of/pci: Add pci_register_io_range() and pci_pio_to_address()

Some architectures do not have a simple view of the PCI I/O space and
instead use a range of CPU addresses that map to bus addresses.  For some
architectures these ranges will be expressed by OF bindings in a device
tree file.

This patch introduces a pci_register_io_range() helper function with a
generic implementation that can be used by such architectures to keep track
of the I/O ranges described by the PCI bindings.  If the PCI_IOBASE macro
is not defined, that signals lack of support for PCI and we return an
error.

In order to retrieve the CPU address associated with an I/O port, a new
helper function pci_pio_to_address() is introduced.  This will search in
the list of ranges registered with pci_register_io_range() and return the
CPU address that corresponds to the given port.

[arnd: add dummy !CONFIG_OF pci_pio_to_address() to fix build errors]
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
CC: Grant Likely <grant.likely@linaro.org>
This commit is contained in:
Liviu Dudau 2014-09-29 15:29:21 +01:00 committed by Bjorn Helgaas
parent 112eeaa7f8
commit 41f8bba7f5
2 changed files with 116 additions and 0 deletions

View File

@ -5,6 +5,8 @@
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/pci_regs.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/string.h>
/* Max address size we deal with */
@ -601,12 +603,119 @@ const __be32 *of_get_address(struct device_node *dev, int index, u64 *size,
}
EXPORT_SYMBOL(of_get_address);
#ifdef PCI_IOBASE
struct io_range {
struct list_head list;
phys_addr_t start;
resource_size_t size;
};
static LIST_HEAD(io_range_list);
static DEFINE_SPINLOCK(io_range_lock);
#endif
/*
* Record the PCI IO range (expressed as CPU physical address + size).
* Return a negative value if an error has occured, zero otherwise
*/
int __weak pci_register_io_range(phys_addr_t addr, resource_size_t size)
{
int err = 0;
#ifdef PCI_IOBASE
struct io_range *range;
resource_size_t allocated_size = 0;
/* check if the range hasn't been previously recorded */
spin_lock(&io_range_lock);
list_for_each_entry(range, &io_range_list, list) {
if (addr >= range->start && addr + size <= range->start + size) {
/* range already registered, bail out */
goto end_register;
}
allocated_size += range->size;
}
/* range not registed yet, check for available space */
if (allocated_size + size - 1 > IO_SPACE_LIMIT) {
/* if it's too big check if 64K space can be reserved */
if (allocated_size + SZ_64K - 1 > IO_SPACE_LIMIT) {
err = -E2BIG;
goto end_register;
}
size = SZ_64K;
pr_warn("Requested IO range too big, new size set to 64K\n");
}
/* add the range to the list */
range = kzalloc(sizeof(*range), GFP_KERNEL);
if (!range) {
err = -ENOMEM;
goto end_register;
}
range->start = addr;
range->size = size;
list_add_tail(&range->list, &io_range_list);
end_register:
spin_unlock(&io_range_lock);
#endif
return err;
}
phys_addr_t pci_pio_to_address(unsigned long pio)
{
phys_addr_t address = (phys_addr_t)OF_BAD_ADDR;
#ifdef PCI_IOBASE
struct io_range *range;
resource_size_t allocated_size = 0;
if (pio > IO_SPACE_LIMIT)
return address;
spin_lock(&io_range_lock);
list_for_each_entry(range, &io_range_list, list) {
if (pio >= allocated_size && pio < allocated_size + range->size) {
address = range->start + pio - allocated_size;
break;
}
allocated_size += range->size;
}
spin_unlock(&io_range_lock);
#endif
return address;
}
unsigned long __weak pci_address_to_pio(phys_addr_t address)
{
#ifdef PCI_IOBASE
struct io_range *res;
resource_size_t offset = 0;
unsigned long addr = -1;
spin_lock(&io_range_lock);
list_for_each_entry(res, &io_range_list, list) {
if (address >= res->start && address < res->start + res->size) {
addr = res->start - address + offset;
break;
}
offset += res->size;
}
spin_unlock(&io_range_lock);
return addr;
#else
if (address > IO_SPACE_LIMIT)
return (unsigned long)-1;
return (unsigned long) address;
#endif
}
static int __of_address_to_resource(struct device_node *dev,

View File

@ -55,7 +55,9 @@ extern void __iomem *of_iomap(struct device_node *device, int index);
extern const __be32 *of_get_address(struct device_node *dev, int index,
u64 *size, unsigned int *flags);
extern int pci_register_io_range(phys_addr_t addr, resource_size_t size);
extern unsigned long pci_address_to_pio(phys_addr_t addr);
extern phys_addr_t pci_pio_to_address(unsigned long pio);
extern int of_pci_range_parser_init(struct of_pci_range_parser *parser,
struct device_node *node);
@ -80,6 +82,11 @@ static inline const __be32 *of_get_address(struct device_node *dev, int index,
return NULL;
}
static inline phys_addr_t pci_pio_to_address(unsigned long pio)
{
return 0;
}
static inline int of_pci_range_parser_init(struct of_pci_range_parser *parser,
struct device_node *node)
{