mmc: core: Read performance enhancements registers for SD cards
authorUlf Hansson <ulf.hansson@linaro.org>
Tue, 4 May 2021 16:12:21 +0000 (18:12 +0200)
committerUlf Hansson <ulf.hansson@linaro.org>
Mon, 14 Jun 2021 11:57:36 +0000 (13:57 +0200)
In SD spec v6.x the SD function extension registers for performance
enhancements were introduced. These registers let the SD card announce
supports for various performance related features, like "self-maintenance",
"cache" and "command queuing".

Let's extend the parsing of SD function extension registers and store the
information in the struct mmc_card. This prepares for subsequent changes to
implement the complete support for new the performance enhancement
features.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
Link: https://lore.kernel.org/r/20210504161222.101536-11-ulf.hansson@linaro.org
drivers/mmc/core/sd.c
include/linux/mmc/card.h

index 2e687f1..0b882aa 100644 (file)
@@ -1058,6 +1058,55 @@ out:
        return err;
 }
 
+static int sd_parse_ext_reg_perf(struct mmc_card *card, u8 fno, u8 page,
+                                u16 offset)
+{
+       int err;
+       u8 *reg_buf;
+
+       reg_buf = kzalloc(512, GFP_KERNEL);
+       if (!reg_buf)
+               return -ENOMEM;
+
+       err = sd_read_ext_reg(card, fno, page, offset, 512, reg_buf);
+       if (err) {
+               pr_warn("%s: error %d reading PERF func of ext reg\n",
+                       mmc_hostname(card->host), err);
+               goto out;
+       }
+
+       /* PERF revision. */
+       card->ext_perf.rev = reg_buf[0];
+
+       /* FX_EVENT support at bit 0. */
+       if (reg_buf[1] & BIT(0))
+               card->ext_perf.feature_support |= SD_EXT_PERF_FX_EVENT;
+
+       /* Card initiated self-maintenance support at bit 0. */
+       if (reg_buf[2] & BIT(0))
+               card->ext_perf.feature_support |= SD_EXT_PERF_CARD_MAINT;
+
+       /* Host initiated self-maintenance support at bit 1. */
+       if (reg_buf[2] & BIT(1))
+               card->ext_perf.feature_support |= SD_EXT_PERF_HOST_MAINT;
+
+       /* Cache support at bit 0. */
+       if (reg_buf[4] & BIT(0))
+               card->ext_perf.feature_support |= SD_EXT_PERF_CACHE;
+
+       /* Command queue support indicated via queue depth bits (0 to 4). */
+       if (reg_buf[6] & 0x1f)
+               card->ext_perf.feature_support |= SD_EXT_PERF_CMD_QUEUE;
+
+       card->ext_perf.fno = fno;
+       card->ext_perf.page = page;
+       card->ext_perf.offset = offset;
+
+out:
+       kfree(reg_buf);
+       return err;
+}
+
 static int sd_parse_ext_reg(struct mmc_card *card, u8 *gen_info_buf,
                            u16 *next_ext_addr)
 {
@@ -1102,6 +1151,10 @@ static int sd_parse_ext_reg(struct mmc_card *card, u8 *gen_info_buf,
        if (sfc == 0x1)
                return sd_parse_ext_reg_power(card, fno, page, offset);
 
+       /* Standard Function Code for performance enhancement. */
+       if (sfc == 0x2)
+               return sd_parse_ext_reg_perf(card, fno, page, offset);
+
        return 0;
 }
 
index 03a862e..2867af0 100644 (file)
@@ -201,6 +201,12 @@ struct sd_ext_reg {
 #define SD_EXT_POWER_OFF_NOTIFY        (1<<0)
 #define SD_EXT_POWER_SUSTENANCE        (1<<1)
 #define SD_EXT_POWER_DOWN_MODE (1<<2)
+/* Performance Enhancement Function. */
+#define SD_EXT_PERF_FX_EVENT   (1<<0)
+#define SD_EXT_PERF_CARD_MAINT (1<<1)
+#define SD_EXT_PERF_HOST_MAINT (1<<2)
+#define SD_EXT_PERF_CACHE      (1<<3)
+#define SD_EXT_PERF_CMD_QUEUE  (1<<4)
 };
 
 struct sdio_cccr {
@@ -305,6 +311,7 @@ struct mmc_card {
        struct sd_ssr           ssr;            /* yet more SD information */
        struct sd_switch_caps   sw_caps;        /* switch (CMD6) caps */
        struct sd_ext_reg       ext_power;      /* SD extension reg for PM */
+       struct sd_ext_reg       ext_perf;       /* SD extension reg for PERF */
 
        unsigned int            sdio_funcs;     /* number of SDIO functions */
        atomic_t                sdio_funcs_probed; /* number of probed SDIO funcs */