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 <[email protected]>
> Signed-off-by: Zhou Wang <[email protected]>
> Tested-by: Fabrice Gasnier <[email protected]>
>
> [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)_/¯
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