oolong/mali_kbase_mem.c

/*
 *
 * (C) COPYRIGHT 2010-2016 ARM Limited. All rights reserved.
 *
 * This program is free software and is provided to you under the terms of the
 * GNU General Public License version 2 as published by the Free Software
 * Foundation, and any use by you of this program is subject to the terms
 * of such GNU licence.
 *
 * A copy of the licence is included with the program, and can also be obtained
 * from Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA  02110-1301, USA.
 *
 */

/**
 * @file mali_kbase_mem.c
 * Base kernel memory APIs
 */
#ifdef CONFIG_DMA_SHARED_BUFFER
#include <linux/dma-buf.h>
#endif				/* CONFIG_DMA_SHARED_BUFFER */
#ifdef CONFIG_UMP
#include <linux/ump.h>
#endif				/* CONFIG_UMP */
#include <linux/kernel.h>
#include <linux/bug.h>
#include <linux/compat.h>
#include <linux/sched/mm.h>

#include <mali_kbase_config.h>
#include <mali_kbase.h>
#include <mali_midg_regmap.h>
#include <mali_kbase_cache_policy.h>
#include <mali_kbase_hw.h>
#include <mali_kbase_hwaccess_time.h>
#include <mali_kbase_tlstream.h>

/**
 * @brief Check the zone compatibility of two regions.
 */
static int kbase_region_tracker_match_zone(struct kbase_va_region *reg1,
		struct kbase_va_region *reg2)
{
	return ((reg1->flags & KBASE_REG_ZONE_MASK) ==
		(reg2->flags & KBASE_REG_ZONE_MASK));
}

/* This function inserts a region into the tree. */
static void kbase_region_tracker_insert(struct kbase_context *kctx, struct kbase_va_region *new_reg)
{
	u64 start_pfn = new_reg->start_pfn;
	struct rb_node **link = &(kctx->reg_rbtree.rb_node);
	struct rb_node *parent = NULL;

	/* Find the right place in the tree using tree search */
	while (*link) {
		struct kbase_va_region *old_reg;

		parent = *link;
		old_reg = rb_entry(parent, struct kbase_va_region, rblink);

		/* RBTree requires no duplicate entries. */
		KBASE_DEBUG_ASSERT(old_reg->start_pfn != start_pfn);

		if (old_reg->start_pfn > start_pfn)
			link = &(*link)->rb_left;
		else
			link = &(*link)->rb_right;
	}

	/* Put the new node there, and rebalance tree */
	rb_link_node(&(new_reg->rblink), parent, link);
	rb_insert_color(&(new_reg->rblink), &(kctx->reg_rbtree));
}

/* Find allocated region enclosing free range. */
static struct kbase_va_region *kbase_region_tracker_find_region_enclosing_range_free(
		struct kbase_context *kctx, u64 start_pfn, size_t nr_pages)
{
	struct rb_node *rbnode;
	struct kbase_va_region *reg;

	u64 end_pfn = start_pfn + nr_pages;

	rbnode = kctx->reg_rbtree.rb_node;
	while (rbnode) {
		u64 tmp_start_pfn, tmp_end_pfn;

		reg = rb_entry(rbnode, struct kbase_va_region, rblink);
		tmp_start_pfn = reg->start_pfn;
		tmp_end_pfn = reg->start_pfn + reg->nr_pages;

		/* If start is lower than this, go left. */
		if (start_pfn < tmp_start_pfn)
			rbnode = rbnode->rb_left;
		/* If end is higher than this, then go right. */
		else if (end_pfn > tmp_end_pfn)
			rbnode = rbnode->rb_right;
		else	/* Enclosing */
			return reg;
	}

	return NULL;
}

/* Find region enclosing given address. */
struct kbase_va_region *kbase_region_tracker_find_region_enclosing_address(struct kbase_context *kctx, u64 gpu_addr)
{
	struct rb_node *rbnode;
	struct kbase_va_region *reg;
	u64 gpu_pfn = gpu_addr >> PAGE_SHIFT;

	KBASE_DEBUG_ASSERT(kctx != NULL);

	lockdep_assert_held(&kctx->reg_lock);

	rbnode = kctx->reg_rbtree.rb_node;
	while (rbnode) {
		u64 tmp_start_pfn, tmp_end_pfn;

		reg = rb_entry(rbnode, struct kbase_va_region, rblink);
		tmp_start_pfn = reg->start_pfn;
		tmp_end_pfn = reg->start_pfn + reg->nr_pages;

		/* If start is lower than this, go left. */
		if (gpu_pfn < tmp_start_pfn)
			rbnode = rbnode->rb_left;
		/* If end is higher than this, then go right. */
		else if (gpu_pfn >= tmp_end_pfn)
			rbnode = rbnode->rb_right;
		else	/* Enclosing */
			return reg;
	}

	return NULL;
}

/* Find region with given base address */
struct kbase_va_region *kbase_region_tracker_find_region_base_address(struct kbase_context *kctx, u64 gpu_addr)
{
	u64 gpu_pfn = gpu_addr >> PAGE_SHIFT;
	struct rb_node *rbnode;
	struct kbase_va_region *reg;

	KBASE_DEBUG_ASSERT(kctx != NULL);

	lockdep_assert_held(&kctx->reg_lock);

	rbnode = kctx->reg_rbtree.rb_node;
	while (rbnode) {
		reg = rb_entry(rbnode, struct kbase_va_region, rblink);
		if (reg->start_pfn > gpu_pfn)
			rbnode = rbnode->rb_left;
		else if (reg->start_pfn < gpu_pfn)
			rbnode = rbnode->rb_right;
		else
			return reg;

	}

	return NULL;
}

/* Find region meeting given requirements */
static struct kbase_va_region *kbase_region_tracker_find_region_meeting_reqs(struct kbase_context *kctx, struct kbase_va_region *reg_reqs, size_t nr_pages, size_t align)
{
	struct rb_node *rbnode;
	struct kbase_va_region *reg;

	/* Note that this search is a linear search, as we do not have a target
	   address in mind, so does not benefit from the rbtree search */
	rbnode = rb_first(&(kctx->reg_rbtree));
	while (rbnode) {
		reg = rb_entry(rbnode, struct kbase_va_region, rblink);
		if ((reg->nr_pages >= nr_pages) &&
				(reg->flags & KBASE_REG_FREE) &&
				kbase_region_tracker_match_zone(reg, reg_reqs)) {
			/* Check alignment */
			u64 start_pfn = (reg->start_pfn + align - 1) & ~(align - 1);

			if ((start_pfn >= reg->start_pfn) &&
					(start_pfn <= (reg->start_pfn + reg->nr_pages - 1)) &&
					((start_pfn + nr_pages - 1) <= (reg->start_pfn + reg->nr_pages - 1)))
				return reg;
		}
		rbnode = rb_next(rbnode);
	}

	return NULL;
}

/**
 * @brief Remove a region object from the global list.
 *
 * The region reg is removed, possibly by merging with other free and
 * compatible adjacent regions.  It must be called with the context
 * region lock held. The associated memory is not released (see
 * kbase_free_alloced_region). Internal use only.
 */
static int kbase_remove_va_region(struct kbase_context *kctx, struct kbase_va_region *reg)
{
	struct rb_node *rbprev;
	struct kbase_va_region *prev = NULL;
	struct rb_node *rbnext;
	struct kbase_va_region *next = NULL;

	int merged_front = 0;
	int merged_back = 0;
	int err = 0;

	/* Try to merge with the previous block first */
	rbprev = rb_prev(&(reg->rblink));
	if (rbprev) {
		prev = rb_entry(rbprev, struct kbase_va_region, rblink);
		if ((prev->flags & KBASE_REG_FREE) && kbase_region_tracker_match_zone(prev, reg)) {
			/* We're compatible with the previous VMA, merge with it */
			prev->nr_pages += reg->nr_pages;
			rb_erase(&(reg->rblink), &kctx->reg_rbtree);
			reg = prev;
			merged_front = 1;
		}
	}

	/* Try to merge with the next block second */
	/* Note we do the lookup here as the tree may have been rebalanced. */
	rbnext = rb_next(&(reg->rblink));
	if (rbnext) {
		/* We're compatible with the next VMA, merge with it */
		next = rb_entry(rbnext, struct kbase_va_region, rblink);
		if ((next->flags & KBASE_REG_FREE) && kbase_region_tracker_match_zone(next, reg)) {
			next->start_pfn = reg->start_pfn;
			next->nr_pages += reg->nr_pages;
			rb_erase(&(reg->rblink), &kctx->reg_rbtree);
			merged_back = 1;
			if (merged_front) {
				/* We already merged with prev, free it */
				kbase_free_alloced_region(reg);
			}
		}
	}

	/* If we failed to merge then we need to add a new block */
	if (!(merged_front || merged_back)) {
		/*
		 * We didn't merge anything. Add a new free
		 * placeholder and remove the original one.
		 */
		struct kbase_va_region *free_reg;

		free_reg = kbase_alloc_free_region(kctx, reg->start_pfn, reg->nr_pages, reg->flags & KBASE_REG_ZONE_MASK);
		if (!free_reg) {
			err = -ENOMEM;
			goto out;
		}

		rb_replace_node(&(reg->rblink), &(free_reg->rblink), &(kctx->reg_rbtree));
	}

 out:
	return err;
}

/**
 * @brief Insert a VA region to the list, replacing the current at_reg.
 */
static int kbase_insert_va_region_nolock(struct kbase_context *kctx, struct kbase_va_region *new_reg, struct kbase_va_region *at_reg, u64 start_pfn, size_t nr_pages)
{
	int err = 0;

	/* Must be a free region */
	KBASE_DEBUG_ASSERT((at_reg->flags & KBASE_REG_FREE) != 0);
	/* start_pfn should be contained within at_reg */
	KBASE_DEBUG_ASSERT((start_pfn >= at_reg->start_pfn) && (start_pfn < at_reg->start_pfn + at_reg->nr_pages));
	/* at least nr_pages from start_pfn should be contained within at_reg */
	KBASE_DEBUG_ASSERT(start_pfn + nr_pages <= at_reg->start_pfn + at_reg->nr_pages);

	new_reg->start_pfn = start_pfn;
	new_reg->nr_pages = nr_pages;

