Messages in this thread Patch in this message | | | Date | Mon, 26 Jan 2015 18:25:39 -0500 | From | Murali Karicheri <> | Subject | Re: [PATCH v4 4/6] of/pci: add of_pci_dma_configure() update dma configuration |
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On 01/23/2015 06:41 PM, Bjorn Helgaas wrote: > On Fri, Jan 23, 2015 at 05:32:37PM -0500, Murali Karicheri wrote: >> Add of_pci_dma_configure() to allow updating the dma configuration >> of the pci device using the configuration from DT of the parent of >> the root bridge device. >> >> Cc: Joerg Roedel<joro@8bytes.org> >> Cc: Grant Likely<grant.likely@linaro.org> >> Cc: Rob Herring<robh+dt@kernel.org> >> Cc: Bjorn Helgaas<bhelgaas@google.com> >> Cc: Will Deacon<will.deacon@arm.com> >> Cc: Russell King<linux@arm.linux.org.uk> >> Cc: Arnd Bergmann<arnd@arndb.de> >> Cc: Suravee Suthikulpanit<Suravee.Suthikulpanit@amd.com> >> >> Signed-off-by: Murali Karicheri<m-karicheri2@ti.com> >> --- >> drivers/of/of_pci.c | 39 +++++++++++++++++++++++++++++++++++++++ >> include/linux/of_pci.h | 12 ++++++++++++ >> 2 files changed, 51 insertions(+) >> >> diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c >> index 88471d3..34878c9 100644 >> --- a/drivers/of/of_pci.c >> +++ b/drivers/of/of_pci.c >> @@ -2,6 +2,7 @@ >> #include<linux/export.h> >> #include<linux/of.h> >> #include<linux/of_address.h> >> +#include<linux/of_device.h> >> #include<linux/of_pci.h> >> #include<linux/slab.h> >> >> @@ -229,6 +230,44 @@ parse_failed: >> return err; >> } >> EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources); >> + >> +/** >> + * of_get_pci_root_bridge_parent - get the OF node of the root bridge's parent >> + * @dev: ptr to pci_dev struct of the pci device >> + * >> + * This function will traverse the bus up to the root bus starting with >> + * the child and return the OF node ptr to root bridge device's parent device. >> + */ >> +struct device_node *of_get_pci_root_bridge_parent(struct pci_dev *dev) > > I'm not an OF person, but this interface seems like it might be too > special-purpose. Maybe it would be enough to add > "of_get_pci_root_bridge()", and the caller could do this: > > struct device *bridge = of_get_pci_root_bridge(dev); > struct device_node *parent_np = bridge->parent->of_node; > > Also, the name "of_get_..." suggests that it increments a refcount, as > of_get_parent() does. But you aren't doing anything with the refcount. > > But I guess an "of_get_pci_root_bridge()" isn't doing anything OF-related, > so maybe we should just add a "pci_get_host_bridge(struct pci_dev *)" > to PCI instead.
Bjorn,
Thanks for the comment.
I think adding pci_get_host_bridge() is a good idea. There is already similar function in host-bridge.c. I have added this function re-using existing function find_pci_root_bus(). See the incremental diff below after this change. Does this look good?
diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c index 34878c9..77b15b5 100644 --- a/drivers/of/of_pci.c +++ b/drivers/of/of_pci.c @@ -232,26 +232,6 @@ parse_failed: EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources);
/** - * of_get_pci_root_bridge_parent - get the OF node of the root bridge's parent - * @dev: ptr to pci_dev struct of the pci device - * - * This function will traverse the bus up to the root bus starting with - * the child and return the OF node ptr to root bridge device's parent device. - */ -struct device_node *of_get_pci_root_bridge_parent(struct pci_dev *dev) -{ - struct pci_bus *bus = dev->bus; - struct device *bridge; - - while (!pci_is_root_bus(bus)) - bus = bus->parent; - bridge = bus->bridge; - - return bridge->parent->of_node; -} -EXPORT_SYMBOL_GPL(of_get_pci_root_bridge_parent); - -/** * of_pci_dma_configure - Setup DMA configuration * @dev: ptr to pci_dev struct of the pci device * @@ -261,10 +241,9 @@ EXPORT_SYMBOL_GPL(of_get_pci_root_bridge_parent); void of_pci_dma_configure(struct pci_dev *pci_dev) { struct device *dev = &pci_dev->dev; - struct device_node *parent_np; + struct device *bridge = pci_get_host_bridge(pci_dev);
- parent_np = of_get_pci_root_bridge_parent(pci_dev); - of_dma_configure(dev, parent_np); + of_dma_configure(dev, bridge->parent->of_node); } EXPORT_SYMBOL_GPL(of_pci_dma_configure);
diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c index 0e5f3c9..9803aa6 100644 --- a/drivers/pci/host-bridge.c +++ b/drivers/pci/host-bridge.c @@ -23,6 +23,13 @@ static struct pci_host_bridge *find_pci_host_bridge(struct pci_bus *bus) return to_pci_host_bridge(root_bus->bridge); }
+struct device *pci_get_host_bridge(struct pci_dev *dev) +{ + struct pci_bus *root_bus = find_pci_root_bus(dev->bus); + + return root_bus->bridge; +} + void pci_set_host_bridge_release(struct pci_host_bridge *bridge, void (*release_fn)(struct pci_host_bridge *), void *release_data) diff --git a/include/linux/pci.h b/include/linux/pci.h index 9603094..5bcdfa6 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -513,6 +513,8 @@ static inline struct pci_dev *pci_upstream_bridge(struct pci_dev *dev) return dev->bus->self; }
+struct device *pci_get_host_bridge(struct pci_dev *dev); + #ifdef CONFIG_PCI_MSI static inline bool pci_dev_msi_enabled(struct pci_dev *pci_dev) { @@ -1823,6 +1825,7 @@ int pci_vpd_find_tag(const u8 *buf, unsigned int off, unsigned int len, u8 rdt); int pci_vpd_find_info_keyword(const u8 *buf, unsigned int off, unsigned int len, const char *kw);
/* PCI <-> OF binding helpers */ #ifdef CONFIG_OF struct device_node;
> > Bjorn > >> +{ >> + struct pci_bus *bus = dev->bus; >> + struct device *bridge; >> + >> + while (!pci_is_root_bus(bus)) >> + bus = bus->parent; >> + bridge = bus->bridge; >> + >> + return bridge->parent->of_node; >> +} >> +EXPORT_SYMBOL_GPL(of_get_pci_root_bridge_parent); >> + >> +/** >> + * of_pci_dma_configure - Setup DMA configuration >> + * @dev: ptr to pci_dev struct of the pci device >> + * >> + * Function to update PCI devices's DMA configuration using the same >> + * info from the OF node of root host bridge's parent. >> + */ >> +void of_pci_dma_configure(struct pci_dev *pci_dev) >> +{ >> + struct device *dev =&pci_dev->dev; >> + struct device_node *parent_np; >> + >> + parent_np = of_get_pci_root_bridge_parent(pci_dev); >> + of_dma_configure(dev, parent_np); >> +} >> +EXPORT_SYMBOL_GPL(of_pci_dma_configure); >> + >> #endif /* CONFIG_OF_ADDRESS */ >> >> #ifdef CONFIG_PCI_MSI >> diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h >> index ce0e5ab..0465a2a 100644 >> --- a/include/linux/of_pci.h >> +++ b/include/linux/of_pci.h >> @@ -16,6 +16,8 @@ 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_get_pci_domain_nr(struct device_node *node); >> +struct device_node *of_get_pci_root_bridge_parent(struct pci_dev *dev); >> +void of_pci_dma_configure(struct pci_dev *pci_dev); >> #else >> static inline int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq) >> { >> @@ -50,6 +52,16 @@ of_get_pci_domain_nr(struct device_node *node) >> { >> return -1; >> } >> + >> +static inline struct device_node >> +*of_get_pci_root_bridge_parent(struct pci_dev *dev) >> +{ >> + return NULL; >> +} >> + >> +static inline void of_pci_dma_configure(struct pci_dev *pci_dev) >> +{ >> +} >> #endif >> >> #if defined(CONFIG_OF_ADDRESS) >> -- >> 1.7.9.5 >>
-- Murali Karicheri Linux Kernel, Texas Instruments
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