| Message ID | 1411003825-21521-9-git-send-email-Liviu.Dudau@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Sep 18, 2014 at 02:30:23AM +0100, Liviu Dudau wrote: > Provide a function to parse the PCI DT ranges that can be used to > create a pci_host_bridge structure together with its associated > bus. > > Cc: Bjorn Helgaas <bhelgaas@google.com> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Grant Likely <grant.likely@linaro.org> > Cc: Rob Herring <robh+dt@kernel.org> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> > --- > drivers/of/of_pci.c | 108 +++++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/of_pci.h | 11 +++++ > 2 files changed, 119 insertions(+) > > diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c > index 7eaeac2..c18b8da 100644 > --- a/drivers/of/of_pci.c > +++ b/drivers/of/of_pci.c > @@ -1,7 +1,9 @@ > #include <linux/kernel.h> > #include <linux/export.h> > #include <linux/of.h> > +#include <linux/of_address.h> > #include <linux/of_pci.h> > +#include <linux/slab.h> > > #include "of_private.h" > > @@ -151,6 +153,112 @@ int of_pci_get_domain_nr(struct device_node *node, bool allocate_if_missing) > } > EXPORT_SYMBOL_GPL(of_pci_get_domain_nr); > > +/** > + * of_pci_get_host_bridge_resources - Parse PCI host bridge resources from DT > + * @dev: device node of the host bridge having the range property > + * @busno: bus number associated with the bridge root bus > + * @bus_max: maximum number of busses for this bridge > + * @resources: list where the range of resources will be added after DT parsing > + * @io_base: pointer to a variable that will contain on return the physical > + * address for the start of the I/O range. > + * > + * It is the callers job to free the @resources list. > + * > + * This function will parse the "ranges" property of a PCI host bridge device > + * node and setup the resource mapping based on its content. It is expected > + * that the property conforms with the Power ePAPR document. > + * > + * It returns zero if the range parsing has been successful or a standard error > + * value if it failed. > + */ > +int of_pci_get_host_bridge_resources(struct device_node *dev, > + unsigned char busno, unsigned char bus_max, > + struct list_head *resources, resource_size_t *io_base) > +{ > + struct resource *res; > + struct resource *bus_range; > + struct of_pci_range range; > + struct of_pci_range_parser parser; > + char range_type[4]; > + int err; > + > + if (!io_base) > + return -EINVAL; > + *io_base = OF_BAD_ADDR; > + > + bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL); > + if (!bus_range) > + return -ENOMEM; > + > + pr_info("PCI host bridge %s ranges:\n", dev->full_name); > + > + err = of_pci_parse_bus_range(dev, bus_range); > + if (err) { > + bus_range->start = busno; > + bus_range->end = bus_max; > + bus_range->flags = IORESOURCE_BUS; > + pr_info(" No bus range found for %s, using %pR\n", > + dev->full_name, &bus_range); > + } else { > + if (bus_range->end > bus_range->start + bus_max) > + bus_range->end = bus_range->start + bus_max; > + } > + pci_add_resource(resources, bus_range); > + > + /* Check for ranges property */ > + err = of_pci_range_parser_init(&parser, dev); > + if (err) > + goto parse_failed; > + > + pr_debug("Parsing ranges property...\n"); > + for_each_of_pci_range(&parser, &range) { > + /* Read next ranges element */ > + if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO) > + snprintf(range_type, 4, " IO"); > + else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM) > + snprintf(range_type, 4, "MEM"); > + else > + snprintf(range_type, 4, "err"); > + pr_info(" %s %#010llx..%#010llx -> %#010llx\n", range_type, > + range.cpu_addr, range.cpu_addr + range.size - 1, > + range.pci_addr); > + > + /* > + * If we failed translation or got a zero-sized region > + * then skip this range > + */ > + if (range.cpu_addr == OF_BAD_ADDR || range.size == 0) > + continue; > + > + res = kzalloc(sizeof(struct resource), GFP_KERNEL); > + if (!res) { > + err = -ENOMEM; > + goto parse_failed; > + } > + > + err = of_pci_range_to_resource(&range, dev, res); > + if (err) { > + kfree(res); > + goto parse_failed; > + } > + > + if (resource_type(res) == IORESOURCE_IO) { > + if (*io_base != OF_BAD_ADDR) > + pr_warn("More than one I/O resource converted. CPU offset for old range lost!