14 files changed, 651 insertions, 8 deletions

diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX
index 9e642c5bf526..8dfc6708a257 100644
--- a/Documentation/00-INDEX
+++ b/Documentation/00-INDEX
@@ -232,6 +232,8 @@ memory.txt
         - info on typical Linux memory problems.
 mips/
         - directory with info about Linux on MIPS architecture.
+mmc/
+        - directory with info about the MMC subsystem
 mono.txt
         - how to execute Mono-based .NET binaries with the help of BINFMT_MISC.
 mutex-design.txt
diff --git a/Documentation/mmc/00-INDEX b/Documentation/mmc/00-INDEX
new file mode 100644
index 000000000000..fca586f5b853
--- /dev/null
+++ b/Documentation/mmc/00-INDEX
@@ -0,0 +1,4 @@
+00-INDEX
+        - this file
+mmc-dev-attrs.txt
+        - info on SD and MMC device attributes
diff --git a/Documentation/mmc/mmc-dev-attrs.txt b/Documentation/mmc/mmc-dev-attrs.txt
new file mode 100644
index 000000000000..ff2bd685bced
--- /dev/null
+++ b/Documentation/mmc/mmc-dev-attrs.txt
@@ -0,0 +1,56 @@
+SD and MMC Device Attributes
+============================
+
+All attributes are read-only.
+
+        cid                     Card Identifaction Register
+        csd                     Card Specific Data Register
+        scr                     SD Card Configuration Register (SD only)
+        date                    Manufacturing Date (from CID Register)
+        fwrev                   Firmware/Product Revision (from CID Register) (SD and MMCv1 only)
+        hwrev                   Hardware/Product Revision (from CID Register) (SD and MMCv1 only)
+        manfid                  Manufacturer ID (from CID Register)
+        name                    Product Name (from CID Register)
+        oemid                   OEM/Application ID (from CID Register)
+        serial                  Product Serial Number (from CID Register)
+        erase_size              Erase group size
+        preferred_erase_size    Preferred erase size
+
+Note on Erase Size and Preferred Erase Size:
+
+        "erase_size" is the  minimum size, in bytes, of an erase
+        operation.  For MMC, "erase_size" is the erase group size
+        reported by the card.  Note that "erase_size" does not apply
+        to trim or secure trim operations where the minimum size is
+        always one 512 byte sector.  For SD, "erase_size" is 512
+        if the card is block-addressed, 0 otherwise.
+
+        SD/MMC cards can erase an arbitrarily large area up to and
+        including the whole card.  When erasing a large area it may
+        be desirable to do it in smaller chunks for three reasons:
+                1. A single erase command will make all other I/O on
+                the card wait.  This is not a problem if the whole card
+                is being erased, but erasing one partition will make
+                I/O for another partition on the same card wait for the
+                duration of the erase - which could be a several
+                minutes.
+                2. To be able to inform the user of erase progress.
+                3. The erase timeout becomes too large to be very
+                useful.  Because the erase timeout contains a margin
+                which is multiplied by the size of the erase area,
+                the value can end up being several minutes for large
+                areas.
+
+        "erase_size" is not the most efficient unit to erase
+        (especially for SD where it is just one sector),
+        hence "preferred_erase_size" provides a good chunk
+        size for erasing large areas.
+
+        For MMC, "preferred_erase_size" is the high-capacity
+        erase size if a card specifies one, otherwise it is
+        based on the capacity of the card.
+
+        For SD, "preferred_erase_size" is the allocation unit
+        size specified by the card.
+
+        "preferred_erase_size" is in bytes.
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 83240faa1dc8..5db49b124ffa 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1050,6 +1050,352 @@ void mmc_detect_change(struct mmc_host *host, unsigned long delay)
 
 EXPORT_SYMBOL(mmc_detect_change);
 
+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;
+