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.
Introduce 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.
Signed-off-by: Liviu Dudau Liviu.Dudau@arm.com --- drivers/of/address.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of_address.h | 1 + 2 files changed, 62 insertions(+)
diff --git a/drivers/of/address.c b/drivers/of/address.c index 5edfcb0..1345733 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -5,6 +5,7 @@ #include <linux/module.h> #include <linux/of_address.h> #include <linux/pci_regs.h> +#include <linux/slab.h> #include <linux/string.h>
/* Max address size we deal with */ @@ -601,12 +602,72 @@ const __be32 *of_get_address(struct device_node *dev, int index, u64 *size, } EXPORT_SYMBOL(of_get_address);
+struct io_range { + struct list_head list; + phys_addr_t start; + resource_size_t size; +}; + +static LIST_HEAD(io_range_list); + +/* + * 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) +{ +#ifdef PCI_IOBASE + struct io_range *res; + resource_size_t allocated_size = 0; + + /* check if the range hasn't been previously recorded */ + list_for_each_entry(res, &io_range_list, list) { + if (addr >= res->start && addr + size <= res->start + size) + return 0; + allocated_size += res->size; + } + + /* range not registed yet, check for available space */ + if (allocated_size + size - 1 > IO_SPACE_LIMIT) + return -E2BIG; + + /* add the range to the list */ + res = kzalloc(sizeof(*res), GFP_KERNEL); + if (!res) + return -ENOMEM; + + res->start = addr; + res->size = size; + + list_add_tail(&res->list, &io_range_list); + + return 0; +#else + return -EINVAL; +#endif +} + unsigned long __weak pci_address_to_pio(phys_addr_t address) { +#ifdef PCI_IOBASE + struct io_range *res; + resource_size_t offset = 0; + + list_for_each_entry(res, &io_range_list, list) { + if (address >= res->start && + address < res->start + res->size) { + return res->start - address + offset; + } + offset += res->size; + } + + return (unsigned long)-1; +#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, diff --git a/include/linux/of_address.h b/include/linux/of_address.h index c13b878..ac4aac4 100644 --- a/include/linux/of_address.h +++ b/include/linux/of_address.h @@ -55,6 +55,7 @@ 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 int of_pci_range_parser_init(struct of_pci_range_parser *parser,