memremap: Convert to XArray

/* SPDX-License-Identifier: GPL-2.0 */

/* Copyright(c) 2015 Intel Corporation. All rights reserved. */

#include <linux/radix-tree.h>

#include <linux/device.h>

#include <linux/types.h>

#include <linux/pfn_t.h>

#include <linux/io.h>

#include <linux/kasan.h>

#include <linux/mm.h>

#include <linux/memory_hotplug.h>

#include <linux/mm.h>

#include <linux/pfn_t.h>

#include <linux/swap.h>

#include <linux/swapops.h>

#include <linux/types.h>

#include <linux/wait_bit.h>

#include <linux/xarray.h>

static DEFINE_MUTEX(pgmap_lock);

static RADIX_TREE(pgmap_radix, GFP_KERNEL);

static DEFINE_XARRAY(pgmap_array);

#define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1)

#define SECTION_SIZE (1UL << PA_SECTION_SHIFT)

static unsigned long order_at(struct resource *res, unsigned long pgoff)

{

	unsigned long phys_pgoff = PHYS_PFN(res->start) + pgoff;

	unsigned long nr_pages, mask;

	nr_pages = PHYS_PFN(resource_size(res));

	if (nr_pages == pgoff)

		return ULONG_MAX;

	/*

	 * What is the largest aligned power-of-2 range available from

	 * this resource pgoff to the end of the resource range,

	 * considering the alignment of the current pgoff?

	 */

	mask = phys_pgoff | rounddown_pow_of_two(nr_pages - pgoff);

	if (!mask)

		return ULONG_MAX;

	return find_first_bit(&mask, BITS_PER_LONG);

}

#define foreach_order_pgoff(res, order, pgoff) \

	for (pgoff = 0, order = order_at((res), pgoff); order < ULONG_MAX; \

			pgoff += 1UL << order, order = order_at((res), pgoff))

#if IS_ENABLED(CONFIG_DEVICE_PRIVATE)

vm_fault_t device_private_entry_fault(struct vm_area_struct *vma,

		       unsigned long addr,

EXPORT_SYMBOL(device_private_entry_fault);

#endif /* CONFIG_DEVICE_PRIVATE */

static void pgmap_radix_release(struct resource *res, unsigned long end_pgoff)

static void pgmap_array_delete(struct resource *res)

{

	unsigned long pgoff, order;

	mutex_lock(&pgmap_lock);

	foreach_order_pgoff(res, order, pgoff) {

		if (pgoff >= end_pgoff)

			break;

		radix_tree_delete(&pgmap_radix, PHYS_PFN(res->start) + pgoff);

	}

	mutex_unlock(&pgmap_lock);

	xa_store_range(&pgmap_array, PHYS_PFN(res->start), PHYS_PFN(res->end),

			NULL, GFP_KERNEL);

	synchronize_rcu();

}

	mem_hotplug_done();

	untrack_pfn(NULL, PHYS_PFN(align_start), align_size);

	pgmap_radix_release(res, -1);

	pgmap_array_delete(res);

	dev_WARN_ONCE(dev, pgmap->altmap.alloc,

		      "%s: failed to free all reserved pages\n", __func__);

}

	struct vmem_altmap *altmap = pgmap->altmap_valid ?

			&pgmap->altmap : NULL;

	struct resource *res = &pgmap->res;

	unsigned long pfn, pgoff, order;

	unsigned long pfn;

	pgprot_t pgprot = PAGE_KERNEL;

	int error, nid, is_ram;

	struct dev_pagemap *conflict_pgmap;

	pgmap->dev = dev;

	mutex_lock(&pgmap_lock);

	error = 0;

	foreach_order_pgoff(res, order, pgoff) {

		error = __radix_tree_insert(&pgmap_radix,

				PHYS_PFN(res->start) + pgoff, order, pgmap);

		if (error) {

			dev_err(dev, "%s: failed: %d\n", __func__, error);

			break;

		}

	}

	mutex_unlock(&pgmap_lock);

	error = xa_err(xa_store_range(&pgmap_array, PHYS_PFN(res->start),

				PHYS_PFN(res->end), pgmap, GFP_KERNEL));

	if (error)

		goto err_radix;

		goto err_array;

	nid = dev_to_node(dev);

	if (nid < 0)

 err_kasan:

	untrack_pfn(NULL, PHYS_PFN(align_start), align_size);

 err_pfn_remap:

 err_radix:

	pgmap_radix_release(res, pgoff);

	pgmap_array_delete(res);

 err_array:

	return ERR_PTR(error);

}

EXPORT_SYMBOL(devm_memremap_pages);

	/* fall back to slow path lookup */

	rcu_read_lock();

	pgmap = radix_tree_lookup(&pgmap_radix, PHYS_PFN(phys));

	pgmap = xa_load(&pgmap_array, PHYS_PFN(phys));

	if (pgmap && !percpu_ref_tryget_live(pgmap->ref))

		pgmap = NULL;

	rcu_read_unlock();