	/* Regions are a whole use, so swap and delete old one. */
	if (at_reg->start_pfn == start_pfn && at_reg->nr_pages == nr_pages) {
		rb_replace_node(&(at_reg->rblink), &(new_reg->rblink), &(kctx->reg_rbtree));
		kbase_free_alloced_region(at_reg);
	}
	/* New region replaces the start of the old one, so insert before. */
	else if (at_reg->start_pfn == start_pfn) {
		at_reg->start_pfn += nr_pages;
		KBASE_DEBUG_ASSERT(at_reg->nr_pages >= nr_pages);
		at_reg->nr_pages -= nr_pages;

		kbase_region_tracker_insert(kctx, new_reg);
	}
	/* New region replaces the end of the old one, so insert after. */
	else if ((at_reg->start_pfn + at_reg->nr_pages) == (start_pfn + nr_pages)) {
		at_reg->nr_pages -= nr_pages;

		kbase_region_tracker_insert(kctx, new_reg);
	}
	/* New region splits the old one, so insert and create new */
	else {
		struct kbase_va_region *new_front_reg;

		new_front_reg = kbase_alloc_free_region(kctx,
				at_reg->start_pfn,
				start_pfn - at_reg->start_pfn,
				at_reg->flags & KBASE_REG_ZONE_MASK);

		if (new_front_reg) {
			at_reg->nr_pages -= nr_pages + new_front_reg->nr_pages;
			at_reg->start_pfn = start_pfn + nr_pages;

			kbase_region_tracker_insert(kctx, new_front_reg);
			kbase_region_tracker_insert(kctx, new_reg);
		} else {
			err = -ENOMEM;
		}
	}

	return err;
}

/**
 * @brief Add a VA region to the list.
 */
int kbase_add_va_region(struct kbase_context *kctx,
		struct kbase_va_region *reg, u64 addr,
		size_t nr_pages, size_t align)
{
	struct kbase_va_region *tmp;
	u64 gpu_pfn = addr >> PAGE_SHIFT;
	int err = 0;

	KBASE_DEBUG_ASSERT(kctx != NULL);
	KBASE_DEBUG_ASSERT(reg != NULL);

	lockdep_assert_held(&kctx->reg_lock);

	if (!align)
		align = 1;

	/* must be a power of 2 */
	KBASE_DEBUG_ASSERT((align & (align - 1)) == 0);
	KBASE_DEBUG_ASSERT(nr_pages > 0);

	/* Path 1: Map a specific address. Find the enclosing region, which *must* be free. */
	if (gpu_pfn) {
		struct device *dev = kctx->kbdev->dev;

		KBASE_DEBUG_ASSERT(!(gpu_pfn & (align - 1)));

		tmp = kbase_region_tracker_find_region_enclosing_range_free(kctx, gpu_pfn, nr_pages);
		if (!tmp) {
			dev_warn(dev, "Enclosing region not found: 0x%08llx gpu_pfn, %zu nr_pages", gpu_pfn, nr_pages);
			err = -ENOMEM;
			goto exit;
		}

		if ((!kbase_region_tracker_match_zone(tmp, reg)) ||
				(!(tmp->flags & KBASE_REG_FREE))) {
			dev_warn(dev, "Zone mismatch: %lu != %lu", tmp->flags & KBASE_REG_ZONE_MASK, reg->flags & KBASE_REG_ZONE_MASK);
			dev_warn(dev, "!(tmp->flags & KBASE_REG_FREE): tmp->start_pfn=0x%llx tmp->flags=0x%lx tmp->nr_pages=0x%zx gpu_pfn=0x%llx nr_pages=0x%zx\n", tmp->start_pfn, tmp->flags, tmp->nr_pages, gpu_pfn, nr_pages);
			dev_warn(dev, "in function %s (%p, %p, 0x%llx, 0x%zx, 0x%zx)\n", __func__, kctx, reg, addr, nr_pages, align);
			err = -ENOMEM;
			goto exit;
		}

		err = kbase_insert_va_region_nolock(kctx, reg, tmp, gpu_pfn, nr_pages);
		if (err) {
			dev_warn(dev, "Failed to insert va region");
			err = -ENOMEM;
			goto exit;
		}

		goto exit;
	}

	/* Path 2: Map any free address which meets the requirements.  */
	{
		u64 start_pfn;

		/*
		 * Depending on the zone the allocation request is for
		 * we might need to retry it.
		 */
		do {
			tmp = kbase_region_tracker_find_region_meeting_reqs(
					kctx, reg, nr_pages, align);
			if (tmp) {
				start_pfn = (tmp->start_pfn + align - 1) &
						~(align - 1);
				err = kbase_insert_va_region_nolock(kctx, reg,
						tmp, start_pfn, nr_pages);
				break;
			}

			/*
			 * If the allocation is not from the same zone as JIT
			 * then don't retry, we're out of VA and there is
			 * nothing which can be done about it.
			 */
			if ((reg->flags & KBASE_REG_ZONE_MASK) !=
					KBASE_REG_ZONE_CUSTOM_VA)
				break;
		} while (kbase_jit_evict(kctx));

		if (!tmp)
			err = -ENOMEM;
	}

 exit:
	return err;
}

/**
 * @brief Initialize the internal region tracker data structure.
 */
static void kbase_region_tracker_ds_init(struct kbase_context *kctx,
		struct kbase_va_region *same_va_reg,
		struct kbase_va_region *exec_reg,
		struct kbase_va_region *custom_va_reg)
{
	kctx->reg_rbtree = RB_ROOT;
	kbase_region_tracker_insert(kctx, same_va_reg);

	/* exec and custom_va_reg doesn't always exist */
	if (exec_reg && custom_va_reg) {
		kbase_region_tracker_insert(kctx, exec_reg);
		kbase_region_tracker_insert(kctx, custom_va_reg);
	}
}

void kbase_region_tracker_term(struct kbase_context *kctx)
{
	struct rb_node *rbnode;
	struct kbase_va_region *reg;

	do {
		rbnode = rb_first(&(kctx->reg_rbtree));
		if (rbnode) {
			rb_erase(rbnode, &(kctx->reg_rbtree));
			reg = rb_entry(rbnode, struct kbase_va_region, rblink);
			kbase_free_alloced_region(reg);
		}
	} while (rbnode);
}

/**
 * Initialize the region tracker data structure.
 */
int kbase_region_tracker_init(struct kbase_context *kctx)
{
	struct kbase_va_region *same_va_reg;
	struct kbase_va_region *exec_reg = NULL;
	struct kbase_va_region *custom_va_reg = NULL;
	size_t same_va_bits = sizeof(void *) * BITS_PER_BYTE;
	u64 custom_va_size = KBASE_REG_ZONE_CUSTOM_VA_SIZE;
	u64 gpu_va_limit = (1ULL << kctx->kbdev->gpu_props.mmu.va_bits) >> PAGE_SHIFT;
	u64 same_va_pages;
	int err;

	/* Take the lock as kbase_free_alloced_region requires it */
	kbase_gpu_vm_lock(kctx);

#if defined(CONFIG_ARM64)
	same_va_bits = VA_BITS;
#elif defined(CONFIG_X86_64)
	same_va_bits = 47;
#elif defined(CONFIG_64BIT)
#error Unsupported 64-bit architecture
#endif

#ifdef CONFIG_64BIT
	if (kctx->is_compat)
		same_va_bits = 32;
	else if (kbase_hw_has_feature(kctx->kbdev, BASE_HW_FEATURE_33BIT_VA))
		same_va_bits = 33;
#endif

	if (kctx->kbdev->gpu_props.mmu.va_bits < same_va_bits) {
		err = -EINVAL;
		goto fail_unlock;
	}

	same_va_pages = (1ULL << (same_va_bits - PAGE_SHIFT)) - 1;
	/* all have SAME_VA */
	same_va_reg = kbase_alloc_free_region(kctx, 1,
			same_va_pages,
			KBASE_REG_ZONE_SAME_VA);

	if (!same_va_reg) {
		err = -ENOMEM;
		goto fail_unlock;
	}

#ifdef CONFIG_64BIT
	/* 32-bit clients have exec and custom VA zones */
	if (kctx->is_compat) {
#endif
		if (gpu_va_limit <= KBASE_REG_ZONE_CUSTOM_VA_BASE) {
			err = -EINVAL;
			goto fail_free_same_va;
		}
		/* If the current size of TMEM is out of range of the
		 * virtual address space addressable by the MMU then
		 * we should shrink it to fit
		 */
		if ((KBASE_REG_ZONE_CUSTOM_VA_BASE + KBASE_REG_ZONE_CUSTOM_VA_SIZE) >= gpu_va_limit)
			custom_va_size = gpu_va_limit - KBASE_REG_ZONE_CUSTOM_VA_BASE;

		exec_reg = kbase_alloc_free_region(kctx,
				KBASE_REG_ZONE_EXEC_BASE,
				KBASE_REG_ZONE_EXEC_SIZE,
				KBASE_REG_ZONE_EXEC);

		if (!exec_reg) {
			err = -ENOMEM;
			goto fail_free_same_va;
		}

		custom_va_reg = kbase_alloc_free_region(kctx,
				KBASE_REG_ZONE_CUSTOM_VA_BASE,
				custom_va_size, KBASE_REG_ZONE_CUSTOM_VA);

		if (!custom_va_reg) {
			err = -ENOMEM;
			goto fail_free_exec;
		}
#ifdef CONFIG_64BIT
	}
#endif

	kbase_region_tracker_ds_init(kctx, same_va_reg, exec_reg, custom_va_reg);

	kctx->same_va_end = same_va_pages + 1;

	kbase_gpu_vm_unlock(kctx);
	return 0;

fail_free_exec:
	kbase_free_alloced_region(exec_reg);
fail_free_same_va:
	kbase_free_alloced_region(same_va_reg);
fail_unlock:
	kbase_gpu_vm_unlock(kctx);
	return err;
}

int kbase_region_tracker_init_jit(struct kbase_context *kctx, u64 jit_va_pages)
{
#ifdef CONFIG_64BIT
	struct kbase_va_region *same_va;
	struct kbase_va_region *custom_va_reg;
	u64 same_va_bits;
	u64 total_va_size;
	int err;

