linux-hardened/include/linux/msi.h
Yinghai Lu 8e149e09f9 pci/irq: restore mask_bits in msi shutdown -v3
[PATCH 1/2] pci/irq: restore mask_bits in msi shutdown -v3

Yinghai found that kexec'ing a RHEL 5.1 kernel with 2.6.25-rc3+ kernels
prevents his NIC from working.  He bisected to

| commit 89d694b9db
| Author: Thomas Gleixner <tglx@linutronix.de>
| Date:   Mon Feb 18 18:25:17 2008 +0100
|
|   genirq: do not leave interupts enabled on free_irq
|
|   The default_disable() function was changed in commit:
|
|    76d2160147
|    genirq: do not mask interrupts by default
|

For MSI, default_shutdown will call mask_bit for msi device.  All mask bits
will left disabled after free_irq.  Then in the kexec case, the next kernel
can only use msi_enable bit, so all device's MSI can not be used.

So lets to restore the mask bit to its pci reset defined value (enabled) when
we disable the kernels use of msi to be a little friendlier to kexec'd kernels.

Extend msi_set_mask_bit to msi_set_mask_bits to take mask, so we can fully
restore that to 0x00 instead of 0xfe.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@hobbes.lan>
2008-04-29 09:11:12 -07:00

50 lines
1.4 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 */
extern void mask_msi_irq(unsigned int irq);
extern void unmask_msi_irq(unsigned int irq);
extern void read_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 type : 5; /* {0: unused, 5h:MSI, 11h:MSI-X} */
__u8 maskbit : 1; /* mask-pending bit supported ? */
__u8 masked : 1;
__u8 is_64 : 1; /* Address size: 0=32bit 1=64bit */
__u8 pos; /* Location of the msi capability */
__u32 maskbits_mask; /* mask bits mask */
__u16 entry_nr; /* specific enabled entry */
unsigned default_irq; /* default pre-assigned irq */
}msi_attrib;
unsigned int irq;
struct list_head list;
void __iomem *mask_base;
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 */