mmc: queue: let host controllers specify maximum discard timeout

[pandora-kernel.git] / drivers / mmc / core / core.c

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 68091dd..ac82865 100644 (file)
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1245,7 +1245,7 @@ static unsigned int mmc_mmc_erase_timeout(struct mmc_card *card,
                 */
                timeout_clks <<= 1;
                timeout_us += (timeout_clks * 1000) /
-                             (card->host->ios.clock / 1000);
+                             (mmc_host_clk_rate(card->host) / 1000);
 
                erase_timeout = timeout_us / 1000;
 
@@ -1516,6 +1516,82 @@ int mmc_erase_group_aligned(struct mmc_card *card, unsigned int from,
 }
 EXPORT_SYMBOL(mmc_erase_group_aligned);
 
+static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
+                                           unsigned int arg)
+{
+       struct mmc_host *host = card->host;
+       unsigned int max_discard, x, y, qty = 0, max_qty, timeout;
+       unsigned int last_timeout = 0;
+
+       if (card->erase_shift)
+               max_qty = UINT_MAX >> card->erase_shift;
+       else if (mmc_card_sd(card))
+               max_qty = UINT_MAX;
+       else
+               max_qty = UINT_MAX / card->erase_size;
+
+       /* Find the largest qty with an OK timeout */
+       do {
+               y = 0;
+               for (x = 1; x && x <= max_qty && max_qty - x >= qty; x <<= 1) {
+                       timeout = mmc_erase_timeout(card, arg, qty + x);
+                       if (timeout > host->max_discard_to)
+                               break;
+                       if (timeout < last_timeout)
+                               break;
+                       last_timeout = timeout;
+                       y = x;
+               }
+               qty += y;
+       } while (y);
+
+       if (!qty)
+               return 0;
+
+       if (qty == 1)
+               return 1;
+
+       /* Convert qty to sectors */
+       if (card->erase_shift)
+               max_discard = --qty << card->erase_shift;
+       else if (mmc_card_sd(card))
+               max_discard = qty;
+       else
+               max_discard = --qty * card->erase_size;
+
+       return max_discard;
+}
+
+unsigned int mmc_calc_max_discard(struct mmc_card *card)
+{
+       struct mmc_host *host = card->host;
+       unsigned int max_discard, max_trim;
+
+       if (!host->max_discard_to)
+               return UINT_MAX;
+
+       /*
+        * Without erase_group_def set, MMC erase timeout depends on clock
+        * frequence which can change.  In that case, the best choice is
+        * just the preferred erase size.
+        */
+       if (mmc_card_mmc(card) && !(card->ext_csd.erase_group_def & 1))
+               return card->pref_erase;
+
+       max_discard = mmc_do_calc_max_discard(card, MMC_ERASE_ARG);
+       if (mmc_can_trim(card)) {
+               max_trim = mmc_do_calc_max_discard(card, MMC_TRIM_ARG);
+               if (max_trim < max_discard)
+                       max_discard = max_trim;
+       } else if (max_discard < card->erase_size) {
+               max_discard = 0;
+       }
+       pr_debug("%s: calculated max. discard sectors %u for timeout %u ms\n",
+                mmc_hostname(host), max_discard, host->max_discard_to);
+       return max_discard;
+}
+EXPORT_SYMBOL(mmc_calc_max_discard);
+
 int mmc_set_blocklen(struct mmc_card *card, unsigned int blocklen)
 {
        struct mmc_command cmd = {0};