Revert "x86: blacklist DMAR on Intel G31/G33 chipsets"

This reverts commit e51af6630848406fc97adbd71443818cdcda297b, which was
wrongly hoovered up and submitted about a month after a better fix had
already been merged.

The better fix is commit cbda1ba898647aeb4ee770b803c922f595e97731
("PCI/iommu: blacklist DMAR on Intel G31/G33 chipsets"), where we do
this blacklisting based on the DMI identification for the offending
motherboard, since sometimes this chipset (or at least a chipset with
the same PCI ID) apparently _does_ actually have an IOMMU.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/x86/include/asm/iommu.h

@@ -6,7 +6,6 @@ extern void no_iommu_init(void);
 extern struct dma_mapping_ops nommu_dma_ops;
 extern int force_iommu, no_iommu;
 extern int iommu_detected;
-extern int dmar_disabled;
 
 extern unsigned long iommu_nr_pages(unsigned long addr, unsigned long len);
 

arch/x86/kernel/early-quirks.c

@@ -188,20 +188,6 @@ static void __init ati_bugs_contd(int num, int slot, int func)
 }
 #endif
 
-#ifdef CONFIG_DMAR
-static void __init intel_g33_dmar(int num, int slot, int func)
-{
-	struct acpi_table_header *dmar_tbl;
-	acpi_status status;
-
-	status = acpi_get_table(ACPI_SIG_DMAR, 0, &dmar_tbl);
-	if (ACPI_SUCCESS(status)) {
-		printk(KERN_INFO "BIOS BUG: DMAR advertised on Intel G31/G33 chipset -- ignoring\n");
-		dmar_disabled = 1;
-	}
-}
-#endif
-
 #define QFLAG_APPLY_ONCE 	0x1
 #define QFLAG_APPLIED		0x2
 #define QFLAG_DONE		(QFLAG_APPLY_ONCE|QFLAG_APPLIED)
@@ -225,10 +211,6 @@ static struct chipset early_qrk[] __initdata = {
 	  PCI_CLASS_SERIAL_SMBUS, PCI_ANY_ID, 0, ati_bugs },
 	{ PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS,
 	  PCI_CLASS_SERIAL_SMBUS, PCI_ANY_ID, 0, ati_bugs_contd },
-#ifdef CONFIG_DMAR
-	{ PCI_VENDOR_ID_INTEL, 0x29c0,
-	  PCI_CLASS_BRIDGE_HOST, PCI_ANY_ID, 0, intel_g33_dmar },
-#endif
 	{}
 };