Message ID | 1407860725-25202-4-git-send-email-Liviu.Dudau@arm.com |
---|---|
State | New |
Headers | show |
On Tue, Aug 12, 2014 at 11:25 AM, Liviu Dudau <Liviu.Dudau@arm.com> wrote: > 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. > > Cc: Grant Likely <grant.likely@linaro.org> > Cc: Rob Herring <robh+dt@kernel.org> > Cc: Arnd Bergmann <arnd@arndb.de> > Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> Acked-by: Rob Herring <robh@kernel.org> > --- > drivers/of/address.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/of_address.h | 2 + > 2 files changed, 97 insertions(+) > > diff --git a/drivers/of/address.c b/drivers/of/address.c > index 5edfcb0..4dab700 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 +602,106 @@ 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) > +{ > +#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) > + return 0; > + allocated_size += range->size; > + } > + spin_unlock(&io_range_lock); > + > + /* 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) > + return -E2BIG; > + > + 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) > + return -ENOMEM; > + > + range->start = addr; > + range->size = size; > + > + list_add_tail(&range->list, &io_range_list); > +#endif > + > + return 0; > +} > + > +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; > + > + 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..28e6836 100644 > --- a/include/linux/of_address.h > +++ b/include/linux/of_address.h > @@ -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); > -- > 2.0.4 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/of/address.c b/drivers/of/address.c index 5edfcb0..4dab700 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 +602,106 @@ 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) +{ +#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) + return 0; + allocated_size += range->size; + } + spin_unlock(&io_range_lock); + + /* 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) + return -E2BIG; + + 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) + return -ENOMEM; + + range->start = addr; + range->size = size; + + list_add_tail(&range->list, &io_range_list); +#endif + + return 0; +} + +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; + + 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..28e6836 100644 --- a/include/linux/of_address.h +++ b/include/linux/of_address.h @@ -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);
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. Cc: Grant Likely <grant.likely@linaro.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> --- drivers/of/address.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of_address.h | 2 + 2 files changed, 97 insertions(+)