habanalabs: add virtual memory and MMU modules

This patch adds the Virtual Memory and MMU modules.

Goya has an internal MMU which provides process isolation on the internal
DDR. The internal MMU also performs translations for transactions that go
from Goya to the Host.

The driver is responsible for allocating and freeing memory on the DDR
upon user request. It also provides an interface to map and unmap DDR and
Host memory to the device address space.

The MMU in Goya supports 3-level and 4-level page tables. With 3-level, the
size of each page is 2MB, while with 4-level the size of each page is 4KB.

In the DDR, the physical pages are always 2MB.

Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Omer Shpigelman <oshpigelman@habana.ai>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 691 insertions, 0 deletions

diff --git a/drivers/misc/habanalabs/mmu.c b/drivers/misc/habanalabs/mmu.c
new file mode 100644
index 000000000000..79c70d92e74b
--- /dev/null
+++ b/drivers/misc/habanalabs/mmu.c
@@ -0,0 +1,691 @@
+// 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/genalloc.h>
+#include <linux/slab.h>
+
+static struct pgt_info *get_pgt_info(struct hl_ctx *ctx, u64 addr)
+{
+	struct pgt_info *pgt_info = NULL;
+
+	hash_for_each_possible(ctx->mmu_hash, pgt_info, node,
+				(unsigned long) addr)
+		if (addr == pgt_info->addr)
+			break;
+
+	return pgt_info;
+}
+
+static void free_hop(struct hl_ctx *ctx, u64 hop_addr)
+{
+	struct pgt_info *pgt_info = get_pgt_info(ctx, hop_addr);
+
+	gen_pool_free(pgt_info->ctx->hdev->mmu_pgt_pool, pgt_info->addr,
+			ctx->hdev->asic_prop.mmu_hop_table_size);
+	hash_del(&pgt_info->node);
+
+	kfree(pgt_info);
+}
+
+static u64 alloc_hop(struct hl_ctx *ctx)
+{
+	struct hl_device *hdev = ctx->hdev;
+	struct pgt_info *pgt_info;
+	u64 addr;
+
+	pgt_info = kmalloc(sizeof(*pgt_info), GFP_KERNEL);
+	if (!pgt_info)
+		return ULLONG_MAX;
+
+	addr = (u64) gen_pool_alloc(hdev->mmu_pgt_pool,
+			hdev->asic_prop.mmu_hop_table_size);
+	if (!addr) {
+		dev_err(hdev->dev, "failed to allocate page\n");
+		kfree(pgt_info);
+		return ULLONG_MAX;
+	}
+
+	pgt_info->addr = addr;
+	pgt_info->ctx = ctx;
+	pgt_info->num_of_ptes = 0;
+	hash_add(ctx->mmu_hash, &pgt_info->node, addr);
+
+	return addr;
+}
+
+static inline void clear_pte(struct hl_device *hdev, u64 pte_addr)
+{
+	/* clear the last and present bits */
+	hdev->asic_funcs->write_pte(hdev, pte_addr, 0);
+}
+
+static inline void get_pte(struct hl_ctx *ctx, u64 hop_addr)
+{
+	get_pgt_info(ctx, hop_addr)->num_of_ptes++;
+}
+
+/*
+ * put_pte - decrement the num of ptes and free the hop if possible
+ *
+ * @ctx: pointer to the context structure
+ * @hop_addr: addr of the hop
+ *
+ * This function returns the number of ptes left on this hop. If the number is
+ * 0, it means the pte was freed.
