From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757420AbbA0AAX (ORCPT ); Mon, 26 Jan 2015 19:00:23 -0500 Received: from mail-qg0-f43.google.com ([209.85.192.43]:54145 "EHLO mail-qg0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756767AbbA0AAT (ORCPT ); Mon, 26 Jan 2015 19:00:19 -0500 MIME-Version: 1.0 In-Reply-To: <54C6CCF3.7080308@ti.com> References: <1422052359-12384-1-git-send-email-m-karicheri2@ti.com> <1422052359-12384-5-git-send-email-m-karicheri2@ti.com> <20150123234124.GW29776@google.com> <54C6CCF3.7080308@ti.com> From: Bjorn Helgaas Date: Mon, 26 Jan 2015 17:59:58 -0600 Message-ID: Subject: Re: [PATCH v4 4/6] of/pci: add of_pci_dma_configure() update dma configuration To: Murali Karicheri Cc: linux-arm , "linux-kernel@vger.kernel.org" , "linux-pci@vger.kernel.org" , "devicetree@vger.kernel.org" , "open list:INTEL IOMMU (VT-d)" , Joerg Roedel , Grant Likely , Rob Herring , Will Deacon , Russell King , Arnd Bergmann , Suravee Suthikulpanit Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 26, 2015 at 5:25 PM, Murali Karicheri wrote: > 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 >>> Cc: Grant Likely >>> Cc: Rob Herring >>> Cc: Bjorn Helgaas >>> Cc: Will Deacon >>> Cc: Russell King >>> Cc: Arnd Bergmann >>> Cc: Suravee Suthikulpanit >>> >>> Signed-off-by: Murali Karicheri >>> --- >>> 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 >>> #include >>> #include >>> +#include >>> #include >>> #include >>> >>> @@ -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? I like the implementation, but I think either we need to take a reference on the host bridge, or change the name to something like "pci_find_host_bridge()", because using "_get_" is conventional for functions that acquire a reference. Since host bridges are hot-pluggable, at least in theory, I vote for taking a reference. Then of course, you'd have to add code to drop the reference when you're finished with it. Bjorn > 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bjorn Helgaas Subject: Re: [PATCH v4 4/6] of/pci: add of_pci_dma_configure() update dma configuration Date: Mon, 26 Jan 2015 17:59:58 -0600 Message-ID: References: <1422052359-12384-1-git-send-email-m-karicheri2@ti.com> <1422052359-12384-5-git-send-email-m-karicheri2@ti.com> <20150123234124.GW29776@google.com> <54C6CCF3.7080308@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <54C6CCF3.7080308-l0cyMroinI0@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Murali Karicheri Cc: "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Russell King , Arnd Bergmann , "linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Will Deacon , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "open list:INTEL IOMMU (VT-d)" , Rob Herring , Grant Likely , linux-arm List-Id: devicetree@vger.kernel.org On Mon, Jan 26, 2015 at 5:25 PM, Murali Karicheri wrote: > 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 >>> Cc: Grant Likely >>> Cc: Rob Herring >>> Cc: Bjorn Helgaas >>> Cc: Will Deacon >>> Cc: Russell King >>> Cc: Arnd Bergmann >>> Cc: Suravee Suthikulpanit >>> >>> Signed-off-by: Murali Karicheri >>> --- >>> 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 >>> #include >>> #include >>> +#include >>> #include >>> #include >>> >>> @@ -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? I like the implementation, but I think either we need to take a reference on the host bridge, or change the name to something like "pci_find_host_bridge()", because using "_get_" is conventional for functions that acquire a reference. Since host bridges are hot-pluggable, at least in theory, I vote for taking a reference. Then of course, you'd have to add code to drop the reference when you're finished with it. Bjorn > 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: bhelgaas@google.com (Bjorn Helgaas) Date: Mon, 26 Jan 2015 17:59:58 -0600 Subject: [PATCH v4 4/6] of/pci: add of_pci_dma_configure() update dma configuration In-Reply-To: <54C6CCF3.7080308@ti.com> References: <1422052359-12384-1-git-send-email-m-karicheri2@ti.com> <1422052359-12384-5-git-send-email-m-karicheri2@ti.com> <20150123234124.GW29776@google.com> <54C6CCF3.7080308@ti.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Jan 26, 2015 at 5:25 PM, Murali Karicheri wrote: > 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 >>> Cc: Grant Likely >>> Cc: Rob Herring >>> Cc: Bjorn Helgaas >>> Cc: Will Deacon >>> Cc: Russell King >>> Cc: Arnd Bergmann >>> Cc: Suravee Suthikulpanit >>> >>> Signed-off-by: Murali Karicheri >>> --- >>> 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 >>> #include >>> #include >>> +#include >>> #include >>> #include >>> >>> @@ -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? I like the implementation, but I think either we need to take a reference on the host bridge, or change the name to something like "pci_find_host_bridge()", because using "_get_" is conventional for functions that acquire a reference. Since host bridges are hot-pluggable, at least in theory, I vote for taking a reference. Then of course, you'd have to add code to drop the reference when you're finished with it. Bjorn > 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