143 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			143 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Copyright (C) 2004 Matthew Wilcox <matthew@wil.cx>
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 * Copyright (C) 2004 Intel Corp.
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 *
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 * This code is released under the GNU General Public License version 2.
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 */
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/*
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 * mmconfig.c - Low-level direct PCI config space access via MMCONFIG
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 */
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#include <linux/pci.h>
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#include <linux/init.h>
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#include <asm/e820.h>
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#include <asm/pci_x86.h>
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#include <acpi/acpi.h>
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/* Assume systems with more busses have correct MCFG */
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#define mmcfg_virt_addr ((void __iomem *) fix_to_virt(FIX_PCIE_MCFG))
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/* The base address of the last MMCONFIG device accessed */
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static u32 mmcfg_last_accessed_device;
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static int mmcfg_last_accessed_cpu;
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/*
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 * Functions for accessing PCI configuration space with MMCONFIG accesses
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 */
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static u32 get_base_addr(unsigned int seg, int bus, unsigned devfn)
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{
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	struct acpi_mcfg_allocation *cfg;
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	int cfg_num;
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	for (cfg_num = 0; cfg_num < pci_mmcfg_config_num; cfg_num++) {
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		cfg = &pci_mmcfg_config[cfg_num];
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		if (cfg->pci_segment == seg &&
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		    (cfg->start_bus_number <= bus) &&
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		    (cfg->end_bus_number >= bus))
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			return cfg->address;
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	}
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	/* Fall back to type 0 */
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	return 0;
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}
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/*
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 * This is always called under pci_config_lock
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 */
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static void pci_exp_set_dev_base(unsigned int base, int bus, int devfn)
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{
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	u32 dev_base = base | (bus << 20) | (devfn << 12);
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	int cpu = smp_processor_id();
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	if (dev_base != mmcfg_last_accessed_device ||
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	    cpu != mmcfg_last_accessed_cpu) {
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		mmcfg_last_accessed_device = dev_base;
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		mmcfg_last_accessed_cpu = cpu;
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		set_fixmap_nocache(FIX_PCIE_MCFG, dev_base);
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	}
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}
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static int pci_mmcfg_read(unsigned int seg, unsigned int bus,
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			  unsigned int devfn, int reg, int len, u32 *value)
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{
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	unsigned long flags;
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	u32 base;
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	if ((bus > 255) || (devfn > 255) || (reg > 4095)) {
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err:		*value = -1;
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		return -EINVAL;
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	}
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	base = get_base_addr(seg, bus, devfn);
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	if (!base)
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		goto err;
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	spin_lock_irqsave(&pci_config_lock, flags);
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	pci_exp_set_dev_base(base, bus, devfn);
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	switch (len) {
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	case 1:
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		*value = mmio_config_readb(mmcfg_virt_addr + reg);
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		break;
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	case 2:
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		*value = mmio_config_readw(mmcfg_virt_addr + reg);
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		break;
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	case 4:
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		*value = mmio_config_readl(mmcfg_virt_addr + reg);
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		break;
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	}
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	spin_unlock_irqrestore(&pci_config_lock, flags);
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	return 0;
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}
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static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
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			   unsigned int devfn, int reg, int len, u32 value)
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{
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	unsigned long flags;
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	u32 base;
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	if ((bus > 255) || (devfn > 255) || (reg > 4095))
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		return -EINVAL;
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	base = get_base_addr(seg, bus, devfn);
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	if (!base)
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		return -EINVAL;
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	spin_lock_irqsave(&pci_config_lock, flags);
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	pci_exp_set_dev_base(base, bus, devfn);
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	switch (len) {
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	case 1:
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		mmio_config_writeb(mmcfg_virt_addr + reg, value);
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		break;
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	case 2:
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		mmio_config_writew(mmcfg_virt_addr + reg, value);
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		break;
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	case 4:
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		mmio_config_writel(mmcfg_virt_addr + reg, value);
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		break;
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	}
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	spin_unlock_irqrestore(&pci_config_lock, flags);
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	return 0;
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}
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static struct pci_raw_ops pci_mmcfg = {
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	.read =		pci_mmcfg_read,
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	.write =	pci_mmcfg_write,
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};
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int __init pci_mmcfg_arch_init(void)
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{
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	printk(KERN_INFO "PCI: Using MMCONFIG for extended config space\n");
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	raw_pci_ext_ops = &pci_mmcfg;
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	return 1;
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}
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void __init pci_mmcfg_arch_free(void)
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{
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}
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