70aab281e1
The reference counting of dax_region objects is needlessly complicated,
has lead to confusion [1], and has hidden a bug [2]. Towards cleaning up
that mess introduce alloc_dev_dax_id() to minimize the holding of a
dax_region reference to only what dev_dax_release() needs, the
dax_region->ida.
Part of the reason for the mess was the design to dereference a
dax_region in all cases in free_dev_dax_id() even if the id was
statically assigned by the upper level dax_region driver. Remove the
need to call "is_static(dax_region)" by tracking whether the id is
dynamic directly in the dev_dax instance itself.
With that flag the dax_region pinning and release per dev_dax instance
can move to alloc_dev_dax_id() and free_dev_dax_id() respectively.
A follow-on cleanup address the unnecessary references in the dax_region
setup and drivers.
Fixes: 0f3da14a4f ("device-dax: introduce 'seed' devices")
Link: http://lore.kernel.org/r/20221203095858.612027-1-liuyongqiang13@huawei.com [1]
Link: http://lore.kernel.org/r/3cf0890b-4eb0-e70e-cd9c-2ecc3d496263@hpe.com [2]
Reported-by: Yongqiang Liu <liuyongqiang13@huawei.com>
Reported-by: Paul Cassella <cassella@hpe.com>
Reported-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/168577284563.1672036.13493034988900989554.stgit@dwillia2-xfh.jf.intel.com
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
118 lines
3.2 KiB
C
118 lines
3.2 KiB
C
/* 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 {
|
|
struct device dev;
|
|
int range_id;
|
|
int id;
|
|
};
|
|
|
|
/**
|
|
* 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: resource-span + pgoff tuples for the instance
|
|
*/
|
|
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;
|
|
int nr_range;
|
|
struct dev_dax_range {
|
|
unsigned long pgoff;
|
|
struct range range;
|
|
struct dax_mapping *mapping;
|
|
} *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
|