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authorBen Hutchings <bhutchings@solarflare.com>2011-05-11 12:41:18 -0400
committerBen Hutchings <bhutchings@solarflare.com>2011-05-12 10:16:32 -0400
commit747df2258b1b9a2e25929ef496262c339c380009 (patch)
tree7f0ff222afed691599f24473e0b8d10b36f48cf2 /fs/btrfs/tree-log.c
parentff538818f4a82c4cf02d2d6bd6ac5c7360b9d41d (diff)
sfc: Always map MCDI shared memory as uncacheable
We enabled write-combining for memory-mapped registers in commit 65f0b417dee94f779ce9b77102b7d73c93723b39, but inhibited it for the MCDI shared memory where this is not supported. However, write-combining mappings also allow read-reordering, which may also be a problem. I found that when an SFC9000-family controller is connected to an Intel 3000 chipset, and write-combining is enabled, the controller stops responding to PCIe read requests during driver initialisation while the driver is polling for completion of an MCDI command. This results in an NMI and system hang. Adding read memory barriers between all reads to the shared memory area appears to reduce but not eliminate the probability of this. We have not yet established whether this is a bug in our BIU or in the PCIe bridge. For now, work around by mapping the shared memory area separately. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Diffstat (limited to 'fs/btrfs/tree-log.c')
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/*
 *	pci.h
 *
 *	PCI defines and function prototypes
 *	Copyright 1994, Drew Eckhardt
 *	Copyright 1997--1999 Martin Mares <mj@ucw.cz>
 *
 *	For more information, please consult the following manuals (look at
 *	http://www.pcisig.com/ for how to get them):
 *
 *	PCI BIOS Specification
 *	PCI Local Bus Specification
 *	PCI to PCI Bridge Specification
 *	PCI System Design Guide
 */

#ifndef LINUX_PCI_H
#define LINUX_PCI_H

#include <linux/pci_regs.h>	/* The pci register defines */

/*
 * The PCI interface treats multi-function devices as independent
 * devices.  The slot/function address of each device is encoded
 * in a single byte as follows:
 *
 *	7:3 = slot
 *	2:0 = function
 */
#define PCI_DEVFN(slot, func)	((((slot) & 0x1f) << 3) | ((func) & 0x07))
#define PCI_SLOT(devfn)		(((devfn) >> 3) & 0x1f)
#define PCI_FUNC(devfn)		((devfn) & 0x07)

/* Ioctls for /proc/bus/pci/X/Y nodes. */
#define PCIIOC_BASE		('P' << 24 | 'C' << 16 | 'I' << 8)
#define PCIIOC_CONTROLLER	(PCIIOC_BASE | 0x00)	/* Get controller for PCI device. */
#define PCIIOC_MMAP_IS_IO	(PCIIOC_BASE | 0x01)	/* Set mmap state to I/O space. */
#define PCIIOC_MMAP_IS_MEM	(PCIIOC_BASE | 0x02)	/* Set mmap state to MEM space. */
#define PCIIOC_WRITE_COMBINE	(PCIIOC_BASE | 0x03)	/* Enable/disable write-combining. */

#ifdef __KERNEL__

#include <linux/mod_devicetable.h>

#include <linux/types.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/list.h>
#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/kobject.h>
#include <asm/atomic.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/irqreturn.h>

/* Include the ID list */
#include <linux/pci_ids.h>

/* pci_slot represents a physical slot */
struct pci_slot {
	struct pci_bus *bus;		/* The bus this slot is on */
	struct list_head list;		/* node in list of slots on this bus */
	struct hotplug_slot *hotplug;	/* Hotplug info (migrate over time) */
	unsigned char number;		/* PCI_SLOT(pci_dev->devfn) */
	struct kobject kobj;
};

static inline const char *pci_slot_name(const struct pci_slot *slot)
{
	return kobject_name(&slot->kobj);
}

/* File state for mmap()s on /proc/bus/pci/X/Y */
enum pci_mmap_state {
	pci_mmap_io,
	pci_mmap_mem
};

/* This defines the direction arg to the DMA mapping routines. */
#define PCI_DMA_BIDIRECTIONAL	0
#define PCI_DMA_TODEVICE	1
#define PCI_DMA_FROMDEVICE	2
#define PCI_DMA_NONE		3

/*
 *  For PCI devices, the region numbers are assigned this way:
 */
enum {
	/* #0-5: standard PCI resources */
	PCI_STD_RESOURCES,
	PCI_STD_RESOURCE_END = 5,

