On Wed, Jul 01, 2015 at 10:43:33AM +0100, Zhou Wang wrote: > This patch had added by Arnd Bergmann during last reviewing of v1 patchset[1]. > > PCI core codes call pcibios_align_resource(). In ARM specific one, it will > dereference pci_sys_data and call sys->align_resource. If we try to unify ARM > and ARM64 PCIe API in pcie-designware. it will bring kernel crash when run into > this dereferencing. > > However, in ARM there is only pci-mvebu which implements align_resource. So > add align_resource call back in pci_host_bridge structure and override > pcibios_align_resource with it. > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > Signed-off-by: Zhou Wang <wangzhou1@xxxxxxxxxxxxx> > Tested-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx> > > [1] http://www.spinics.net/lists/linux-pci/msg41671.html > --- > arch/arm/kernel/bios32.c | 6 ------ > drivers/pci/host/pci-mvebu.c | 47 ++++++++++++++++++++++++++++---------------- > drivers/pci/setup-res.c | 27 ++++++++++++++++++++----- > include/linux/pci.h | 3 +++ > 4 files changed, 55 insertions(+), 28 deletions(-) > > diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c > index fcbbbb1..b01189f 100644 > --- a/arch/arm/kernel/bios32.c > +++ b/arch/arm/kernel/bios32.c > @@ -468,7 +468,6 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw, > sys->busnr = busnr; > sys->swizzle = hw->swizzle; > sys->map_irq = hw->map_irq; > - sys->align_resource = hw->align_resource; > INIT_LIST_HEAD(&sys->resources); > > if (hw->private_data) > @@ -588,8 +587,6 @@ char * __init pcibios_setup(char *str) > resource_size_t pcibios_align_resource(void *data, const struct resource *res, > resource_size_t size, resource_size_t align) > { > - struct pci_dev *dev = data; > - struct pci_sys_data *sys = dev->sysdata; > resource_size_t start = res->start; > > if (res->flags & IORESOURCE_IO && start & 0x300) > @@ -597,9 +594,6 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res, > > start = (start + align - 1) & ~(align - 1); > > - if (sys->align_resource) > - return sys->align_resource(dev, res, start, size, align); > - > return start; > } > > diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c > index 1ab8635..155d05f 100644 > --- a/drivers/pci/host/pci-mvebu.c > +++ b/drivers/pci/host/pci-mvebu.c > @@ -22,6 +22,8 @@ > #include <linux/of_pci.h> > #include <linux/of_platform.h> > > +#include "../pci.h" /* HACK to see pci_find_host_bridge */ > + > /* > * PCIe unit register offsets. > */ > @@ -751,27 +753,20 @@ static int mvebu_pcie_setup(int nr, struct pci_sys_data *sys) > return 1; > } > > -static struct pci_bus *mvebu_pcie_scan_bus(int nr, struct pci_sys_data *sys) > +static resource_size_t mvebu_pcie_align_resource(void *data, > + const struct resource *res, > + resource_size_t size, > + resource_size_t align) > { > - struct mvebu_pcie *pcie = sys_to_pcie(sys); > - struct pci_bus *bus; > + struct pci_dev *dev = data; > > - bus = pci_create_root_bus(&pcie->pdev->dev, sys->busnr, > - &mvebu_pcie_ops, sys, &sys->resources); > - if (!bus) > - return NULL; > + resource_size_t start = res->start; > > - pci_scan_child_bus(bus); > + if (res->flags & IORESOURCE_IO && start & 0x300) > + start = (start + 0x3ff) & ~0x3ff; > > - return bus; > -} > + start = (start + align - 1) & ~(align - 1); Honestly, I don't see here anything that is mvebu specific. Could you move this function in the generic pci/host area and have a flag in the pci_host_bridge structure whether the function should be called or not? I know that in a way that looks very close to the existing implementation which uses pcibios_align_resource, but the problem with pcibios_ version is that it is arch specific and not driver specific the way we want. Having this version as a generic implementation would also remove at least 2 more arch version, possibly more after testing by the arch maintainers. Best regards, Liviu > > -static resource_size_t mvebu_pcie_align_resource(struct pci_dev *dev, > - const struct