aha/include/linux/msi.h
Michael Ellerman 9c8313343c MSI: Give archs the option to allocate all MSI/Xs at once.
This patch introduces an optional function, arch_setup_msi_irqs(),
(note the plural) which gives an arch the opportunity to do per-device
setup for MSI/X and then allocate all the requested MSI/Xs at once.

If that's not required by the arch, the default version simply calls
arch_setup_msi_irq() for each MSI irq required.

arch_setup_msi_irqs() is passed a pdev, attached to the pdev is a list
of msi_descs with irq == 0, it is up to the arch to connect these up to
an irq (via set_irq_msi()) or return an error. For convenience the number
of vectors and the type are passed also.

All msi_descs with irq != 0 are considered allocated, and the arch
teardown routine will be called on them when necessary.

The existing semantics of pci_enable_msix() are that if the requested
number of irqs can not be allocated, the maximum number that _could_ be
allocated is returned. To support that, we define that in case of an
error from arch_setup_msi_irqs(), the number of msi_descs with irq != 0
are considered allocated, and are counted toward the "max that could be
allocated".


Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 19:02:38 -07:00

48 lines
1.3 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 */
__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 int arch_msi_check_device(struct pci_dev* dev, int nvec, int type);
#endif /* LINUX_MSI_H */