\n"); It'd be nice if the output included a hint about which device this warning applies to. > + *io_base = range.cpu_addr; > + } > + > + pci_add_resource_offset(resources, res, res->start - range.pci_addr); > + } > + > + return 0; > + > +parse_failed: > + pci_free_resource_list(resources); > + return err; > +} > +EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources); > + > #ifdef CONFIG_PCI_MSI > > static LIST_HEAD(of_pci_msi_chip_list); > diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h > index 3a3824c..a4b8a85 100644 > --- a/include/linux/of_pci.h > +++ b/include/linux/of_pci.h > @@ -16,6 +16,10 @@ int of_pci_get_devfn(struct device_node *np); > int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin); > int of_pci_parse_bus_range(struct device_node *node, struct resource *res); > int of_pci_get_domain_nr(struct device_node *node, bool allocate_if_missing); > +int of_pci_get_host_bridge_resources(struct device_node *dev, > + unsigned char busno, unsigned char bus_max, > + struct list_head *resources, resource_size_t *io_base); > + > #else > static inline int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq) > { > @@ -50,6 +54,13 @@ of_pci_get_domain_nr(struct device_node *node, bool allocate_if_missing) > { > return -1; > } > + > +int of_pci_get_host_bridge_resources(struct device_node *dev, > + unsigned char busno, unsigned char bus_max, > + struct list_head *resources, resource_size_t *io_base); > +{ > + return -EINVAL; > +} > #endif > > #if defined(CONFIG_OF) && defined(CONFIG_PCI_MSI) > -- > 2.1.0 >
On 09/19/2014 04:06 PM, Bjorn Helgaas wrote: > On Thu, Sep 18, 2014 at 02:30:23AM +0100, Liviu Dudau wrote: >> Provide a function to parse the PCI DT ranges that can be used to >> create a pci_host_bridge structure together with its associated >> bus. >> >> Cc: Bjorn Helgaas <bhelgaas@google.com> >> Cc: Arnd Bergmann <arnd@arndb.de> >> Cc: Grant Likely <grant.likely@linaro.org> >> Cc: Rob Herring <robh+dt@kernel.org> >> Cc: Catalin Marinas <catalin.marinas@arm.com> >> Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> >> --- [...] >> +int of_pci_get_host_bridge_resources(struct device_node *dev, >> + unsigned char busno, unsigned char bus_max, >> + struct list_head *resources, resource_size_t *io_base) >> +{ >> + struct resource *res; >> + struct resource *bus_range; >> + struct of_pci_range range; >> + struct of_pci_range_parser parser; >> + char range_type[4]; >> + int err; >> + >> + if (!io_base) >> + return -EINVAL; >> + *io_base = OF_BAD_ADDR; >> + >> + bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL); This function does a lot of kalloc's but there is not an easy way to undo those allocations. Hot unplug of a host bridge or probe error handling would leak memory. You could pass in struct device and use the devm_ variant (also addressing Bjorn's comment), but not having an uninit/remove function make what clean-up drivers have to do error prone. For example, on uninit a driver needs to call pci_free_resource_list. Rob
On Sat, Sep 20, 2014 at 01:28:38AM +0100, Rob Herring wrote: > On 09/19/2014 04:06 PM, Bjorn Helgaas wrote: > > On Thu, Sep 18, 2014 at 02:30:23AM +0100, Liviu Dudau wrote: > >> Provide a function to parse the PCI DT ranges that can be used to > >> create a pci_host_bridge structure together with its associated > >> bus. > >> > >> Cc: Bjorn Helgaas <bhelgaas@google.com> > >> Cc: Arnd Bergmann <arnd@arndb.de> > >> Cc: Grant Likely <grant.likely@linaro.org> > >> Cc: Rob Herring <robh+dt@kernel.org> > >> Cc: Catalin Marinas <catalin.marinas@arm.com> > >> Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> > >> --- > > [...] > > >> +int of_pci_get_host_bridge_resources(struct device_node *dev, > >> + unsigned char busno, unsigned char bus_max, > >> + struct list_head *resources, resource_size_t *io_base) > >> +{ > >> + struct resource *res; > >> + struct resource *bus_range; > >> + struct of_pci_range range; > >> + struct of_pci_range_parser parser; > >> + char range_type[4]; > >> + int err; > >> + > >> + if (!io_base) > >> + return -EINVAL; > >> + *io_base = OF_BAD_ADDR; > >> + > >> + bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL); > > This function does a lot of kalloc's but there