dax-private.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright(c) 2016 Intel Corporation. All rights reserved.
 */
#ifndef __DAX_PRIVATE_H__
#define __DAX_PRIVATE_H__

#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/idr.h>

/* private routines between core files */
struct dax_device;
struct dax_device *inode_dax(struct inode *inode);
struct inode *dax_inode(struct dax_device *dax_dev);
int dax_bus_init(void);
void dax_bus_exit(void);

/**
 * struct dax_region - mapping infrastructure for dax devices
 * @id: kernel-wide unique region for a memory range
 * @target_node: effective numa node if this memory range is onlined
 * @kref: to pin while other agents have a need to do lookups
 * @dev: parent device backing this region
 * @align: allocation and mapping alignment for child dax devices
 * @ida: instance id allocator
 * @res: resource tree to track instance allocations
 * @seed: allow userspace to find the first unbound seed device
 * @youngest: allow userspace to find the most recently created device
 */
struct dax_region {
	int id;
	int target_node;
	struct kref kref;
	struct device *dev;
	unsigned int align;
	struct ida ida;
	struct resource res;
	struct device *seed;
	struct device *youngest;
};

/**
 * struct dax_mapping - device to display mapping range attributes
 * @dev: device representing this range
 * @range_id: index within dev_dax ranges array
 * @id: ida of this mapping
 */
struct dax_mapping {
	struct device dev;
	int range_id;
	int id;
};

/**
 * struct dev_dax_range - tuple represenging a range of memory used by dev_dax
 * @pgoff: page offset
 * @range: resource-span
 * @mapping: reference to the dax_mapping for this range
 */
struct dev_dax_range {
	unsigned long pgoff;
	struct range range;
	struct dax_mapping *mapping;
};

/**
 * struct dev_dax - instance data for a subdivision of a dax region, and
 * data while the device is activated in the driver.
 * @region - parent region
 * @dax_dev - core dax functionality
 * @target_node: effective numa node if dev_dax memory range is onlined
 * @dyn_id: is this a dynamic or statically created instance
 * @id: ida allocated id when the dax_region is not static
 * @ida: mapping id allocator
 * @dev - device core
 * @pgmap - pgmap for memmap setup / lifetime (driver owned)
 * @nr_range: size of @ranges
 * @ranges: range tuples of memory used
 */
struct dev_dax {
	struct dax_region *region;
	struct dax_device *dax_dev;
	unsigned int align;
	int target_node;
	bool dyn_id;
	int id;
	struct ida ida;
	struct device dev;
	struct dev_pagemap *pgmap;
	bool memmap_on_memory;
	int nr_range;
	struct dev_dax_range *ranges;
};

/*
 * While run_dax() is potentially a generic operation that could be
 * defined in include/linux/dax.h we don't want to grow any users
 * outside of drivers/dax/
 */
void run_dax(struct dax_device *dax_dev);

static inline struct dev_dax *to_dev_dax(struct device *dev)
{
	return container_of(dev, struct dev_dax, dev);
}

static inline struct dax_mapping *to_dax_mapping(struct device *dev)
{
	return container_of(dev, struct dax_mapping, dev);
}

phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff, unsigned long size);

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static inline bool dax_align_valid(unsigned long align)
{
	if (align == PUD_SIZE && IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD))
		return true;
	if (align == PMD_SIZE && has_transparent_hugepage())
		return true;
	if (align == PAGE_SIZE)
		return true;
	return false;
}
#else
static inline bool dax_align_valid(unsigned long align)
{
	return align == PAGE_SIZE;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif