linux/lib/devres.c
Zijun Hu 9bd133f05b lib: devres: Simplify API devm_ioport_unmap() implementation
Simplify devm_ioport_unmap() implementation by dedicated API
devres_release(), compared with current solution, namely
ioport_unmap() + devres_destroy(), devres_release() has below advantages:

- it is simpler if devm_ioport_unmap()'s parameter @addr was ever
  returned by devm_ioport_map().

- it can avoid unnecessary ioport_unmap(@addr) if @addr was not
  ever returned by devm_ioport_map().

Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20240918-fix_lib_devres-v1-2-e696ab5486e6@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-14 08:21:09 +02:00

399 lines
10 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/bug.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/gfp_types.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/of_address.h>
#include <linux/types.h>
enum devm_ioremap_type {
DEVM_IOREMAP = 0,
DEVM_IOREMAP_UC,
DEVM_IOREMAP_WC,
DEVM_IOREMAP_NP,
};
void devm_ioremap_release(struct device *dev, void *res)
{
iounmap(*(void __iomem **)res);
}
static int devm_ioremap_match(struct device *dev, void *res, void *match_data)
{
return *(void **)res == match_data;
}
static void __iomem *__devm_ioremap(struct device *dev, resource_size_t offset,
resource_size_t size,
enum devm_ioremap_type type)
{
void __iomem **ptr, *addr = NULL;
ptr = devres_alloc_node(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL,
dev_to_node(dev));
if (!ptr)
return NULL;
switch (type) {
case DEVM_IOREMAP:
addr = ioremap(offset, size);
break;
case DEVM_IOREMAP_UC:
addr = ioremap_uc(offset, size);
break;
case DEVM_IOREMAP_WC:
addr = ioremap_wc(offset, size);
break;
case DEVM_IOREMAP_NP:
addr = ioremap_np(offset, size);
break;
}
if (addr) {
*ptr = addr;
devres_add(dev, ptr);
} else
devres_free(ptr);
return addr;
}
/**
* devm_ioremap - Managed ioremap()
* @dev: Generic device to remap IO address for
* @offset: Resource address to map
* @size: Size of map
*
* Managed ioremap(). Map is automatically unmapped on driver detach.
*/
void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
resource_size_t size)
{
return __devm_ioremap(dev, offset, size, DEVM_IOREMAP);
}
EXPORT_SYMBOL(devm_ioremap);
/**
* devm_ioremap_uc - Managed ioremap_uc()
* @dev: Generic device to remap IO address for
* @offset: Resource address to map
* @size: Size of map
*
* Managed ioremap_uc(). Map is automatically unmapped on driver detach.
*/
void __iomem *devm_ioremap_uc(struct device *dev, resource_size_t offset,
resource_size_t size)
{
return __devm_ioremap(dev, offset, size, DEVM_IOREMAP_UC);
}
EXPORT_SYMBOL_GPL(devm_ioremap_uc);
/**
* devm_ioremap_wc - Managed ioremap_wc()
* @dev: Generic device to remap IO address for
* @offset: Resource address to map
* @size: Size of map
*
* Managed ioremap_wc(). Map is automatically unmapped on driver detach.
*/
void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset,
resource_size_t size)
{
return __devm_ioremap(dev, offset, size, DEVM_IOREMAP_WC);
}
EXPORT_SYMBOL(devm_ioremap_wc);
/**
* devm_iounmap - Managed iounmap()
* @dev: Generic device to unmap for
* @addr: Address to unmap
*
* Managed iounmap(). @addr must have been mapped using devm_ioremap*().
