kernel-ark/include/linux/msi.h
Ben Hutchings 30da552428 PCI: MSI: Restore read_msi_msg_desc(); add get_cached_msi_msg_desc()
commit 2ca1af9aa3285c6a5f103ed31ad09f7399fc65d7 "PCI: MSI: Remove
unsafe and unnecessary hardware access" changed read_msi_msg_desc() to
return the last MSI message written instead of reading it from the
device, since it may be called while the device is in a reduced
power state.

However, the pSeries platform code really does need to read messages
from the device, since they are initially written by firmware.
Therefore:
- Restore the previous behaviour of read_msi_msg_desc()
- Add new functions get_cached_msi_msg{,_desc}() which return the
  last MSI message written
- Use the new functions where appropriate

Acked-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-07-30 09:41:39 -07:00

59 lines
1.8 KiB
C

#ifndef LINUX_MSI_H
#define LINUX_MSI_H
#include <linux/list.h>
struct msi_msg {
u32 address_lo; /* low 32 bits of msi message address */
u32 address_hi; /* high 32 bits of msi message address */
u32 data; /* 16 bits of msi message data */
};
/* Helper functions */
struct irq_desc;
extern void mask_msi_irq(unsigned int irq);
extern void unmask_msi_irq(unsigned int irq);
extern void read_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg);
extern void get_cached_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg);
extern void write_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg);
extern void read_msi_msg(unsigned int irq, struct msi_msg *msg);
extern void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg);
extern void write_msi_msg(unsigned int irq, struct msi_msg *msg);
struct msi_desc {
struct {
__u8 is_msix : 1;
__u8 multiple: 3; /* log2 number of messages */
__u8 maskbit : 1; /* mask-pending bit supported ? */
__u8 is_64 : 1; /* Address size: 0=32bit 1=64bit */
__u8 pos; /* Location of the msi capability */
__u16 entry_nr; /* specific enabled entry */
unsigned default_irq; /* default pre-assigned irq */
} msi_attrib;
u32 masked; /* mask bits */
unsigned int irq;
struct list_head list;
union {
void __iomem *mask_base;
u8 mask_pos;
};
struct pci_dev *dev;
/* Last set MSI message */
struct msi_msg msg;
};
/*
* The arch hook for setup up msi irqs
*/
int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc);
void arch_teardown_msi_irq(unsigned int irq);
extern int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type);
extern void arch_teardown_msi_irqs(struct pci_dev *dev);
extern int arch_msi_check_device(struct pci_dev* dev, int nvec, int type);
#endif /* LINUX_MSI_H */