src/patches/suse-2.6.27.25/patches.suse/acpi-dsdt-initrd-v0.9a-2.6.25.patch

   1 From: Eric Piel <piel@localhost.(none)>
   2 Subject: [PATCH 1/1] ACPI: initramfs DSDT override support
   3 Patch-mainline: not yet
   4
   5
   6 Permits to load of DSDT (the main ACPI table) from initramfs. In case this
   7 option is selected, the initramfs is parsed at ACPI initialization (very early
   8 boot time) to look for a file DSDT.aml . This aims at allowing users to
   9 override the DSDT without recompiling the kernel. This is done by adding a new
  10 feature to the initramfs parser so that one specific file can be directly
  11 copied into memory.
  12
  13 This is derived from the patch v0.8 from http://gaugusch.at/kernel.shtml but
  14 with kernel inclusion in mind: some clean-up's in the documentation, default
  15 set to No, a kernel parameter to disable it at runtime, and most important, a
  16 different approach for reading the initramfs which avoids using the filesystem
  17 infrastructure.
  18
  19 It also contains a fix for compilation on non-ACPI platforms provided by Rene Rebe.
  20
  21 Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net>
  22 Signed-off-by: Thomas Renninger <trenn@suse.de>
  23 Signed-off-by: Len Brown <len.brown@intel.com>
  24 ---
  25  Documentation/acpi/dsdt-override.txt     |   12 ++++
  26  Documentation/acpi/initramfs-add-dsdt.sh |   43 +++++++++++++++++
  27  Documentation/kernel-parameters.txt      |    3 +
  28  drivers/acpi/Kconfig                     |   11 ++++
  29  drivers/acpi/osl.c                       |   26 ++++++++++
  30  drivers/acpi/tables/tbxface.c            |    7 --
  31  init/initramfs.c                         |   76 +++++++++++++++++++++++++++++++
  32  7 files changed, 170 insertions(+), 8 deletions(-)
  33  create mode 100644 Documentation/acpi/initramfs-add-dsdt.sh
  34
  35 --- a/Documentation/acpi/dsdt-override.txt
  36 +++ b/Documentation/acpi/dsdt-override.txt
  37 @@ -1,7 +1,15 @@
  38 -Linux supports a method of overriding the BIOS DSDT:
  39 +Linux supports two methods of overriding the BIOS DSDT:
  40
  41  CONFIG_ACPI_CUSTOM_DSDT builds the image into the kernel.
  42
  43 -When to use this method is described in detail on the
  44 +CONFIG_ACPI_CUSTOM_DSDT_INITRD adds the image to the initrd.
  45 +
  46 +When to use these methods is described in detail on the
  47  Linux/ACPI home page:
  48  http://www.lesswatts.org/projects/acpi/overridingDSDT.php
  49 +
  50 +Note that if both options are used, the DSDT supplied
  51 +by the INITRD method takes precedence.
  52 +
  53 +Documentation/initramfs-add-dsdt.sh is provided for convenience
  54 +for use with the CONFIG_ACPI_CUSTOM_DSDT_INITRD method.
  55 --- /dev/null
  56 +++ b/Documentation/acpi/initramfs-add-dsdt.sh
  57 @@ -0,0 +1,43 @@
  58 +#!/bin/bash
  59 +# Adds a DSDT file to the initrd (if it's an initramfs)
  60 +# first argument is the name of archive
  61 +# second argument is the name of the file to add
  62 +# The file will be copied as /DSDT.aml
  63 +
  64 +# 20060126: fix "Premature end of file" with some old cpio (Roland Robic)
  65 +# 20060205: this time it should really work
  66 +
  67 +# check the arguments
  68 +if [ $# -ne 2 ]; then
  69 +       program_name=$(basename $0)
  70 +       echo "\
  71 +$program_name: too few arguments
  72 +Usage: $program_name initrd-name.img DSDT-to-add.aml
  73 +Adds a DSDT file to an initrd (in initramfs format)
  74 +
  75 +  initrd-name.img: filename of the initrd in initramfs format
  76 +  DSDT-to-add.aml: filename of the DSDT file to add
  77 +  " 1>&2
  78 +    exit 1
  79 +fi
  80 +
  81 +# we should check it's an initramfs
  82 +
  83 +tempcpio=$(mktemp -d)
  84 +# cleanup on exit, hangup, interrupt, quit, termination
  85 +trap 'rm -rf $tempcpio' 0 1 2 3 15
  86 +
  87 +# extract the archive
  88 +gunzip -c "$1" > "$tempcpio"/initramfs.cpio || exit 1
  89 +
  90 +# copy the DSDT file at the root of the directory so that we can call it "/DSDT.aml"
  91 +cp -f "$2" "$tempcpio"/DSDT.aml
  92 +
  93 +# add the file
  94 +cd "$tempcpio"
  95 +(echo DSDT.aml | cpio --quiet -H newc -o -A -O "$tempcpio"/initramfs.cpio) || exit 1
  96 +cd "$OLDPWD"
  97 +
  98 +# re-compress the archive
  99 +gzip -c "$tempcpio"/initramfs.cpio > "$1"
 100 +
 101 --- a/Documentation/kernel-parameters.txt
 102 +++ b/Documentation/kernel-parameters.txt
 103 @@ -179,6 +179,9 @@ and is between 256 and 4096 characters.
