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linux/arch/x86/pci/pci.h
Gary Hade 62f420f828 PCI: use _CRS for PCI resource allocation
Use _CRS for PCI resource allocation

This patch resolves an issue where incorrect PCI memory and i/o ranges
are being assigned to hotplugged PCI devices on some IBM systems.  The
resource mis-allocation not only makes the PCI device unuseable but
often makes the entire system unuseable due to resulting machine checks.

The hotplug capable PCI slots on the affected systems are not located
under a standard P2P bridge but are instead located under PCI root
bridges or subtractive decode P2P bridges.  For example, the IBM x3850
contains 2 hotplug capable PCI-X slots and 4 hotplug capable PCIe slots
with the PCI-X slots each located under a PCI root bridge and the PCIe
slots each located under a subtractive decode P2P bridge.

The current i386/x86_64 PCI resource allocation code does not use _CRS
returned resource information.  No other resource information source is
available for slots that are not below a standard P2P bridge so
incorrect ranges are being allocated from e820 hole causing the bad
result.

This patch causes the kernel to use _CRS returned resource info.  It is
roughly based on a change provided by Matthew Wilcox for the ia64 kernel
in 2005.  Due to possible buggy BIOS factor and possible yet to be
discovered kernel issues the function is disabled by default and can be
enabled with pci=use_crs.

Signed-off-by: Gary Hade <gary.hade@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12 15:03:18 -07:00

152 lines
4.0 KiB
C

/*
* Low-Level PCI Access for i386 machines.
*
* (c) 1999 Martin Mares <mj@ucw.cz>
*/
#undef DEBUG
#ifdef DEBUG
#define DBG(x...) printk(x)
#else
#define DBG(x...)
#endif
#define PCI_PROBE_BIOS 0x0001
#define PCI_PROBE_CONF1 0x0002
#define PCI_PROBE_CONF2 0x0004
#define PCI_PROBE_MMCONF 0x0008
#define PCI_PROBE_MASK 0x000f
#define PCI_PROBE_NOEARLY 0x0010
#define PCI_NO_SORT 0x0100
#define PCI_BIOS_SORT 0x0200
#define PCI_NO_CHECKS 0x0400
#define PCI_USE_PIRQ_MASK 0x0800
#define PCI_ASSIGN_ROMS 0x1000
#define PCI_BIOS_IRQ_SCAN 0x2000
#define PCI_ASSIGN_ALL_BUSSES 0x4000
#define PCI_CAN_SKIP_ISA_ALIGN 0x8000
#define PCI_USE__CRS 0x10000
extern unsigned int pci_probe;
extern unsigned long pirq_table_addr;
enum pci_bf_sort_state {
pci_bf_sort_default,
pci_force_nobf,
pci_force_bf,
pci_dmi_bf,
};
/* pci-i386.c */
extern unsigned int pcibios_max_latency;
void pcibios_resource_survey(void);
int pcibios_enable_resources(struct pci_dev *, int);
/* pci-pc.c */
extern int pcibios_last_bus;
extern struct pci_bus *pci_root_bus;
extern struct pci_ops pci_root_ops;
/* pci-irq.c */
struct irq_info {
u8 bus, devfn; /* Bus, device and function */
struct {
u8 link; /* IRQ line ID, chipset dependent, 0=not routed */
u16 bitmap; /* Available IRQs */
} __attribute__((packed)) irq[4];
u8 slot; /* Slot number, 0=onboard */
u8 rfu;
} __attribute__((packed));
struct irq_routing_table {
u32 signature; /* PIRQ_SIGNATURE should be here */
u16 version; /* PIRQ_VERSION */
u16 size; /* Table size in bytes */
u8 rtr_bus, rtr_devfn; /* Where the interrupt router lies */
u16 exclusive_irqs; /* IRQs devoted exclusively to PCI usage */
u16 rtr_vendor, rtr_device; /* Vendor and device ID of interrupt router */
u32 miniport_data; /* Crap */
u8 rfu[11];
u8 checksum; /* Modulo 256 checksum must give zero */
struct irq_info slots[0];
} __attribute__((packed));
extern unsigned int pcibios_irq_mask;
extern int pcibios_scanned;
extern spinlock_t pci_config_lock;
extern int (*pcibios_enable_irq)(struct pci_dev *dev);
extern void (*pcibios_disable_irq)(struct pci_dev *dev);
extern int pci_conf1_write(unsigned int seg, unsigned int bus,
unsigned int devfn, int reg, int len, u32 value);
extern int pci_conf1_read(unsigned int seg, unsigned int bus,
unsigned int devfn, int reg, int len, u32 *value);
extern int pci_direct_probe(void);
extern void pci_direct_init(int type);
extern void pci_pcbios_init(void);
extern void pci_mmcfg_init(int type);
extern void pcibios_sort(void);
/* pci-mmconfig.c */
/* Verify the first 16 busses. We assume that systems with more busses
get MCFG right. */
#define PCI_MMCFG_MAX_CHECK_BUS 16
extern DECLARE_BITMAP(pci_mmcfg_fallback_slots, 32*PCI_MMCFG_MAX_CHECK_BUS);
extern int __init pci_mmcfg_arch_reachable(unsigned int seg, unsigned int bus,
unsigned int devfn);
extern int __init pci_mmcfg_arch_init(void);
/*
* AMD Fam10h CPUs are buggy, and cannot access MMIO config space
* on their northbrige except through the * %eax register. As such, you MUST
* NOT use normal IOMEM accesses, you need to only use the magic mmio-config
* accessor functions.
* In fact just use pci_config_*, nothing else please.
*/
static inline unsigned char mmio_config_readb(void __iomem *pos)
{
u8 val;
asm volatile("movb (%1),%%al" : "=a" (val) : "r" (pos));
return val;
}
static inline unsigned short mmio_config_readw(void __iomem *pos)
{
u16 val;
asm volatile("movw (%1),%%ax" : "=a" (val) : "r" (pos));
return val;
}
static inline unsigned int mmio_config_readl(void __iomem *pos)
{
u32 val;
asm volatile("movl (%1),%%eax" : "=a" (val) : "r" (pos));
return val;
}
static inline void mmio_config_writeb(void __iomem *pos, u8 val)
{
asm volatile("movb %%al,(%1)" :: "a" (val), "r" (pos) : "memory");
}
static inline void mmio_config_writew(void __iomem *pos, u16 val)
{
asm volatile("movw %%ax,(%1)" :: "a" (val), "r" (pos) : "memory");
}
static inline void mmio_config_writel(void __iomem *pos, u32 val)
{
asm volatile("movl %%eax,(%1)" :: "a" (val), "r" (pos) : "memory");
}