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

[pandora-kernel.git] / arch / x86 / kernel / amd_iommu_init.c

diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index 9dc91b4..3bacb4d 100644 (file)
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -19,8 +19,8 @@
 
 #include <linux/pci.h>
 #include <linux/acpi.h>
-#include <linux/gfp.h>
 #include <linux/list.h>
+#include <linux/slab.h>
 #include <linux/sysdev.h>
 #include <linux/interrupt.h>
 #include <linux/msi.h>
@@ -120,6 +120,7 @@ struct ivmd_header {
 bool amd_iommu_dump;
 
 static int __initdata amd_iommu_detected;
+static bool __initdata amd_iommu_disabled;
 
 u16 amd_iommu_last_bdf;                        /* largest PCI device id we have
                                           to handle */
@@ -138,9 +139,9 @@ int amd_iommus_present;
 bool amd_iommu_np_cache __read_mostly;
 
 /*
- * Set to true if ACPI table parsing and hardware intialization went properly
+ * The ACPI table parsing functions set this variable on an error
  */
-static bool amd_iommu_initialized;
+static int __initdata amd_iommu_init_err;
 
 /*
  * List of protection domains - used during resume
@@ -391,9 +392,11 @@ static int __init find_last_devid_acpi(struct acpi_table_header *table)
         */
        for (i = 0; i < table->length; ++i)
                checksum += p[i];
-       if (checksum != 0)
+       if (checksum != 0) {
                /* ACPI table corrupt */
-               return -ENODEV;
+               amd_iommu_init_err = -ENODEV;
+               return 0;
+       }
 
        p += IVRS_HEADER_LENGTH;
 
@@ -436,7 +439,7 @@ static u8 * __init alloc_command_buffer(struct amd_iommu *iommu)
        if (cmd_buf == NULL)
                return NULL;
 
-       iommu->cmd_buf_size = CMD_BUFFER_SIZE;
+       iommu->cmd_buf_size = CMD_BUFFER_SIZE | CMD_BUFFER_UNINITIALIZED;
 
        return cmd_buf;
 }
@@ -472,12 +475,13 @@ static void iommu_enable_command_buffer(struct amd_iommu *iommu)
                    &entry, sizeof(entry));
 
        amd_iommu_reset_cmd_buffer(iommu);
+       iommu->cmd_buf_size &= ~(CMD_BUFFER_UNINITIALIZED);
 }
 
 static void __init free_command_buffer(struct amd_iommu *iommu)
 {
        free_pages((unsigned long)iommu->cmd_buf,
-                  get_order(iommu->cmd_buf_size));
+                  get_order(iommu->cmd_buf_size & ~(CMD_BUFFER_UNINITIALIZED)));
 }
 
 /* allocates the memory where the IOMMU will log its events to */
@@ -920,11 +924,16 @@ static int __init init_iommu_all(struct acpi_table_header *table)
                                    h->mmio_phys);
 
                        iommu = kzalloc(sizeof(struct amd_iommu), GFP_KERNEL);
-                       if (iommu == NULL)
-                               return -ENOMEM;
+                       if (iommu == NULL) {
+                               amd_iommu_init_err = -ENOMEM;
+                               return 0;
+                       }
+
                        ret = init_iommu_one(iommu, h);
-                       if (ret)
-                               return ret;
+                       if (ret) {
+                               amd_iommu_init_err = ret;
+                               return 0;
+                       }
                        break;
                default:
                        break;
@@ -934,8 +943,6 @@ static int __init init_iommu_all(struct acpi_table_header *table)
        }
        WARN_ON(p != end);
 
-       amd_iommu_initialized = true;
-
        return 0;
 }
 
@@ -1211,6 +1218,10 @@ static int __init amd_iommu_init(void)
        if (acpi_table_parse("IVRS", find_last_devid_acpi) != 0)
                return -ENODEV;
 
+       ret = amd_iommu_init_err;
+       if (ret)
+               goto out;
+
        dev_table_size     = tbl_size(DEV_TABLE_ENTRY_SIZE);
        alias_table_size   = tbl_size(ALIAS_TABLE_ENTRY_SIZE);
        rlookup_table_size = tbl_size(RLOOKUP_TABLE_ENTRY_SIZE);
@@ -1270,12 +1281,19 @@ static int __init amd_iommu_init(void)
        if (acpi_table_parse("IVRS", init_iommu_all) != 0)
                goto free;
 
-       if (!amd_iommu_initialized)
+       if (amd_iommu_init_err) {
+               ret = amd_iommu_init_err;
                goto free;
+       }
 
        if (acpi_table_parse("IVRS", init_memory_definitions) != 0)
                goto free;
 
+       if (amd_iommu_init_err) {
+               ret = amd_iommu_init_err;
+               goto free;
+       }
+
        ret = sysdev_class_register(&amd_iommu_sysdev_class);
        if (ret)
                goto free;
@@ -1288,6 +1306,8 @@ static int __init amd_iommu_init(void)
        if (ret)
                goto free;
 
+       enable_iommus();
+
        if (iommu_pass_through)
                ret = amd_iommu_init_passthrough();
        else
@@ -1300,8 +1320,6 @@ static int __init amd_iommu_init(void)
 
        amd_iommu_init_notifier();
 
-       enable_iommus();
-
        if (iommu_pass_through)
                goto out;
 
@@ -1315,6 +1333,7 @@ out:
        return ret;
 
 free:
+       disable_iommus();
 
        amd_iommu_uninit_devices();
 
@@ -1354,6 +1373,9 @@ void __init amd_iommu_detect(void)
        if (no_iommu || (iommu_detected && !gart_iommu_aperture))
                return;
 
+       if (amd_iommu_disabled)
+               return;
+
        if (acpi_table_parse("IVRS", early_amd_iommu_detect) == 0) {
                iommu_detected = 1;
                amd_iommu_detected = 1;
@@ -1383,6 +1405,8 @@ static int __init parse_amd_iommu_options(char *str)
        for (; *str; ++str) {
                if (strncmp(str, "fullflush", 9) == 0)
                        amd_iommu_unmap_flush = true;
+               if (strncmp(str, "off", 3) == 0)
+                       amd_iommu_disabled = true;
        }
 
        return 1;