_idx = MMU_HOP4;
		hop_addr[hop_idx] = hl_mmu_get_next_hop_addr(ctx, curr_pte);
		if (hop_addr[hop_idx] == ULLONG_MAX)
			goto not_mapped;

		hop_pte_addr[hop_idx] =
				get_hop_pte_addr(ctx, mmu_prop, hop_addr, virt_addr, hop_idx);
		curr_pte = *(u64 *) (uintptr_t) hop_pte_addr[hop_idx];
		clear_hop3 = false;
	}

	if (hdev->dram_default_page_mapping && is_dram_addr) {
		u64 default_pte = (prop->mmu_dram_default_page_addr &
				HOP_PHYS_ADDR_MASK) | mmu_prop->last_mask |
					PAGE_PRESENT_MASK;
		if (curr_pte == default_pte) {
			dev_err(hdev->dev,
				"DRAM: hop3 PTE points to zero page, can't unmap, va: 0x%llx\n",
					virt_addr);
			goto not_mapped;
		}

		if (!(curr_pte & PAGE_PRESENT_MASK)) {
			dev_err(hdev->dev,
				"DRAM: hop3 PTE is cleared! can't unmap, va: 0x%llx\n",
					virt_addr);
			goto not_mapped;
		}

		hop_idx = MMU_HOP3;
		hl_mmu_dr_write_final_pte(ctx, hop_pte_addr[hop_idx], default_pte);
		hl_mmu_dr_put_pte(ctx, hop_addr[hop_idx]);
	} else {
		if (!(curr_pte & PAGE_PRESENT_MASK))
			goto not_mapped;

		if (hop_addr[MMU_HOP4])
			hl_mmu_dr_clear_pte(ctx, hop_pte_addr[MMU_HOP4]);
		else
			hl_mmu_dr_clear_pte(ctx, hop_pte_addr[MMU_HOP3]);

		if (hop_addr[MMU_HOP4] && !hl_mmu_dr_put_pte(ctx, hop_addr[MMU_HOP4]))
			clear_hop3 = true;

		if (!clear_hop3)
			goto mapped;

		for (hop_idx = MMU_HOP3; hop_idx >= 0; hop_idx--) {
			hl_mmu_dr_clear_pte(ctx, hop_pte_addr[hop_idx]);

			if (hop_idx == MMU_HOP0)
				break;

			if (hl_mmu_dr_put_pte(ctx, hop_addr[hop_idx]))
				goto mapped;
		}
	}

mapped:
	return 0;

not_mapped:
	dev_err(hdev->dev, "virt addr 0x%llx is not mapped to phys addr\n",
		virt_addr);

	return -EINVAL;
}

static int hl_mmu_v1_map(struct hl_ctx *ctx, u64 virt_addr, u64 phys_addr,
			u32 page_size, bool is_dram_addr)
{
	u64 hop_addr[MMU_V1_MAX_HOPS] = {0}, hop_pte_addr[MMU_V1_MAX_HOPS] = {0}, curr_pte = 0;
	struct hl_device *hdev = ctx->hdev;
	struct asic_fixed_properties *prop = &hdev->asic_prop;
	struct hl_mmu_properties *mmu_prop;
	bool is_huge, hop_new[MMU_V1_MAX_HOPS] = {false};
	int num_hops, hop_idx, prev_hop, rc = -ENOMEM;

	/*
	 * This mapping function can map a page or a huge page. For huge page
	 * there are only 3 hops rather than 4. Currently the DRAM allocation
	 * uses huge pages only but user memory could have been allocated with
	 * one of the two page sizes. Since this is a common code for all the
	 * three cases, we need this hugs page check.
	 */
	if (is_dram_addr) {
		mmu_prop = &prop->dmmu;
		is_huge = true;
	} else if (page_size == prop->pmmu_huge.page_size) {
		mmu_prop = &prop->pmmu_huge;
		is_huge = true;
	} else {
		mmu_prop = &prop->pmmu;
		is_huge = false;
	}

