Re: [PATCH v12 2/8] ARM/PCI: remove align_resource in pci_sys_data
From: Bjorn Helgaas
Date: Tue Oct 27 2015 - 17:12:42 EST
[+cc Russell]
On Mon, Oct 26, 2015 at 07:35:44PM +0800, Zhou Wang wrote:
> From: gabriele paoloni <gabriele.paoloni@xxxxxxxxxx>
>
> This patch is needed in order to unify the PCIe designware framework for ARM and
> ARM64 architectures. In the PCIe designware unification process we are calling
> pci_create_root_bus() passing a "sysdata" parameter that is the same for both
> ARM and ARM64 and is of type "struct pcie_port*". In the ARM case this will
> cause a problem with the function pcibios_align_resource(); in fact this will
> cast "dev->sysdata" to "struct pci_sys_data*", whereas designware had passed a
> "struct pcie_port*" pointer.
>
> This patch solves the issue by removing "align_resource" from "pci_sys_data"
> struct and defining a static global function pointer in "bios32.c"
It's not ideal to have the global function pointer. Adding a pointer
to struct pci_ops would be another alternative, but I don't know that
this is worth that since there's only one user.
I added Russell just so he's aware; he merged 029baf14a027 ("ARM:
7683/1: pci: add a align_resource hook"), which added
pci_sys_data->align_resource in the first place.
I added some background to the changelog in the process of reviewing
this.
commit 7685ae4693bcd7b2fc02b1e0b957860b1638d31e
Author: Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx>
Date: Mon Oct 26 19:35:44 2015 +0800
ARM/PCI: Replace pci_sys_data->align_resource with global function pointer
dw_pcie_host_init() creates the PCI host bridge with pci_common_init_dev(),
an ARM-specific function that supplies the ARM-specific pci_sys_data
structure as the PCI "sysdata". To use dw_pcie_host_init() on other
architectures, we will copy the internals of pci_common_init_dev() into
pcie-designware.c instead of calling it, and dw_pcie_host_init() will
supply the DesignWare pcie_port structure as "sysdata".
Most ARM "sysdata" users are specific to non-DesignWare host bridges;
they'll be unaffected because those bridges will continue to have the ARM
pci_sys_data. Most of the rest are ARM-generic functions called by
pci_common_init_dev(); these will be unaffected because dw_pcie_host_init()
will no longer call pci_common_init().
But the ARM pcibios_align_resource() can be called by the PCI core for any
bridge, so it can't depend on sysdata since it may be either pci_sys_data
or pcie_port.
Remove the pcibios_align_resource() dependency on sysdata by replacing the
pci_sys_data->align_resource pointer with a global function pointer.
This is less general (we can no longer have per-host bridge
align_resource() methods), but the pci_sys_data->align_resource pointer was
used only by Marvell (see mvebu_pcie_enable()), so this would only be a
problem if we had a system with a combination of Marvell and other host
bridges
[bhelgaas: changelog]
Signed-off-by: Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx>
Signed-off-by: Zhou Wang <wangzhou1@xxxxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Acked-by: Pratyush Anand <pratyush.anand@xxxxxxxxx>
diff --git a/arch/arm/include/asm/mach/pci.h b/arch/arm/include/asm/mach/pci.h
index 8857d28..0070e85 100644
--- a/arch/arm/include/asm/mach/pci.h
+++ b/arch/arm/include/asm/mach/pci.h
@@ -52,12 +52,6 @@ struct pci_sys_data {
u8 (*swizzle)(struct pci_dev *, u8 *);
/* IRQ mapping */
int (*map_irq)(const struct pci_dev *, u8, u8);
- /* Resource alignement requirements */
- resource_size_t (*align_resource)(struct pci_dev *dev,
- const struct resource *res,
- resource_size_t start,
- resource_size_t size,
- resource_size_t align);
void *private_data; /* platform controller private data */
};
diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
index 874e182..6551d28 100644
--- a/arch/arm/kernel/bios32.c
+++ b/arch/arm/kernel/bios32.c
@@ -17,6 +17,11 @@
#include <asm/mach/pci.h>
static int debug_pci;
+static resource_size_t (*align_resource)(struct pci_dev *dev,
+ const struct resource *res,
+ resource_size_t start,
+ resource_size_t size,
+ resource_size_t align) = NULL;
/*
* We can't use pci_get_device() here since we are
@@ -456,7 +461,7 @@ 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;
+ align_resource = hw->align_resource;
INIT_LIST_HEAD(&sys->resources);
if (hw->private_data)
@@ -572,7 +577,6 @@ 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)
@@ -580,8 +584,8 @@ 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);
+ if (align_resource)
+ return align_resource(dev, res, start, size, align);
return start;
}
>
> Signed-off-by: Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx>
> Signed-off-by: Zhou Wang <wangzhou1@xxxxxxxxxxxxx>
> Acked-by: Pratyush Anand <pratyush.anand@xxxxxxxxx>
> ---
> arch/arm/include/asm/mach/pci.h | 6 ------
> arch/arm/kernel/bios32.c | 12 ++++++++----
> 2 files changed, 8 insertions(+), 10 deletions(-)
>
> diff --git a/arch/arm/include/asm/mach/pci.h b/arch/arm/include/asm/mach/pci.h
> index 8857d28..0070e85 100644
> --- a/arch/arm/include/asm/mach/pci.h
> +++ b/arch/arm/include/asm/mach/pci.h
> @@ -52,12 +52,6 @@ struct pci_sys_data {
> u8 (*swizzle)(struct pci_dev *, u8 *);
> /* IRQ mapping */
> int (*map_irq)(const struct pci_dev *, u8, u8);
> - /* Resource alignement requirements */
> - resource_size_t (*align_resource)(struct pci_dev *dev,
> - const struct resource *res,
> - resource_size_t start,
> - resource_size_t size,
> - resource_size_t align);
> void *private_data; /* platform controller private data */
> };
>
> diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
> index 874e182..6551d28 100644
> --- a/arch/arm/kernel/bios32.c
> +++ b/arch/arm/kernel/bios32.c
> @@ -17,6 +17,11 @@
> #include <asm/mach/pci.h>
>
> static int debug_pci;
> +static resource_size_t (*align_resource)(struct pci_dev *dev,
> + const struct resource *res,
> + resource_size_t start,
> + resource_size_t size,
> + resource_size_t align) = NULL;
>
> /*
> * We can't use pci_get_device() here since we are
> @@ -456,7 +461,7 @@ 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;
> + align_resource = hw->align_resource;
> INIT_LIST_HEAD(&sys->resources);
>
> if (hw->private_data)
> @@ -572,7 +577,6 @@ 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)
> @@ -580,8 +584,8 @@ 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);
> + if (align_resource)
> + return align_resource(dev, res, start, size, align);
>
> return start;
> }
> --
> 1.9.1
>
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