releases/5.0.10/nfit-ars-avoid-stale-ars-results.patch

   1 From ddaf917919fa4ff38a4e87397717069e75aee8f4 Mon Sep 17 00:00:00 2001
   2 From: Dan Williams <dan.j.williams@intel.com>
   3 Date: Mon, 22 Apr 2019 16:08:26 -0700
   4 Subject: nfit/ars: Avoid stale ARS results
   5
   6 commit 78153dd45e7e0596ba32b15d02bda08e1513111e upstream.
   7
   8 Gate ARS result consumption on whether the OS issued start-ARS since the
   9 previous consumption. The BIOS may only clear its result buffers after a
  10 successful start-ARS.
  11
  12 Fixes: 0caeef63e6d2 ("libnvdimm: Add a poison list and export badblocks")
  13 Cc: <stable@vger.kernel.org>
  14 Reported-by: Krzysztof Rusocki <krzysztof.rusocki@intel.com>
  15 Reported-by: Vishal Verma <vishal.l.verma@intel.com>
  16 Reviewed-by: Toshi Kani <toshi.kani@hpe.com>
  17 Signed-off-by: Dan Williams <dan.j.williams@intel.com>
  18 Signed-off-by: Sasha Levin <sashal@kernel.org>
  19 ---
  20  drivers/acpi/nfit/core.c | 17 ++++++++++++++++-
  21  drivers/acpi/nfit/nfit.h |  1 +
  22  2 files changed, 17 insertions(+), 1 deletion(-)
  23
  24 diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
  25 index 61d3fd65fbe9..4be4dc3e8aa6 100644
  26 --- a/drivers/acpi/nfit/core.c
  27 +++ b/drivers/acpi/nfit/core.c
  28 @@ -2661,7 +2661,10 @@ static int ars_start(struct acpi_nfit_desc *acpi_desc,
  29
  30         if (rc < 0)
  31                 return rc;
  32 -       return cmd_rc;
  33 +       if (cmd_rc < 0)
  34 +               return cmd_rc;
  35 +       set_bit(ARS_VALID, &acpi_desc->scrub_flags);
  36 +       return 0;
  37  }
  38
  39  static int ars_continue(struct acpi_nfit_desc *acpi_desc)
  40 @@ -2754,6 +2757,17 @@ static int ars_status_process_records(struct acpi_nfit_desc *acpi_desc)
  41          */
  42         if (ars_status->out_length < 44)
  43                 return 0;
  44 +
  45 +       /*
  46 +        * Ignore potentially stale results that are only refreshed
  47 +        * after a start-ARS event.
  48 +        */
  49 +       if (!test_and_clear_bit(ARS_VALID, &acpi_desc->scrub_flags)) {
  50 +               dev_dbg(acpi_desc->dev, "skip %d stale records\n",
  51 +                               ars_status->num_records);
  52 +               return 0;
  53 +       }
  54 +
  55         for (i = 0; i < ars_status->num_records; i++) {
  56                 /* only process full records */
  57                 if (ars_status->out_length
  58 @@ -3238,6 +3252,7 @@ static int acpi_nfit_register_regions(struct acpi_nfit_desc *acpi_desc)
  59         struct nfit_spa *nfit_spa;
  60         int rc;
  61
  62 +       set_bit(ARS_VALID, &acpi_desc->scrub_flags);
  63         list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
  64                 switch (nfit_spa_type(nfit_spa->spa)) {
  65                 case NFIT_SPA_VOLATILE:
  66 diff --git a/drivers/acpi/nfit/nfit.h b/drivers/acpi/nfit/nfit.h
  67 index d14bad687fb8..0cbe5009eb2c 100644
  68 --- a/drivers/acpi/nfit/nfit.h
  69 +++ b/drivers/acpi/nfit/nfit.h
  70 @@ -213,6 +213,7 @@ struct nfit_mem {
  71  enum scrub_flags {
  72         ARS_BUSY,
  73         ARS_CANCEL,
  74 +       ARS_VALID,
  75         ARS_POLL,
  76  };
  77
  78 --
  79 2.19.1
  80