is not an easy way to > undo those allocations. Hot unplug of a host bridge or probe error > handling would leak memory. > > You could pass in struct device and use the devm_ variant (also > addressing Bjorn's comment), but not having an uninit/remove function > make what clean-up drivers have to do error prone. For example, on > uninit a driver needs to call pci_free_resource_list. If the function fails to parse the ranges for whatever reason it will call pci_free_resource_list on the resources that have been added already and it will clean up. If it is successful, then it is the job of the caller to free the list, as mentioned in the comment associated with the function. The reason why I am reluctant to use devm_ here is that the ranges are only parsed here, no filtering is applied. Architectures and/or host bridge drivers can/could impose additional restrictions to the list before passing it to pci_scan_root_bus() for example. Best regards, Liviu > > Rob >
On Mon, Sep 22, 2014 at 12:55 PM, Liviu Dudau <Liviu.Dudau@arm.com> wrote: > On Sat, Sep 20, 2014 at 01:28:38AM +0100, Rob Herring wrote: >> On 09/19/2014 04:06 PM, Bjorn Helgaas wrote: >> > On Thu, Sep 18, 2014 at 02:30:23AM +0100, Liviu Dudau wrote: >> >> Provide a function to parse the PCI DT ranges that can be used to >> >> create a pci_host_bridge structure together with its associated >> >> bus. >> >> >> >> Cc: Bjorn Helgaas <bhelgaas@google.com> >> >> Cc: Arnd Bergmann <arnd@arndb.de> >> >> Cc: Grant Likely <grant.likely@linaro.org> >> >> Cc: Rob Herring <robh+dt@kernel.org> >> >> Cc: Catalin Marinas <catalin.marinas@arm.com> >> >> Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> >> >> --- >> >> [...] >> >> >> +int of_pci_get_host_bridge_resources(struct device_node *dev, >> >> + unsigned char busno, unsigned char bus_max, >> >> + struct list_head *resources, resource_size_t *io_base) >> >> +{ >> >> + struct resource *res; >> >> + struct resource *bus_range; >> >> + struct of_pci_range range; >> >> + struct of_pci_range_parser parser; >> >> + char range_type[4]; >> >> + int err; >> >> + >> >> + if (!io_base) >> >> + return -EINVAL; >> >> + *io_base = OF_BAD_ADDR; >> >> + >> >> + bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL); >> >> This function does a lot of kalloc's but there is not an easy way to >> undo those allocations. Hot unplug of a host bridge or probe error >> handling would leak memory. >> >> You could pass in struct device and use the devm_ variant (also >> addressing Bjorn's comment), but not having an uninit/remove function >> make what clean-up drivers have to do error prone. For example, on >> uninit a driver needs to call pci_free_resource_list. > > If the function fails to parse the ranges for whatever reason it will > call pci_free_resource_list on the resources that have been added already > and it will clean up. If it is successful, then it is the job of the caller > to free the list, as mentioned in the comment associated with the function. > > The reason why I am reluctant to use devm_ here is that the ranges are only > parsed here, no filtering is applied. Architectures and/or host bridge > drivers can/could impose additional restrictions to the list before passing > it to pci_scan_root_bus() for example. Okay, as long as the caller has a single clean-up responsibility, I guess it is fine. Rob
diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c index 7eaeac2..c18b8da 100644 --- a/drivers/of/of_pci.c +++ b/drivers/of/of_pci.c @@ -1,7 +1,9 @@ #include <linux/kernel.h> #include <linux/export.h> #include <linux/of.h> +#include <linux/of_address.h> #include <linux/of_pci.h> +#include <linux/slab.h> #include "of_private.h" @@ -151,6 +153,112 @@ int of_pci_get_domain_nr(struct device_node *node, bool allocate_if_missing) } EXPORT_SYMBOL_GPL(of_pci_get_domain_nr); +/** + * of_pci_get_host_bridge_resources - Parse PCI host bridge resources from DT + * @dev: device node of the host bridge having the range property + * @busno: bus number associated with the bridge root bus + * @bus_max: maximum number of busses for this bridge + * @resources: list where the range of resources will be added after DT parsing + * @io_base: pointer to a variable that will contain on return the physical + * address for