	/*
	 * Nothing to do for 32-bit clients, JIT uses the existing
	 * custom VA zone.
	 */
	if (kctx->is_compat)
		return 0;

#if defined(CONFIG_ARM64)
	same_va_bits = VA_BITS;
#elif defined(CONFIG_X86_64)
	same_va_bits = 47;
#elif defined(CONFIG_64BIT)
#error Unsupported 64-bit architecture
#endif

	if (kbase_hw_has_feature(kctx->kbdev, BASE_HW_FEATURE_33BIT_VA))
		same_va_bits = 33;

	total_va_size = (1ULL << (same_va_bits - PAGE_SHIFT)) - 1;

	kbase_gpu_vm_lock(kctx);

	/*
	 * Modify the same VA free region after creation. Be careful to ensure
	 * that allocations haven't been made as they could cause an overlap
	 * to happen with existing same VA allocations and the custom VA zone.
	 */
	same_va = kbase_region_tracker_find_region_base_address(kctx,
			PAGE_SIZE);
	if (!same_va) {
		err = -ENOMEM;
		goto fail_unlock;
	}

	/* The region flag or region size has changed since creation so bail. */
	if ((!(same_va->flags & KBASE_REG_FREE)) ||
			(same_va->nr_pages != total_va_size)) {
		err = -ENOMEM;
		goto fail_unlock;
	}

	/* It's safe to adjust the same VA zone now */
	same_va->nr_pages -= jit_va_pages;
	kctx->same_va_end -= jit_va_pages;

	/*
	 * Create a custom VA zone at the end of the VA for allocations which
	 * JIT can use so it doesn't have to allocate VA from the kernel.
	 */
	custom_va_reg = kbase_alloc_free_region(kctx,
				kctx->same_va_end,
				jit_va_pages,
				KBASE_REG_ZONE_CUSTOM_VA);
	if (!custom_va_reg) {
		/*
		 * The context will be destroyed if we fail here so no point
		 * reverting the change we made to same_va.
		 */
		err = -ENOMEM;
		goto fail_unlock;
	}

	kbase_region_tracker_insert(kctx, custom_va_reg);

	kbase_gpu_vm_unlock(kctx);
	return 0;

fail_unlock:
	kbase_gpu_vm_unlock(kctx);
	return err;
#else
	return 0;
#endif
}

int kbase_mem_init(struct kbase_device *kbdev)
{
	struct kbasep_mem_device *memdev;

	KBASE_DEBUG_ASSERT(kbdev);

	memdev = &kbdev->memdev;
	kbdev->mem_pool_max_size_default = KBASE_MEM_POOL_MAX_SIZE_KCTX;

	/* Initialize memory usage */
	atomic_set(&memdev->used_pages, 0);

	return kbase_mem_pool_init(&kbdev->mem_pool,
			KBASE_MEM_POOL_MAX_SIZE_KBDEV, kbdev, NULL);
}

void kbase_mem_halt(struct kbase_device *kbdev)
{
	CSTD_UNUSED(kbdev);
}

void kbase_mem_term(struct kbase_device *kbdev)
{
	struct kbasep_mem_device *memdev;
	int pages;

	KBASE_DEBUG_ASSERT(kbdev);

	memdev = &kbdev->memdev;

	pages = atomic_read(&memdev->used_pages);
	if (pages != 0)
		dev_warn(kbdev->dev, "%s: %d pages in use!\n", __func__, pages);

	kbase_mem_pool_term(&kbdev->mem_pool);
}

/**
 * @brief Allocate a free region object.
 *
 * The allocated object is not part of any list yet, and is flagged as
 * KBASE_REG_FREE. No mapping is allocated yet.
 *
 * zone is KBASE_REG_ZONE_CUSTOM_VA, KBASE_REG_ZONE_SAME_VA, or KBASE_REG_ZONE_EXEC
 *
 */
struct kbase_va_region *kbase_alloc_free_region(struct kbase_context *kctx, u64 start_pfn, size_t nr_pages, int zone)
{
	struct kbase_va_region *new_reg;

	KBASE_DEBUG_ASSERT(kctx != NULL);

	/* zone argument should only contain zone related region flags */
	KBASE_DEBUG_ASSERT((zone & ~KBASE_REG_ZONE_MASK) == 0);
	KBASE_DEBUG_ASSERT(nr_pages > 0);
	/* 64-bit address range is the max */
	KBASE_DEBUG_ASSERT(start_pfn + nr_pages <= (U64_MAX / PAGE_SIZE));

	new_reg = kzalloc(sizeof(*new_reg), GFP_KERNEL);

	if (!new_reg)
		return NULL;

	new_reg->cpu_alloc = NULL; /* no alloc bound yet */
	new_reg->gpu_alloc = NULL; /* no alloc bound yet */
	new_reg->kctx = kctx;
	new_reg->flags = zone | KBASE_REG_FREE;

	new_reg->flags |= KBASE_REG_GROWABLE;

	new_reg->start_pfn = start_pfn;
	new_reg->nr_pages = nr_pages;

	return new_reg;
}

/**
 * @brief Free a region object.
 *
 * The described region must be freed of any mapping.
 *
 * If the region is not flagged as KBASE_REG_FREE, the region's
 * alloc object will be released.
 * It is a bug if no alloc object exists for non-free regions.
 *
 */
void kbase_free_alloced_region(struct kbase_va_region *reg)
{
	if (!(reg->flags & KBASE_REG_FREE)) {
		/*
		 * The physical allocation should have been removed from the
		 * eviction list before this function is called. However, in the
		 * case of abnormal process termination or the app leaking the
		 * memory kbase_mem_free_region is not called so it can still be
		 * on the list at termination time of the region tracker.
		 */
		if (!list_empty(&reg->gpu_alloc->evict_node)) {
			/*
			 * Unlink the physical allocation before unmaking it
			 * evictable so that the allocation isn't grown back to
			 * its last backed size as we're going to unmap it
			 * anyway.
			 */
			reg->cpu_alloc->reg = NULL;
			if (reg->cpu_alloc != reg->gpu_alloc)
				reg->gpu_alloc->reg = NULL;

			/*
			 * If a region has been made evictable then we must
			 * unmake it before trying to free it.
			 * If the memory hasn't been reclaimed it will be
			 * unmapped and freed below, if it has been reclaimed
			 * then the operations below are no-ops.
			 */
			if (reg->flags & KBASE_REG_DONT_NEED) {
				KBASE_DEBUG_ASSERT(reg->cpu_alloc->type ==
						   KBASE_MEM_TYPE_NATIVE);
				kbase_mem_evictable_unmake(reg->gpu_alloc);
			}
		}

		/*
		 * Remove the region from the sticky resource metadata
		 * list should it be there.
		 */
		kbase_sticky_resource_release(reg->kctx, NULL,
				reg->start_pfn << PAGE_SHIFT);

		kbase_mem_phy_alloc_put(reg->cpu_alloc);
		kbase_mem_phy_alloc_put(reg->gpu_alloc);
		/* To detect use-after-free in debug builds */
		KBASE_DEBUG_CODE(reg->flags |= KBASE_REG_FREE);
	}
	kfree(reg);
}

void kbase_mmu_update(struct kbase_context *kctx)
{
	KBASE_DEBUG_ASSERT(kctx != NULL);
	lockdep_assert_held(&kctx->kbdev->js_data.runpool_irq.lock);
	/* ASSERT that the context has a valid as_nr, which is only the case
	 * when it's scheduled in.
	 *
	 * as_nr won't change because the caller has the runpool_irq lock */
	KBASE_DEBUG_ASSERT(kctx->as_nr != KBASEP_AS_NR_INVALID);
	lockdep_assert_held(&kctx->kbdev->as[kctx->as_nr].transaction_mutex);

	kctx->kbdev->mmu_mode->update(kctx);
}

void kbase_mmu_disable(struct kbase_context *kctx)
{
	KBASE_DEBUG_ASSERT(kctx != NULL);
	/* ASSERT that the context has a valid as_nr, which is only the case
	 * when it's scheduled in.
	 *
	 * as_nr won't change because the caller has the runpool_irq lock */
	KBASE_DEBUG_ASSERT(kctx->as_nr != KBASEP_AS_NR_INVALID);

	kctx->kbdev->mmu_mode->disable_as(kctx->kbdev, kctx->as_nr);
}

void kbase_mmu_disable_as(struct kbase_device *kbdev, int as_nr)
{
	kbdev->mmu_mode->disable_as(kbdev, as_nr);
}

int kbase_gpu_mmap(struct kbase_context *kctx, struct kbase_va_region *reg, u64 addr, size_t nr_pages, size_t align)
{
	int err;
	size_t i = 0;
	unsigned long attr;
	unsigned long mask = ~KBASE_REG_MEMATTR_MASK;

	if ((kctx->kbdev->system_coherency == COHERENCY_ACE) &&
		(reg->flags & KBASE_REG_SHARE_BOTH))
		attr = KBASE_REG_MEMATTR_INDEX(AS_MEMATTR_INDEX_OUTER_WA);
	else
		attr = KBASE_REG_MEMATTR_INDEX(AS_MEMATTR_INDEX_WRITE_ALLOC);

