[PATCH] x86, HPET: ignore any PCI BARs that match an HPET we already know about

[Bjorn Helgaas <bjorn.helgaas@hp.com>]

We often discover the HPET early, via the static ACPI HPET table, before
enumerating PCI devices.  If the HPET is implemented as a PCI function,
we will discover it again during PCI device enumeration.  We must ignore
the PCI function so we don't inadvertently move it out from under the
driver.

I think it's better to ignore *any* PCI BAR that matches a previously
discovered HPET; that way we don't need platform-specific knowledge,
and we won't have to add more quirks for future machines.

This is for a regression from 2.6.34, but the reporter has been
unable to test it yet.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=18482
Reported-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
---

 arch/x86/kernel/quirks.c |   21 +++++++++++++++++++++
 arch/x86/pci/fixup.c     |   28 ----------------------------
 2 files changed, 21 insertions(+), 28 deletions(-)


diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index 939b9e9..99a7d4b 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -507,6 +507,27 @@ static void force_disable_hpet_msi(struct pci_dev *unused)
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS,
 			 force_disable_hpet_msi);
 
+static void disable_pci_hpet(struct pci_dev *dev)
+{
+	int i;
+
+	if (!hpet_address)
+		return;
+
+	for (i = 0; i < 6; i++) {
+		struct resource *res = &dev->resource[i];
+
+		if (resource_type(res) == IORESOURCE_MEM &&
+		    res->start == hpet_address) {
+			dev_info(&dev->dev, "BAR %d: %pR is an HPET we found earlier; ignoring this BAR\n",
+				 i, res);
+			res->flags = 0;
+			res->start = 0;
+			res->end = 0;
+		}
+	}
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, disable_pci_hpet);
 #endif
 
 #if defined(CONFIG_PCI) && defined(CONFIG_NUMA)
diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
index 6dd8955..08eba69 100644
--- a/arch/x86/pci/fixup.c
+++ b/arch/x86/pci/fixup.c
@@ -493,31 +493,3 @@ static void __devinit pci_siemens_interrupt_controller(struct pci_dev *dev)
 }
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SIEMENS, 0x0015,
 			  pci_siemens_interrupt_controller);
-
-/*
- * SB600: Disable BAR1 on device 14.0 to avoid HPET resources from
- * confusing the PCI engine:
- */
-static void sb600_disable_hpet_bar(struct pci_dev *dev)
-{
-	u8 val;
-
-	/*
-	 * The SB600 and SB700 both share the same device
-	 * ID, but the PM register 0x55 does something different
-	 * for the SB700, so make sure we are dealing with the
-	 * SB600 before touching the bit:
-	 */
-
-	pci_read_config_byte(dev, 0x08, &val);
-
-	if (val < 0x2F) {
-		outb(0x55, 0xCD6);
-		val = inb(0xCD7);
-
-		/* Set bit 7 in PM register 0x55 */
-		outb(0x55, 0xCD6);
-		outb(val | 0x80, 0xCD7);
-	}
-}
-DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_ATI, 0x4385, sb600_disable_hpet_bar);