ARM: 7683/1: pci: add a align_resource hook (029baf14) · Commits · 戴 / test

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:

Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by:

Russell King <rmk+kernel@arm.linux.org.uk>

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;
		}

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