	KBASE_DEBUG_ASSERT(kctx != NULL);
	KBASE_DEBUG_ASSERT(reg != NULL);

	err = kbase_add_va_region(kctx, reg, addr, nr_pages, align);
	if (err)
		return err;

	if (reg->gpu_alloc->type == KBASE_MEM_TYPE_ALIAS) {
		u64 stride;
		struct kbase_mem_phy_alloc *alloc;

		alloc = reg->gpu_alloc;
		stride = alloc->imported.alias.stride;
		KBASE_DEBUG_ASSERT(alloc->imported.alias.aliased);
		for (i = 0; i < alloc->imported.alias.nents; i++) {
			if (alloc->imported.alias.aliased[i].alloc) {
				err = kbase_mmu_insert_pages(kctx,
						reg->start_pfn + (i * stride),
						alloc->imported.alias.aliased[i].alloc->pages + alloc->imported.alias.aliased[i].offset,
						alloc->imported.alias.aliased[i].length,
						reg->flags);
				if (err)
					goto bad_insert;

				kbase_mem_phy_alloc_gpu_mapped(alloc->imported.alias.aliased[i].alloc);
			} else {
				err = kbase_mmu_insert_single_page(kctx,
					reg->start_pfn + i * stride,
					page_to_phys(kctx->aliasing_sink_page),
					alloc->imported.alias.aliased[i].length,
					(reg->flags & mask) | attr);

				if (err)
					goto bad_insert;
			}
		}
	} else {
		err = kbase_mmu_insert_pages(kctx, reg->start_pfn,
				kbase_get_gpu_phy_pages(reg),
				kbase_reg_current_backed_size(reg),
				reg->flags);
		if (err)
			goto bad_insert;
		kbase_mem_phy_alloc_gpu_mapped(reg->gpu_alloc);
	}

	return err;

bad_insert:
	if (reg->gpu_alloc->type == KBASE_MEM_TYPE_ALIAS) {
		u64 stride;

		stride = reg->gpu_alloc->imported.alias.stride;
		KBASE_DEBUG_ASSERT(reg->gpu_alloc->imported.alias.aliased);
		while (i--)
			if (reg->gpu_alloc->imported.alias.aliased[i].alloc) {
				kbase_mmu_teardown_pages(kctx, reg->start_pfn + (i * stride), reg->gpu_alloc->imported.alias.aliased[i].length);
				kbase_mem_phy_alloc_gpu_unmapped(reg->gpu_alloc->imported.alias.aliased[i].alloc);
			}
	}

	kbase_remove_va_region(kctx, reg);

	return err;
}

int kbase_gpu_munmap(struct kbase_context *kctx, struct kbase_va_region *reg)
{
	int err;

	if (reg->start_pfn == 0)
		return 0;

	if (reg->gpu_alloc && reg->gpu_alloc->type == KBASE_MEM_TYPE_ALIAS) {
		size_t i;

		err = kbase_mmu_teardown_pages(kctx, reg->start_pfn, reg->nr_pages);
		KBASE_DEBUG_ASSERT(reg->gpu_alloc->imported.alias.aliased);
		for (i = 0; i < reg->gpu_alloc->imported.alias.nents; i++)
			if (reg->gpu_alloc->imported.alias.aliased[i].alloc)
				kbase_mem_phy_alloc_gpu_unmapped(reg->gpu_alloc->imported.alias.aliased[i].alloc);
	} else {
		err = kbase_mmu_teardown_pages(kctx, reg->start_pfn, kbase_reg_current_backed_size(reg));
		kbase_mem_phy_alloc_gpu_unmapped(reg->gpu_alloc);
	}

	if (err)
		return err;

	err = kbase_remove_va_region(kctx, reg);
	return err;
}

static struct kbase_cpu_mapping *kbasep_find_enclosing_cpu_mapping_of_region(const struct kbase_va_region *reg, unsigned long uaddr, size_t size)
{
	struct kbase_cpu_mapping *map;
	struct list_head *pos;

	KBASE_DEBUG_ASSERT(reg != NULL);
	KBASE_DEBUG_ASSERT(reg->cpu_alloc);

	if ((uintptr_t) uaddr + size < (uintptr_t) uaddr) /* overflow check */
		return NULL;

	list_for_each(pos, &reg->cpu_alloc->mappings) {
		map = list_entry(pos, struct kbase_cpu_mapping, mappings_list);
		if (map->vm_start <= uaddr && map->vm_end >= uaddr + size)
			return map;
	}

	return NULL;
}

int kbasep_find_enclosing_cpu_mapping_offset(
	struct kbase_context *kctx, u64 gpu_addr,
	unsigned long uaddr, size_t size, u64 *offset)
{
	struct kbase_cpu_mapping *map = NULL;
	const struct kbase_va_region *reg;
	int err = -EINVAL;

	KBASE_DEBUG_ASSERT(kctx != NULL);

	kbase_gpu_vm_lock(kctx);

	reg = kbase_region_tracker_find_region_enclosing_address(kctx, gpu_addr);
	if (reg && !(reg->flags & KBASE_REG_FREE)) {
		map = kbasep_find_enclosing_cpu_mapping_of_region(reg, uaddr,
				size);
		if (map) {
			*offset = (uaddr - PTR_TO_U64(map->vm_start)) +
						 (map->page_off << PAGE_SHIFT);
			err = 0;
		}
	}

	kbase_gpu_vm_unlock(kctx);

	return err;
}

void kbase_sync_single(struct kbase_context *kctx,
		phys_addr_t cpu_pa, phys_addr_t gpu_pa,
		off_t offset, size_t size, enum kbase_sync_type sync_fn)
{
	struct page *cpu_page;

	cpu_page = pfn_to_page(PFN_DOWN(cpu_pa));

	if (likely(cpu_pa == gpu_pa)) {
		dma_addr_t dma_addr;

		BUG_ON(!cpu_page);
		BUG_ON(offset + size > PAGE_SIZE);

		dma_addr = kbase_dma_addr(cpu_page) + offset;
		if (sync_fn == KBASE_SYNC_TO_CPU)
			dma_sync_single_for_cpu(kctx->kbdev->dev, dma_addr,
					size, DMA_BIDIRECTIONAL);
		else if (sync_fn == KBASE_SYNC_TO_DEVICE)
			dma_sync_single_for_device(kctx->kbdev->dev, dma_addr,
					size, DMA_BIDIRECTIONAL);
	} else {
		void *src = NULL;
		void *dst = NULL;
		struct page *gpu_page;

		if (WARN(!gpu_pa, "No GPU PA found for infinite cache op"))
			return;

		gpu_page = pfn_to_page(PFN_DOWN(gpu_pa));

		if (sync_fn == KBASE_SYNC_TO_DEVICE) {
			src = ((unsigned char *)kmap(cpu_page)) + offset;
			dst = ((unsigned char *)kmap(gpu_page)) + offset;
		} else if (sync_fn == KBASE_SYNC_TO_CPU) {
			dma_sync_single_for_cpu(kctx->kbdev->dev,
					kbase_dma_addr(gpu_page) + offset,
					size, DMA_BIDIRECTIONAL);
			src = ((unsigned char *)kmap(gpu_page)) + offset;
			dst = ((unsigned char *)kmap(cpu_page)) + offset;
		}
		memcpy(dst, src, size);
		kunmap(gpu_page);
		kunmap(cpu_page);
		if (sync_fn == KBASE_SYNC_TO_DEVICE)
			dma_sync_single_for_device(kctx->kbdev->dev,
					kbase_dma_addr(gpu_page) + offset,
					size, DMA_BIDIRECTIONAL);
	}
}

static int kbase_do_syncset(struct kbase_context *kctx,
		struct base_syncset *set, enum kbase_sync_type sync_fn)
{
	int err = 0;
	struct basep_syncset *sset = &set->basep_sset;
	struct kbase_va_region *reg;
	struct kbase_cpu_mapping *map;
	unsigned long start;
	size_t size;
	phys_addr_t *cpu_pa;
	phys_addr_t *gpu_pa;
	u64 page_off, page_count;
	u64 i;
	off_t offset;

	kbase_os_mem_map_lock(kctx);
	kbase_gpu_vm_lock(kctx);

	/* find the region where the virtual address is contained */
	reg = kbase_region_tracker_find_region_enclosing_address(kctx,
			sset->mem_handle.basep.handle);
	if (!reg) {
		dev_warn(kctx->kbdev->dev, "Can't find region at VA 0x%016llX",
				sset->mem_handle.basep.handle);
		err = -EINVAL;
		goto out_unlock;
	}

	if (!(reg->flags & KBASE_REG_CPU_CACHED))
		goto out_unlock;

	start = (uintptr_t)sset->user_addr;
	size = (size_t)sset->size;

	map = kbasep_find_enclosing_cpu_mapping_of_region(reg, start, size);
	if (!map) {
		dev_warn(kctx->kbdev->dev, "Can't find CPU mapping 0x%016lX for VA 0x%016llX",
				start, sset->mem_handle.basep.handle);
		err = -EINVAL;
		goto out_unlock;
	}

	offset = start & (PAGE_SIZE - 1);
	page_off = map->page_off + ((start - map->vm_start) >> PAGE_SHIFT);
	page_count = (size + offset + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
	cpu_pa = kbase_get_cpu_phy_pages(reg);
	gpu_pa = kbase_get_gpu_phy_pages(reg);

	/* Sync first page */
	if (cpu_pa[page_off]) {
		size_t sz = MIN(((size_t) PAGE_SIZE - offset), size);

		kbase_sync_single(kctx, cpu_pa[page_off], gpu_pa[page_off],
				offset, sz, sync_fn);
	}

	/* Sync middle pages (if any) */
	for (i = 1; page_count > 2 && i < page_count - 1; i++) {
		/* we grow upwards, so bail on first non-present page */
		if (!cpu_pa[page_off + i])
			break;

		kbase_sync_single(kctx, cpu_pa[page_off + i],
				gpu_pa[page_off + i], 0, PAGE_SIZE, sync_fn);
	}

	/* Sync last page (if any) */
	if (page_count > 1 && cpu_pa[page_off + page_count - 1]) {
		size_t sz = ((start + size - 1) & ~PAGE_MASK) + 1;

		kbase_sync_single(kctx, cpu_pa[page_off + page_count - 1],
				gpu_pa[page_off + page_count - 1], 0, sz,
				sync_fn);
	}

out_unlock:
	kbase_gpu_vm_unlock(kctx);
	kbase_os_mem_map_unlock(kctx);
	return err;
}

int kbase_sync_now(struct kbase_context *kctx, struct base_syncset *syncset)
{
	int err = -EINVAL;
	struct basep_syncset *sset;

	KBASE_DEBUG_ASSERT(kctx != NULL);
	KBASE_DEBUG_ASSERT(syncset != NULL);

	sset = &syncset->basep_sset;

	switch (sset->type) {
	case BASE_SYNCSET_OP_MSYNC:
		err = kbase_do_syncset(kctx, syncset, KBASE_SYNC_TO_DEVICE);
		break;

	case BASE_SYNCSET_OP_CSYNC:
		err = kbase_do_syncset(kctx, syncset, KBASE_SYNC_TO_CPU);
		break;

	default:
		dev_warn(kctx->kbdev->dev, "Unknown msync op %d\n", sset->type);
		break;
	}

	return err;
}

/* vm lock must be held */
int kbase_mem_free_region(struct kbase_context *kctx, struct kbase_va_region *reg)
{
	int err;

