kernel-ark/lib/devres.c
Thierry Reding 75096579c3 lib: devres: Introduce devm_ioremap_resource()
The devm_request_and_ioremap() function is very useful and helps avoid a
whole lot of boilerplate. However, one issue that keeps popping up is
its lack of a specific error code to determine which of the steps that
it performs failed. Furthermore, while the function gives an example and
suggests what error code to return on failure, a wide variety of error
codes are used throughout the tree.

In an attempt to fix these problems, this patch adds a new function that
drivers can transition to. The devm_ioremap_resource() returns a pointer
to the remapped I/O memory on success or an ERR_PTR() encoded error code
on failure. Callers can check for failure using IS_ERR() and determine
its cause by extracting the error code using PTR_ERR().

devm_request_and_ioremap() is implemented as a wrapper around the new
API and return NULL on failure as before. This ensures that backwards
compatibility is maintained until all users have been converted to the
new API, at which point the old devm_request_and_ioremap() function
should be removed.

A semantic patch is included which can be used to convert from the old
devm_request_and_ioremap() API to the new devm_ioremap_resource() API.
Some non-trivial cases may require manual intervention, though.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-22 09:41:43 -08:00

435 lines
10 KiB
C

#include <linux/pci.h>
#include <linux/io.h>
#include <linux/gfp.h>
#include <linux/export.h>
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;
}
/**
* devm_ioremap - Managed ioremap()
* @dev: Generic device to remap IO address for
* @offset: BUS offset 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,
unsigned long size)
{
void __iomem **ptr, *addr;
ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return NULL;
addr = ioremap(offset, size);
if (addr) {
*ptr = addr;
devres_add(dev, ptr);
} else
devres_free(ptr);
return addr;
}
EXPORT_SYMBOL(devm_ioremap);
/**
* devm_ioremap_nocache - Managed ioremap_nocache()
* @dev: Generic device to remap IO address for
* @offset: BUS offset to map
* @size: Size of map
*
* Managed ioremap_nocache(). Map is automatically unmapped on driver
* detach.
*/
void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
unsigned long size)
{
void __iomem **ptr, *addr;
ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return NULL;
addr = ioremap_nocache(offset, size);
if (addr) {
*ptr = addr;
devres_add(dev, ptr);
} else
devres_free(ptr);
return addr;
}
EXPORT_SYMBOL(devm_ioremap_nocache);
/**
* 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_destroy(dev, devm_ioremap_release, devm_ioremap_match,
(void *)addr));
iounmap(addr);
}
EXPORT_SYMBOL(devm_iounmap);
/**
* 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 either as cacheable or as non-cacheable memory depending on
* the resource's flags. All operations are managed and will be undone on
* driver detach.
*
* Returns a pointer to the remapped memory or an ERR_PTR() encoded error code
* on failure. 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);
*/
void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res)
{
resource_size_t size;
const char *name;
void __iomem *dest_ptr;
BUG_ON(!dev);
if (!res || resource_type(res) != IORESOURCE_MEM) {
dev_err(dev, "invalid resource\n");
return ERR_PTR(-EINVAL);
}
size = resource_size(res);
name = res->name ?: dev_name(dev);
if (!devm_request_mem_region(dev, res->start, size, name)) {
dev_err(dev, "can't request region for resource %pR\n", res);
return ERR_PTR(-EBUSY);
}
if (res->flags & IORESOURCE_CACHEABLE)
dest_ptr = devm_ioremap(dev, res->start, size);
else
dest_ptr = devm_ioremap_nocache(dev, res->start, size);
if (!dest_ptr) {
dev_err(dev, "ioremap failed for resource %pR\n", res);
devm_release_mem_region(dev, res->start, size);
dest_ptr = ERR_PTR(-ENOMEM);
}
return dest_ptr;
}
EXPORT_SYMBOL(devm_ioremap_resource);
/**
* devm_request_and_ioremap() - Check, request region, and ioremap resource
* @dev: Generic device to handle the resource for
* @res: resource to be handled
*
* Takes all necessary steps to ioremap a mem resource. Uses managed device, so
* everything is undone on driver detach. Checks arguments, so you can feed
* it the result from e.g. platform_get_resource() directly. Returns the
* remapped pointer or NULL on error. Usage example:
*
* res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
* base = devm_request_and_ioremap(&pdev->dev, res);
* if (!base)
* return -EADDRNOTAVAIL;
*/
void __iomem *devm_request_and_ioremap(struct device *device,
struct resource *res)
{
void __iomem *dest_ptr;
dest_ptr = devm_ioremap_resource(device, res);
if (IS_ERR(dest_ptr))
return NULL;
return dest_ptr;
}
EXPORT_SYMBOL(devm_request_and_ioremap);
#ifdef CONFIG_HAS_IOPORT
/*
* 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.
