+void mmc_init_erase(struct mmc_card *card)
+{
+ unsigned int sz;
+
+ if (is_power_of_2(card->erase_size))
+ card->erase_shift = ffs(card->erase_size) - 1;
+ else
+ card->erase_shift = 0;
+
+ /*
+ * It is possible to erase an arbitrarily large area of an SD or MMC
+ * card. That is not desirable because it can take a long time
+ * (minutes) potentially delaying more important I/O, and also the
+ * timeout calculations become increasingly hugely over-estimated.
+ * Consequently, 'pref_erase' is defined as a guide to limit erases
+ * to that size and alignment.
+ *
+ * For SD cards that define Allocation Unit size, limit erases to one
+ * Allocation Unit at a time. For MMC cards that define High Capacity
+ * Erase Size, whether it is switched on or not, limit to that size.
+ * Otherwise just have a stab at a good value. For modern cards it
+ * will end up being 4MiB. Note that if the value is too small, it
+ * can end up taking longer to erase.
+ */
+ if (mmc_card_sd(card) && card->ssr.au) {
+ card->pref_erase = card->ssr.au;
+ card->erase_shift = ffs(card->ssr.au) - 1;
+ } else if (card->ext_csd.hc_erase_size) {
+ card->pref_erase = card->ext_csd.hc_erase_size;
+ } else {
+ sz = (card->csd.capacity << (card->csd.read_blkbits - 9)) >> 11;
+ if (sz < 128)
+ card->pref_erase = 512 * 1024 / 512;
+ else if (sz < 512)
+ card->pref_erase = 1024 * 1024 / 512;
+ else if (sz < 1024)
+ card->pref_erase = 2 * 1024 * 1024 / 512;
+ else
+ card->pref_erase = 4 * 1024 * 1024 / 512;
+ if (card->pref_erase < card->erase_size)
+ card->pref_erase = card->erase_size;
+ else {
+ sz = card->pref_erase % card->erase_size;
+ if (sz)
+ card->pref_erase += card->erase_size - sz;
+ }
+ }
+}
+
+static void mmc_set_mmc_erase_timeout(struct mmc_card *card,
+ struct mmc_command *cmd,
+ unsigned int arg, unsigned int qty)
+{
+ unsigned int erase_timeout;
+
+ if (card->ext_csd.erase_group_def & 1) {
+ /* High Capacity Erase Group Size uses HC timeouts */
+ if (arg == MMC_TRIM_ARG)
+ erase_timeout = card->ext_csd.trim_timeout;
+ else
+ erase_timeout = card->ext_csd.hc_erase_timeout;
+ } else {
+ /* CSD Erase Group Size uses write timeout */
+ unsigned int mult = (10 << card->csd.r2w_factor);
+ unsigned int timeout_clks = card->csd.tacc_clks * mult;
+ unsigned int timeout_us;
+
+ /* Avoid overflow: e.g. tacc_ns=80000000 mult=1280 */
+ if (card->csd.tacc_ns < 1000000)
+ timeout_us = (card->csd.tacc_ns * mult) / 1000;
+ else
+ timeout_us = (card->csd.tacc_ns / 1000) * mult;
+
+ /*
+ * ios.clock is only a target. The real clock rate might be
+ * less but not that much less, so fudge it by multiplying by 2.
+ */
+ timeout_clks <<= 1;
+ timeout_us += (timeout_clks * 1000) /
+ (card->host->ios.clock / 1000);
+
+ erase_timeout = timeout_us / 1000;
+
+ /*
+ * Theoretically, the calculation could underflow so round up
+ * to 1ms in that case.
+ */
+ if (!erase_timeout)
+ erase_timeout = 1;
+ }
+
+ /* Multiplier for secure operations */
+ if (arg & MMC_SECURE_ARGS) {
+ if (arg == MMC_SECURE_ERASE_ARG)
+ erase_timeout *= card->ext_csd.sec_erase_mult;
+ else
+ erase_timeout *= card->ext_csd.sec_trim_mult;
+ }
+
+ erase_timeout *= qty;
+
+ /*
+ * Ensure at least a 1 second timeout for SPI as per
+ * 'mmc_set_data_timeout()'
+ */
+ if (mmc_host_is_spi(card->host) && erase_timeout < 1000)
+ erase_timeout = 1000;
+
+ cmd->erase_timeout = erase_timeout;
+}
+
+static void mmc_set_sd_erase_timeout(struct mmc_card *card,
+ struct mmc_command *cmd, unsigned int arg,
+ unsigned int qty)
+{
+ if (card->ssr.erase_timeout) {
+ /* Erase timeout specified in SD Status Register (SSR) */
+ cmd->erase_timeout = card->ssr.erase_timeout * qty +
+ card->ssr.erase_offset;
+ } else {
+ /*
+ * Erase timeout not specified in SD Status Register (SSR) so
+ * use 250ms per write block.
