[PATCH] msi: refactor and move the msi irq_chip into the arch code

It turns out msi_ops was simply not enough to abstract the architecture
specific details of msi.  So I have moved the resposibility of constructing
the struct irq_chip to the architectures, and have two architecture specific
functions arch_setup_msi_irq, and arch_teardown_msi_irq.

For simple architectures those functions can do all of the work.  For
architectures with platform dependencies they can call into the appropriate
platform code.

With this msi.c is finally free of assuming you have an apic, and this
actually takes less code.

The helpers for the architecture specific code are declared in the linux/msi.h
to keep them separate from the msi functions used by drivers in linux/pci.h

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg KH <greg@kroah.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 49 insertions, 0 deletions

diff --git a/include/linux/msi.h b/include/linux/msi.h
new file mode 100644
index 000000000000..c7ef94343673
--- /dev/null
+++ b/include/linux/msi.h
@@ -0,0 +1,49 @@
+#ifndef LINUX_MSI_H
+#define LINUX_MSI_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 */
+};
+
+/* Heper 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	unused	: 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;
+
+	struct {
+		__u16	head;
+		__u16	tail;
+	}link;
+
+	void __iomem *mask_base;
+	struct pci_dev *dev;
+
+#ifdef CONFIG_PM
+	/* PM save area for MSIX address/data */
+	struct msi_msg msg_save;
+#endif
+};
+
+/*
+ * The arch hook for setup up msi irqs
+ */
+int arch_setup_msi_irq(unsigned int irq, struct pci_dev *dev);
+void arch_teardown_msi_irq(unsigned int irq);
+
+
+#endif /* LINUX_MSI_H */