*/
void devm_iounmap(struct device *dev, void __iomem *addr)
{
WARN_ON(devres_release(dev, devm_ioremap_release, devm_ioremap_match,
(__force void *)addr));
}
EXPORT_SYMBOL(devm_iounmap);
static void __iomem *
__devm_ioremap_resource(struct device *dev, const struct resource *res,
enum devm_ioremap_type type)
{
resource_size_t size;
void __iomem *dest_ptr;
char *pretty_name;
int ret;
BUG_ON(!dev);
if (!res || resource_type(res) != IORESOURCE_MEM) {
ret = dev_err_probe(dev, -EINVAL, "invalid resource %pR\n", res);
return IOMEM_ERR_PTR(ret);
}
if (type == DEVM_IOREMAP && res->flags & IORESOURCE_MEM_NONPOSTED)
type = DEVM_IOREMAP_NP;
size = resource_size(res);
if (res->name)
pretty_name = devm_kasprintf(dev, GFP_KERNEL, "%s %s",
dev_name(dev), res->name);
else
pretty_name = devm_kstrdup(dev, dev_name(dev), GFP_KERNEL);
if (!pretty_name) {
ret = dev_err_probe(dev, -ENOMEM, "can't generate pretty name for resource %pR\n", res);
return IOMEM_ERR_PTR(ret);
}
if (!devm_request_mem_region(dev, res->start, size, pretty_name)) {
ret = dev_err_probe(dev, -EBUSY, "can't request region for resource %pR\n", res);
return IOMEM_ERR_PTR(ret);
}
dest_ptr = __devm_ioremap(dev, res->start, size, type);
if (!dest_ptr) {
devm_release_mem_region(dev, res->start, size);
ret = dev_err_probe(dev, -ENOMEM, "ioremap failed for resource %pR\n", res);
return IOMEM_ERR_PTR(ret);
}
return dest_ptr;
}
/**
* devm_ioremap_resource() - check, request region, and ioremap resource
* @dev: generic device to handle the resource for
* @res: resource to be handled
*
* Checks that a resource is a valid memory region, requests the memory
* region and ioremaps it. All operations are managed and will be undone
* on driver detach.
*
* Usage example:
*
* res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
* base = devm_ioremap_resource(&pdev->dev, res);
* if (IS_ERR(base))
* return PTR_ERR(base);
*
* Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
* on failure.
*/
void __iomem *devm_ioremap_resource(struct device *dev,
const struct resource *res)
{
return __devm_ioremap_resource(dev, res, DEVM_IOREMAP);
}
EXPORT_SYMBOL(devm_ioremap_resource);
/**
* devm_ioremap_resource_wc() - write-combined variant of
* devm_ioremap_resource()
* @dev: generic device to handle the resource for
* @res: resource to be handled
*
* Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
* on failure.
*/
void __iomem *devm_ioremap_resource_wc(struct device *dev,
const struct resource *res)
{
return __devm_ioremap_resource(dev, res, DEVM_IOREMAP_WC);
}
/*
* devm_of_iomap - Requests a resource and maps the memory mapped IO
* for a given device_node managed by a given device
*
* Checks that a resource is a valid memory region, requests the memory
* region and ioremaps it. All operations are managed and will be undone
* on driver detach of the device.
*
* This is to be used when a device requests/maps resources described
* by other device tree nodes (children or otherwise).
*
* @dev: The device "managing" the resource
* @node: The device-tree node where the resource resides
* @index: index of the MMIO range in the "reg" property
* @size: Returns the size of the resource (pass NULL if not needed)
*
* Usage example:
*
* base = devm_of_iomap(&pdev->dev, node, 0, NULL);
* if (IS_ERR(base))
* return PTR_ERR(base);
*
* Please Note: This is not a one-to-one replacement for of_iomap() because the
* of_iomap() function does not track whether the region is already mapped. If
* two drivers try to map the same memory, the of_iomap() function will succeed
* but the devm_of_iomap() function will return -EBUSY.
*
* Return: a pointer to the requested and mapped memory or an ERR_PTR() encoded
* error code on failure.
*/
void __iomem *devm_of_iomap(struct device *dev, struct device_node *node, int index,
resource_size_t *size)
{
struct resource res;
if (of_address_to_resource(node, index, &res))
return IOMEM_ERR_PTR(-EINVAL);
if (size)
*size = resource_size(&res);
return devm_ioremap_resource(dev, &res);
}
EXPORT_SYMBOL(devm_of_iomap);
#ifdef CONFIG_HAS_IOPORT_MAP
/*
* Generic iomap devres
*/
static void devm_ioport_map_release(struct device *dev, void *res)
{
ioport_unmap(*(void __iomem **)res);
}
static int devm_ioport_map_match(struct device *dev, void *res,
void *match_data)
{
return *(void **)res == match_data;
}
/**
* devm_ioport_map - Managed ioport_map()
* @dev: Generic device to map ioport for
* @port: Port to map
* @nr: Number of ports to map
*
* Managed ioport_map(). Map is automatically unmapped on driver
* detach.
