[mirror_ubuntu-artful-kernel.git] / drivers / pci / access.c

#include <linux/pci.h>
#include <linux/module.h>
#include <linux/ioport.h>

#include "pci.h"

/*
 * This interrupt-safe spinlock protects all accesses to PCI
 * configuration space.
 */

static DEFINE_SPINLOCK(pci_lock);

/*
 *  Wrappers for all PCI configuration access functions.  They just check
 *  alignment, do locking and call the low-level functions pointed to
 *  by pci_dev->ops.
 */

#define PCI_byte_BAD 0
#define PCI_word_BAD (pos & 1)
#define PCI_dword_BAD (pos & 3)

#define PCI_OP_READ(size,type,len) \
int pci_bus_read_config_##size \
	(struct pci_bus *bus, unsigned int devfn, int pos, type *value)	\
{									\
	int res;							\
	unsigned long flags;						\
	u32 data = 0;							\
	if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER;	\
	spin_lock_irqsave(&pci_lock, flags);				\
	res = bus->ops->read(bus, devfn, pos, len, &data);		\
	*value = (type)data;						\
	spin_unlock_irqrestore(&pci_lock, flags);			\
	return res;							\
}

#define PCI_OP_WRITE(size,type,len) \
int pci_bus_write_config_##size \
	(struct pci_bus *bus, unsigned int devfn, int pos, type value)	\
{									\
	int res;							\
	unsigned long flags;						\
	if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER;	\
	spin_lock_irqsave(&pci_lock, flags);				\
	res = bus->ops->write(bus, devfn, pos, len, value);		\
	spin_unlock_irqrestore(&pci_lock, flags);			\
	return res;							\
}

PCI_OP_READ(byte, u8, 1)
PCI_OP_READ(word, u16, 2)
PCI_OP_READ(dword, u32, 4)
PCI_OP_WRITE(byte, u8, 1)
PCI_OP_WRITE(word, u16, 2)
PCI_OP_WRITE(dword, u32, 4)

EXPORT_SYMBOL(pci_bus_read_config_byte);
EXPORT_SYMBOL(pci_bus_read_config_word);
EXPORT_SYMBOL(pci_bus_read_config_dword);
EXPORT_SYMBOL(pci_bus_write_config_byte);
EXPORT_SYMBOL(pci_bus_write_config_word);
EXPORT_SYMBOL(pci_bus_write_config_dword);

static u32 pci_user_cached_config(struct pci_dev *dev, int pos)
{
	u32 data;

	data = dev->saved_config_space[pos/sizeof(dev->saved_config_space[0])];
	data >>= (pos % sizeof(dev->saved_config_space[0])) * 8;
	return data;
}

#define PCI_USER_READ_CONFIG(size,type)					\
int pci_user_read_config_##size						\
	(struct pci_dev *dev, int pos, type *val)			\
{									\
	unsigned long flags;						\
	int ret = 0;							\
	u32 data = -1;							\
	if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER;	\
	spin_lock_irqsave(&pci_lock, flags);				\
	if (likely(!dev->block_ucfg_access))				\
		ret = dev->bus->ops->read(dev->bus, dev->devfn,		\
					pos, sizeof(type), &data);	\
	else if (pos < sizeof(dev->saved_config_space))			\
		data = pci_user_cached_config(dev, pos); 		\
	spin_unlock_irqrestore(&pci_lock, flags);			\
	*val = (type)data;						\
	return ret;							\
}

#define PCI_USER_WRITE_CONFIG(size,type)				\
int pci_user_write_config_##size					\
	(struct pci_dev *dev, int pos, type val)			\
{									\
	unsigned long flags;						\
	int ret = -EIO;							\
	if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER;	\
	spin_lock_irqsave(&pci_lock, flags);				\
	if (likely(!dev->block_ucfg_access))				\
		ret = dev->bus->ops->write(dev->bus, dev->devfn,	\
					pos, sizeof(type), val);	\
	spin_unlock_irqrestore(&pci_lock, flags);			\
	return ret;							\
}

