[PATCH] x86_64: Rename IOMMU option, fix help and mark option embedded.

 - Rename the GART_IOMMU option to IOMMU to make clear it's not
   just for AMD
 - Rewrite the help text to better emphatise this fact
 - Make it an embedded option because too many people get it wrong.

To my astonishment I discovered the aacraid driver tests this
symbol directly. This looks quite broken to me - it's an internal
implementation detail of the PCI DMA API. Can the maintainer
please clarify what this test was intended to do?

Cc: linux-scsi@vger.kernel.org
Cc: alan@redhat.com
Cc: markh@osdl.org
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

6 files changed, 21 insertions, 19 deletions

diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index fc75275..e8c52a1 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -386,24 +386,26 @@ config HPET_EMULATE_RTC
 	bool "Provide RTC interrupt"
 	depends on HPET_TIMER && RTC=y
 
-config GART_IOMMU
-	bool "K8 GART IOMMU support"
+# Mark as embedded because too many people got it wrong.
+# The code disables itself when not needed.
+config IOMMU
+	bool "IOMMU support" if EMBEDDED
 	default y
 	select SWIOTLB
 	select AGP
 	depends on PCI
 	help
-	  Support for hardware IOMMU in AMD's Opteron/Athlon64 Processors
-	  and for the bounce buffering software IOMMU.
-	  Needed to run systems with more than 3GB of memory properly with
-	  32-bit PCI devices that do not support DAC (Double Address Cycle).
-	  The IOMMU can be turned off at runtime with the iommu=off parameter.
-  	  Normally the kernel will take the right choice by itself.
-  	  This option includes a driver for the AMD Opteron/Athlon64 IOMMU
-  	  northbridge and a software emulation used on other systems without
-	  hardware IOMMU.  If unsure, say Y.
-
-# need this always selected by GART_IOMMU for the VIA workaround
+	  Support for full DMA access of devices with 32bit memory access only
+	  on systems with more than 3GB. This is usually needed for USB,
+	  sound, many IDE/SATA chipsets and some other devices.
+	  Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
+	  based IOMMU and a software bounce buffer based IOMMU used on Intel
+	  systems and as fallback.
+	  The code is only active when needed (enough memory and limited
+	  device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
+	  too.
+
+# need this always selected by IOMMU for the VIA workaround
 config SWIOTLB
 	bool
 
@@ -503,7 +505,7 @@ config REORDER
 
 config K8_NB
 	def_bool y
-	depends on AGP_AMD64 || GART_IOMMU || (PCI && NUMA)
+	depends on AGP_AMD64 || IOMMU || (PCI && NUMA)
 
 endmenu
 
diff --git a/arch/x86_64/Kconfig.debug b/arch/x86_64/Kconfig.debug
index ea31b4c..0226f08 100644
--- a/arch/x86_64/Kconfig.debug
+++ b/arch/x86_64/Kconfig.debug
@@ -13,7 +13,7 @@ config DEBUG_RODATA
 	 If in doubt, say "N".
 
 config IOMMU_DEBUG
-       depends on GART_IOMMU && DEBUG_KERNEL
+       depends on IOMMU && DEBUG_KERNEL
        bool "Enable IOMMU debugging"
        help
          Force the IOMMU to on even when you have less than 4GB of
diff --git a/arch/x86_64/kernel/Makefile b/arch/x86_64/kernel/Makefile
index f927d11..fd106bd 100644
--- a/arch/x86_64/kernel/Makefile
+++ b/arch/x86_64/kernel/Makefile
@@ -28,7 +28,7 @@ obj-$(CONFIG_PM)		+= suspend.o
 obj-$(CONFIG_SOFTWARE_SUSPEND)	+= suspend_asm.o
 obj-$(CONFIG_CPU_FREQ)		+= cpufreq/
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
-obj-$(CONFIG_GART_IOMMU)	+= pci-gart.o aperture.o
+obj-$(CONFIG_IOMMU)		+= pci-gart.o aperture.o
 obj-$(CONFIG_SWIOTLB)		+= pci-swiotlb.o
 obj-$(CONFIG_KPROBES)		+= kprobes.o
 obj-$(CONFIG_X86_PM_TIMER)	+= pmtimer.o
diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index 519cd4e..c768d8a 100644
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -319,7 +319,7 @@ void __init check_ioapic(void)
 				vendor &= 0xffff;
 				switch (vendor) { 
 				case PCI_VENDOR_ID_VIA:
-#ifdef CONFIG_GART_IOMMU
+#ifdef CONFIG_IOMMU
 					if ((end_pfn > MAX_DMA32_PFN ||
 					     force_iommu) &&
 					    !iommu_aperture_allowed) {
diff --git a/arch/x86_64/kernel/pci-dma.c b/arch/x86_64/kernel/pci-dma.c
index 117bceb..33926c3 100644
--- a/arch/x86_64/kernel/pci-dma.c
+++ b/arch/x86_64/kernel/pci-dma.c
@@ -266,7 +266,7 @@ __init int iommu_setup(char *p)
 		    swiotlb = 1;
 #endif
 
-#ifdef CONFIG_GART_IOMMU
+#ifdef CONFIG_IOMMU
 	    gart_parse_options(p);
 #endif
 
diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c
index 9dadb9a..816203d 100644
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -702,7 +702,7 @@ void __init setup_arch(char **cmdline_p)
 
 	e820_setup_gap();
 
-#ifdef CONFIG_GART_IOMMU
+#ifdef CONFIG_IOMMU
 	iommu_hole_init();
 #endif