 104
 105         acpi_no_auto_ssdt       [HW,ACPI] Disable automatic loading of SSDT
 106
 107 +       acpi_no_initrd_override [KNL,ACPI]
 108 +                       Disable loading custom ACPI tables from the initramfs
 109 +
 110         acpi_os_name=   [HW,ACPI] Tell ACPI BIOS the name of the OS
 111                         Format: To spoof as Windows 98: ="Microsoft Windows"
 112
 113 --- a/drivers/acpi/Kconfig
 114 +++ b/drivers/acpi/Kconfig
 115 @@ -301,6 +301,17 @@ config ACPI_CUSTOM_DSDT
 116         bool
 117         default ACPI_CUSTOM_DSDT_FILE != ""
 118
 119 +config ACPI_CUSTOM_DSDT_INITRD
 120 +       bool "Read Custom DSDT from initramfs"
 121 +       depends on BLK_DEV_INITRD
 122 +       default n
 123 +       help
 124 +         This option supports a custom DSDT by optionally loading it from initrd.
 125 +         See Documentation/acpi/dsdt-override.txt
 126 +
 127 +         If you are not using this feature now, but may use it later,
 128 +         it is safe to say Y here.
 129 +
 130  config ACPI_BLACKLIST_YEAR
 131         int "Disable ACPI for systems before Jan 1st this year" if X86_32
 132         default 0
 133 --- a/drivers/acpi/osl.c
 134 +++ b/drivers/acpi/osl.c
 135 @@ -96,6 +96,11 @@ static DEFINE_SPINLOCK(acpi_res_lock);
 136  #define        OSI_STRING_LENGTH_MAX 64        /* arbitrary */
 137  static char osi_additional_string[OSI_STRING_LENGTH_MAX];
 138
 139 +#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
 140 +static int acpi_no_initrd_override;
 141 +extern struct acpi_table_header *acpi_find_dsdt_initrd(void);
 142 +#endif
 143 +
 144  /*
 145   * "Ode to _OSI(Linux)"
 146   *
 147 @@ -325,7 +330,7 @@ acpi_os_predefined_override(const struct
 148         return AE_OK;
 149  }
 150
 151 -acpi_status
 152 +acpi_status __init
 153  acpi_os_table_override(struct acpi_table_header * existing_table,
 154                        struct acpi_table_header ** new_table)
 155  {
 156 @@ -338,6 +343,16 @@ acpi_os_table_override(struct acpi_table
 157         if (strncmp(existing_table->signature, "DSDT", 4) == 0)
 158                 *new_table = (struct acpi_table_header *)AmlCode;
 159  #endif
 160 +#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
 161 +       if ((strncmp(existing_table->signature, "DSDT", 4) == 0) &&
 162 +           !acpi_no_initrd_override) {
 163 +               struct acpi_table_header *initrd_table;
 164 +
 165 +               initrd_table = acpi_find_dsdt_initrd();
 166 +               if (initrd_table)
 167 +                       *new_table = initrd_table;
 168 +       }
 169 +#endif
 170         if (*new_table != NULL) {
 171                 printk(KERN_WARNING PREFIX "Override [%4.4s-%8.8s], "
 172                            "this is unsafe: tainting kernel\n",
 173 @@ -348,6 +363,15 @@ acpi_os_table_override(struct acpi_table
 174         return AE_OK;
 175  }
 176
 177 +#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
 178 +static int __init acpi_no_initrd_override_setup(char *s)
 179 +{
 180 +       acpi_no_initrd_override = 1;
 181 +       return 1;
 182 +}
 183 +__setup("acpi_no_initrd_override", acpi_no_initrd_override_setup);
 184 +#endif
 185 +
 186  static irqreturn_t acpi_irq(int irq, void *dev_id)
 187  {
 188         u32 handled;
 189 --- a/drivers/acpi/tables/tbxface.c
 190 +++ b/drivers/acpi/tables/tbxface.c
 191 @@ -487,7 +487,7 @@ ACPI_EXPORT_SYMBOL(acpi_get_table_by_ind
 192   *              the RSDT/XSDT.