+ */
+static inline int put_pte(struct hl_ctx *ctx, u64 hop_addr)
+{
+	struct pgt_info *pgt_info = get_pgt_info(ctx, hop_addr);
+	int num_of_ptes_left;
+
+	pgt_info->num_of_ptes--;
+
+	/*
+	 * Need to save the number of ptes left because free_hop might free
+	 * the pgt_info
+	 */
+	num_of_ptes_left = pgt_info->num_of_ptes;
+	if (!num_of_ptes_left)
+		free_hop(ctx, hop_addr);
+
+	return num_of_ptes_left;
+}
+
+static inline u64 get_hop0_addr(struct hl_ctx *ctx)
+{
+	return ctx->hdev->asic_prop.mmu_pgt_addr +
+			(ctx->asid * ctx->hdev->asic_prop.mmu_hop_table_size);
+}
+
+static inline u64 get_hopN_pte_addr(struct hl_ctx *ctx, u64 hop_addr,
+					u64 virt_addr, u64 mask, u64 shift)
+{
+	return hop_addr + ctx->hdev->asic_prop.mmu_pte_size *
+			((virt_addr & mask) >> shift);
+}
+
+static inline u64 get_hop0_pte_addr(struct hl_ctx *ctx, u64 hop_addr, u64 vaddr)
+{
+	return get_hopN_pte_addr(ctx, hop_addr, vaddr, HOP0_MASK, HOP0_SHIFT);
+}
+
+static inline u64 get_hop1_pte_addr(struct hl_ctx *ctx, u64 hop_addr, u64 vaddr)
+{
+	return get_hopN_pte_addr(ctx, hop_addr, vaddr, HOP1_MASK, HOP1_SHIFT);
+}
+
+static inline u64 get_hop2_pte_addr(struct hl_ctx *ctx, u64 hop_addr, u64 vaddr)
+{
+	return get_hopN_pte_addr(ctx, hop_addr, vaddr, HOP2_MASK, HOP2_SHIFT);
+}
+
+static inline u64 get_hop3_pte_addr(struct hl_ctx *ctx, u64 hop_addr, u64 vaddr)
+{
+	return get_hopN_pte_addr(ctx, hop_addr, vaddr, HOP3_MASK, HOP3_SHIFT);
+}
+
+static inline u64 get_hop4_pte_addr(struct hl_ctx *ctx, u64 hop_addr, u64 vaddr)
+{
+	return get_hopN_pte_addr(ctx, hop_addr, vaddr, HOP4_MASK, HOP4_SHIFT);
+}
+
+static inline u64 get_next_hop_addr(u64 curr_pte)
+{
+	if (curr_pte & PAGE_PRESENT_MASK)
+		return curr_pte & PHYS_ADDR_MASK;
+	else
+		return ULLONG_MAX;
+}
+
+static inline u64 get_alloc_next_hop_addr(struct hl_ctx *ctx, u64 curr_pte,
+						bool *is_new_hop)
+{
+	u64 hop_addr = get_next_hop_addr(curr_pte);
+
+	if (hop_addr == ULLONG_MAX) {
+		hop_addr = alloc_hop(ctx);
+		*is_new_hop = true;
+	}
+
+	return hop_addr;
+}
+
+/*
+ * hl_mmu_init - init the mmu module
+ *
+ * @hdev: pointer to the habanalabs device structure
+ *
+ * This function does the following:
+ * - Allocate max_asid zeroed hop0 pgts so no mapping is available
+ * - Enable mmu in hw
+ * - Invalidate the mmu cache
+ * - Create a pool of pages for pgts
+ * - Returns 0 on success
+ *
+ * This function depends on DMA QMAN to be working!
+ */
+int hl_mmu_init(struct hl_device *hdev)
+{
+	struct asic_fixed_properties *prop = &hdev->asic_prop;
+	int rc;
+
+	if (!hdev->mmu_enable)
+		return 0;
+
+	/* MMU HW init was already done in device hw_init() */
+
+	mutex_init(&hdev->mmu_cache_lock);
+
+	hdev->mmu_pgt_pool =
+			gen_pool_create(__ffs(prop->mmu_hop_table_size), -1);
+
+	if (!hdev->mmu_pgt_pool) {
+		dev_err(hdev->dev, "Failed to create page gen pool\n");
+		rc = -ENOMEM;
+		goto err_pool_create;
+	}
+
+	rc = gen_pool_add(hdev->mmu_pgt_pool, prop->mmu_pgt_addr +
+			prop->mmu_hop0_tables_total_size,
+			prop->mmu_pgt_size - prop->mmu_hop0_tables_total_size,
+			-1);
+	if (rc) {
+		dev_err(hdev->dev, "Failed to add memory to page gen pool\n");
+		goto err_pool_add;
+	}
+
+	return 0;
+
+err_pool_add:
+	gen_pool_destroy(hdev->mmu_pgt_pool);
+err_pool_create:
+	mutex_destroy(&hdev->mmu_cache_lock);
+
+	return rc;
+}
+
+/*
+ * hl_mmu_fini - release the mmu module.