*/
void __iomem * devm_ioport_map(struct device *dev, unsigned long port,
unsigned int nr)
{
void __iomem **ptr, *addr;
ptr = devres_alloc(devm_ioport_map_release, sizeof(*ptr), GFP_KERNEL);
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)
{
ioport_unmap(addr);
WARN_ON(devres_destroy(dev, devm_ioport_map_release,
devm_ioport_map_match, (void *)addr));
}
EXPORT_SYMBOL(devm_ioport_unmap);
#ifdef CONFIG_PCI
/*
* PCI iomap devres
*/
#define PCIM_IOMAP_MAX PCI_ROM_RESOURCE
struct pcim_iomap_devres {
void __iomem *table[PCIM_IOMAP_MAX];
};
static void pcim_iomap_release(struct device *gendev, void *res)
{
struct pci_dev *dev = container_of(gendev, struct pci_dev, dev);
struct pcim_iomap_devres *this = res;
int i;
for (i = 0; i < PCIM_IOMAP_MAX; i++)
if (this->table[i])
pci_iounmap(dev, this->table[i]);
}
/**
* pcim_iomap_table - access iomap allocation table
* @pdev: PCI device to access iomap table for
*
* Access iomap allocation table for @dev. If iomap table doesn't
* exist and @pdev is managed, it will be allocated. All iomaps
* recorded in the iomap table are automatically unmapped on driver
* detach.
*
* This function might sleep when the table is first allocated but can
* be safely called without context and guaranteed to succed once
* allocated.
*/
void __iomem * const * pcim_iomap_table(struct pci_dev *pdev)
{
struct pcim_iomap_devres *dr, *new_dr;
dr = devres_find(&pdev->dev, pcim_iomap_release, NULL, NULL);
if (dr)
return dr->table;
new_dr = devres_alloc(pcim_iomap_release, sizeof(*new_dr), GFP_KERNEL);
if (!new_dr)
return NULL;
dr = devres_get(&pdev->dev, new_dr, NULL, NULL);
return dr->table;
}
EXPORT_SYMBOL(pcim_iomap_table);
/**
* pcim_iomap - Managed pcim_iomap()
* @pdev: PCI device to iomap for
* @bar: BAR to iomap
* @maxlen: Maximum length of iomap
*
* Managed pci_iomap(). Map is automatically unmapped on driver
* detach.
*/
void __iomem * pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen)
{
void __iomem **tbl;
BUG_ON(bar >= PCIM_IOMAP_MAX);
tbl = (void __iomem **)pcim_iomap_table(pdev);
if (!tbl || tbl[bar]) /* duplicate mappings not allowed */
return NULL;
tbl[bar] = pci_iomap(pdev, bar, maxlen);
return tbl[bar];
}
EXPORT_SYMBOL(pcim_iomap);
/**
* pcim_iounmap - Managed pci_iounmap()
* @pdev: PCI device to iounmap for
* @addr: Address to unmap
*
* Managed pci_iounmap(). @addr must have been mapped using pcim_iomap().
*/
void pcim_iounmap(struct pci_dev *pdev, void __iomem *addr)
{
void __iomem **tbl;
int i;
pci_iounmap(pdev, addr);
tbl = (void __iomem **)pcim_iomap_table(pdev);
BUG_ON(!tbl);
for (i = 0; i < PCIM_IOMAP_MAX; i++)
if (tbl[i] == addr) {
tbl[i] = NULL;
return;
}
WARN_ON(1);
}
EXPORT_SYMBOL(pcim_iounmap);
/**
* pcim_iomap_regions - Request and iomap PCI BARs
* @pdev: PCI device to map IO resources for
* @mask: Mask of BARs to request and iomap
* @name: Name used when requesting regions
*
* Request and iomap regions specified by @mask.
*/
int pcim_iomap_regions(struct pci_dev *pdev, int mask, const char *name)
{
void __iomem * const *iomap;
int i, rc;
iomap = pcim_iomap_table(pdev);
if (!iomap)
return -ENOMEM;
for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
unsigned long len;
if (!(mask & (1 << i)))
continue;
rc = -EINVAL;
len = pci_resource_len(pdev, i);
if (!len)
goto err_inval;
rc = pci_request_region(pdev, i, name);
if (rc)
goto err_inval;
rc = -ENOMEM;
if (!pcim_iomap(pdev, i, 0))
goto err_region;
}
return 0;
err_region:
pci_release_region(pdev, i);
err_inval:
while (--i >= 0) {
if (!(mask & (1 << i)))
continue;
pcim_iounmap(pdev, iomap[i]);
pci_release_region(pdev, i);
}
return rc;
}
EXPORT_SYMBOL(pcim_iomap_regions);
/**
* pcim_iomap_regions_request_all - Request all BARs and iomap specified ones
* @pdev: PCI device to map IO resources for
* @mask: Mask of BARs to iomap
* @name: Name used when requesting regions
*
* Request all PCI BARs and iomap regions specified by @mask.
*/
int pcim_iomap_regions_request_all(struct pci_dev *pdev, int mask,
const char *name)
{
int request_mask = ((1 << 6) - 1) & ~mask;
int rc;
rc = pci_request_selected_regions(pdev, request_mask, name);
if (rc)
return rc;
rc = pcim_iomap_regions(pdev, mask, name);
if (rc)
pci_release_selected_regions(pdev, request_mask);
return rc;
}
EXPORT_SYMBOL(pcim_iomap_regions_request_all);
/**
* pcim_iounmap_regions - Unmap and release PCI BARs
* @pdev: PCI device to map IO resources for
* @mask: Mask of BARs to unmap and release
*
* Unmap and release regions specified by @mask.
*/
void pcim_iounmap_regions(struct pci_dev *pdev, int mask)
{
void __iomem * const *iomap;
int i;
iomap = pcim_iomap_table(pdev);
if (!iomap)
return;
for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
if (!(mask & (1 << i)))
continue;
pcim_iounmap(pdev, iomap[i]);
pci_release_region(pdev, i);
}
}
EXPORT_SYMBOL(pcim_iounmap_regions);
#endif /* CONFIG_PCI */
#endif /* CONFIG_HAS_IOPORT */