linux_dsm_epyc7002/tools/testing/nvdimm/test/iomap.c
Dan Williams a95c90f1e2 mm, devm_memremap_pages: fix shutdown handling
The last step before devm_memremap_pages() returns success is to allocate
a release action, devm_memremap_pages_release(), to tear the entire setup
down.  However, the result from devm_add_action() is not checked.

Checking the error from devm_add_action() is not enough.  The api
currently relies on the fact that the percpu_ref it is using is killed by
the time the devm_memremap_pages_release() is run.  Rather than continue
this awkward situation, offload the responsibility of killing the
percpu_ref to devm_memremap_pages_release() directly.  This allows
devm_memremap_pages() to do the right thing relative to init failures and
shutdown.

Without this change we could fail to register the teardown of
devm_memremap_pages().  The likelihood of hitting this failure is tiny as
small memory allocations almost always succeed.  However, the impact of
the failure is large given any future reconfiguration, or disable/enable,
of an nvdimm namespace will fail forever as subsequent calls to
devm_memremap_pages() will fail to setup the pgmap_radix since there will
be stale entries for the physical address range.

An argument could be made to require that the ->kill() operation be set in
the @pgmap arg rather than passed in separately.  However, it helps code
readability, tracking the lifetime of a given instance, to be able to grep
the kill routine directly at the devm_memremap_pages() call site.

Link: http://lkml.kernel.org/r/154275558526.76910.7535251937849268605.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Fixes: e8d5134833 ("memremap: change devm_memremap_pages interface...")
Reviewed-by: "Jérôme Glisse" <jglisse@redhat.com>
Reported-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 12:11:47 -08:00