+ *
+ * @hdev: pointer to the habanalabs device structure
+ *
+ * This function does the following:
+ * - Disable mmu in hw
+ * - free the pgts pool
+ *
+ * All ctxs should be freed before calling this func
+ */
+void hl_mmu_fini(struct hl_device *hdev)
+{
+	if (!hdev->mmu_enable)
+		return;
+
+	gen_pool_destroy(hdev->mmu_pgt_pool);
+
+	mutex_destroy(&hdev->mmu_cache_lock);
+
+	/* MMU HW fini will be done in device hw_fini() */
+}
+
+/*
+ * hl_mmu_ctx_init - init a ctx for using the mmu module
+ *
+ * @ctx: pointer to the context structure
+ *
+ * This function does the following:
+ * - Init a mutex to protect the concurrent mapping flow
+ * - Init a hash to hold all pgts related to this ctx
+ */
+void hl_mmu_ctx_init(struct hl_ctx *ctx)
+{
+	if (!ctx->hdev->mmu_enable)
+		return;
+
+	mutex_init(&ctx->mmu_lock);
+	hash_init(ctx->mmu_hash);
+}
+
+/*
+ * 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
+ */
+void hl_mmu_ctx_fini(struct hl_ctx *ctx)
+{
+	struct pgt_info *pgt_info;
+	struct hlist_node *tmp;
+	int i;
+
+	if (!ctx->hdev->mmu_enable)
+		return;
+
+	if (!hash_empty(ctx->mmu_hash))
+		dev_err(ctx->hdev->dev,
+				"ctx is freed while it has pgts in use\n");
+
+	hash_for_each_safe(ctx->mmu_hash, i, tmp, pgt_info, node) {
+		dev_err(ctx->hdev->dev,
+			"pgt_info of addr 0x%llx of asid %d was not destroyed, num_ptes: %d\n",
+			pgt_info->addr, ctx->asid, pgt_info->num_of_ptes);
+		free_hop(ctx, pgt_info->addr);
+	}
+
+	mutex_destroy(&ctx->mmu_lock);
+}
+
+static int _hl_mmu_unmap(struct hl_ctx *ctx, u64 virt_addr)
+{
+	struct hl_device *hdev = ctx->hdev;
+	u64 hop0_addr = 0, hop0_pte_addr = 0,
+		hop1_addr = 0, hop1_pte_addr = 0,
+		hop2_addr = 0, hop2_pte_addr = 0,
+		hop3_addr = 0, hop3_pte_addr = 0,
+		hop4_addr = 0, hop4_pte_addr = 0,
+		curr_pte;
+	int clear_hop3 = 1;
+
+	hop0_addr = get_hop0_addr(ctx);
+
+	hop0_pte_addr = get_hop0_pte_addr(ctx, hop0_addr, virt_addr);
+
+	curr_pte = hdev->asic_funcs->read_pte(hdev, hop0_pte_addr);
+
+	hop1_addr = get_next_hop_addr(curr_pte);
+
+	if (hop1_addr == ULLONG_MAX)
+		goto not_mapped;
+
+	hop1_pte_addr = get_hop1_pte_addr(ctx, hop1_addr, virt_addr);
+
+	curr_pte = hdev->asic_funcs->read_pte(hdev, hop1_pte_addr);
+
+	hop2_addr = get_next_hop_addr(curr_pte);
+
+	if (hop2_addr == ULLONG_MAX)
+		goto not_mapped;
+
+	hop2_pte_addr = get_hop2_pte_addr(ctx, hop2_addr, virt_addr);
+
+	curr_pte = hdev->asic_funcs->read_pte(hdev, hop2_pte_addr);
+
+	hop3_addr = get_next_hop_addr(curr_pte);
+
+	if (hop3_addr == ULLONG_MAX)
+		goto not_mapped;
+
+	hop3_pte_addr = get_hop3_pte_addr(ctx, hop3_addr, virt_addr);
+
+	curr_pte = hdev->asic_funcs->read_pte(hdev, hop3_pte_addr);
+
+	if (!(curr_pte & LAST_MASK)) {
+		hop4_addr = get_next_hop_addr(curr_pte);
+
+		if (hop4_addr == ULLONG_MAX)
+			goto not_mapped;
+
+		hop4_pte_addr = get_hop4_pte_addr(ctx, hop4_addr, virt_addr);
+
+		curr_pte = hdev->asic_funcs->read_pte(hdev, hop4_pte_addr);
+
+		clear_hop3 = 0;
+	}
+
+	if (!(curr_pte & PAGE_PRESENT_MASK))