PCI_USER_READ_CONFIG(byte, u8)
PCI_USER_READ_CONFIG(word, u16)
PCI_USER_READ_CONFIG(dword, u32)
PCI_USER_WRITE_CONFIG(byte, u8)
PCI_USER_WRITE_CONFIG(word, u16)
PCI_USER_WRITE_CONFIG(dword, u32)

/**
 * pci_block_user_cfg_access - Block userspace PCI config reads/writes
 * @dev:	pci device struct
 *
 * This function blocks any userspace PCI config accesses from occurring.
 * When blocked, any writes will be bit bucketed and reads will return the
 * data saved using pci_save_state for the first 64 bytes of config
 * space and return 0xff for all other config reads.
 **/
void pci_block_user_cfg_access(struct pci_dev *dev)
{
	unsigned long flags;

	pci_save_state(dev);

	/* spinlock to synchronize with anyone reading config space now */
	spin_lock_irqsave(&pci_lock, flags);
	dev->block_ucfg_access = 1;
	spin_unlock_irqrestore(&pci_lock, flags);
}
EXPORT_SYMBOL_GPL(pci_block_user_cfg_access);

/**
 * pci_unblock_user_cfg_access - Unblock userspace PCI config reads/writes
 * @dev:	pci device struct
 *
 * This function allows userspace PCI config accesses to resume.
 **/
void pci_unblock_user_cfg_access(struct pci_dev *dev)
{
	unsigned long flags;

