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6abaa0c9fe
linux-next/drivers/mmc/core/mmc.c
Pierre Ossman 6abaa0c9fe mmc: support unsafe resume of cards 
Since many have the system root on MMC/SD we must allow some foot
shooting when it comes to resume.

We cannot detect if a card is removed and reinserted during suspend,
so the safe approach would be to assume it was, avoiding potential
filesystem corruption. This will of course not work if you cannot
release the card before suspend.

This commit adds a compile time option that makes the MMC layer
assume the card wasn't touched if it is redetected upon resume.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
2007-05-01 16:00:02 +02:00

532 lines
12 KiB
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/*
* linux/drivers/mmc/mmc.c
*
* Copyright (C) 2003-2004 Russell King, All Rights Reserved.
* Copyright (C) 2005-2007 Pierre Ossman, All Rights Reserved.
* MMCv4 support Copyright (C) 2006 Philip Langdale, All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/err.h>
#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/mmc.h>
#include "core.h"
#include "sysfs.h"
#include "mmc_ops.h"
static const unsigned int tran_exp[] = {
10000, 100000, 1000000, 10000000,
0, 0, 0, 0
};
static const unsigned char tran_mant[] = {
0, 10, 12, 13, 15, 20, 25, 30,
35, 40, 45, 50, 55, 60, 70, 80,
};
static const unsigned int tacc_exp[] = {
1, 10, 100, 1000, 10000, 100000, 1000000, 10000000,
};
static const unsigned int tacc_mant[] = {
0, 10, 12, 13, 15, 20, 25, 30,
35, 40, 45, 50, 55, 60, 70, 80,
};
#define UNSTUFF_BITS(resp,start,size) \
({ \
const int __size = size; \
const u32 __mask = (__size < 32 ? 1 << __size : 0) - 1; \
const int __off = 3 - ((start) / 32); \
const int __shft = (start) & 31; \
u32 __res; \
\
__res = resp[__off] >> __shft; \
if (__size + __shft > 32) \
__res |= resp[__off-1] << ((32 - __shft) % 32); \
__res & __mask; \
})
/*
* Given the decoded CSD structure, decode the raw CID to our CID structure.
*/
static void mmc_decode_cid(struct mmc_card *card)
{
u32 *resp = card->raw_cid;
/*
* The selection of the format here is based upon published
* specs from sandisk and from what people have reported.
*/
switch (card->csd.mmca_vsn) {
case 0: /* MMC v1.0 - v1.2 */
case 1: /* MMC v1.4 */
card->cid.manfid = UNSTUFF_BITS(resp, 104, 24);
card->cid.prod_name[0] = UNSTUFF_BITS(resp, 96, 8);
card->cid.prod_name[1] = UNSTUFF_BITS(resp, 88, 8);
card->cid.prod_name[2] = UNSTUFF_BITS(resp, 80, 8);
card->cid.prod_name[3] = UNSTUFF_BITS(resp, 72, 8);
card->cid.prod_name[4] = UNSTUFF_BITS(resp, 64, 8);
card->cid.prod_name[5] = UNSTUFF_BITS(resp, 56, 8);
card->cid.prod_name[6] = UNSTUFF_BITS(resp, 48, 8);
card->cid.hwrev = UNSTUFF_BITS(resp, 44, 4);
card->cid.fwrev = UNSTUFF_BITS(resp, 40, 4);
card->cid.serial = UNSTUFF_BITS(resp, 16, 24);
card->cid.month = UNSTUFF_BITS(resp, 12, 4);
card->cid.year = UNSTUFF_BITS(resp, 8, 4) + 1997;
break;
case 2: /* MMC v2.0 - v2.2 */
case 3: /* MMC v3.1 - v3.3 */
case 4: /* MMC v4 */
card->cid.manfid = UNSTUFF_BITS(resp, 120, 8);
card->cid.oemid = UNSTUFF_BITS(resp, 104, 16);