+		goto not_mapped;
+
+	clear_pte(hdev, hop4_addr ? hop4_pte_addr : hop3_pte_addr);
+
+	if (hop4_addr && !put_pte(ctx, hop4_addr))
+		clear_hop3 = 1;
+
+	if (!clear_hop3)
+		goto flush;
+	clear_pte(hdev, hop3_pte_addr);
+
+	if (put_pte(ctx, hop3_addr))
+		goto flush;
+	clear_pte(hdev, hop2_pte_addr);
+
+	if (put_pte(ctx, hop2_addr))
+		goto flush;
+	clear_pte(hdev, hop1_pte_addr);
+
+	if (put_pte(ctx, hop1_addr))
+		goto flush;
+	clear_pte(hdev, hop0_pte_addr);
+
+flush:
+	/* flush all writes from all cores to reach PCI */
+	mb();
+
+	hdev->asic_funcs->read_pte(hdev,
+				hop4_addr ? hop4_pte_addr : hop3_pte_addr);
+
+	return 0;
+
+not_mapped:
+	dev_err(hdev->dev, "virt addr 0x%llx is not mapped to phys addr\n",
+		virt_addr);
+
+	return -EINVAL;
+}
+
+/*
+ * hl_mmu_unmap - unmaps a virtual addr
+ *
+ * @ctx: pointer to the context structure
+ * @virt_addr: virt addr to map from
+ * @page_size: size of the page to unmap
+ *
+ * This function does the following:
+ * - Check that the virt addr is mapped
+ * - Unmap the virt addr and frees pgts if possible
+ * - Returns 0 on success, -EINVAL if the given addr is not mapped
+ *
+ * Because this function changes the page tables in the device and because it
+ * changes the MMU hash, it must be protected by a lock.
+ * However, because it maps only a single page, the lock should be implemented
+ * in a higher level in order to protect the entire mapping of the memory area
+ */
+int hl_mmu_unmap(struct hl_ctx *ctx, u64 virt_addr, u32 page_size)
+{
+	struct hl_device *hdev = ctx->hdev;
+	u64 real_virt_addr;
+	u32 real_page_size, npages;
+	int i, rc;
+
+	if (!hdev->mmu_enable)
+		return 0;
+
+	/*
+	 * The H/W handles mapping of 4KB/2MB page. Hence if the host page size
+	 * is bigger, we break it to sub-pages and unmap them separately.
+	 */
+	if ((page_size % PAGE_SIZE_2MB) == 0) {
+		real_page_size = PAGE_SIZE_2MB;
+	} else if ((page_size % PAGE_SIZE_4KB) == 0) {
+		real_page_size = PAGE_SIZE_4KB;
+	} else {
+		dev_err(hdev->dev,
+			"page size of %u is not 4KB nor 2MB aligned, can't unmap\n",
+				page_size);
+
+		return -EFAULT;
+	}
+
+	npages = page_size / real_page_size;
+	real_virt_addr = virt_addr;
+
+	for (i = 0 ; i < npages ; i++) {
+		rc = _hl_mmu_unmap(ctx, real_virt_addr);
+		if (rc)
+			return rc;
+
+		real_virt_addr += real_page_size;
+	}
+
+	return 0;
+}
+
+static int _hl_mmu_map(struct hl_ctx *ctx, u64 virt_addr, u64 phys_addr,
+		u32 page_size)
+{
+	struct hl_device *hdev = ctx->hdev;
+	u64 hop0_addr = 0, hop0_pte_addr = 0,
+		hop1_addr = 0, hop1_pte_addr = 0,
+		hop2_addr = 0, hop2_pte_addr = 0,
+		hop3_addr = 0, hop3_pte_addr = 0,
+		hop4_addr = 0, hop4_pte_addr = 0,
+		curr_pte = 0;
+	bool hop1_new = false, hop2_new = false, hop3_new = false,
+		hop4_new = false, is_huge;
+	int rc = -ENOMEM;
+
+	/*
+	 * This mapping function can map a 4KB/2MB page. For 2MB page there are
+	 * only 3 hops rather than 4. Currently the DRAM allocation uses 2MB
+	 * 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.
