releases/2.6.36.4/tpm-autodetect-itpm-devices.patch

   1 From 3f0d3d016d89a5efb8b926d4707eb21fa13f3d27 Mon Sep 17 00:00:00 2001
   2 From: Matthew Garrett <mjg@redhat.com>
   3 Date: Thu, 21 Oct 2010 17:42:40 -0400
   4 Subject: tpm: Autodetect itpm devices
   5
   6 From: Matthew Garrett <mjg@redhat.com>
   7
   8 commit 3f0d3d016d89a5efb8b926d4707eb21fa13f3d27 upstream.
   9
  10 Some Lenovos have TPMs that require a quirk to function correctly. This can
  11 be autodetected by checking whether the device has a _HID of INTC0102. This
  12 is an invalid PNPid, and as such is discarded by the pnp layer - however
  13 it's still present in the ACPI code, so we can pull it out that way. This
  14 means that the quirk won't be automatically applied on non-ACPI systems,
  15 but without ACPI we don't have any way to identify the chip anyway so I
  16 don't think that's a great concern.
  17
  18 Signed-off-by: Matthew Garrett <mjg@redhat.com>
  19 Acked-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
  20 Tested-by: Jiri Kosina <jkosina@suse.cz>
  21 Tested-by: Andy Isaacson <adi@hexapodia.org>
  22 Signed-off-by: James Morris <jmorris@namei.org>
  23 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  24
  25 ---
  26  drivers/char/tpm/tpm_tis.c |   24 ++++++++++++++++++++++++
  27  1 file changed, 24 insertions(+)
  28
  29 --- a/drivers/char/tpm/tpm_tis.c
  30 +++ b/drivers/char/tpm/tpm_tis.c
  31 @@ -25,6 +25,7 @@
  32  #include <linux/slab.h>
  33  #include <linux/interrupt.h>
  34  #include <linux/wait.h>
  35 +#include <linux/acpi.h>
  36  #include "tpm.h"
  37
  38  #define TPM_HEADER_SIZE 10
  39 @@ -78,6 +79,26 @@ enum tis_defaults {
  40  static LIST_HEAD(tis_chips);
  41  static DEFINE_SPINLOCK(tis_lock);
  42
  43 +#ifdef CONFIG_ACPI
  44 +static int is_itpm(struct pnp_dev *dev)
  45 +{
  46 +       struct acpi_device *acpi = pnp_acpi_device(dev);
  47 +       struct acpi_hardware_id *id;
  48 +
  49 +       list_for_each_entry(id, &acpi->pnp.ids, list) {
  50 +               if (!strcmp("INTC0102", id->id))
  51 +                       return 1;
  52 +       }
  53 +
  54 +       return 0;
  55 +}
  56 +#else
  57 +static int is_itpm(struct pnp_dev *dev)
  58 +{
  59 +       return 0;
  60 +}
  61 +#endif
  62 +
  63  static int check_locality(struct tpm_chip *chip, int l)
  64  {
  65         if ((ioread8(chip->vendor.iobase + TPM_ACCESS(l)) &
  66 @@ -474,6 +495,9 @@ static int tpm_tis_init(struct device *d
  67                  "1.2 TPM (device-id 0x%X, rev-id %d)\n",
  68                  vendor >> 16, ioread8(chip->vendor.iobase + TPM_RID(0)));
  69
  70 +       if (is_itpm(to_pnp_dev(dev)))
  71 +               itpm = 1;
  72 +
  73         if (itpm)
  74                 dev_info(dev, "Intel iTPM workaround enabled\n");
  75