+ */
+ cmd->erase_timeout = 250 * qty;
+ }
+
+ /* Must not be less than 1 second */
+ if (cmd->erase_timeout < 1000)
+ cmd->erase_timeout = 1000;
+}
+
+static void mmc_set_erase_timeout(struct mmc_card *card,
+ struct mmc_command *cmd, unsigned int arg,
+ unsigned int qty)
+{
+ if (mmc_card_sd(card))
+ mmc_set_sd_erase_timeout(card, cmd, arg, qty);
+ else
+ mmc_set_mmc_erase_timeout(card, cmd, arg, qty);
+}
+
+static int mmc_do_erase(struct mmc_card *card, unsigned int from,
+ unsigned int to, unsigned int arg)
+{
+ struct mmc_command cmd;
+ unsigned int qty = 0;
+ int err;
+
+ /*
+ * qty is used to calculate the erase timeout which depends on how many
+ * erase groups (or allocation units in SD terminology) are affected.
+ * We count erasing part of an erase group as one erase group.
+ * For SD, the allocation units are always a power of 2. For MMC, the
+ * erase group size is almost certainly also power of 2, but it does not
+ * seem to insist on that in the JEDEC standard, so we fall back to
+ * division in that case. SD may not specify an allocation unit size,
+ * in which case the timeout is based on the number of write blocks.
+ *
+ * Note that the timeout for secure trim 2 will only be correct if the
+ * number of erase groups specified is the same as the total of all
+ * preceding secure trim 1 commands. Since the power may have been
+ * lost since the secure trim 1 commands occurred, it is generally
+ * impossible to calculate the secure trim 2 timeout correctly.
+ */
+ if (card->erase_shift)
+ qty += ((to >> card->erase_shift) -
+ (from >> card->erase_shift)) + 1;
+ else if (mmc_card_sd(card))
+ qty += to - from + 1;
+ else
+ qty += ((to / card->erase_size) -
+ (from / card->erase_size)) + 1;
+
+ if (!mmc_card_blockaddr(card)) {
+ from <<= 9;
+ to <<= 9;
+ }
+
+ memset(&cmd, 0, sizeof(struct mmc_command));
+ if (mmc_card_sd(card))
+ cmd.opcode = SD_ERASE_WR_BLK_START;
+ else
+ cmd.opcode = MMC_ERASE_GROUP_START;
+ cmd.arg = from;
+ cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
+ err = mmc_wait_for_cmd(card->host, &cmd, 0);
+ if (err) {
+ printk(KERN_ERR "mmc_erase: group start error %d, "
+ "status %#x\n", err, cmd.resp[0]);
+ err = -EINVAL;
+ goto out;
+ }
+
+ memset(&cmd, 0, sizeof(struct mmc_command));
+ if (mmc_card_sd(card))
+ cmd.opcode = SD_ERASE_WR_BLK_END;
+ else
+ cmd.opcode = MMC_ERASE_GROUP_END;
+ cmd.arg = to;
+ cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
+ err = mmc_wait_for_cmd(card->host, &cmd, 0);
+ if (err) {
+ printk(KERN_ERR "mmc_erase: group end error %d, status %#x\n",
+ err, cmd.resp[0]);
+ err = -EINVAL;
+ goto out;
+ }
+
+ memset(&cmd, 0, sizeof(struct mmc_command));
+ cmd.opcode = MMC_ERASE;
+ cmd.arg = arg;
+ cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
+ mmc_set_erase_timeout(card, &cmd, arg, qty);
+ err = mmc_wait_for_cmd(card->host, &cmd, 0);
+ if (err) {
+ printk(KERN_ERR "mmc_erase: erase error %d, status %#x\n",
+ err, cmd.resp[0]);
+ err = -EIO;
+ goto out;
+ }
+
+ if (mmc_host_is_spi(card->host))
+ goto out;
+
+ do {
+ memset(&cmd, 0, sizeof(struct mmc_command));
+ cmd.opcode = MMC_SEND_STATUS;
+ cmd.arg = card->rca << 16;
+ cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
+ /* Do not retry else we can't see errors */
+ err = mmc_wait_for_cmd(card->host, &cmd, 0);
+ if (err || (cmd.resp[0] & 0xFDF92000)) {
+ printk(KERN_ERR "error %d requesting status %#x\n",
+ err, cmd.resp[0]);
+ err = -EIO;
+ goto out;
+ }
+ } while (!(cmd.resp[0] & R1_READY_FOR_DATA) ||
+ R1_CURRENT_STATE(cmd.resp[0]) == 7);
+out:
+ return err;
+}
+
+/**
+ * mmc_erase - erase sectors.