+	 */
+	is_huge = page_size == PAGE_SIZE_2MB;
+
+	hop0_addr = get_hop0_addr(ctx);
+
+	hop0_pte_addr = get_hop0_pte_addr(ctx, hop0_addr, virt_addr);
+
+	curr_pte = hdev->asic_funcs->read_pte(hdev, hop0_pte_addr);
+
+	hop1_addr = get_alloc_next_hop_addr(ctx, curr_pte, &hop1_new);
+
+	if (hop1_addr == ULLONG_MAX)
+		goto err;
+
+	hop1_pte_addr = get_hop1_pte_addr(ctx, hop1_addr, virt_addr);
+
+	curr_pte = hdev->asic_funcs->read_pte(hdev, hop1_pte_addr);
+
+	hop2_addr = get_alloc_next_hop_addr(ctx, curr_pte, &hop2_new);
+
+	if (hop2_addr == ULLONG_MAX)
+		goto err;
+
+	hop2_pte_addr = get_hop2_pte_addr(ctx, hop2_addr, virt_addr);
+
+	curr_pte = hdev->asic_funcs->read_pte(hdev, hop2_pte_addr);
+
+	hop3_addr = get_alloc_next_hop_addr(ctx, curr_pte, &hop3_new);
+
+	if (hop3_addr == ULLONG_MAX)
+		goto err;
+
+	hop3_pte_addr = get_hop3_pte_addr(ctx, hop3_addr, virt_addr);
+
+	curr_pte = hdev->asic_funcs->read_pte(hdev, hop3_pte_addr);
+
+	if (!is_huge) {
+		hop4_addr = get_alloc_next_hop_addr(ctx, curr_pte, &hop4_new);
+
+		if (hop4_addr == ULLONG_MAX)
+			goto err;
+
+		hop4_pte_addr = get_hop4_pte_addr(ctx, hop4_addr, virt_addr);
+
+		curr_pte = hdev->asic_funcs->read_pte(hdev, hop4_pte_addr);
+	}
+
+	if (curr_pte & PAGE_PRESENT_MASK) {
+		dev_err(hdev->dev,
+				"mapping already exists for virt_addr 0x%llx\n",
+					virt_addr);
+
+		dev_dbg(hdev->dev, "hop0 pte: 0x%llx (0x%llx)\n",
+				hdev->asic_funcs->read_pte(hdev, hop0_pte_addr),
+				hop0_pte_addr);
+		dev_dbg(hdev->dev, "hop1 pte: 0x%llx (0x%llx)\n",
+				hdev->asic_funcs->read_pte(hdev, hop1_pte_addr),
+				hop1_pte_addr);
+		dev_dbg(hdev->dev, "hop2 pte: 0x%llx (0x%llx)\n",
+				hdev->asic_funcs->read_pte(hdev, hop2_pte_addr),
+				hop2_pte_addr);
+		dev_dbg(hdev->dev, "hop3 pte: 0x%llx (0x%llx)\n",
+				hdev->asic_funcs->read_pte(hdev, hop3_pte_addr),
+				hop3_pte_addr);
+
+		if (!is_huge)
+			dev_dbg(hdev->dev, "hop4 pte: 0x%llx (0x%llx)\n",
+				hdev->asic_funcs->read_pte(hdev,
+							hop4_pte_addr),
+							hop4_pte_addr);
+
+		rc = EINVAL;
+		goto err;
+	}
+
+	curr_pte = (phys_addr & PTE_PHYS_ADDR_MASK) | LAST_MASK
+			| PAGE_PRESENT_MASK;
+
+	hdev->asic_funcs->write_pte(hdev,
+				is_huge ? hop3_pte_addr : hop4_pte_addr,
+				curr_pte);
+
+	if (hop1_new) {
+		curr_pte = (hop1_addr & PTE_PHYS_ADDR_MASK) |
+				PAGE_PRESENT_MASK;
+		ctx->hdev->asic_funcs->write_pte(ctx->hdev, hop0_pte_addr,
+				curr_pte);
+	}
+	if (hop2_new) {
+		curr_pte = (hop2_addr & PTE_PHYS_ADDR_MASK) |
+				PAGE_PRESENT_MASK;
+		ctx->hdev->asic_funcs->write_pte(ctx->hdev, hop1_pte_addr,
+				curr_pte);
+		get_pte(ctx, hop1_addr);
+	}
+	if (hop3_new) {
+		curr_pte = (hop3_addr & PTE_PHYS_ADDR_MASK) |
+				PAGE_PRESENT_MASK;
+		ctx->hdev->asic_funcs->write_pte(ctx->hdev, hop2_pte_addr,
+				curr_pte);
+		get_pte(ctx, hop2_addr);
+	}
+
+	if (!is_huge) {
+		if (hop4_new) {
+			curr_pte = (hop4_addr & PTE_PHYS_ADDR_MASK) |
+					PAGE_PRESENT_MASK;