	KBASE_DEBUG_ASSERT(kctx != NULL);
	KBASE_DEBUG_ASSERT(reg != NULL);
	lockdep_assert_held(&kctx->reg_lock);

	/*
	 * Unlink the physical allocation before unmaking it evictable so
	 * that the allocation isn't grown back to its last backed size
	 * as we're going to unmap it anyway.
	 */
	reg->cpu_alloc->reg = NULL;
	if (reg->cpu_alloc != reg->gpu_alloc)
		reg->gpu_alloc->reg = NULL;

	/*
	 * If a region has been made evictable then we must unmake it
	 * before trying to free it.
	 * If the memory hasn't been reclaimed it will be unmapped and freed
	 * below, if it has been reclaimed then the operations below are no-ops.
	 */
	if (reg->flags & KBASE_REG_DONT_NEED) {
		KBASE_DEBUG_ASSERT(reg->cpu_alloc->type ==
				   KBASE_MEM_TYPE_NATIVE);
		kbase_mem_evictable_unmake(reg->gpu_alloc);
	}

	err = kbase_gpu_munmap(kctx, reg);
	if (err) {
		dev_warn(reg->kctx->kbdev->dev, "Could not unmap from the GPU...\n");
		goto out;
	}
	if (kbase_hw_has_issue(kctx->kbdev, BASE_HW_ISSUE_6367)) {
		/* Wait for GPU to flush write buffer before freeing physical pages */
		kbase_wait_write_flush(kctx);
	}
	/* This will also free the physical pages */
	kbase_free_alloced_region(reg);

 out:
	return err;
}

/**
 * @brief Free the region from the GPU and unregister it.
 *
 * This function implements the free operation on a memory segment.
 * It will loudly fail if called with outstanding mappings.
 */
int kbase_mem_free(struct kbase_context *kctx, u64 gpu_addr)
{
	int err = 0;
	struct kbase_va_region *reg;

	KBASE_DEBUG_ASSERT(kctx != NULL);

	if (gpu_addr == 0) {
		dev_warn(kctx->kbdev->dev, "gpu_addr 0 is reserved for the ringbuffer and it's an error to try to free it using kbase_mem_free\n");
		return -EINVAL;
	}
	kbase_gpu_vm_lock(kctx);

	if (gpu_addr >= BASE_MEM_COOKIE_BASE &&
	    gpu_addr < BASE_MEM_FIRST_FREE_ADDRESS) {
		int cookie = PFN_DOWN(gpu_addr - BASE_MEM_COOKIE_BASE);

		reg = kctx->pending_regions[cookie];
		if (!reg) {
			err = -EINVAL;
			goto out_unlock;
		}

		/* ask to unlink the cookie as we'll free it */

		kctx->pending_regions[cookie] = NULL;
		kctx->cookies |= (1UL << cookie);

		kbase_free_alloced_region(reg);
	} else {
		/* A real GPU va */
		/* Validate the region */
		reg = kbase_region_tracker_find_region_base_address(kctx, gpu_addr);
		if (!reg || (reg->flags & KBASE_REG_FREE)) {
			dev_warn(kctx->kbdev->dev, "kbase_mem_free called with nonexistent gpu_addr 0x%llX",
					gpu_addr);
			err = -EINVAL;
			goto out_unlock;
		}

		if ((reg->flags & KBASE_REG_ZONE_MASK) == KBASE_REG_ZONE_SAME_VA) {
			/* SAME_VA must be freed through munmap */
			dev_warn(kctx->kbdev->dev, "%s called on SAME_VA memory 0x%llX", __func__,
					gpu_addr);
			err = -EINVAL;
			goto out_unlock;
		}
		err = kbase_mem_free_region(kctx, reg);
	}

 out_unlock:
	kbase_gpu_vm_unlock(kctx);
	return err;
}

void kbase_update_region_flags(struct kbase_context *kctx,
		struct kbase_va_region *reg, unsigned long flags)
{
	KBASE_DEBUG_ASSERT(reg != NULL);
	KBASE_DEBUG_ASSERT((flags & ~((1ul << BASE_MEM_FLAGS_NR_BITS) - 1)) == 0);

	reg->flags |= kbase_cache_enabled(flags, reg->nr_pages);
	/* all memory is now growable */
	reg->flags |= KBASE_REG_GROWABLE;

	if (flags & BASE_MEM_GROW_ON_GPF)
		reg->flags |= KBASE_REG_PF_GROW;

	if (flags & BASE_MEM_PROT_CPU_WR)
		reg->flags |= KBASE_REG_CPU_WR;

	if (flags & BASE_MEM_PROT_CPU_RD)
		reg->flags |= KBASE_REG_CPU_RD;

	if (flags & BASE_MEM_PROT_GPU_WR)
		reg->flags |= KBASE_REG_GPU_WR;

	if (flags & BASE_MEM_PROT_GPU_RD)
		reg->flags |= KBASE_REG_GPU_RD;

	if (0 == (flags & BASE_MEM_PROT_GPU_EX))
		reg->flags |= KBASE_REG_GPU_NX;

	if (flags & BASE_MEM_COHERENT_SYSTEM ||
			flags & BASE_MEM_COHERENT_SYSTEM_REQUIRED)
		reg->flags |= KBASE_REG_SHARE_BOTH;
	else if (flags & BASE_MEM_COHERENT_LOCAL)
		reg->flags |= KBASE_REG_SHARE_IN;

	/* Set up default MEMATTR usage */
	if (kctx->kbdev->system_coherency == COHERENCY_ACE &&
		(reg->flags & KBASE_REG_SHARE_BOTH)) {
		reg->flags |=
			KBASE_REG_MEMATTR_INDEX(AS_MEMATTR_INDEX_DEFAULT_ACE);
	} else {
		reg->flags |=
			KBASE_REG_MEMATTR_INDEX(AS_MEMATTR_INDEX_DEFAULT);
	}
}

int kbase_alloc_phy_pages_helper(
	struct kbase_mem_phy_alloc *alloc,
	size_t nr_pages_requested)
{
	int new_page_count __maybe_unused;
	size_t old_page_count = alloc->nents;

	KBASE_DEBUG_ASSERT(alloc->type == KBASE_MEM_TYPE_NATIVE);
	KBASE_DEBUG_ASSERT(alloc->imported.kctx);

	if (nr_pages_requested == 0)
		goto done; /*nothing to do*/

	new_page_count = kbase_atomic_add_pages(
			nr_pages_requested, &alloc->imported.kctx->used_pages);
	kbase_atomic_add_pages(nr_pages_requested, &alloc->imported.kctx->kbdev->memdev.used_pages);

	/* Increase mm counters before we allocate pages so that this
	 * allocation is visible to the OOM killer */
	kbase_process_page_usage_inc(alloc->imported.kctx, nr_pages_requested);

	if (kbase_mem_pool_alloc_pages(&alloc->imported.kctx->mem_pool,
			nr_pages_requested, alloc->pages + old_page_count) != 0)
		goto no_alloc;

	/*
	 * Request a zone cache update, this scans only the new pages an
	 * appends their information to the zone cache. if the update
	 * fails then clear the cache so we fall-back to doing things
	 * page by page.
	 */
	if (kbase_zone_cache_update(alloc, old_page_count) != 0)
		kbase_zone_cache_clear(alloc);

	kbase_tlstream_aux_pagesalloc(
			(u32)alloc->imported.kctx->id,
			(u64)new_page_count);

	alloc->nents += nr_pages_requested;
done:
	return 0;

no_alloc:
	kbase_process_page_usage_dec(alloc->imported.kctx, nr_pages_requested);
	kbase_atomic_sub_pages(nr_pages_requested, &alloc->imported.kctx->used_pages);
	kbase_atomic_sub_pages(nr_pages_requested, &alloc->imported.kctx->kbdev->memdev.used_pages);

	return -ENOMEM;
}

int kbase_free_phy_pages_helper(
	struct kbase_mem_phy_alloc *alloc,
	size_t nr_pages_to_free)
{
	struct kbase_context *kctx = alloc->imported.kctx;
	bool syncback;
	bool reclaimed = (alloc->evicted != 0);
	phys_addr_t *start_free;

	int new_page_count __maybe_unused;

	KBASE_DEBUG_ASSERT(alloc->type == KBASE_MEM_TYPE_NATIVE);
	KBASE_DEBUG_ASSERT(alloc->imported.kctx);
	KBASE_DEBUG_ASSERT(alloc->nents >= nr_pages_to_free);

	/* early out if nothing to do */
	if (nr_pages_to_free == 0)
		return 0;

	start_free = alloc->pages + alloc->nents - nr_pages_to_free;

	syncback = alloc->properties & KBASE_MEM_PHY_ALLOC_ACCESSED_CACHED;

	/*
	 * Clear the zone cache, we don't expect JIT allocations to be
	 * shrunk in parts so there is no point trying to optimize for that
	 * by scanning for the changes caused by freeing this memory and
	 * updating the existing cache entries.
	 */
	kbase_zone_cache_clear(alloc);

	kbase_mem_pool_free_pages(&kctx->mem_pool,
				  nr_pages_to_free,
				  start_free,
				  syncback,
				  reclaimed);

	alloc->nents -= nr_pages_to_free;