404 lines
10 KiB
C

/*
* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
#include <linux/memremap.h>
#include <linux/rculist.h>
#include <linux/export.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/pfn_t.h>
#include <linux/acpi.h>
#include <linux/io.h>
#include <linux/mm.h>
#include "nfit_test.h"
static LIST_HEAD(iomap_head);
static struct iomap_ops {
nfit_test_lookup_fn nfit_test_lookup;
nfit_test_evaluate_dsm_fn evaluate_dsm;
struct list_head list;
} iomap_ops = {
.list = LIST_HEAD_INIT(iomap_ops.list),
};
void nfit_test_setup(nfit_test_lookup_fn lookup,
nfit_test_evaluate_dsm_fn evaluate)
{
iomap_ops.nfit_test_lookup = lookup;
iomap_ops.evaluate_dsm = evaluate;
list_add_rcu(&iomap_ops.list, &iomap_head);
}
EXPORT_SYMBOL(nfit_test_setup);
void nfit_test_teardown(void)
{
list_del_rcu(&iomap_ops.list);
synchronize_rcu();
}
EXPORT_SYMBOL(nfit_test_teardown);
static struct nfit_test_resource *__get_nfit_res(resource_size_t resource)
{
struct iomap_ops *ops;
ops = list_first_or_null_rcu(&iomap_head, typeof(*ops), list);
if (ops)
return ops->nfit_test_lookup(resource);
return NULL;
}
struct nfit_test_resource *get_nfit_res(resource_size_t resource)
{
struct nfit_test_resource *res;
rcu_read_lock();
res = __get_nfit_res(resource);
rcu_read_unlock();
return res;
}
EXPORT_SYMBOL(get_nfit_res);
void __iomem *__nfit_test_ioremap(resource_size_t offset, unsigned long size,
void __iomem *(*fallback_fn)(resource_size_t, unsigned long))
{
struct nfit_test_resource *nfit_res = get_nfit_res(offset);
if (nfit_res)
return (void __iomem *) nfit_res->buf + offset
- nfit_res->res.start;
return fallback_fn(offset, size);
}
void __iomem *__wrap_devm_ioremap_nocache(struct device *dev,
resource_size_t offset, unsigned long size)
{
struct nfit_test_resource *nfit_res = get_nfit_res(offset);
if (nfit_res)
return (void __iomem *) nfit_res->buf + offset
- nfit_res->res.start;
return devm_ioremap_nocache(dev, offset, size);
}
EXPORT_SYMBOL(__wrap_devm_ioremap_nocache);
void *__wrap_devm_memremap(struct device *dev, resource_size_t offset,
size_t size, unsigned long flags)
{
struct nfit_test_resource *nfit_res = get_nfit_res(offset);
if (nfit_res)
return nfit_res->buf + offset - nfit_res->res.start;
return devm_memremap(dev, offset, size, flags);
}
EXPORT_SYMBOL(__wrap_devm_memremap);
static void nfit_test_kill(void *_pgmap)
{
struct dev_pagemap *pgmap = _pgmap;
pgmap->kill(pgmap->ref);
}
void *__wrap_devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
{
resource_size_t offset = pgmap->res.start;
struct nfit_test_resource *nfit_res = get_nfit_res(offset);
if (nfit_res) {
int rc;
rc = devm_add_action_or_reset(dev, nfit_test_kill, pgmap);
if (rc)
return ERR_PTR(rc);
return nfit_res->buf + offset - nfit_res->res.start;
}
return devm_memremap_pages(dev, pgmap);
}
EXPORT_SYMBOL_GPL(__wrap_devm_memremap_pages);
pfn_t __wrap_phys_to_pfn_t(phys_addr_t addr, unsigned long flags)
{
struct nfit_test_resource *nfit_res = get_nfit_res(addr);
if (nfit_res)
flags &= ~PFN_MAP;
return phys_to_pfn_t(addr, flags);
}
EXPORT_SYMBOL(__wrap_phys_to_pfn_t);
void *__wrap_memremap(resource_size_t offset, size_t size,
unsigned long flags)
{
struct nfit_test_resource *nfit_res = get_nfit_res(offset);
if (nfit_res)
return nfit_res->buf + offset - nfit_res->res.start;
return memremap(offset, size, flags);
}
EXPORT_SYMBOL(__wrap_memremap);
void __wrap_devm_memunmap(struct device *dev, void *addr)
{
struct nfit_test_resource *nfit_res = get_nfit_res((long) addr);
if (nfit_res)
return;
return devm_memunmap(dev, addr);
}
EXPORT_SYMBOL(__wrap_devm_memunmap);
void __iomem *__wrap_ioremap_nocache(resource_size_t offset, unsigned long size)
{
return __nfit_test_ioremap(offset, size, ioremap_nocache);
}
EXPORT_SYMBOL(__wrap_ioremap_nocache);
void __iomem *__wrap_ioremap_wc(resource_size_t offset, unsigned long size)
{
return __nfit_test_ioremap(offset, size, ioremap_wc);
}
EXPORT_SYMBOL(__wrap_ioremap_wc);
void __wrap_iounmap(volatile void __iomem *addr)
{
struct nfit_test_resource *nfit_res = get_nfit_res((long) addr);
if (nfit_res)
return;
return iounmap(addr);
}
EXPORT_SYMBOL(__wrap_iounmap);
void __wrap_memunmap(void *addr)
{
struct nfit_test_resource *nfit_res = get_nfit_res((long) addr);
if (nfit_res)
return;
return memunmap(addr);
}
EXPORT_SYMBOL(__wrap_memunmap);
static bool nfit_test_release_region(struct device *dev,
struct resource *parent, resource_size_t start,
resource_size_t n);
static void nfit_devres_release(struct device *dev, void *data)
{
struct resource *res = *((struct resource **) data);
WARN_ON(!nfit_test_release_region(NULL, &iomem_resource, res->start,
resource_size(res)));
}
static int match(struct device *dev, void *__res, void *match_data)
