git.openwrt.org Git - openwrt/staging/svanheule.git/blob

   1 From d8748eda96b47efea833e2a6ea478bb370654f1d Mon Sep 17 00:00:00 2001
   2 From: Jonathan Bell <jonathan@raspberrypi.com>
   3 Date: Wed, 20 Mar 2024 13:00:30 +0000
   4 Subject: [PATCH 0983/1085] drivers: mmc: preallocate a block for SD extension
   5  register accesses
   6
   7 The Performance Extension register is regularly accessed in a hot path
   8 to do write cache flushes. Don't invoke kmalloc/kfree for every access,
   9 preallocate a 512B buffer for this purpose.
  10
  11 Also remove an unused alloc in sd_enable_cache().
  12
  13 Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
  14 ---
  15  drivers/mmc/core/bus.c   |  2 ++
  16  drivers/mmc/core/sd.c    | 34 +++++++++++-----------------------
  17  include/linux/mmc/card.h |  1 +
  18  3 files changed, 14 insertions(+), 23 deletions(-)
  19
  20 --- a/drivers/mmc/core/bus.c
  21 +++ b/drivers/mmc/core/bus.c
  22 @@ -264,6 +264,8 @@ static void mmc_release_card(struct devi
  23
  24         sdio_free_common_cis(card);
  25
  26 +       kfree(card->ext_reg_buf);
  27 +
  28         kfree(card->info);
  29
  30         kfree(card);
  31 --- a/drivers/mmc/core/sd.c
  32 +++ b/drivers/mmc/core/sd.c
  33 @@ -1026,9 +1026,8 @@ int sd_write_ext_reg(struct mmc_card *ca
  34         struct scatterlist sg;
  35         u8 *reg_buf;
  36
  37 -       reg_buf = kzalloc(512, GFP_KERNEL);
  38 -       if (!reg_buf)
  39 -               return -ENOMEM;
  40 +       reg_buf = card->ext_reg_buf;
  41 +       memset(reg_buf, 0, 512);
  42
  43         mrq.cmd = &cmd;
  44         mrq.data = &data;
  45 @@ -1060,8 +1059,6 @@ int sd_write_ext_reg(struct mmc_card *ca
  46         mmc_set_data_timeout(&data, card);
  47         mmc_wait_for_req(host, &mrq);
  48
  49 -       kfree(reg_buf);
  50 -
  51         /*
  52          * Note that, the SD card is allowed to signal busy on DAT0 up to 1s
  53          * after the CMD49. Although, let's leave this to be managed by the
  54 @@ -1102,9 +1099,7 @@ static int sd_parse_ext_reg_power(struct
  55         int err;
  56         u8 *reg_buf;
  57
  58 -       reg_buf = kzalloc(512, GFP_KERNEL);
  59 -       if (!reg_buf)
  60 -               return -ENOMEM;
  61 +       reg_buf = card->ext_reg_buf;
  62
  63         /* Read the extension register for power management function. */
  64         err = sd_read_ext_reg(card, fno, page, offset, 512, reg_buf);
  65 @@ -1134,7 +1129,6 @@ static int sd_parse_ext_reg_power(struct
  66         card->ext_power.offset = offset;
  67
  68  out:
  69 -       kfree(reg_buf);
  70         return err;
  71  }
  72
  73 @@ -1144,9 +1138,7 @@ static int sd_parse_ext_reg_perf(struct
  74         int err;
  75         u8 *reg_buf;
  76
  77 -       reg_buf = kzalloc(512, GFP_KERNEL);
  78 -       if (!reg_buf)
  79 -               return -ENOMEM;
  80 +       reg_buf = card->ext_reg_buf;
  81
  82         err = sd_read_ext_reg(card, fno, page, offset, 512, reg_buf);
  83         if (err) {
  84 @@ -1189,7 +1181,6 @@ static int sd_parse_ext_reg_perf(struct
  85         card->ext_perf.offset = offset;
  86
  87  out:
  88 -       kfree(reg_buf);
  89         return err;
  90  }
  91
  92 @@ -1260,6 +1251,12 @@ static int sd_read_ext_regs(struct mmc_c
  93         if (!gen_info_buf)
  94                 return -ENOMEM;
  95
  96 +       card->ext_reg_buf = kzalloc(512, GFP_KERNEL);
  97 +       if (!card->ext_reg_buf) {
  98 +               err = -ENOMEM;
  99 +               goto out;
 100 +       }
 101 +
 102         /*
 103          * Read 512 bytes of general info, which is found at function number 0,
 104          * at page 0 and with no offset.
 105 @@ -1326,9 +1323,7 @@ static int sd_flush_cache(struct mmc_hos
 106         if (!sd_cache_enabled(host))
 107                 return 0;
 108
 109 -       reg_buf = kzalloc(512, GFP_KERNEL);
 110 -       if (!reg_buf)
 111 -               return -ENOMEM;
 112 +       reg_buf = card->ext_reg_buf;
 113
 114         /*
 115          * Set Flush Cache at bit 0 in the performance enhancement register at
 116 @@ -1364,21 +1359,15 @@ static int sd_flush_cache(struct mmc_hos
 117         if (reg_buf[0] & BIT(0))
 118                 err = -ETIMEDOUT;
 119  out:
 120 -       kfree(reg_buf);
 121         return err;
 122  }
 123
 124  static int sd_enable_cache(struct mmc_card *card)
 125  {
 126 -       u8 *reg_buf;
 127         int err;
 128
 129         card->ext_perf.feature_enabled &= ~SD_EXT_PERF_CACHE;
 130
 131 -       reg_buf = kzalloc(512, GFP_KERNEL);
 132 -       if (!reg_buf)
 133 -               return -ENOMEM;
 134 -
 135         /*
 136          * Set Cache Enable at bit 0 in the performance enhancement register at
 137          * 260 bytes offset.
 138 @@ -1397,7 +1386,6 @@ static int sd_enable_cache(struct mmc_ca
 139                 card->ext_perf.feature_enabled |= SD_EXT_PERF_CACHE;
 140
 141  out:
 142 -       kfree(reg_buf);
 143         return err;
 144  }
 145
 146 --- a/include/linux/mmc/card.h
 147 +++ b/include/linux/mmc/card.h
 148 @@ -320,6 +320,7 @@ struct mmc_card {
 149         struct sd_switch_caps   sw_caps;        /* switch (CMD6) caps */
 150         struct sd_ext_reg       ext_power;      /* SD extension reg for PM */
 151         struct sd_ext_reg       ext_perf;       /* SD extension reg for PERF */
 152 +       u8                      *ext_reg_buf;   /* 512 byte block for extension register R/W */
 153
 154         unsigned int            sdio_funcs;     /* number of SDIO functions */
 155         atomic_t                sdio_funcs_probed; /* number of probed SDIO funcs */