	/*
	 * If the allocation was not evicted (i.e. evicted == 0) then
	 * the page accounting needs to be done.
	 */
	if (!reclaimed) {
		kbase_process_page_usage_dec(kctx, nr_pages_to_free);
		new_page_count = kbase_atomic_sub_pages(nr_pages_to_free,
							&kctx->used_pages);
		kbase_atomic_sub_pages(nr_pages_to_free,
				       &kctx->kbdev->memdev.used_pages);

		kbase_tlstream_aux_pagesalloc(
				(u32)kctx->id,
				(u64)new_page_count);
	}

	return 0;
}

void kbase_mem_kref_free(struct kref *kref)
{
	struct kbase_mem_phy_alloc *alloc;

	alloc = container_of(kref, struct kbase_mem_phy_alloc, kref);

	switch (alloc->type) {
	case KBASE_MEM_TYPE_NATIVE: {
		WARN_ON(!alloc->imported.kctx);
		/*
		 * The physical allocation must have been removed from the
		 * eviction list before trying to free it.
		 */
		WARN_ON(!list_empty(&alloc->evict_node));
		kbase_free_phy_pages_helper(alloc, alloc->nents);
		break;
	}
	case KBASE_MEM_TYPE_ALIAS: {
		/* just call put on the underlying phy allocs */
		size_t i;
		struct kbase_aliased *aliased;

		aliased = alloc->imported.alias.aliased;
		if (aliased) {
			for (i = 0; i < alloc->imported.alias.nents; i++)
				if (aliased[i].alloc)
					kbase_mem_phy_alloc_put(aliased[i].alloc);
			vfree(aliased);
		}
		break;
	}
	case KBASE_MEM_TYPE_RAW:
		/* raw pages, external cleanup */
		break;
 #ifdef CONFIG_UMP
	case KBASE_MEM_TYPE_IMPORTED_UMP:
		ump_dd_release(alloc->imported.ump_handle);
		break;
#endif
#ifdef CONFIG_DMA_SHARED_BUFFER
	case KBASE_MEM_TYPE_IMPORTED_UMM:
		dma_buf_detach(alloc->imported.umm.dma_buf,
			       alloc->imported.umm.dma_attachment);
		dma_buf_put(alloc->imported.umm.dma_buf);
		break;
#endif
	case KBASE_MEM_TYPE_IMPORTED_USER_BUF:
		if (alloc->imported.user_buf.mm)
			mmdrop(alloc->imported.user_buf.mm);
		kfree(alloc->imported.user_buf.pages);
		break;
	case KBASE_MEM_TYPE_TB:{
		void *tb;

		tb = alloc->imported.kctx->jctx.tb;
		kbase_device_trace_buffer_uninstall(alloc->imported.kctx);
		vfree(tb);
		break;
	}
	default:
		WARN(1, "Unexecpted free of type %d\n", alloc->type);
		break;
	}

	/* Free based on allocation type */
	if (alloc->properties & KBASE_MEM_PHY_ALLOC_LARGE)
		vfree(alloc);
	else
		kfree(alloc);
}

int kbase_alloc_phy_pages(struct kbase_va_region *reg, size_t vsize, size_t size)
{
	KBASE_DEBUG_ASSERT(reg != NULL);
	KBASE_DEBUG_ASSERT(vsize > 0);

	/* validate user provided arguments */
	if (size > vsize || vsize > reg->nr_pages)
		goto out_term;

	/* Prevent vsize*sizeof from wrapping around.
	 * For instance, if vsize is 2**29+1, we'll allocate 1 byte and the alloc won't fail.
	 */
	if ((size_t) vsize > ((size_t) -1 / sizeof(*reg->cpu_alloc->pages)))
		goto out_term;

	KBASE_DEBUG_ASSERT(vsize != 0);

	if (kbase_alloc_phy_pages_helper(reg->cpu_alloc, size) != 0)
		goto out_term;

	reg->cpu_alloc->reg = reg;
	if (reg->cpu_alloc != reg->gpu_alloc) {
		if (kbase_alloc_phy_pages_helper(reg->gpu_alloc, size) != 0)
			goto out_rollback;
		reg->gpu_alloc->reg = reg;
	}

	return 0;

out_rollback:
	kbase_free_phy_pages_helper(reg->cpu_alloc, size);
out_term:
	return -1;
}

bool kbase_check_alloc_flags(unsigned long flags)
{
	/* Only known input flags should be set. */
	if (flags & ~BASE_MEM_FLAGS_INPUT_MASK)
		return false;

	/* At least one flag should be set */
	if (flags == 0)
		return false;

	/* Either the GPU or CPU must be reading from the allocated memory */
	if ((flags & (BASE_MEM_PROT_CPU_RD | BASE_MEM_PROT_GPU_RD)) == 0)
		return false;

	/* Either the GPU or CPU must be writing to the allocated memory */
	if ((flags & (BASE_MEM_PROT_CPU_WR | BASE_MEM_PROT_GPU_WR)) == 0)
		return false;

	/* GPU cannot be writing to GPU executable memory and cannot grow the memory on page fault. */
	if ((flags & BASE_MEM_PROT_GPU_EX) && (flags & (BASE_MEM_PROT_GPU_WR | BASE_MEM_GROW_ON_GPF)))
		return false;

	/* GPU should have at least read or write access otherwise there is no
	   reason for allocating. */
	if ((flags & (BASE_MEM_PROT_GPU_RD | BASE_MEM_PROT_GPU_WR)) == 0)
		return false;

	/* BASE_MEM_IMPORT_SHARED is only valid for imported memory */
	if ((flags & BASE_MEM_IMPORT_SHARED) == BASE_MEM_IMPORT_SHARED)
		return false;

	return true;
}

bool kbase_check_import_flags(unsigned long flags)
{
	/* Only known input flags should be set. */
	if (flags & ~BASE_MEM_FLAGS_INPUT_MASK)
		return false;

	/* At least one flag should be set */
	if (flags == 0)
		return false;

	/* Imported memory cannot be GPU executable */
	if (flags & BASE_MEM_PROT_GPU_EX)
		return false;

	/* Imported memory cannot grow on page fault */
	if (flags & BASE_MEM_GROW_ON_GPF)
		return false;

	/* GPU should have at least read or write access otherwise there is no
	   reason for importing. */
	if ((flags & (BASE_MEM_PROT_GPU_RD | BASE_MEM_PROT_GPU_WR)) == 0)
		return false;

	/* Secure memory cannot be read by the CPU */
	if ((flags & BASE_MEM_SECURE) && (flags & BASE_MEM_PROT_CPU_RD))
		return false;

	return true;
}

/**
 * @brief Acquire the per-context region list lock
 */
void kbase_gpu_vm_lock(struct kbase_context *kctx)
{
	KBASE_DEBUG_ASSERT(kctx != NULL);
	mutex_lock(&kctx->reg_lock);
}

/**
 * @brief Release the per-context region list lock
 */
void kbase_gpu_vm_unlock(struct kbase_context *kctx)
{
	KBASE_DEBUG_ASSERT(kctx != NULL);
	mutex_unlock(&kctx->reg_lock);
}

/**
 * kbase_jit_destroy_worker - Deferred worker which frees JIT allocations
 * @work: Work item
 *
 * This function does the work of freeing JIT allocations whose physical
 * backing has been released.
 */
static void kbase_jit_destroy_worker(struct work_struct *work)
{
	struct kbase_context *kctx;
	struct kbase_va_region *reg;

	kctx = container_of(work, struct kbase_context, jit_work);
	do {
		mutex_lock(&kctx->jit_lock);
		if (list_empty(&kctx->jit_destroy_head))
			reg = NULL;
		else
			reg = list_first_entry(&kctx->jit_destroy_head,
				struct kbase_va_region, jit_node);

		if (reg) {
			list_del(&reg->jit_node);
			mutex_unlock(&kctx->jit_lock);

			kbase_gpu_vm_lock(kctx);
			kbase_mem_free_region(kctx, reg);
			kbase_gpu_vm_unlock(kctx);
		} else
			mutex_unlock(&kctx->jit_lock);
	} while (reg);
}

int kbase_jit_init(struct kbase_context *kctx)
{
	INIT_LIST_HEAD(&kctx->jit_active_head);
	INIT_LIST_HEAD(&kctx->jit_pool_head);
	INIT_LIST_HEAD(&kctx->jit_destroy_head);
	mutex_init(&kctx->jit_lock);
	INIT_WORK(&kctx->jit_work, kbase_jit_destroy_worker);

	return 0;
}

struct kbase_va_region *kbase_jit_allocate(struct kbase_context *kctx,
		struct base_jit_alloc_info *info)
{
	struct kbase_va_region *reg = NULL;
	struct kbase_va_region *walker;
	struct kbase_va_region *temp;
	size_t current_diff = SIZE_MAX;

	int ret;

	mutex_lock(&kctx->jit_lock);
	/*
	 * Scan the pool for an existing allocation which meets our
	 * requirements and remove it.
	 */
	list_for_each_entry_safe(walker, temp, &kctx->jit_pool_head, jit_node) {

		if (walker->nr_pages >= info->va_pages) {
			size_t min_size, max_size, diff;

			/*
			 * The JIT allocations VA requirements have been
			 * meet, it's suitable but other allocations
			 * might be a better fit.
			 */
			min_size = min_t(size_t, walker->gpu_alloc->nents,
					info->commit_pages);
			max_size = max_t(size_t, walker->gpu_alloc->nents,
					info->commit_pages);
			diff = max_size - min_size;

			if (current_diff > diff) {
				current_diff = diff;
				reg = walker;
			}

			/* The allocation is an exact match, stop looking */
			if (current_diff == 0)
				break;
		}
	}

	if (reg) {
		/*
		 * Remove the found region from the pool and add it to the
		 * active list.
		 */
		list_del_init(&reg->jit_node);
		list_add(&reg->jit_node, &kctx->jit_active_head);

		/* Release the jit lock before modifying the allocation */
		mutex_unlock(&kctx->jit_lock);

		kbase_gpu_vm_lock(kctx);

		/* Make the physical backing no longer reclaimable */
		if (!kbase_mem_evictable_unmake(reg->gpu_alloc))
			goto update_failed;

		/* Grow the backing if required */
		if (reg->gpu_alloc->nents < info->commit_pages) {
			size_t delta;
			size_t old_size = reg->gpu_alloc->nents;