	num_hops = is_huge ? (MMU_V1_MAX_HOPS - 1) : MMU_V1_MAX_HOPS;

	for (hop_idx = MMU_HOP0; hop_idx < num_hops; hop_idx++) {
		if (hop_idx == MMU_HOP0) {
			hop_addr[hop_idx] = hl_mmu_dr_get_hop0_addr(ctx);
		} else {
			hop_addr[hop_idx] =
				hl_mmu_dr_get_alloc_next_hop_addr(ctx, curr_pte, &hop_new[hop_idx]);
			if (hop_addr[hop_idx] == ULLONG_MAX)
				goto err;
		}

		hop_pte_addr[hop_idx] =
				get_hop_pte_addr(ctx, mmu_prop, hop_addr, virt_addr, hop_idx);
		curr_pte = *(u64 *) (uintptr_t) hop_pte_addr[hop_idx];
	}

	if (hdev->dram_default_page_mapping && is_dram_addr) {
		u64 default_pte = (prop->mmu_dram_default_page_addr &
					HOP_PHYS_ADDR_MASK) | mmu_prop->last_mask |
						PAGE_PRESENT_MASK;

		if (curr_pte != default_pte) {
			dev_err(hdev->dev,
				"DRAM: mapping already exists for virt_addr 0x%llx\n",
					virt_addr);
			rc = -EINVAL;
			goto err;
		}

		for (hop_idx = MMU_HOP1; hop_idx < num_hops; hop_idx++) {
			if (hop_new[hop_idx]) {
				dev_err(hdev->dev, "DRAM mapping should not allocate more hops\n");
				rc = -EFAULT;
				goto err;
			}
		}
	} else if (curr_pte & PAGE_PRESENT_MASK) {
		dev_err(hdev->dev,
			"mapping already exists for virt_addr 0x%llx\n",
				virt_addr);

		for (hop_idx = MMU_HOP0; hop_idx < num_hops; hop_idx++)
			dev_dbg(hdev->dev, "hop%d pte: 0x%llx (0x%llx)\n", hop_idx,
					*(u64 *) (uintptr_t) hop_pte_addr[hop_idx],
					hop_pte_addr[hop_idx]);

		rc = -EINVAL;
		goto err;
	}

	curr_pte = (phys_addr & HOP_PHYS_ADDR_MASK) | mmu_prop->last_mask
			| PAGE_PRESENT_MASK;

	hl_mmu_dr_write_final_pte(ctx, hop_pte_addr[num_hops - 1], curr_pte);

	for (hop_idx = MMU_HOP1; hop_idx < num_hops; hop_idx++) {
		prev_hop = hop_idx - 1;

		if (hop_new[hop_idx]) {
			curr_pte = (hop_addr[hop_idx] & HOP_PHYS_ADDR_MASK) | PAGE_PRESENT_MASK;
			hl_mmu_dr_write_pte(ctx, hop_pte_addr[prev_hop], curr_pte);
			if (hop_idx != MMU_HOP1)
				hl_mmu_dr_get_pte(ctx, hop_addr[prev_hop]);
		}
	}

	hl_mmu_dr_get_pte(ctx, hop_addr[num_hops - 1]);

	return 0;

err:
	for (hop_idx = num_hops; hop_idx > MMU_HOP0; hop_idx--) {
		if (hop_new[hop_idx])
			hl_mmu_dr_free_hop(ctx, hop_addr[hop_idx]);
	}

	return rc;
}

/*
 * hl_mmu_v1_swap_out - marks all mapping of the given ctx as swapped out
 *
 * @ctx: pointer to the context structure
 *
 */
static void hl_mmu_v1_swap_out(struct hl_ctx *ctx)
{

}

/*
 * hl_mmu_v1_swap_in - marks all mapping of the given ctx as swapped in
 *
 * @ctx: pointer to the context structure
 *
 */
static void hl_mmu_v1_swap_in(struct hl_ctx *ctx)
{