+			ctx->hdev->asic_funcs->write_pte(ctx->hdev,
+					hop3_pte_addr, curr_pte);
+			get_pte(ctx, hop3_addr);
+		}
+
+		get_pte(ctx, hop4_addr);
+	} else {
+		get_pte(ctx, hop3_addr);
+	}
+
+	/* flush all writes from all cores to reach PCI */
+	mb();
+
+	hdev->asic_funcs->read_pte(hdev,
+				is_huge ? hop3_pte_addr : hop4_pte_addr);
+
+	return 0;
+
+err:
+	if (hop4_new)
+		free_hop(ctx, hop4_addr);
+	if (hop3_new)
+		free_hop(ctx, hop3_addr);
+	if (hop2_new)
+		free_hop(ctx, hop2_addr);
+	if (hop1_new)
+		free_hop(ctx, hop1_addr);
+
+	return rc;
+}
+
+/*
+ * hl_mmu_map - maps a virtual addr to physical addr
+ *
+ * @ctx: pointer to the context structure
+ * @virt_addr: virt addr to map from
+ * @phys_addr: phys addr to map to
+ * @page_size: physical page size
+ *
+ * This function does the following:
+ * - Check that the virt addr is not mapped
+ * - Allocate pgts as necessary in order to map the virt addr to the phys
+ * - Returns 0 on success, -EINVAL if addr is already mapped, or -ENOMEM.
+ *
+ * Because this function changes the page tables in the device and because it
+ * changes the MMU hash, it must be protected by a lock.
+ * However, because it maps only a single page, the lock should be implemented
+ * in a higher level in order to protect the entire mapping of the memory area
+ */
+int hl_mmu_map(struct hl_ctx *ctx, u64 virt_addr, u64 phys_addr, u32 page_size)
+{
+	struct hl_device *hdev = ctx->hdev;
+	u64 real_virt_addr;
+	u32 real_page_size, npages;
+	int i, rc, mapped_cnt = 0;
+
+	if (!hdev->mmu_enable)
+		return 0;
+
+	/*
+	 * The H/W handles mapping of 4KB/2MB page. Hence if the host page size
+	 * is bigger, we break it to sub-pages and map them separately.
+	 */
+	if ((page_size % PAGE_SIZE_2MB) == 0) {
+		real_page_size = PAGE_SIZE_2MB;
+	} else if ((page_size % PAGE_SIZE_4KB) == 0) {
+		real_page_size = PAGE_SIZE_4KB;
+	} else {
+		dev_err(hdev->dev,
+			"page size of %u is not 4KB nor 2MB aligned, can't map\n",
+				page_size);
+
+		return -EFAULT;
+	}
+
+	npages = page_size / real_page_size;
+	real_virt_addr = virt_addr;
+
+	for (i = 0 ; i < npages ; i++) {
+		rc = _hl_mmu_map(ctx, real_virt_addr, phys_addr,
+				real_page_size);
+		if (rc)
+			goto err;
+
+		real_virt_addr += real_page_size;
+		mapped_cnt++;
+	}
+
+	return 0;
+
+err:
+	real_virt_addr = virt_addr;
+	for (i = 0 ; i < mapped_cnt ; i++) {
+		if (_hl_mmu_unmap(ctx, real_virt_addr))
+			dev_warn_ratelimited(hdev->dev,
+				"failed to unmap va: 0x%llx\n", real_virt_addr);
+
+		real_virt_addr += real_page_size;
+	}
+
+	return rc;
+}
+
+/*
+ * hl_mmu_swap_out - marks all mapping of the given ctx as swapped out
+ *
+ * @ctx: pointer to the context structure
+ *
+ */
+void hl_mmu_swap_out(struct hl_ctx *ctx)
+{
+
+}
+
+/*
+ * hl_mmu_swap_in - marks all mapping of the given ctx as swapped in
+ *
+ * @ctx: pointer to the context structure
+ *
+ */
+void hl_mmu_swap_in(struct hl_ctx *ctx)
+{
+
+}