			/* Allocate some more pages */
			delta = info->commit_pages - reg->gpu_alloc->nents;
			if (kbase_alloc_phy_pages_helper(reg->gpu_alloc, delta)
					!= 0)
				goto update_failed;

			if (reg->cpu_alloc != reg->gpu_alloc) {
				if (kbase_alloc_phy_pages_helper(
						reg->cpu_alloc, delta) != 0) {
					kbase_free_phy_pages_helper(
							reg->gpu_alloc, delta);
					goto update_failed;
				}
			}

			ret = kbase_mem_grow_gpu_mapping(kctx, reg,
					info->commit_pages, old_size);
			/*
			 * The grow failed so put the allocation back in the
			 * pool and return failure.
			 */
			if (ret)
				goto update_failed;
		}
		kbase_gpu_vm_unlock(kctx);
	} else {
		/* No suitable JIT allocation was found so create a new one */
		u64 flags = BASE_MEM_PROT_CPU_RD | BASE_MEM_PROT_GPU_RD |
				BASE_MEM_PROT_GPU_WR | BASE_MEM_GROW_ON_GPF |
				BASE_MEM_COHERENT_LOCAL;
		u64 gpu_addr;
		u16 alignment;

		mutex_unlock(&kctx->jit_lock);

		reg = kbase_mem_alloc(kctx, info->va_pages, info->commit_pages,
				info->extent, &flags, &gpu_addr, &alignment);
		if (!reg)
			goto out_unlocked;

		mutex_lock(&kctx->jit_lock);
		list_add(&reg->jit_node, &kctx->jit_active_head);
		mutex_unlock(&kctx->jit_lock);
	}

	return reg;

update_failed:
	/*
	 * An update to an allocation from the pool failed, chances
	 * are slim a new allocation would fair any better so return
	 * the allocation to the pool and return the function with failure.
	 */
	kbase_gpu_vm_unlock(kctx);
	mutex_lock(&kctx->jit_lock);
	list_del_init(&reg->jit_node);
	list_add(&reg->jit_node, &kctx->jit_pool_head);
	mutex_unlock(&kctx->jit_lock);
out_unlocked:
	return NULL;
}

void kbase_jit_free(struct kbase_context *kctx, struct kbase_va_region *reg)
{
	/* The physical backing of memory in the pool is always reclaimable */
	down_read(&kctx->process_mm->mmap_sem);
	kbase_gpu_vm_lock(kctx);
	kbase_mem_evictable_make(reg->gpu_alloc);
	kbase_gpu_vm_unlock(kctx);
	up_read(&kctx->process_mm->mmap_sem);

	mutex_lock(&kctx->jit_lock);
	list_del_init(&reg->jit_node);
	list_add(&reg->jit_node, &kctx->jit_pool_head);
	mutex_unlock(&kctx->jit_lock);
}

void kbase_jit_backing_lost(struct kbase_va_region *reg)
{
	struct kbase_context *kctx = reg->kctx;

	/*
	 * JIT allocations will always be on a list, if the region
	 * is not on a list then it's not a JIT allocation.
	 */
	if (list_empty(&reg->jit_node))
		return;

	/*
	 * Freeing the allocation requires locks we might not be able
	 * to take now, so move the allocation to the free list and kick
	 * the worker which will do the freeing.
	 */
	mutex_lock(&kctx->jit_lock);
	list_del_init(&reg->jit_node);
	list_add(&reg->jit_node, &kctx->jit_destroy_head);
	mutex_unlock(&kctx->jit_lock);

	schedule_work(&kctx->jit_work);
}

bool kbase_jit_evict(struct kbase_context *kctx)
{
	struct kbase_va_region *reg = NULL;

	lockdep_assert_held(&kctx->reg_lock);

	/* Free the oldest allocation from the pool */
	mutex_lock(&kctx->jit_lock);
	if (!list_empty(&kctx->jit_pool_head)) {
		reg = list_entry(kctx->jit_pool_head.prev,
				struct kbase_va_region, jit_node);
		list_del(&reg->jit_node);
	}
	mutex_unlock(&kctx->jit_lock);

	if (reg)
		kbase_mem_free_region(kctx, reg);

	return (reg != NULL);
}

void kbase_jit_term(struct kbase_context *kctx)
{
	struct kbase_va_region *walker;

	/* Free all allocations for this context */

	/*
	 * Flush the freeing of allocations whose backing has been freed
	 * (i.e. everything in jit_destroy_head).
	 */
	cancel_work_sync(&kctx->jit_work);

	kbase_gpu_vm_lock(kctx);
	/* Free all allocations from the pool */
	while (!list_empty(&kctx->jit_pool_head)) {
		walker = list_first_entry(&kctx->jit_pool_head,
				struct kbase_va_region, jit_node);
		list_del(&walker->jit_node);
		kbase_mem_free_region(kctx, walker);
	}

	/* Free all allocations from active list */
	while (!list_empty(&kctx->jit_active_head)) {
		walker = list_first_entry(&kctx->jit_active_head,
				struct kbase_va_region, jit_node);
		list_del(&walker->jit_node);
		kbase_mem_free_region(kctx, walker);
	}
	kbase_gpu_vm_unlock(kctx);
}

static int kbase_jd_user_buf_map(struct kbase_context *kctx,
		struct kbase_va_region *reg)
{
	long pinned_pages;
	struct kbase_mem_phy_alloc *alloc;
	struct page **pages;
	phys_addr_t *pa;
	long i;
	int err = -ENOMEM;
	unsigned long address;
	struct mm_struct *mm;
	struct device *dev;
	unsigned long offset;
	unsigned long local_size;

	alloc = reg->gpu_alloc;
	pa = kbase_get_gpu_phy_pages(reg);
	address = alloc->imported.user_buf.address;
	mm = alloc->imported.user_buf.mm;

	KBASE_DEBUG_ASSERT(alloc->type == KBASE_MEM_TYPE_IMPORTED_USER_BUF);

	pages = alloc->imported.user_buf.pages;

	pinned_pages = get_user_pages(
			address,
			alloc->imported.user_buf.nr_pages,
			(reg->flags & KBASE_REG_GPU_WR) ? FOLL_WRITE : 0,
			pages, NULL);

	if (pinned_pages <= 0)
		return pinned_pages;

	if (pinned_pages != alloc->imported.user_buf.nr_pages) {
		for (i = 0; i < pinned_pages; i++)
			put_page(pages[i]);
		return -ENOMEM;
	}

	dev = kctx->kbdev->dev;
	offset = address & ~PAGE_MASK;
	local_size = alloc->imported.user_buf.size;

	for (i = 0; i < pinned_pages; i++) {
		dma_addr_t dma_addr;
		unsigned long min;

		min = MIN(PAGE_SIZE - offset, local_size);
		dma_addr = dma_map_page(dev, pages[i],
				offset, min,
				DMA_BIDIRECTIONAL);
		if (dma_mapping_error(dev, dma_addr))
			goto unwind;

		alloc->imported.user_buf.dma_addrs[i] = dma_addr;
		pa[i] = page_to_phys(pages[i]);

		local_size -= min;
		offset = 0;
	}

	alloc->nents = pinned_pages;

	err = kbase_mmu_insert_pages(kctx, reg->start_pfn, pa,
			kbase_reg_current_backed_size(reg),
			reg->flags);
	if (err == 0)
		return 0;

	alloc->nents = 0;
	/* fall down */
unwind:
	while (i--) {
		dma_unmap_page(kctx->kbdev->dev,
				alloc->imported.user_buf.dma_addrs[i],
				PAGE_SIZE, DMA_BIDIRECTIONAL);
		put_page(pages[i]);
		pages[i] = NULL;
	}

	return err;
}

static void kbase_jd_user_buf_unmap(struct kbase_context *kctx,
		struct kbase_mem_phy_alloc *alloc, bool writeable)
{
	long i;
	struct page **pages;
	unsigned long size = alloc->imported.user_buf.size;

	KBASE_DEBUG_ASSERT(alloc->type == KBASE_MEM_TYPE_IMPORTED_USER_BUF);
	pages = alloc->imported.user_buf.pages;
	for (i = 0; i < alloc->imported.user_buf.nr_pages; i++) {
		unsigned long local_size;
		dma_addr_t dma_addr = alloc->imported.user_buf.dma_addrs[i];

		local_size = MIN(size, PAGE_SIZE - (dma_addr & ~PAGE_MASK));
		dma_unmap_page(kctx->kbdev->dev, dma_addr, local_size,
				DMA_BIDIRECTIONAL);
		if (writeable)
			set_page_dirty_lock(pages[i]);
		put_page(pages[i]);
		pages[i] = NULL;

		size -= local_size;
	}
	alloc->nents = 0;
}

#ifdef CONFIG_DMA_SHARED_BUFFER
extern int kbase_jd_umm_map(struct kbase_context *kctx,
		struct kbase_va_region *reg)
{
	struct sg_table *sgt;
	struct scatterlist *s;
	int i;
	phys_addr_t *pa;
	int err;
	size_t count = 0;
	struct kbase_mem_phy_alloc *alloc;

	alloc = reg->gpu_alloc;

	KBASE_DEBUG_ASSERT(alloc->type == KBASE_MEM_TYPE_IMPORTED_UMM);
	KBASE_DEBUG_ASSERT(alloc->imported.umm.sgt == NULL);
	sgt = dma_buf_map_attachment(alloc->imported.umm.dma_attachment,
			DMA_BIDIRECTIONAL);

	if (IS_ERR_OR_NULL(sgt))
		return -EINVAL;

	/* save for later */
	alloc->imported.umm.sgt = sgt;

	pa = kbase_get_gpu_phy_pages(reg);
	KBASE_DEBUG_ASSERT(pa);

	for_each_sg(sgt->sgl, s, sgt->nents, i) {
		int j;
		size_t pages = PFN_UP(sg_dma_len(s));

		WARN_ONCE(sg_dma_len(s) & (PAGE_SIZE-1),
		"sg_dma_len(s)=%u is not a multiple of PAGE_SIZE\n",
		sg_dma_len(s));

		WARN_ONCE(sg_dma_address(s) & (PAGE_SIZE-1),
		"sg_dma_address(s)=%llx is not aligned to PAGE_SIZE\n",
		(unsigned long long) sg_dma_address(s));

		for (j = 0; (j < pages) && (count < reg->nr_pages); j++,
				count++)
			*pa++ = sg_dma_address(s) + (j << PAGE_SHIFT);
		WARN_ONCE(j < pages,
		"sg list from dma_buf_map_attachment > dma_buf->size=%zu\n",
		alloc->imported.umm.dma_buf->size);
	}

	if (WARN_ONCE(count < reg->nr_pages,
			"sg list from dma_buf_map_attachment < dma_buf->size=%zu\n",
			alloc->imported.umm.dma_buf->size)) {
		err = -EINVAL;
		goto out;
	}