	/* #6: expansion ROM resource */
	PCI_ROM_RESOURCE,

	/* device specific resources */
#ifdef CONFIG_PCI_IOV
	PCI_IOV_RESOURCES,
	PCI_IOV_RESOURCE_END = PCI_IOV_RESOURCES + PCI_SRIOV_NUM_BARS - 1,
#endif

	/* resources assigned to buses behind the bridge */
#define PCI_BRIDGE_RESOURCE_NUM 4

	PCI_BRIDGE_RESOURCES,
	PCI_BRIDGE_RESOURCE_END = PCI_BRIDGE_RESOURCES +
				  PCI_BRIDGE_RESOURCE_NUM - 1,

	/* total resources associated with a PCI device */
	PCI_NUM_RESOURCES,

	/* preserve this for compatibility */
	DEVICE_COUNT_RESOURCE
};

typedef int __bitwise pci_power_t;

#define PCI_D0		((pci_power_t __force) 0)
#define PCI_D1		((pci_power_t __force) 1)
#define PCI_D2		((pci_power_t __force) 2)
#define PCI_D3hot	((pci_power_t __force) 3)
#define PCI_D3cold	((pci_power_t __force) 4)
#define PCI_UNKNOWN	((pci_power_t __force) 5)
#define PCI_POWER_ERROR	((pci_power_t __force) -1)

/* Remember to update this when the list above changes! */
extern const char *pci_power_names[];

static inline const char *pci_power_name(pci_power_t state)
{
	return pci_power_names[1 + (int) state];
}

#define PCI_PM_D2_DELAY	200
#define PCI_PM_D3_WAIT	10
#define PCI_PM_BUS_WAIT	50

/** The pci_channel state describes connectivity between the CPU and
 *  the pci device.  If some PCI bus between here and the pci device
 *  has crashed or locked up, this info is reflected here.
 */
typedef unsigned int __bitwise pci_channel_state_t;

enum pci_channel_state {
	/* I/O channel is in normal state */
	pci_channel_io_normal = (__force pci_channel_state_t) 1,

	/* I/O to channel is blocked */
	pci_channel_io_frozen = (__force pci_channel_state_t) 2,

	/* PCI card is dead */
	pci_channel_io_perm_failure = (__force pci_channel_state_t) 3,
};

typedef unsigned int __bitwise pcie_reset_state_t;

enum pcie_reset_state {
	/* Reset is NOT asserted (Use to deassert reset) */
	pcie_deassert_reset = (__force pcie_reset_state_t) 1,

	/* Use #PERST to reset PCI-E device */
	pcie_warm_reset = (__force pcie_reset_state_t) 2,

	/* Use PCI-E Hot Reset to reset device */
	pcie_hot_reset = (__force pcie_reset_state_t) 3
};

typedef unsigned short __bitwise pci_dev_flags_t;
enum pci_dev_flags {
	/* INTX_DISABLE in PCI_COMMAND register disables MSI
	 * generation too.
	 */
	PCI_DEV_FLAGS_MSI_INTX_DISABLE_BUG = (__force pci_dev_flags_t) 1,
	/* Device configuration is irrevocably lost if disabled into D3 */
	PCI_DEV_FLAGS_NO_D3 = (__force pci_dev_flags_t) 2,
};

enum pci_irq_reroute_variant {
	INTEL_IRQ_REROUTE_VARIANT = 1,
	MAX_IRQ_REROUTE_VARIANTS = 3
};

typedef unsigned short __bitwise pci_bus_flags_t;
enum pci_bus_flags {
	PCI_BUS_FLAGS_NO_MSI   = (__force pci_bus_flags_t) 1,
	PCI_BUS_FLAGS_NO_MMRBC = (__force pci_bus_flags_t) 2,
};

/* Based on the PCI Hotplug Spec, but some values are made up by us */
enum pci_bus_speed {
	PCI_SPEED_33MHz			= 0x00,
	PCI_SPEED_66MHz			= 0x01,
	PCI_SPEED_66MHz_PCIX		= 0x02,
	PCI_SPEED_100MHz_PCIX		= 0x03,
	PCI_SPEED_133MHz_PCIX		= 0x04,
	PCI_SPEED_66MHz_PCIX_ECC	= 0x05,
	PCI_SPEED_100MHz_PCIX_ECC	= 0x06,
	PCI_SPEED_133MHz_PCIX_ECC	= 0x07,
	PCI_SPEED_66MHz_PCIX_266	= 0x09,
	PCI_SPEED_100MHz_PCIX_266	= 0x0a,
	PCI_SPEED_133MHz_PCIX_266	= 0x0b,
	AGP_UNKNOWN			= 0x0c,
	AGP_1X				= 0x0d,
	AGP_2X				= 0x0e,
	AGP_4X				= 0x0f,
	AGP_8X				= 0x10,
	PCI_SPEED_66MHz_PCIX_533	= 0x11,
	PCI_SPEED_100MHz_PCIX_533	= 0x12,
	PCI_SPEED_133MHz_PCIX_533	= 0x13,
	PCIE_SPEED_2_5GT		= 0x14,
	PCIE_SPEED_5_0GT		= 0x15,
	PCIE_SPEED_8_0GT		= 0x16,
	PCI_SPEED_UNKNOWN		= 0xff,
};

