x86 iommu: add more documentation

Fix coding style in pci-dma_64.c and add stubs for documentation. I
hope someone fills the rest, I understand maybe off and soft...

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 23 insertions, 10 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index dafd001bf833..43c527d72f2f 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -812,6 +812,19 @@ and is between 256 and 4096 characters. It is defined in the file
 
         inttest=        [IA64]
 
+        iommu=          [x86]
+                off
+                force
+                noforce
+                biomerge
+                panic
+                nopanic
+                merge
+                nomerge
+                forcesac
+                soft
+
+
         intel_iommu=    [DMAR] Intel IOMMU driver (DMAR) option
                 off
                         Disable intel iommu driver.
diff --git a/arch/x86/kernel/pci-dma_64.c b/arch/x86/kernel/pci-dma_64.c
index 375cb2bc45be..ada5a0604992 100644
--- a/arch/x86/kernel/pci-dma_64.c
+++ b/arch/x86/kernel/pci-dma_64.c
@@ -232,32 +232,32 @@ static __init int iommu_setup(char *p)
                 return -EINVAL;
 
         while (*p) {
-                if (!strncmp(p,"off",3))
+                if (!strncmp(p, "off", 3))
                         no_iommu = 1;
                 /* gart_parse_options has more force support */
-                if (!strncmp(p,"force",5))
+                if (!strncmp(p, "force", 5))
                         force_iommu = 1;
-                if (!strncmp(p,"noforce",7)) {
+                if (!strncmp(p, "noforce", 7)) {
                         iommu_merge = 0;
                         force_iommu = 0;
                 }
 
-                if (!strncmp(p, "biomerge",8)) {
+                if (!strncmp(p, "biomerge", 8)) {
                         iommu_bio_merge = 4096;
                         iommu_merge = 1;
                         force_iommu = 1;
                 }
-                if (!strncmp(p, "panic",5))
+                if (!strncmp(p, "panic", 5))
                         panic_on_overflow = 1;
-                if (!strncmp(p, "nopanic",7))
+                if (!strncmp(p, "nopanic", 7))
                         panic_on_overflow = 0;
-                if (!strncmp(p, "merge",5)) {
+                if (!strncmp(p, "merge", 5)) {
                         iommu_merge = 1;
                         force_iommu = 1;
                 }
-                if (!strncmp(p, "nomerge",7))
+                if (!strncmp(p, "nomerge", 7))
                         iommu_merge = 0;
-                if (!strncmp(p, "forcesac",8))
+                if (!strncmp(p, "forcesac", 8))
                         iommu_sac_force = 1;
                 if (!strncmp(p, "allowdac", 8))
                         forbid_dac = 0;
@@ -265,7 +265,7 @@ static __init int iommu_setup(char *p)
                         forbid_dac = -1;
 
 #ifdef CONFIG_SWIOTLB
-                if (!strncmp(p, "soft",4))
+                if (!strncmp(p, "soft", 4))
                         swiotlb = 1;
 #endif