	/* Update nents as we now have pages to map */
	alloc->nents = count;

	err = kbase_mmu_insert_pages(kctx, reg->start_pfn,
			kbase_get_gpu_phy_pages(reg),
			kbase_reg_current_backed_size(reg),
			reg->flags | KBASE_REG_GPU_WR | KBASE_REG_GPU_RD);

out:
	if (err) {
		dma_buf_unmap_attachment(alloc->imported.umm.dma_attachment,
				alloc->imported.umm.sgt, DMA_BIDIRECTIONAL);
		alloc->imported.umm.sgt = NULL;
	}

	return err;
}

extern void kbase_jd_umm_unmap(struct kbase_context *kctx,
		struct kbase_mem_phy_alloc *alloc)
{
	KBASE_DEBUG_ASSERT(kctx);
	KBASE_DEBUG_ASSERT(alloc);
	KBASE_DEBUG_ASSERT(alloc->imported.umm.dma_attachment);
	KBASE_DEBUG_ASSERT(alloc->imported.umm.sgt);
	dma_buf_unmap_attachment(alloc->imported.umm.dma_attachment,
	    alloc->imported.umm.sgt, DMA_BIDIRECTIONAL);
	alloc->imported.umm.sgt = NULL;
	alloc->nents = 0;
}
#endif				/* CONFIG_DMA_SHARED_BUFFER */

#if (defined(CONFIG_KDS) && defined(CONFIG_UMP)) \
		|| defined(CONFIG_DMA_SHARED_BUFFER_USES_KDS)
static void add_kds_resource(struct kds_resource *kds_res,
		struct kds_resource **kds_resources, u32 *kds_res_count,
		unsigned long *kds_access_bitmap, bool exclusive)
{
	u32 i;

	for (i = 0; i < *kds_res_count; i++) {
		/* Duplicate resource, ignore */
		if (kds_resources[i] == kds_res)
			return;
	}

	kds_resources[*kds_res_count] = kds_res;
	if (exclusive)
		set_bit(*kds_res_count, kds_access_bitmap);
	(*kds_res_count)++;
}
#endif

struct kbase_mem_phy_alloc *kbase_map_external_resource(
		struct kbase_context *kctx, struct kbase_va_region *reg,
		struct mm_struct *locked_mm
#ifdef CONFIG_KDS
		, u32 *kds_res_count, struct kds_resource **kds_resources,
		unsigned long *kds_access_bitmap, bool exclusive
#endif
		)
{
	int err;

	/* decide what needs to happen for this resource */
	switch (reg->gpu_alloc->type) {
	case BASE_MEM_IMPORT_TYPE_USER_BUFFER: {
		if (reg->gpu_alloc->imported.user_buf.mm != locked_mm)
			goto exit;

		reg->gpu_alloc->imported.user_buf.current_mapping_usage_count++;
		if (reg->gpu_alloc->imported.user_buf.current_mapping_usage_count == 1) {
			err = kbase_jd_user_buf_map(kctx, reg);
			if (err) {
				reg->gpu_alloc->imported.user_buf.current_mapping_usage_count--;
				goto exit;
			}
		}
	}
	break;
	case BASE_MEM_IMPORT_TYPE_UMP: {
#if defined(CONFIG_KDS) && defined(CONFIG_UMP)
		if (kds_res_count) {
			struct kds_resource *kds_res;

			kds_res = ump_dd_kds_resource_get(
					reg->gpu_alloc->imported.ump_handle);
			if (kds_res)
				add_kds_resource(kds_res, kds_resources,
						kds_res_count,
						kds_access_bitmap, exclusive);
		}
#endif				/*defined(CONFIG_KDS) && defined(CONFIG_UMP) */
		break;
	}
#ifdef CONFIG_DMA_SHARED_BUFFER
	case BASE_MEM_IMPORT_TYPE_UMM: {
#ifdef CONFIG_DMA_SHARED_BUFFER_USES_KDS
		if (kds_res_count) {
			struct kds_resource *kds_res;

			kds_res = get_dma_buf_kds_resource(
					reg->gpu_alloc->imported.umm.dma_buf);
			if (kds_res)
				add_kds_resource(kds_res, kds_resources,
						kds_res_count,
						kds_access_bitmap, exclusive);
		}
#endif
		reg->gpu_alloc->imported.umm.current_mapping_usage_count++;
		if (reg->gpu_alloc->imported.umm.current_mapping_usage_count == 1) {
			err = kbase_jd_umm_map(kctx, reg);
			if (err) {
				reg->gpu_alloc->imported.umm.current_mapping_usage_count--;
				goto exit;
			}
		}
		break;
	}
#endif
	default:
		goto exit;
	}

	return kbase_mem_phy_alloc_get(reg->gpu_alloc);
exit:
	return NULL;
}

void kbase_unmap_external_resource(struct kbase_context *kctx,
		struct kbase_va_region *reg, struct kbase_mem_phy_alloc *alloc)
{
	switch (alloc->type) {
#ifdef CONFIG_DMA_SHARED_BUFFER
	case KBASE_MEM_TYPE_IMPORTED_UMM: {
		alloc->imported.umm.current_mapping_usage_count--;

		if (alloc->imported.umm.current_mapping_usage_count == 0) {
			if (reg && reg->gpu_alloc == alloc)
				kbase_mmu_teardown_pages(
						kctx,
						reg->start_pfn,
						kbase_reg_current_backed_size(reg));

			kbase_jd_umm_unmap(kctx, alloc);
		}
	}
	break;
#endif /* CONFIG_DMA_SHARED_BUFFER */
	case KBASE_MEM_TYPE_IMPORTED_USER_BUF: {
		alloc->imported.user_buf.current_mapping_usage_count--;

		if (alloc->imported.user_buf.current_mapping_usage_count == 0) {
			bool writeable = true;

			if (reg && reg->gpu_alloc == alloc)
				kbase_mmu_teardown_pages(
						kctx,
						reg->start_pfn,
						kbase_reg_current_backed_size(reg));

			if (reg && ((reg->flags & KBASE_REG_GPU_WR) == 0))
				writeable = false;

			kbase_jd_user_buf_unmap(kctx, alloc, writeable);
		}
	}
	break;
	default:
	break;
	}
	kbase_mem_phy_alloc_put(alloc);
}

struct kbase_ctx_ext_res_meta *kbase_sticky_resource_acquire(
		struct kbase_context *kctx, u64 gpu_addr)
{
	struct kbase_ctx_ext_res_meta *meta = NULL;
	struct kbase_ctx_ext_res_meta *walker;

	lockdep_assert_held(&kctx->reg_lock);

	/*
	 * Walk the per context external resource metadata list for the
	 * metadata which matches the region which is being acquired.
	 */
	list_for_each_entry(walker, &kctx->ext_res_meta_head, ext_res_node) {
		if (walker->gpu_addr == gpu_addr) {
			meta = walker;
			break;
		}
	}

	/* No metadata exists so create one. */
	if (!meta) {
		struct kbase_va_region *reg;

		/* Find the region */
		reg = kbase_region_tracker_find_region_enclosing_address(
				kctx, gpu_addr);
		if (NULL == reg || (reg->flags & KBASE_REG_FREE))
			goto failed;

		/* Allocate the metadata object */
		meta = kzalloc(sizeof(*meta), GFP_KERNEL);
		if (!meta)
			goto failed;

		/*
		 * Fill in the metadata object and acquire a reference
		 * for the physical resource.
		 */
		meta->alloc = kbase_map_external_resource(kctx, reg, NULL
#ifdef CONFIG_KDS
				, NULL, NULL,
				NULL, false
#endif
				);

		if (!meta->alloc)
			goto fail_map;

		meta->gpu_addr = reg->start_pfn << PAGE_SHIFT;

		list_add(&meta->ext_res_node, &kctx->ext_res_meta_head);
	}

	return meta;

fail_map:
	kfree(meta);
failed:
	return NULL;
}

bool kbase_sticky_resource_release(struct kbase_context *kctx,
		struct kbase_ctx_ext_res_meta *meta, u64 gpu_addr)
{
	struct kbase_ctx_ext_res_meta *walker;
	struct kbase_va_region *reg;

	lockdep_assert_held(&kctx->reg_lock);

	/* Search of the metadata if one isn't provided. */
	if (!meta) {
		/*
		 * Walk the per context external resource metadata list for the
		 * metadata which matches the region which is being released.
		 */
		list_for_each_entry(walker, &kctx->ext_res_meta_head,
				ext_res_node) {
			if (walker->gpu_addr == gpu_addr) {
				meta = walker;
				break;
			}
		}
	}

	/* No metadata so just return. */
	if (!meta)
		return false;

	/* Drop the physical memory reference and free the metadata. */
	reg = kbase_region_tracker_find_region_enclosing_address(
			kctx,
			meta->gpu_addr);

	kbase_unmap_external_resource(kctx, reg, meta->alloc);
	list_del(&meta->ext_res_node);
	kfree(meta);

	return true;
}

int kbase_sticky_resource_init(struct kbase_context *kctx)
{
	INIT_LIST_HEAD(&kctx->ext_res_meta_head);

	return 0;
}

void kbase_sticky_resource_term(struct kbase_context *kctx)
{
	struct kbase_ctx_ext_res_meta *walker;

	lockdep_assert_held(&kctx->reg_lock);

	/*
	 * Free any sticky resources which haven't been unmapped.
	 *
	 * Note:
	 * We don't care about refcounts at this point as no future
	 * references to the meta data will be made.
	 * Region termination would find these if we didn't free them
	 * here, but it's more efficient if we do the clean up here.
	 */
	while (!list_empty(&kctx->ext_res_meta_head)) {
		walker = list_first_entry(&kctx->ext_res_meta_head,
				struct kbase_ctx_ext_res_meta, ext_res_node);

		kbase_sticky_resource_release(kctx, walker, 0);
	}
}