iommu: Remove group_mf

The iommu=group_mf is really no longer needed with the addition of ACS
support in IOMMU drivers creating groups. Most multifunction devices
will now be grouped already. If a device has gone to the trouble of
exposing ACS, trust that it works. We can use the device specific ACS
function for fixing devices we trust individually. This largely
reverts bcb71abe.

Signed-off-by: Alex Williamson <[e-mail]>
Signed-off-by: Joerg Roedel <[e-mail]>

Documentation/kernel-parameters.txt

···
 		forcesac
 		soft
 		pt		[x86, IA-64]
-		group_mf	[x86, IA-64]
 
 
 	io7=		[HW] IO7 for Marvel based alpha systems

arch/ia64/include/asm/iommu.h

···
 extern int force_iommu, no_iommu;
 extern int iommu_pass_through;
 extern int iommu_detected;
-extern int iommu_group_mf;
 #else
 #define iommu_pass_through	(0)
 #define no_iommu		(1)
 #define iommu_detected		(0)
-#define iommu_group_mf		(0)
 #endif
 extern void iommu_dma_init(void);
 extern void machvec_init(const char *name);

arch/ia64/kernel/pci-dma.c

···
 #endif
 
 int iommu_pass_through;
-int iommu_group_mf;
 
 /* Dummy device used for NULL arguments (normally ISA). Better would
    be probably a smaller DMA mask, but this is bug-to-bug compatible

arch/x86/include/asm/iommu.h

···
 extern int force_iommu, no_iommu;
 extern int iommu_detected;
 extern int iommu_pass_through;
-extern int iommu_group_mf;
 
 /* 10 seconds */
 #define DMAR_OPERATION_TIMEOUT ((cycles_t) tsc_khz*10*1000)

arch/x86/kernel/pci-dma.c

···
  */
 int iommu_pass_through __read_mostly;
 
-/*
- * Group multi-function PCI devices into a single device-group for the
- * iommu_device_group interface.  This tells the iommu driver to pretend
- * it cannot distinguish between functions of a device, exposing only one
- * group for the device.  Useful for disallowing use of individual PCI
- * functions from userspace drivers.
- */
-int iommu_group_mf __read_mostly;
-
 extern struct iommu_table_entry __iommu_table[], __iommu_table_end[];
 
 /* Dummy device used for NULL arguments (normally ISA). */
···
 #endif
 		if (!strncmp(p, "pt", 2))
 			iommu_pass_through = 1;
-		if (!strncmp(p, "group_mf", 8))
-			iommu_group_mf = 1;
 
 		gart_parse_options(p);