 193   *
 194   ******************************************************************************/
 195 -static acpi_status acpi_tb_load_namespace(void)
 196 +static acpi_status __init acpi_tb_load_namespace(void)
 197  {
 198         acpi_status status;
 199         struct acpi_table_header *table;
 200 @@ -612,7 +612,7 @@ static acpi_status acpi_tb_load_namespac
 201   *
 202   ******************************************************************************/
 203
 204 -acpi_status acpi_load_tables(void)
 205 +acpi_status __init acpi_load_tables(void)
 206  {
 207         acpi_status status;
 208
 209 @@ -630,9 +630,6 @@ acpi_status acpi_load_tables(void)
 210         return_ACPI_STATUS(status);
 211  }
 212
 213 -ACPI_EXPORT_SYMBOL(acpi_load_tables)
 214 -
 215 -
 216  /*******************************************************************************
 217   *
 218   * FUNCTION:    acpi_install_table_handler
 219 --- a/init/initramfs.c
 220 +++ b/init/initramfs.c
 221 @@ -6,6 +6,9 @@
 222  #include <linux/delay.h>
 223  #include <linux/string.h>
 224  #include <linux/syscalls.h>
 225 +#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
 226 +#include <acpi/acpi.h>
 227 +#endif
 228
 229  static __initdata char *message;
 230  static void __init error(char *x)
 231 @@ -80,6 +83,12 @@ static __initdata unsigned long body_len
 232  static __initdata uid_t uid;
 233  static __initdata gid_t gid;
 234  static __initdata unsigned rdev;
 235 +#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
 236 +static __initdata char *file_looked_for;
 237 +static __initdata struct acpi_table_header *file_mem;
 238 +#else
 239 +const char *file_looked_for = NULL;
 240 +#endif
 241
 242  static void __init parse_header(char *s)
 243  {
 244 @@ -113,6 +122,7 @@ static __initdata enum state {
 245         SkipIt,
 246         GotName,
 247         CopyFile,
 248 +       CopyFileMem,
 249         GotSymlink,
 250         Reset
 251  } state, next_state;
 252 @@ -257,6 +267,9 @@ static int __init do_name(void)
 253                 free_hash();
 254                 return 0;
 255         }
 256 +       if (file_looked_for && S_ISREG(mode) &&
 257 +               (strcmp(collected, file_looked_for) == 0))
 258 +               state = CopyFileMem;
 259         if (dry_run)
 260                 return 0;
 261         clean_path(collected, mode);
 262 @@ -289,6 +302,40 @@ static int __init do_name(void)
 263         return 0;
 264  }
 265
 266 +#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
 267 +static int __init do_copy_mem(void)
 268 +{
 269 +       static void *file_current; /* current position in the memory */
 270 +       if (file_mem == NULL) {
 271 +               if (body_len < 4) { /* check especially against empty files */
 272 +                       error("file is less than 4 bytes");
 273 +                       return 1;
 274 +               }
 275 +               file_mem = kmalloc(body_len, GFP_ATOMIC);
 276 +               if (!file_mem) {
 277 +                       error("failed to allocate enough memory");
 278 +                       return 1;
 279 +               }
 280 +               file_current = file_mem;
 281 +       }
 282 +       if (count >= body_len) {
 283 +               memcpy(file_current, victim, body_len);
 284 +               eat(body_len);
 285 +               file_looked_for = NULL; /* don't find files with same name */
 286 +               state = SkipIt;
 287 +               return 0;
 288 +       } else {
 289 +               memcpy(file_current, victim, count);
 290 +               file_current += count;
 291 +               body_len -= count;
 292 +               eat(count);
 293 +               return 1;
 294 +       }
 295 +}
 296 +#else
 297 +#define do_copy_mem NULL
 298 +#endif
 299 +
 300  static int __init do_copy(void)
 301  {
 302         if (count >= body_len) {
 303 @@ -323,6 +370,7 @@ static __initdata int (*actions[])(void)
 304         [SkipIt]        = do_skip,
 305         [GotName]       = do_name,
 306         [CopyFile]      = do_copy,
 307 +       [CopyFileMem]   = do_copy_mem,
 308         [GotSymlink]    = do_symlink,
 309         [Reset]         = do_reset,
 310  };
 311 @@ -560,3 +608,31 @@ static int __init populate_rootfs(void)
 312         return 0;
 313  }
 314  rootfs_initcall(populate_rootfs);
 315 +
 316 +#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
 317 +struct acpi_table_header * __init acpi_find_dsdt_initrd(void)
 318 +{
 319 +       char *err, *ramfs_dsdt_name = "DSDT.aml";
 320 +
 321 +       printk(KERN_INFO "ACPI: Checking initramfs for custom DSDT\n");
 322 +       file_mem = NULL;
 323 +       file_looked_for = ramfs_dsdt_name;
 324 +       err = unpack_to_rootfs((char *)initrd_start,
 325 +                       initrd_end - initrd_start, 1);
 326 +       file_looked_for = NULL;
 327 +
 328 +       if (err) {
 329 +               /*
 330 +                * Even if reading the DSDT file was successful,
 331 +                * we give up if the initramfs cannot be entirely read.
 332 +                */
 333 +               kfree(file_mem);
 334 +               printk(KERN_ERR "ACPI: Aborded because %s.\n", err);
 335 +               return NULL;
 336 +       }
 337 +       if (file_mem)
 338 +               printk(KERN_INFO "ACPI: Found DSDT in %s.\n", ramfs_dsdt_name);
 339 +
 340 +       return file_mem;
 341 +}
 342 +#endif