	/* spinlock to synchronize with anyone reading saved config space */
	spin_lock_irqsave(&pci_lock, flags);
	dev->block_ucfg_access = 0;
	spin_unlock_irqrestore(&pci_lock, flags);
}
EXPORT_SYMBOL_GPL(pci_unblock_user_cfg_access);
Commit	Line	Data
1da177e4 LT	1	#include <linux/pci.h>
	2	#include <linux/module.h>
	3	#include <linux/ioport.h>
	4
48b19148 AB	5	#include "pci.h"
48b19148 AB	6
1da177e4 LT	7	/*
	8	* This interrupt-safe spinlock protects all accesses to PCI
	9	* configuration space.
	10	*/
	11
	12	static DEFINE_SPINLOCK(pci_lock);
	13
	14	/*
	15	* Wrappers for all PCI configuration access functions. They just check
	16	* alignment, do locking and call the low-level functions pointed to
	17	* by pci_dev->ops.
	18	*/
	19
	20	#define PCI_byte_BAD 0
	21	#define PCI_word_BAD (pos & 1)
	22	#define PCI_dword_BAD (pos & 3)
	23
	24	#define PCI_OP_READ(size,type,len) \
	25	int pci_bus_read_config_##size \
	26	(struct pci_bus bus, unsigned int devfn, int pos, type value) \
	27	{ \
	28	int res; \
	29	unsigned long flags; \
	30	u32 data = 0; \
	31	if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
	32	spin_lock_irqsave(&pci_lock, flags); \
	33	res = bus->ops->read(bus, devfn, pos, len, &data); \
	34	*value = (type)data; \
	35	spin_unlock_irqrestore(&pci_lock, flags); \
	36	return res; \
	37	}
	38
	39	#define PCI_OP_WRITE(size,type,len) \
	40	int pci_bus_write_config_##size \
	41	(struct pci_bus *bus, unsigned int devfn, int pos, type value) \
	42	{ \
	43	int res; \
	44	unsigned long flags; \
	45	if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
	46	spin_lock_irqsave(&pci_lock, flags); \
	47	res = bus->ops->write(bus, devfn, pos, len, value); \
	48	spin_unlock_irqrestore(&pci_lock, flags); \
	49	return res; \
	50	}
	51
	52	PCI_OP_READ(byte, u8, 1)
	53	PCI_OP_READ(word, u16, 2)
	54	PCI_OP_READ(dword, u32, 4)
	55	PCI_OP_WRITE(byte, u8, 1)
	56	PCI_OP_WRITE(word, u16, 2)
	57	PCI_OP_WRITE(dword, u32, 4)
	58
	59	EXPORT_SYMBOL(pci_bus_read_config_byte);
	60	EXPORT_SYMBOL(pci_bus_read_config_word);
	61	EXPORT_SYMBOL(pci_bus_read_config_dword);
	62	EXPORT_SYMBOL(pci_bus_write_config_byte);
	63	EXPORT_SYMBOL(pci_bus_write_config_word);
	64	EXPORT_SYMBOL(pci_bus_write_config_dword);
e04b0ea2 BK	65
	66	static u32 pci_user_cached_config(struct pci_dev *dev, int pos)
	67	{
	68	u32 data;
	69
	70	data = dev->saved_config_space[pos/sizeof(dev->saved_config_space[0])];
	71	data >>= (pos % sizeof(dev->saved_config_space[0])) * 8;
	72	return data;
	73	}
	74
	75	#define PCI_USER_READ_CONFIG(size,type) \
	76	int pci_user_read_config_##size \
	77	(struct pci_dev dev, int pos, type val) \
	78	{ \
	79	unsigned long flags; \
	80	int ret = 0; \
	81	u32 data = -1; \
	82	if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
	83	spin_lock_irqsave(&pci_lock, flags); \
	84	if (likely(!dev->block_ucfg_access)) \
	85	ret = dev->bus->ops->read(dev->bus, dev->devfn, \
	86	pos, sizeof(type), &data); \
	87	else if (pos < sizeof(dev->saved_config_space)) \
	88	data = pci_user_cached_config(dev, pos); \
	89	spin_unlock_irqrestore(&pci_lock, flags); \
	90	*val = (type)data; \
	91	return ret; \
	92	}
	93
	94	#define PCI_USER_WRITE_CONFIG(size,type) \
	95	int pci_user_write_config_##size \
	96	(struct pci_dev *dev, int pos, type val) \
	97	{ \
	98	unsigned long flags; \
	99	int ret = -EIO; \
	100	if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
	101	spin_lock_irqsave(&pci_lock, flags); \
	102	if (likely(!dev->block_ucfg_access)) \
	103	ret = dev->bus->ops->write(dev->bus, dev->devfn, \
	104	pos, sizeof(type), val); \
	105	spin_unlock_irqrestore(&pci_lock, flags); \
	106	return ret; \
	107	}
	108
	109	PCI_USER_READ_CONFIG(byte, u8)
	110	PCI_USER_READ_CONFIG(word, u16)
	111	PCI_USER_READ_CONFIG(dword, u32)
	112	PCI_USER_WRITE_CONFIG(byte, u8)
	113	PCI_USER_WRITE_CONFIG(word, u16)
	114	PCI_USER_WRITE_CONFIG(dword, u32)
	115
	116	/**
	117	* pci_block_user_cfg_access - Block userspace PCI config reads/writes
	118	* @dev: pci device struct
	119	*
	120	* This function blocks any userspace PCI config accesses from occurring.
	121	* When blocked, any writes will be bit bucketed and reads will return the
	122	* data saved using pci_save_state for the first 64 bytes of config
	123	* space and return 0xff for all other config reads.
	124	**/
	125	void pci_block_user_cfg_access(struct pci_dev *dev)
	126	{
	127	unsigned long flags;
	128
129	pci_save_state(dev);
130
131	/* spinlock to synchronize with anyone reading config space now */
132	spin_lock_irqsave(&pci_lock, flags);
133	dev->block_ucfg_access = 1;
134	spin_unlock_irqrestore(&pci_lock, flags);
135	}
136	EXPORT_SYMBOL_GPL(pci_block_user_cfg_access);
137
138	/**
139	* pci_unblock_user_cfg_access - Unblock userspace PCI config reads/writes
140	* @dev: pci device struct
141	*
142	* This function allows userspace PCI config accesses to resume.
143	**/
144	void pci_unblock_user_cfg_access(struct pci_dev *dev)
145	{
146	unsigned long flags;
147
148	/* spinlock to synchronize with anyone reading saved config space */
149	spin_lock_irqsave(&pci_lock, flags);
150	dev->block_ucfg_access = 0;
151	spin_unlock_irqrestore(&pci_lock, flags);
152	}
153	EXPORT_SYMBOL_GPL(pci_unblock_user_cfg_access);