Eric Lee / linux-smarc-t335x-v3.2

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Commit a52357259680fe5368c2fabf5949209e231f2aa2

Authored by Joerg Roedel
1 parent b57f95a382
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

x86/amd-iommu: Add amd_iommu=off command line option 

This patch adds a command line option to tell the AMD IOMMU
driver to not initialize any IOMMU it finds.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

Showing 2 changed files with 8 additions and 0 deletions Side-by-side Diff

Documentation/kernel-parameters.txt
Diff comments   View file @ a523572
... ... @@ -324,6 +324,8 @@
324 324 they are unmapped. Otherwise they are
325 325 flushed before they will be reused, which
326 326 is a lot of faster
  327 + off - do not initialize any AMD IOMMU found in
  328 + the system
327 329  
328 330 amijoy.map= [HW,JOY] Amiga joystick support
329 331 Map of devices attached to JOY0DAT and JOY1DAT
arch/x86/kernel/amd_iommu_init.c
Diff comments   View file @ a523572
... ... @@ -120,6 +120,7 @@
120 120 bool amd_iommu_dump;
121 121  
122 122 static int __initdata amd_iommu_detected;
  123 +static bool __initdata amd_iommu_disabled;
123 124  
124 125 u16 amd_iommu_last_bdf; /* largest PCI device id we have
125 126 to handle */
... ... @@ -1372,6 +1373,9 @@
1372 1373 if (no_iommu || (iommu_detected && !gart_iommu_aperture))
1373 1374 return;
1374 1375  
  1376 + if (amd_iommu_disabled)
  1377 + return;
  1378 +
1375 1379 if (acpi_table_parse("IVRS", early_amd_iommu_detect) == 0) {
1376 1380 iommu_detected = 1;
1377 1381 amd_iommu_detected = 1;
... ... @@ -1401,6 +1405,8 @@
1401 1405 for (; *str; ++str) {
1402 1406 if (strncmp(str, "fullflush", 9) == 0)
1403 1407 amd_iommu_unmap_flush = true;
  1408 + if (strncmp(str, "off", 3) == 0)
  1409 + amd_iommu_disabled = true;
1404 1410 }
1405 1411  
1406 1412 return 1;