struct pci_cap_saved_data {
	char cap_nr;
	unsigned int size;
	u32 data[0];
};

struct pci_cap_saved_state {
	struct hlist_node next;
	struct pci_cap_saved_data cap;
};

struct pcie_link_state;
struct pci_vpd;
struct pci_sriov;
struct pci_ats;

/*
 * The pci_dev structure is used to describe PCI devices.
 */
struct pci_dev {
	struct list_head bus_list;	/* node in per-bus list */
	struct pci_bus	*bus;		/* bus this device is on */
	struct pci_bus	*subordinate;	/* bus this device bridges to */

	void		*sysdata;	/* hook for sys-specific extension */
	struct proc_dir_entry *procent;	/* device entry in /proc/bus/pci */
	struct pci_slot	*slot;		/* Physical slot this device is in */

	unsigned int	devfn;		/* encoded device & function index */
	unsigned short	vendor;
	unsigned short	device;
	unsigned short	subsystem_vendor;
	unsigned short	subsystem_device;
	unsigned int	class;		/* 3 bytes: (base,sub,prog-if) */
	u8		revision;	/* PCI revision, low byte of class word */
	u8		hdr_type;	/* PCI header type (`multi' flag masked out) */
	u8		pcie_cap;	/* PCI-E capability offset */
	u8		pcie_type;	/* PCI-E device/port type */
	u8		rom_base_reg;	/* which config register controls the ROM */
	u8		pin;  		/* which interrupt pin this device uses */

	struct pci_driver *driver;	/* which driver has allocated this device */
	u64		dma_mask;	/* Mask of the bits of bus address this
					   device implements.  Normally this is
					   0xffffffff.  You only need to change
					   this if your device has broken DMA
					   or supports 64-bit transfers.  */

	struct device_dma_parameters dma_parms;

	pci_power_t     current_state;  /* Current operating state. In ACPI-speak,
					   this is D0-D3, D0 being fully functional,
					   and D3 being off. */
	int		pm_cap;		/* PM capability offset in the
					   configuration space */
	unsigned int	pme_support:5;	/* Bitmask of states from which PME#
					   can be generated */
	unsigned int	pme_interrupt:1;
	unsigned int	d1_support:1;	/* Low power state D1 is supported */
	unsigned int	d2_support:1;	/* Low power state D2 is supported */
	unsigned int	no_d1d2:1;	/* Only allow D0 and D3 */
	unsigned int	mmio_always_on:1;	/* disallow turning off io/mem
						   decoding during bar sizing */
	unsigned int	wakeup_prepared:1;
	unsigned int	d3_delay;	/* D3->D0 transition time in ms */

#ifdef CONFIG_PCIEASPM
	struct pcie_link_state	*link_state;	/* ASPM link state. */
#endif

	pci_channel_state_t error_state;	/* current connectivity state */
	struct	device	dev;		/* Generic device interface */

	int		cfg_size;	/* Size of configuration space */

	/*
	 * Instead of touching interrupt line and base address registers
	 * directly, use the values stored here. They might be different!
	 */
	unsigned int	irq;
	struct resource resource[DEVICE_COUNT_RESOURCE]; /* I/O and memory regions + expansion ROMs */
	resource_size_t	fw_addr[DEVICE_COUNT_RESOURCE]; /* FW-assigned addr */