{
struct resource *res = *((struct resource **) __res);
resource_size_t start = *((resource_size_t *) match_data);
return res->start == start;
}
static bool nfit_test_release_region(struct device *dev,
struct resource *parent, resource_size_t start,
resource_size_t n)
{
if (parent == &iomem_resource) {
struct nfit_test_resource *nfit_res = get_nfit_res(start);
if (nfit_res) {
struct nfit_test_request *req;
struct resource *res = NULL;
if (dev) {
devres_release(dev, nfit_devres_release, match,
&start);
return true;
}
spin_lock(&nfit_res->lock);
list_for_each_entry(req, &nfit_res->requests, list)
if (req->res.start == start) {
res = &req->res;
list_del(&req->list);
break;
}
spin_unlock(&nfit_res->lock);
WARN(!res || resource_size(res) != n,
"%s: start: %llx n: %llx mismatch: %pr\n",
__func__, start, n, res);
if (res)
kfree(req);
return true;
}
}
return false;
}
static struct resource *nfit_test_request_region(struct device *dev,
struct resource *parent, resource_size_t start,
resource_size_t n, const char *name, int flags)
{
struct nfit_test_resource *nfit_res;
if (parent == &iomem_resource) {
nfit_res = get_nfit_res(start);
if (nfit_res) {
struct nfit_test_request *req;
struct resource *res = NULL;
if (start + n > nfit_res->res.start
+ resource_size(&nfit_res->res)) {
pr_debug("%s: start: %llx n: %llx overflow: %pr\n",
__func__, start, n,
&nfit_res->res);
return NULL;
}
spin_lock(&nfit_res->lock);
list_for_each_entry(req, &nfit_res->requests, list)
if (start == req->res.start) {
res = &req->res;
break;
}
spin_unlock(&nfit_res->lock);
if (res) {
WARN(1, "%pr already busy\n", res);
return NULL;
}
req = kzalloc(sizeof(*req), GFP_KERNEL);
if (!req)
return NULL;
INIT_LIST_HEAD(&req->list);
res = &req->res;
res->start = start;
res->end = start + n - 1;
res->name = name;
res->flags = resource_type(parent);
res->flags |= IORESOURCE_BUSY | flags;
spin_lock(&nfit_res->lock);
list_add(&req->list, &nfit_res->requests);
spin_unlock(&nfit_res->lock);
if (dev) {
struct resource **d;
d = devres_alloc(nfit_devres_release,
sizeof(struct resource *),
GFP_KERNEL);
if (!d)
return NULL;
*d = res;
devres_add(dev, d);
}
pr_debug("%s: %pr\n", __func__, res);
return res;
}
}
if (dev)
return __devm_request_region(dev, parent, start, n, name);
return __request_region(parent, start, n, name, flags);
}
struct resource *__wrap___request_region(struct resource *parent,
resource_size_t start, resource_size_t n, const char *name,
int flags)
{
return nfit_test_request_region(NULL, parent, start, n, name, flags);
}
EXPORT_SYMBOL(__wrap___request_region);
int __wrap_insert_resource(struct resource *parent, struct resource *res)
{
if (get_nfit_res(res->start))
return 0;
return insert_resource(parent, res);
}
EXPORT_SYMBOL(__wrap_insert_resource);
int __wrap_remove_resource(struct resource *res)
{
if (get_nfit_res(res->start))
return 0;
return remove_resource(res);
}
EXPORT_SYMBOL(__wrap_remove_resource);
struct resource *__wrap___devm_request_region(struct device *dev,
struct resource *parent, resource_size_t start,
resource_size_t n, const char *name)
{
if (!dev)
return NULL;
return nfit_test_request_region(dev, parent, start, n, name, 0);
}
EXPORT_SYMBOL(__wrap___devm_request_region);
void __wrap___release_region(struct resource *parent, resource_size_t start,
resource_size_t n)
{
if (!nfit_test_release_region(NULL, parent, start, n))
__release_region(parent, start, n);
}
EXPORT_SYMBOL(__wrap___release_region);
void __wrap___devm_release_region(struct device *dev, struct resource *parent,
resource_size_t start, resource_size_t n)
{
if (!nfit_test_release_region(dev, parent, start, n))
__devm_release_region(dev, parent, start, n);
}
EXPORT_SYMBOL(__wrap___devm_release_region);
acpi_status __wrap_acpi_evaluate_object(acpi_handle handle, acpi_string path,
struct acpi_object_list *p, struct acpi_buffer *buf)
{
struct nfit_test_resource *nfit_res = get_nfit_res((long) handle);
union acpi_object **obj;
if (!nfit_res || strcmp(path, "_FIT") || !buf)
return acpi_evaluate_object(handle, path, p, buf);
obj = nfit_res->buf;
buf->length = sizeof(union acpi_object);
buf->pointer = *obj;
return AE_OK;
}
EXPORT_SYMBOL(__wrap_acpi_evaluate_object);
union acpi_object * __wrap_acpi_evaluate_dsm(acpi_handle handle, const guid_t *guid,
u64 rev, u64 func, union acpi_object *argv4)
{
union acpi_object *obj = ERR_PTR(-ENXIO);
struct iomap_ops *ops;
rcu_read_lock();
ops = list_first_or_null_rcu(&iomap_head, typeof(*ops), list);
if (ops)
obj = ops->evaluate_dsm(handle, guid, rev, func, argv4);
rcu_read_unlock();
if (IS_ERR(obj))
return acpi_evaluate_dsm(handle, guid, rev, func, argv4);
return obj;
}
EXPORT_SYMBOL(__wrap_acpi_evaluate_dsm);
MODULE_LICENSE("GPL v2");