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authorLen Brown <len.brown@intel.com>2008-02-07 04:01:53 -0500
committerLen Brown <len.brown@intel.com>2008-02-07 04:01:53 -0500
commit81e242d0efafb319938d511b115088a5c4523c91 (patch)
treebe22aa41db2288fd7999524d719f333c766a367f /drivers/acpi
parenta733a5da97b238e3e3167d3d0aee8fe1e8d04e97 (diff)
parent04d94886b47b5133915021dcfb1108a8576f6ea7 (diff)
Merge branches 'release' and 'dsdt-override' into release
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/Kconfig17
-rw-r--r--drivers/acpi/osl.c97
2 files changed, 108 insertions, 6 deletions
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index d141bdb3a7d..7ef172c2a1d 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -276,8 +276,10 @@ config ACPI_CUSTOM_DSDT
depends on !STANDALONE
default n
help
- This option is to load a custom ACPI DSDT
- If you don't know what that is, say N.
+ This option supports a custom DSDT by linking it into the kernel.
+ See Documentation/acpi/dsdt-override.txt
+
+ If unsure, say N.
config ACPI_CUSTOM_DSDT_FILE
string "Custom DSDT Table file to include"
@@ -287,6 +289,17 @@ config ACPI_CUSTOM_DSDT_FILE
Enter the full path name to the file which includes the AmlCode
declaration.
+config ACPI_CUSTOM_DSDT_INITRD
+ bool "Read Custom DSDT from initramfs"
+ depends on BLK_DEV_INITRD
+ default n
+ help
+ This option supports a custom DSDT by optionally loading it from initrd.
+ See Documentation/acpi/dsdt-override.txt
+
+ If you are not using this feature now, but may use it later,
+ it is safe to say Y here.
+
config ACPI_BLACKLIST_YEAR
int "Disable ACPI for systems before Jan 1st this year" if X86_32
default 0
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index c2c585366fa..27ccd68b8f4 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -91,6 +91,10 @@ static DEFINE_SPINLOCK(acpi_res_lock);
#define OSI_STRING_LENGTH_MAX 64 /* arbitrary */
static char osi_additional_string[OSI_STRING_LENGTH_MAX];
+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
+static int acpi_no_initrd_override;
+#endif
+
/*
* "Ode to _OSI(Linux)"
*
@@ -329,6 +333,67 @@ acpi_os_predefined_override(const struct acpi_predefined_names *init_val,
return AE_OK;
}
+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
+struct acpi_table_header *acpi_find_dsdt_initrd(void)
+{
+ struct file *firmware_file;
+ mm_segment_t oldfs;
+ unsigned long len, len2;
+ struct acpi_table_header *dsdt_buffer, *ret = NULL;
+ struct kstat stat;
+ char *ramfs_dsdt_name = "/DSDT.aml";
+
+ printk(KERN_INFO PREFIX "Checking initramfs for custom DSDT");
+
+ /*
+ * Never do this at home, only the user-space is allowed to open a file.
+ * The clean way would be to use the firmware loader.
+ * But this code must be run before there is any userspace available.
+ * A static/init firmware infrastructure doesn't exist yet...
+ */
+ if (vfs_stat(ramfs_dsdt_name, &stat) < 0)
+ return ret;
+
+ len = stat.size;
+ /* check especially against empty files */
+ if (len <= 4) {
+ printk(KERN_ERR PREFIX "Failed: DSDT only %lu bytes.\n", len);
+ return ret;
+ }
+
+ firmware_file = filp_open(ramfs_dsdt_name, O_RDONLY, 0);
+ if (IS_ERR(firmware_file)) {
+ printk(KERN_ERR PREFIX "Failed to open %s.\n", ramfs_dsdt_name);
+ return ret;
+ }
+
+ dsdt_buffer = kmalloc(len, GFP_ATOMIC);
+ if (!dsdt_buffer) {
+ printk(KERN_ERR PREFIX "Failed to allocate %lu bytes.\n", len);
+ goto err;
+ }
+
+ oldfs = get_fs();
+ set_fs(KERNEL_DS);
+ len2 = vfs_read(firmware_file, (char __user *)dsdt_buffer, len,
+ &firmware_file->f_pos);
+ set_fs(oldfs);
+ if (len2 < len) {
+ printk(KERN_ERR PREFIX "Failed to read %lu bytes from %s.\n",
+ len, ramfs_dsdt_name);
+ ACPI_FREE(dsdt_buffer);
+ goto err;
+ }
+
+ printk(KERN_INFO PREFIX "Found %lu byte DSDT in %s.\n",
+ len, ramfs_dsdt_name);
+ ret = dsdt_buffer;
+err:
+ filp_close(firmware_file, NULL);
+ return ret;
+}
+#endif
+
acpi_status
acpi_os_table_override(struct acpi_table_header * existing_table,
struct acpi_table_header ** new_table)
@@ -336,17 +401,41 @@ acpi_os_table_override(struct acpi_table_header * existing_table,
if (!existing_table || !new_table)
return AE_BAD_PARAMETER;
+ *new_table = NULL;
+
#ifdef CONFIG_ACPI_CUSTOM_DSDT
if (strncmp(existing_table->signature, "DSDT", 4) == 0)
*new_table = (struct acpi_table_header *)AmlCode;
- else
- *new_table = NULL;
-#else
- *new_table = NULL;
#endif
+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
+ if ((strncmp(existing_table->signature, "DSDT", 4) == 0) &&
+ !acpi_no_initrd_override) {
+ struct acpi_table_header *initrd_table;
+
+ initrd_table = acpi_find_dsdt_initrd();
+ if (initrd_table)
+ *new_table = initrd_table;
+ }
+#endif
+ if (*new_table != NULL) {
+ printk(KERN_WARNING PREFIX "Override [%4.4s-%8.8s], "
+ "this is unsafe: tainting kernel\n",
+ existing_table->signature,
+ existing_table->oem_table_id);
+ add_taint(TAINT_OVERRIDDEN_ACPI_TABLE);
+ }
return AE_OK;
}
+#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
+int __init acpi_no_initrd_override_setup(char *s)
+{
+ acpi_no_initrd_override = 1;
+ return 1;
+}
+__setup("acpi_no_initrd_override", acpi_no_initrd_override_setup);
+#endif
+
static irqreturn_t acpi_irq(int irq, void *dev_id)
{
u32 handled;