	/* These fields are used by common fixups */
	unsigned int	transparent:1;	/* Transparent PCI bridge */
	unsigned int	multifunction:1;/* Part of multi-function device */
	/* keep track of device state */
	unsigned int	is_added:1;
	unsigned int	is_busmaster:1; /* device is busmaster */
	unsigned int	no_msi:1;	/* device may not use msi */
	unsigned int	block_ucfg_access:1;	/* userspace config space access is blocked */
	unsigned int	broken_parity_status:1;	/* Device generates false positive parity */
	unsigned int	irq_reroute_variant:2;	/* device needs IRQ rerouting variant */
	unsigned int 	msi_enabled:1;
	unsigned int	msix_enabled:1;
	unsigned int	ari_enabled:1;	/* ARI forwarding */
	unsigned int	is_managed:1;
	unsigned int	is_pcie:1;	/* Obsolete. Will be removed.
					   Use pci_is_pcie() instead */
	unsigned int    needs_freset:1; /* Dev requires fundamental reset */
	unsigned int	state_saved:1;
	unsigned int	is_physfn:1;
	unsigned int	is_virtfn:1;
	unsigned int	reset_fn:1;
	unsigned int    is_hotplug_bridge:1;
	unsigned int    __aer_firmware_first_valid:1;
	unsigned int	__aer_firmware_first:1;
	pci_dev_flags_t dev_flags;
	atomic_t	enable_cnt;	/* pci_enable_device has been called */

	u32		saved_config_space[16]; /* config space saved at suspend time */
	struct hlist_head saved_cap_space;
	struct bin_attribute *rom_attr; /* attribute descriptor for sysfs ROM entry */
	int rom_attr_enabled;		/* has display of the rom attribute been enabled? */
	struct bin_attribute *res_attr[DEVICE_COUNT_RESOURCE]; /* sysfs file for resources */
	struct bin_attribute *res_attr_wc[DEVICE_COUNT_RESOURCE]; /* sysfs file for WC mapping of resources */
#ifdef CONFIG_PCI_MSI
	struct list_head msi_list;
#endif
	struct pci_vpd *vpd;
#ifdef CONFIG_PCI_IOV
	union {
		struct pci_sriov *sriov;	/* SR-IOV capability related */
		struct pci_dev *physfn;	/* the PF this VF is associated with */
	};
	struct pci_ats	*ats;	/* Address Translation Service */
#endif
};

static inline struct pci_dev *pci_physfn(struct pci_dev *dev)
{
#ifdef CONFIG_PCI_IOV
	if (dev->is_virtfn)
		dev = dev->physfn;
#endif

	return dev;
}

extern struct pci_dev *alloc_pci_dev(void);

#define pci_dev_b(n) list_entry(n, struct pci_dev, bus_list)
#define	to_pci_dev(n) container_of(n, struct pci_dev, dev)
#define for_each_pci_dev(d) while ((d = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, d)) != NULL)

static inline int pci_channel_offline(struct pci_dev *pdev)
{
	return (pdev->error_state != pci_channel_io_normal);
}

static inline struct pci_cap_saved_state *pci_find_saved_cap(
	struct pci_dev *pci_dev, char cap)
{
	struct pci_cap_saved_state *tmp;
	struct hlist_node *pos;

	hlist_for_each_entry(tmp, pos, &pci_dev->saved_cap_space, next) {
		if (tmp->cap.cap_nr == cap)
			return tmp;
	}
	return NULL;
}

static inline void pci_add_saved_cap(struct pci_dev *pci_dev,
	struct pci_cap_saved_state *new_cap)
{
	hlist_add_head(&new_cap->next, &pci_dev->saved_cap_space);
}

/*
 * The first PCI_BRIDGE_RESOURCE_NUM PCI bus resources (those that correspond
 * to P2P or CardBus bridge windows) go in a table.  Additional ones (for
 * buses below host bridges or subtractive decode bridges) go in the list.
 * Use pci_bus_for_each_resource() to iterate through all the resources.
 */

/*
 * PCI_SUBTRACTIVE_DECODE means the bridge forwards the window implicitly
 * and there's no way to program the bridge with the details of the window.
 * This does not apply to ACPI _CRS windows, even with the _DEC subtractive-
 * decode bit set, because they are explicit and can be programmed with _SRS.
 */
#define PCI_SUBTRACTIVE_DECODE	0x1

struct pci_bus_resource {
	struct list_head list;
	struct resource *res;
	unsigned int flags;
};

