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Commit 029baf14 authored by Thomas Petazzoni's avatar Thomas Petazzoni Committed by Russell King
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ARM: 7683/1: pci: add a align_resource hook 



The PCI specifications says that an I/O region must be aligned on a 4
KB boundary, and a memory region aligned on a 1 MB boundary.

However, the Marvell PCIe interfaces rely on address decoding windows
(which allow to associate a range of physical addresses with a given
device). For PCIe memory windows, those windows are defined with a 1
MB granularity (which matches the PCI specs), but PCIe I/O windows can
only be defined with a 64 KB granularity, so they have to be 64 KB
aligned. We therefore need to tell the PCI core about this special
alignement requirement.

The PCI core already calls pcibios_align_resource() in the ARM PCI
core, specifically for such purposes. So this patch extends the ARM
PCI core so that it calls a ->align_resource() hook registered by the
PCI driver, exactly like the existing ->map_irq() and ->swizzle()
hooks.

A particular PCI driver can register a align_resource() hook, and do
its own specific alignement, depending on the specific constraints of
the underlying hardware.

Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 01223f36

arch/arm/include/asm/mach/pci.h

+11 −0
Original line number Diff line number Diff line
@@ -30,6 +30,11 @@ struct hw_pci { 
	void		(*postinit)(void);

	u8		(*swizzle)(struct pci_dev *dev, u8 *pin);

	int		(*map_irq)(const struct pci_dev *dev, u8 slot, u8 pin);

	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);

};



/*
@@ -51,6 +56,12 @@ 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	*/

};

arch/arm/kernel/bios32.c

+6 −0
Original line number Diff line number Diff line
@@ -462,6 +462,7 @@ static void pcibios_init_hw(struct hw_pci *hw, struct list_head *head) 
		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)
@@ -574,6 +575,8 @@ 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)
@@ -581,6 +584,9 @@ 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;

}