the start of the I/O range. + * + * It is the callers job to free the @resources list. + * + * This function will parse the "ranges" property of a PCI host bridge device + * node and setup the resource mapping based on its content. It is expected + * that the property conforms with the Power ePAPR document. + * + * It returns zero if the range parsing has been successful or a standard error + * value if it failed. + */ +int of_pci_get_host_bridge_resources(struct device_node *dev, + unsigned char busno, unsigned char bus_max, + struct list_head *resources, resource_size_t *io_base) +{ + struct resource *res; + struct resource *bus_range; + struct of_pci_range range; + struct of_pci_range_parser parser; + char range_type[4]; + int err; + + if (!io_base) + return -EINVAL; + *io_base = OF_BAD_ADDR; + + bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL); + if (!bus_range) + return -ENOMEM; + + pr_info("PCI host bridge %s ranges:\n", dev->full_name); + + err = of_pci_parse_bus_range(dev, bus_range); + if (err) { + bus_range->start = busno; + bus_range->end = bus_max; + bus_range->flags = IORESOURCE_BUS; + pr_info(" No bus range found for %s, using %pR\n", + dev->full_name, &bus_range); + } else { + if (bus_range->end > bus_range->start + bus_max) + bus_range->end = bus_range->start + bus_max; + } + pci_add_resource(resources, bus_range); + + /* Check for ranges property */ + err = of_pci_range_parser_init(&parser, dev); + if (err) + goto parse_failed; + + pr_debug("Parsing ranges property...\n"); + for_each_of_pci_range(&parser, &range) { + /* Read next ranges element */ + if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO) + snprintf(range_type, 4, " IO"); + else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM) + snprintf(range_type, 4, "MEM"); + else + snprintf(range_type, 4, "err"); + pr_info(" %s %#010llx..%#010llx -> %#010llx\n", range_type, + range.cpu_addr, range.cpu_addr + range.size - 1, + range.pci_addr); + + /* + * If we failed translation or got a zero-sized region + * then skip this range + */ + if (range.cpu_addr == OF_BAD_ADDR || range.size == 0) + continue; + + res = kzalloc(sizeof(struct resource), GFP_KERNEL); + if (!res) { + err = -ENOMEM; + goto parse_failed; + } + + err = of_pci_range_to_resource(&range, dev, res); + if (err) { + kfree(res); + goto parse_failed; + } + + if (resource_type(res) == IORESOURCE_IO) { + if (*io_base != OF_BAD_ADDR) + pr_warn("More than one I/O resource converted. CPU offset for old range lost!\n"); + *io_base = range.cpu_addr; + } + + pci_add_resource_offset(resources, res, res->start - range.pci_addr); + } + + return 0; + +parse_failed: + pci_free_resource_list(resources); + return err; +} +EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources); + #ifdef CONFIG_PCI_MSI static LIST_HEAD(of_pci_msi_chip_list); diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h index 3a3824c..a4b8a85 100644 --- a/include/linux/of_pci.h +++ b/include/linux/of_pci.h @@ -16,6 +16,10 @@ int of_pci_get_devfn(struct device_node *np); int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin); int of_pci_parse_bus_range(struct device_node *node, struct resource *res); int of_pci_get_domain_nr(struct device_node *node, bool allocate_if_missing); +int of_pci_get_host_bridge_resources(struct device_node *dev, + unsigned char busno, unsigned char bus_max, + struct list_head *resources, resource_size_t *io_base); + #else static inline int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq) { @@ -50,6 +54,13 @@ of_pci_get_domain_nr(struct device_node *node, bool allocate_if_missing) { return -1; } + +int of_pci_get_host_bridge_resources(struct device_node *dev, + unsigned char busno, unsigned char bus_max, + struct list_head *resources, resource_size_t *io_base); +{ + return -EINVAL; +} #endif #if defined(CONFIG_OF) && defined(CONFIG_PCI_MSI)
Provide a function to parse the PCI DT ranges that can be used to create a pci_host_bridge structure together with its associated bus. Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Grant Likely <grant.likely@linaro.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> --- drivers/of/of_pci.c | 108 +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of_pci.h | 11 +++++ 2 files changed, 119 insertions(+)