aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/mmc/core/mmc.c
diff options
context:
space:
mode:
authorAdrian Hunter <adrian.hunter@nokia.com>2010-08-11 17:17:46 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-12 11:43:30 -0400
commitdfe86cba7676d58db8de7e623f5e72f1b0d3ca35 (patch)
treeed7e6a267c50e0ba2374dc6895515d7a100961a3 /drivers/mmc/core/mmc.c
parent81d73a32d775ae9674ea6edf0b5b721fc3bc57d9 (diff)
mmc: add erase, secure erase, trim and secure trim operations
SD/MMC cards tend to support an erase operation. In addition, eMMC v4.4 cards can support secure erase, trim and secure trim operations that are all variants of the basic erase command. SD/MMC device attributes "erase_size" and "preferred_erase_size" have been added. "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. Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com> Acked-by: Jens Axboe <axboe@kernel.dk> Cc: Kyungmin Park <kmpark@infradead.org> Cc: Madhusudhan Chikkature <madhu.cr@ti.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Ben Gardiner <bengardiner@nanometrics.ca> Cc: <linux-mmc@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/mmc/core/mmc.c')
-rw-r--r--drivers/mmc/core/mmc.c47
1 files changed, 46 insertions, 1 deletions
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index ccba3869c029..6909a54c39be 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -108,13 +108,23 @@ static int mmc_decode_cid(struct mmc_card *card)
108 return 0; 108 return 0;
109} 109}
110 110
111static void mmc_set_erase_size(struct mmc_card *card)
112{
113 if (card->ext_csd.erase_group_def & 1)
114 card->erase_size = card->ext_csd.hc_erase_size;
115 else
116 card->erase_size = card->csd.erase_size;
117
118 mmc_init_erase(card);
119}
120
111/* 121/*
112 * Given a 128-bit response, decode to our card CSD structure. 122 * Given a 128-bit response, decode to our card CSD structure.
113 */ 123 */
114static int mmc_decode_csd(struct mmc_card *card) 124static int mmc_decode_csd(struct mmc_card *card)
115{ 125{
116 struct mmc_csd *csd = &card->csd; 126 struct mmc_csd *csd = &card->csd;
117 unsigned int e, m; 127 unsigned int e, m, a, b;
118 u32 *resp = card->raw_csd; 128 u32 *resp = card->raw_csd;
119 129
120 /* 130 /*
@@ -152,6 +162,13 @@ static int mmc_decode_csd(struct mmc_card *card)
152 csd->write_blkbits = UNSTUFF_BITS(resp, 22, 4); 162 csd->write_blkbits = UNSTUFF_BITS(resp, 22, 4);
153 csd->write_partial = UNSTUFF_BITS(resp, 21, 1); 163 csd->write_partial = UNSTUFF_BITS(resp, 21, 1);
154 164
165 if (csd->write_blkbits >= 9) {
166 a = UNSTUFF_BITS(resp, 42, 5);
167 b = UNSTUFF_BITS(resp, 37, 5);
168 csd->erase_size = (a + 1) * (b + 1);
169 csd->erase_size <<= csd->write_blkbits - 9;
170 }
171
155 return 0; 172 return 0;
156} 173}
157 174
@@ -261,8 +278,30 @@ static int mmc_read_ext_csd(struct mmc_card *card)
261 if (sa_shift > 0 && sa_shift <= 0x17) 278 if (sa_shift > 0 && sa_shift <= 0x17)
262 card->ext_csd.sa_timeout = 279 card->ext_csd.sa_timeout =
263 1 << ext_csd[EXT_CSD_S_A_TIMEOUT]; 280 1 << ext_csd[EXT_CSD_S_A_TIMEOUT];
281 card->ext_csd.erase_group_def =
282 ext_csd[EXT_CSD_ERASE_GROUP_DEF];
283 card->ext_csd.hc_erase_timeout = 300 *
284 ext_csd[EXT_CSD_ERASE_TIMEOUT_MULT];
285 card->ext_csd.hc_erase_size =
286 ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE] << 10;
287 }
288
289 if (card->ext_csd.rev >= 4) {
290 card->ext_csd.sec_trim_mult =
291 ext_csd[EXT_CSD_SEC_TRIM_MULT];
292 card->ext_csd.sec_erase_mult =
293 ext_csd[EXT_CSD_SEC_ERASE_MULT];
294 card->ext_csd.sec_feature_support =
295 ext_csd[EXT_CSD_SEC_FEATURE_SUPPORT];
296 card->ext_csd.trim_timeout = 300 *
297 ext_csd[EXT_CSD_TRIM_MULT];
264 } 298 }
265 299
300 if (ext_csd[EXT_CSD_ERASED_MEM_CONT])
301 card->erased_byte = 0xFF;
302 else
303 card->erased_byte = 0x0;
304
266out: 305out:
267 kfree(ext_csd); 306 kfree(ext_csd);
268 307
@@ -274,6 +313,8 @@ MMC_DEV_ATTR(cid, "%08x%08x%08x%08x\n", card->raw_cid[0], card->raw_cid[1],
274MMC_DEV_ATTR(csd, "%08x%08x%08x%08x\n", card->raw_csd[0], card->raw_csd[1], 313MMC_DEV_ATTR(csd, "%08x%08x%08x%08x\n", card->raw_csd[0], card->raw_csd[1],
275 card->raw_csd[2], card->raw_csd[3]); 314 card->raw_csd[2], card->raw_csd[3]);
276MMC_DEV_ATTR(date, "%02d/%04d\n", card->cid.month, card->cid.year); 315MMC_DEV_ATTR(date, "%02d/%04d\n", card->cid.month, card->cid.year);
316MMC_DEV_ATTR(erase_size, "%u\n", card->erase_size << 9);
317MMC_DEV_ATTR(preferred_erase_size, "%u\n", card->pref_erase << 9);
277MMC_DEV_ATTR(fwrev, "0x%x\n", card->cid.fwrev); 318MMC_DEV_ATTR(fwrev, "0x%x\n", card->cid.fwrev);
278MMC_DEV_ATTR(hwrev, "0x%x\n", card->cid.hwrev); 319MMC_DEV_ATTR(hwrev, "0x%x\n", card->cid.hwrev);
279MMC_DEV_ATTR(manfid, "0x%06x\n", card->cid.manfid); 320MMC_DEV_ATTR(manfid, "0x%06x\n", card->cid.manfid);
@@ -285,6 +326,8 @@ static struct attribute *mmc_std_attrs[] = {
285 &dev_attr_cid.attr, 326 &dev_attr_cid.attr,
286 &dev_attr_csd.attr, 327 &dev_attr_csd.attr,
287 &dev_attr_date.attr, 328 &dev_attr_date.attr,
329 &dev_attr_erase_size.attr,
330 &dev_attr_preferred_erase_size.attr,
288 &dev_attr_fwrev.attr, 331 &dev_attr_fwrev.attr,
289 &dev_attr_hwrev.attr, 332 &dev_attr_hwrev.attr,
290 &dev_attr_manfid.attr, 333 &dev_attr_manfid.attr,
@@ -421,6 +464,8 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
421 err = mmc_read_ext_csd(card); 464 err = mmc_read_ext_csd(card);
422 if (err) 465 if (err)
423 goto free_card; 466 goto free_card;
467 /* Erase size depends on CSD and Extended CSD */
468 mmc_set_erase_size(card);
424 } 469 }
425 470
426 /* 471 /*