[PATCH] ACPI: use MSI_NOT_SUPPORTED bit

[Randy Dunlap <randy.dunlap@oracle.com>]

On 15 Nov 2006 05:49:41 +0100 Andi Kleen wrote:

> BTW there seems to be a new ACPI FADT bit that says "MSI is broken"
> We should probably check that too as a double check.

Do you mean more than just use that bit when you say "double check"?

I wonder why this hasn't already been done. (?)

How's this look?  Build-tested only.

---
From: Randy Dunlap <randy.dunlap@oracle.com>

Implement use of FADT boot_flags.MSI_NOT_SUPPORTED bit to prevent
assigning MSIs.
Force MSI_NOT_SUPPORTED for ACPI 1.0 tables.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
---
 drivers/acpi/bus.c             |    6 ++++++
 drivers/acpi/tables/tbconvrt.c |    3 ++-
 include/acpi/actbl.h           |    4 +++-
 include/linux/pci.h            |    2 ++
 4 files changed, 13 insertions(+), 2 deletions(-)

--- linux-2619-rc5.orig/include/acpi/actbl.h
+++ linux-2619-rc5/include/acpi/actbl.h
@@ -290,7 +290,7 @@ struct fadt_descriptor_rev1 {
 	ACPI_FADT_COMMON u32 flags;
 };
 
-/* FADT: Prefered Power Management Profiles */
+/* FADT: Preferred Power Management Profiles */
 
 #define PM_UNSPECIFIED                  0
 #define PM_DESKTOP                      1
@@ -304,6 +304,8 @@ struct fadt_descriptor_rev1 {
 
 #define BAF_LEGACY_DEVICES              0x0001
 #define BAF_8042_KEYBOARD_CONTROLLER    0x0002
+#define BAF_VGA_NOT_PRESENT		0x0004
+#define BAF_MSI_NOT_SUPPORTED		0x0008
 
 #define FADT2_REVISION_ID               3
 #define FADT2_MINUS_REVISION_ID         2
--- linux-2619-rc5.orig/drivers/acpi/tables/tbconvrt.c
+++ linux-2619-rc5/drivers/acpi/tables/tbconvrt.c
@@ -289,7 +289,8 @@ acpi_tb_convert_fadt1(struct fadt_descri
 		 * Since there isn't any equivalence in 1.0 and since it is highly
 		 * likely that a 1.0 system has legacy support.
 		 */
-		local_fadt->iapc_boot_arch = BAF_LEGACY_DEVICES;
+		local_fadt->iapc_boot_arch = BAF_LEGACY_DEVICES |
+						BAF_MSI_NOT_SUPPORTED;
 	}
 
 	/*
--- linux-2619-rc5.orig/include/linux/pci.h
+++ linux-2619-rc5/include/linux/pci.h
@@ -610,6 +610,7 @@ static inline int pci_enable_msix(struct
 	struct msix_entry *entries, int nvec) {return -1;}
 static inline void pci_disable_msix(struct pci_dev *dev) {}
 static inline void msi_remove_pci_irq_vectors(struct pci_dev *dev) {}
+static inline void pci_no_msi(void) {}
 #else
 extern void pci_scan_msi_device(struct pci_dev *dev);
 extern int pci_enable_msi(struct pci_dev *dev);
@@ -618,6 +619,7 @@ extern int pci_enable_msix(struct pci_de
 	struct msix_entry *entries, int nvec);
 extern void pci_disable_msix(struct pci_dev *dev);
 extern void msi_remove_pci_irq_vectors(struct pci_dev *dev);
+extern void pci_no_msi(void);
 #endif
 
 #ifdef CONFIG_HT_IRQ
--- linux-2619-rc5.orig/drivers/acpi/bus.c
+++ linux-2619-rc5/drivers/acpi/bus.c
@@ -28,6 +28,7 @@
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/sched.h>
+#include <linux/pci.h>
 #include <linux/pm.h>
 #include <linux/pm_legacy.h>
 #include <linux/device.h>
@@ -637,6 +638,11 @@ void __init acpi_early_init(void)
 	}
 #endif
 
+	if (acpi_fadt.iapc_boot_arch & BAF_MSI_NOT_SUPPORTED) {
+		printk(KERN_DEBUG PREFIX "MSI not supported, disabling it\n");
+		pci_no_msi();
+	}
+
 	status =
 	    acpi_enable_subsystem(~
 				  (ACPI_NO_HARDWARE_INIT |