resource *res, > - resource_size_t start, > - resource_size_t size, > - resource_size_t align) > -{ > if (dev->bus->number != 0) > return start; > > @@ -796,6 +791,25 @@ static resource_size_t mvebu_pcie_align_resource(struct pci_dev *dev, > return start; > } > > +static struct pci_bus *mvebu_pcie_scan_bus(int nr, struct pci_sys_data *sys) > +{ > + struct mvebu_pcie *pcie = sys_to_pcie(sys); > + struct pci_host_bridge *phb; > + struct pci_bus *bus; > + > + bus = pci_create_root_bus(&pcie->pdev->dev, sys->busnr, > + &mvebu_pcie_ops, sys, &sys->resources); > + if (!bus) > + return NULL; > + > + phb = pci_find_host_bridge(bus); > + phb->align_resource = mvebu_pcie_align_resource; > + > + pci_scan_child_bus(bus); > + > + return bus; > +} > + > static void mvebu_pcie_enable(struct mvebu_pcie *pcie) > { > struct hw_pci hw; > @@ -812,7 +826,6 @@ static void mvebu_pcie_enable(struct mvebu_pcie *pcie) > hw.scan = mvebu_pcie_scan_bus; > hw.map_irq = of_irq_parse_and_map_pci; > hw.ops = &mvebu_pcie_ops; > - hw.align_resource = mvebu_pcie_align_resource; > > pci_common_init(&hw); > } > diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c > index 232f925..73abca7 100644 > --- a/drivers/pci/setup-res.c > +++ b/drivers/pci/setup-res.c > @@ -200,7 +200,11 @@ static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev, > } > > static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev, > - int resno, resource_size_t size, resource_size_t align) > + int resno, resource_size_t size, resource_size_t align, > + resource_size_t (*alignf)(void *, > + const struct resource *, > + resource_size_t, > + resource_size_t)) > { > struct resource *res = dev->resource + resno; > resource_size_t min; > @@ -217,7 +221,7 @@ static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev, > */ > ret = pci_bus_alloc_resource(bus, res, size, align, min, > IORESOURCE_PREFETCH | IORESOURCE_MEM_64, > - pcibios_align_resource, dev); > + alignf, dev); > if (ret == 0) > return 0; > > @@ -229,7 +233,7 @@ static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev, > (IORESOURCE_PREFETCH | IORESOURCE_MEM_64)) { > ret = pci_bus_alloc_resource(bus, res, size, align, min, > IORESOURCE_PREFETCH, > - pcibios_align_resource, dev); > + alignf, dev); > if (ret == 0) > return 0; > } > @@ -242,7 +246,7 @@ static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev, > */ > if (res->flags & (IORESOURCE_PREFETCH | IORESOURCE_MEM_64)) > ret = pci_bus_alloc_resource(bus, res, size, align, min, 0, > - pcibios_align_resource, dev); > + alignf, dev); > > return ret; > } > @@ -251,10 +255,23 @@ static int _pci_assign_resource(struct pci_dev *dev, int resno, > resource_size_t size, resource_size_t min_align) > { > struct pci_bus *bus; > + struct pci_host_bridge *phb; > + resource_size_t (*alignf)(void *, > + const struct resource *, > + resource_size_t, > + resource_size_t); > int ret; > > bus = dev->bus; > - while ((ret = __pci_assign_resource(bus, dev, resno, size, min_align))) { > + phb = pci_find_host_bridge(bus); > + > + if (phb->align_resource) > + alignf = phb->align_resource; > + else > + alignf = pcibios_align_resource; > + > + while ((ret = __pci_assign_resource(bus, dev, resno, size, > + min_align, alignf))) { > if (!bus->parent || !bus->self->transparent) > break; > bus = bus->parent; > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 353db8d..39e48fc 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -404,6 +404,9 @@ struct pci_host_bridge { > struct device dev; > struct pci_bus *bus; /* root bus */ > struct list_head windows; /* resource_entry */ > + resource_size_t (*align_resource)(void *data, > + const struct resource *res, > + resource_size_t size, resource_size_t align); > void (*release_fn)(struct pci_host_bridge *); > void *release_data; > unsigned int ignore_reset_delay:1; /* for entire hierarchy */ > -- > 1.9.1 > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯ -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