#define PCI_REGION_FLAG_MASK	0x0fU	/* These bits of resource flags tell us the PCI region flags */

struct pci_bus {
	struct list_head node;		/* node in list of buses */
	struct pci_bus	*parent;	/* parent bus this bridge is on */
	struct list_head children;	/* list of child buses */
	struct list_head devices;	/* list of devices on this bus */
	struct pci_dev	*self;		/* bridge device as seen by parent */
	struct list_head slots;		/* list of slots on this bus */
	struct resource *resource[PCI_BRIDGE_RESOURCE_NUM];
	struct list_head resources;	/* address space routed to this bus */

	struct pci_ops	*ops;		/* configuration access functions */
	void		*sysdata;	/* hook for sys-specific extension */
	struct proc_dir_entry *procdir;	/* directory entry in /proc/bus/pci */

	unsigned char	number;		/* bus number */
	unsigned char	primary;	/* number of primary bridge */
	unsigned char	secondary;	/* number of secondary bridge */
	unsigned char	subordinate;	/* max number of subordinate buses */
	unsigned char	max_bus_speed;	/* enum pci_bus_speed */
	unsigned char	cur_bus_speed;	/* enum pci_bus_speed */

	char		name[48];

	unsigned short  bridge_ctl;	/* manage NO_ISA/FBB/et al behaviors */
	pci_bus_flags_t bus_flags;	/* Inherited by child busses */
	struct device		*bridge;
	struct device		dev;
	struct bin_attribute	*legacy_io; /* legacy I/O for this bus */
	struct bin_attribute	*legacy_mem; /* legacy mem */
	unsigned int		is_added:1;
};

#define pci_bus_b(n)	list_entry(n, struct pci_bus, node)
#define to_pci_bus(n)	container_of(n, struct pci_bus, dev)

/*
 * Returns true if the pci bus is root (behind host-pci bridge),
 * false otherwise
 */
static inline bool pci_is_root_bus(struct pci_bus *pbus)
{
	return !(pbus->parent);
}

#ifdef CONFIG_PCI_MSI
static inline bool pci_dev_msi_enabled(struct pci_dev *pci_dev)
{
	return pci_dev->msi_enabled || pci_dev->msix_enabled;
}
#else
static inline bool pci_dev_msi_enabled(struct pci_dev *pci_dev) { return false; }
#endif

/*
 * Error values that may be returned by PCI functions.
 */
#define PCIBIOS_SUCCESSFUL		0x00
#define PCIBIOS_FUNC_NOT_SUPPORTED	0x81
#define PCIBIOS_BAD_VENDOR_ID		0x83
#define PCIBIOS_DEVICE_NOT_FOUND	0x86
#define PCIBIOS_BAD_REGISTER_NUMBER	0x87
#define PCIBIOS_SET_FAILED		0x88
#define PCIBIOS_BUFFER_TOO_SMALL	0x89

/* Low-level architecture-dependent routines */

struct pci_ops {
	int (*read)(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val);
	int (*write)(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val);
};

/*
 * ACPI needs to be able to access PCI config space before we've done a
 * PCI bus scan and created pci_bus structures.
 */
extern int raw_pci_read(unsigned int domain, unsigned int bus,
			unsigned int devfn, int reg, int len, u32 *val);
extern int raw_pci_write(unsigned int domain, unsigned int bus,
			unsigned int devfn, int reg, int len, u32 val);

struct pci_bus_region {
	resource_size_t start;
	resource_size_t end;
};

struct pci_dynids {
	spinlock_t lock;            /* protects list, index */
	struct list_head list;      /* for IDs added at runtime */
};

/* ---------------------------------------------------------------- */
/** PCI Error Recovery System (PCI-ERS).  If a PCI device driver provides
 *  a set of callbacks in struct pci_error_handlers, then that device driver
 *  will be notified of PCI bus errors, and will be driven to recovery
 *  when an error occurs.
 */

typedef unsigned int __bitwise pci_ers_result_t;

enum pci_ers_result {
	/* no result/none/not supported in device driver */
	PCI_ERS_RESULT_NONE = (__force pci_ers_result_t) 1,

	/* Device driver can recover without slot reset */
	PCI_ERS_RESULT_CAN_RECOVER = (__force pci_ers_result_t) 2,

	/* Device driver wants slot to be reset. */
	PCI_ERS_RESULT_NEED_RESET = (__force pci_ers_result_t) 3,

	/* Device has completely failed, is unrecoverable */
	PCI_ERS_RESULT_DISCONNECT = (__force pci_ers_result_t) 4,

	/* Device driver is fully recovered and operational */
	PCI_ERS_RESULT_RECOVERED = (__force pci_ers_result_t) 5,
};

/* PCI bus error event callbacks */
struct pci_error_handlers {
	/* PCI bus error detected on this device */
	pci_ers_result_t (*error_detected)(struct pci_dev *dev,
					   enum pci_channel_state error);

	/* MMIO has been re-enabled, but not DMA */
	pci_ers_result_t (*mmio_enabled)(struct pci_dev *dev);

	/* PCI Express link has been reset */
	pci_ers_result_t (*link_reset)(struct pci_dev *dev);