}

static int hl_mmu_v1_get_tlb_info(struct hl_ctx *ctx, u64 virt_addr,
				struct hl_mmu_hop_info *hops)
{
	struct hl_device *hdev = ctx->hdev;
	struct asic_fixed_properties *prop = &hdev->asic_prop;
	struct hl_mmu_properties *mmu_prop;
	bool is_dram_addr, is_pmmu_addr, is_pmmu_h_addr, is_huge;
	int i, used_hops;

	is_dram_addr = hl_mem_area_inside_range(virt_addr, prop->dmmu.page_size,
						prop->dmmu.start_addr,
						prop->dmmu.end_addr);
	is_pmmu_addr = hl_mem_area_inside_range(virt_addr, prop->pmmu.page_size,
						prop->pmmu.start_addr,
						prop->pmmu.end_addr);
	is_pmmu_h_addr = hl_mem_area_inside_range(virt_addr,
						prop->pmmu_huge.page_size,
						prop->pmmu_huge.start_addr,
						prop->pmmu_huge.end_addr);
	if (is_dram_addr) {
		mmu_prop = &prop->dmmu;
		is_huge = true;
	} else if (is_pmmu_addr) {
		mmu_prop = &prop->pmmu;
		is_huge = false;
	} else if (is_pmmu_h_addr) {
		mmu_prop = &prop->pmmu_huge;
		is_huge = true;
	} else {
		return -EINVAL;
	}

	used_hops = mmu_prop->num_hops;

	/* huge pages use lesser hops */
	if (is_huge)
		used_hops--;

	hops->hop_info[0].hop_addr = hl_mmu_dr_get_phys_hop0_addr(ctx);
	hops->hop_info[0].hop_pte_addr =
			hl_mmu_get_hop_pte_phys_addr(ctx, mmu_prop, 0,
					hops->hop_info[0].hop_addr, virt_addr);
	hops->hop_info[0].hop_pte_val =
			hdev->asic_funcs->read_pte(hdev,
						hops->hop_info[0].hop_pte_addr);

	for (i = 1 ; i < used_hops ; i++) {
		hops->hop_info[i].hop_addr =
			hl_mmu_get_next_hop_addr(ctx,
					hops->hop_info[i - 1].hop_pte_val);
		if (hops->hop_info[i].hop_addr == ULLONG_MAX)
			return -EFAULT;

		hops->hop_info[i].hop_pte_addr =
				hl_mmu_get_hop_pte_phys_addr(ctx, mmu_prop, i,
						hops->hop_info[i].hop_addr,
						virt_addr);
		hops->hop_info[i].hop_pte_val =
				hdev->asic_funcs->read_pte(hdev,
						hops->hop_info[i].hop_pte_addr);

		if (!(hops->hop_info[i].hop_pte_val & PAGE_PRESENT_MASK))
			return -EFAULT;

		if (hops->hop_info[i].hop_pte_val & mmu_prop->last_mask)
			break;
	}

	/* if passed over all hops then no last hop was found */
	if (i == mmu_prop->num_hops)
		return -EFAULT;

	if (!(hops->hop_info[i].hop_pte_val & PAGE_PRESENT_MASK))
		return -EFAULT;

	hops->used_hops = i + 1;

	return 0;
}

/*
 * hl_mmu_v1_prepare - prepare mmu  for working with mmu v1
 *
 * @hdev: pointer to the device structure
 */
void hl_mmu_v1_set_funcs(struct hl_device *hdev, struct hl_mmu_funcs *mmu)
{
	mmu->init = hl_mmu_dr_init;
	mmu->fini = hl_mmu_dr_fini;
	mmu->ctx_init = hl_mmu_v1_ctx_init;
	mmu->ctx_fini = hl_mmu_v1_ctx_fini;
	mmu->map = hl_mmu_v1_map;
	mmu->unmap = hl_mmu_v1_unmap;
	mmu->flush = hl_mmu_dr_flush;
	mmu->swap_out = hl_mmu_v1_swap_out;
	mmu->swap_in = hl_mmu_v1_swap_in;
	mmu->get_tlb_info = hl_mmu_v1_get_tlb_info;
}