[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 fc75275d8c72..e8c52a1eec06 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 ea31b4c62105..0226f08be874 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 f927d11065fe..fd106bdddd6d 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 519cd4e6f9e7..c768d8a036d0 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 117bcebe9ebc..33926c367250 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 9dadb9a1db2a..816203d57e11 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