*
* Return: a pointer to the remapped memory or NULL on failure.
*/
void __iomem *devm_ioport_map(struct device *dev, unsigned long port,
unsigned int nr)
{
void __iomem **ptr, *addr;
ptr = devres_alloc_node(devm_ioport_map_release, sizeof(*ptr), GFP_KERNEL,
dev_to_node(dev));
if (!ptr)
return NULL;
addr = ioport_map(port, nr);
if (addr) {
*ptr = addr;
devres_add(dev, ptr);
} else
devres_free(ptr);
return addr;
}
EXPORT_SYMBOL(devm_ioport_map);
/**
* devm_ioport_unmap - Managed ioport_unmap()
* @dev: Generic device to unmap for
* @addr: Address to unmap
*
* Managed ioport_unmap(). @addr must have been mapped using
* devm_ioport_map().
*/
void devm_ioport_unmap(struct device *dev, void __iomem *addr)
{
WARN_ON(devres_release(dev, devm_ioport_map_release,
devm_ioport_map_match, (__force void *)addr));
}
EXPORT_SYMBOL(devm_ioport_unmap);
#endif /* CONFIG_HAS_IOPORT_MAP */
static void devm_arch_phys_ac_add_release(struct device *dev, void *res)
{
arch_phys_wc_del(*((int *)res));
}
/**
* devm_arch_phys_wc_add - Managed arch_phys_wc_add()
* @dev: Managed device
* @base: Memory base address
* @size: Size of memory range
*
* Adds a WC MTRR using arch_phys_wc_add() and sets up a release callback.
* See arch_phys_wc_add() for more information.
*/
int devm_arch_phys_wc_add(struct device *dev, unsigned long base, unsigned long size)
{
int *mtrr;
int ret;
mtrr = devres_alloc_node(devm_arch_phys_ac_add_release, sizeof(*mtrr), GFP_KERNEL,
dev_to_node(dev));
if (!mtrr)
return -ENOMEM;
ret = arch_phys_wc_add(base, size);
if (ret < 0) {
devres_free(mtrr);
return ret;
}
*mtrr = ret;
devres_add(dev, mtrr);
return ret;
}
EXPORT_SYMBOL(devm_arch_phys_wc_add);
struct arch_io_reserve_memtype_wc_devres {
resource_size_t start;
resource_size_t size;
};
static void devm_arch_io_free_memtype_wc_release(struct device *dev, void *res)
{
const struct arch_io_reserve_memtype_wc_devres *this = res;
arch_io_free_memtype_wc(this->start, this->size);
}
/**
* devm_arch_io_reserve_memtype_wc - Managed arch_io_reserve_memtype_wc()
* @dev: Managed device
* @start: Memory base address
* @size: Size of memory range
*
* Reserves a memory range with WC caching using arch_io_reserve_memtype_wc()
* and sets up a release callback See arch_io_reserve_memtype_wc() for more
* information.
*/
int devm_arch_io_reserve_memtype_wc(struct device *dev, resource_size_t start,
resource_size_t size)
{
struct arch_io_reserve_memtype_wc_devres *dr;
int ret;
dr = devres_alloc_node(devm_arch_io_free_memtype_wc_release, sizeof(*dr), GFP_KERNEL,
dev_to_node(dev));
if (!dr)
return -ENOMEM;
ret = arch_io_reserve_memtype_wc(start, size);
if (ret < 0) {
devres_free(dr);
return ret;
}
dr->start = start;
dr->size = size;
devres_add(dev, dr);
return ret;
}
EXPORT_SYMBOL(devm_arch_io_reserve_memtype_wc);