+ * @card: card to erase
+ * @from: first sector to erase
+ * @nr: number of sectors to erase
+ * @arg: erase command argument (SD supports only %MMC_ERASE_ARG)
+ *
+ * Caller must claim host before calling this function.
+ */
+int mmc_erase(struct mmc_card *card, unsigned int from, unsigned int nr,
+ unsigned int arg)
+{
+ unsigned int rem, to = from + nr;
+
+ if (!(card->host->caps & MMC_CAP_ERASE) ||
+ !(card->csd.cmdclass & CCC_ERASE))
+ return -EOPNOTSUPP;
+
+ if (!card->erase_size)
+ return -EOPNOTSUPP;
+
+ if (mmc_card_sd(card) && arg != MMC_ERASE_ARG)
+ return -EOPNOTSUPP;
+
+ if ((arg & MMC_SECURE_ARGS) &&
+ !(card->ext_csd.sec_feature_support & EXT_CSD_SEC_ER_EN))
+ return -EOPNOTSUPP;
+
+ if ((arg & MMC_TRIM_ARGS) &&
+ !(card->ext_csd.sec_feature_support & EXT_CSD_SEC_GB_CL_EN))
+ return -EOPNOTSUPP;
+
+ if (arg == MMC_SECURE_ERASE_ARG) {
+ if (from % card->erase_size || nr % card->erase_size)
+ return -EINVAL;
+ }
+
+ if (arg == MMC_ERASE_ARG) {
+ rem = from % card->erase_size;
+ if (rem) {
+ rem = card->erase_size - rem;
+ from += rem;
+ if (nr > rem)
+ nr -= rem;
+ else
+ return 0;
+ }
+ rem = nr % card->erase_size;
+ if (rem)
+ nr -= rem;
+ }
+
+ if (nr == 0)
+ return 0;
+
+ to = from + nr;
+
+ if (to <= from)
+ return -EINVAL;
+
+ /* 'from' and 'to' are inclusive */
+ to -= 1;
+
+ return mmc_do_erase(card, from, to, arg);
+}
+EXPORT_SYMBOL(mmc_erase);
+
+int mmc_can_erase(struct mmc_card *card)
+{
+ if ((card->host->caps & MMC_CAP_ERASE) &&
+ (card->csd.cmdclass & CCC_ERASE) && card->erase_size)
+ return 1;
+ return 0;
+}
+EXPORT_SYMBOL(mmc_can_erase);
+
+int mmc_can_trim(struct mmc_card *card)
+{
+ if (card->ext_csd.sec_feature_support & EXT_CSD_SEC_GB_CL_EN)
+ return 1;
+ return 0;
+}
+EXPORT_SYMBOL(mmc_can_trim);
+
+int mmc_can_secure_erase_trim(struct mmc_card *card)
+{
+ if (card->ext_csd.sec_feature_support & EXT_CSD_SEC_ER_EN)
+ return 1;
+ return 0;
+}
+EXPORT_SYMBOL(mmc_can_secure_erase_trim);
+
+int mmc_erase_group_aligned(struct mmc_card *card, unsigned int from,
+ unsigned int nr)
+{
+ if (!card->erase_size)
+ return 0;
+ if (from % card->erase_size || nr % card->erase_size)
+ return 0;
+ return 1;
+}
+EXPORT_SYMBOL(mmc_erase_group_aligned);
+