card->cid.prod_name[0] = UNSTUFF_BITS(resp, 96, 8);
card->cid.prod_name[1] = UNSTUFF_BITS(resp, 88, 8);
card->cid.prod_name[2] = UNSTUFF_BITS(resp, 80, 8);
card->cid.prod_name[3] = UNSTUFF_BITS(resp, 72, 8);
card->cid.prod_name[4] = UNSTUFF_BITS(resp, 64, 8);
card->cid.prod_name[5] = UNSTUFF_BITS(resp, 56, 8);
card->cid.serial = UNSTUFF_BITS(resp, 16, 32);
card->cid.month = UNSTUFF_BITS(resp, 12, 4);
card->cid.year = UNSTUFF_BITS(resp, 8, 4) + 1997;
break;
default:
printk("%s: card has unknown MMCA version %d\n",
mmc_hostname(card->host), card->csd.mmca_vsn);
mmc_card_set_bad(card);
break;
}
}
/*
* Given a 128-bit response, decode to our card CSD structure.
*/
static void mmc_decode_csd(struct mmc_card *card)
{
struct mmc_csd *csd = &card->csd;
unsigned int e, m, csd_struct;
u32 *resp = card->raw_csd;
/*
* We only understand CSD structure v1.1 and v1.2.
* v1.2 has extra information in bits 15, 11 and 10.
*/
csd_struct = UNSTUFF_BITS(resp, 126, 2);
if (csd_struct != 1 && csd_struct != 2) {
printk("%s: unrecognised CSD structure version %d\n",
mmc_hostname(card->host), csd_struct);
mmc_card_set_bad(card);
return;
}
csd->mmca_vsn = UNSTUFF_BITS(resp, 122, 4);
m = UNSTUFF_BITS(resp, 115, 4);
e = UNSTUFF_BITS(resp, 112, 3);
csd->tacc_ns = (tacc_exp[e] * tacc_mant[m] + 9) / 10;
csd->tacc_clks = UNSTUFF_BITS(resp, 104, 8) * 100;
m = UNSTUFF_BITS(resp, 99, 4);
e = UNSTUFF_BITS(resp, 96, 3);
csd->max_dtr = tran_exp[e] * tran_mant[m];
csd->cmdclass = UNSTUFF_BITS(resp, 84, 12);
e = UNSTUFF_BITS(resp, 47, 3);
m = UNSTUFF_BITS(resp, 62, 12);
csd->capacity = (1 + m) << (e + 2);
csd->read_blkbits = UNSTUFF_BITS(resp, 80, 4);
csd->read_partial = UNSTUFF_BITS(resp, 79, 1);
csd->write_misalign = UNSTUFF_BITS(resp, 78, 1);
csd->read_misalign = UNSTUFF_BITS(resp, 77, 1);
csd->r2w_factor = UNSTUFF_BITS(resp, 26, 3);
csd->write_blkbits = UNSTUFF_BITS(resp, 22, 4);
csd->write_partial = UNSTUFF_BITS(resp, 21, 1);
}
/*
* Read and decode extended CSD.
*/
static int mmc_read_ext_csd(struct mmc_card *card)
{
int err;
u8 *ext_csd;
BUG_ON(!card);
err = MMC_ERR_FAILED;
if (card->csd.mmca_vsn < CSD_SPEC_VER_4)
return MMC_ERR_NONE;
/*
* As the ext_csd is so large and mostly unused, we don't store the
* raw block in mmc_card.
*/
ext_csd = kmalloc(512, GFP_KERNEL);
if (!ext_csd) {
printk(KERN_ERR "%s: could not allocate a buffer to "
"receive the ext_csd. mmc v4 cards will be "
"treated as v3.\n", mmc_hostname(card->host));
return MMC_ERR_FAILED;
}
err = mmc_send_ext_csd(card, ext_csd);
if (err != MMC_ERR_NONE) {
/*
* High capacity cards should have this "magic" size
* stored in their CSD.
*/
if (card->csd.capacity == (4096 * 512)) {
printk(KERN_ERR "%s: unable to read EXT_CSD "
"on a possible high capacity card. "
"Card will be ignored.\n",
mmc_hostname(card->host));
} else {
printk(KERN_WARNING "%s: unable to read "
"EXT_CSD, performance might "
"suffer.\n",
mmc_hostname(card->host));
err = MMC_ERR_NONE;
}
goto out;
}
card->ext_csd.sectors =
ext_csd[EXT_CSD_SEC_CNT + 0] << 0 |
ext_csd[EXT_CSD_SEC_CNT + 1] << 8 |
ext_csd[EXT_CSD_SEC_CNT + 2] << 16 |
ext_csd[EXT_CSD_SEC_CNT + 3] << 24;
if (card->ext_csd.sectors)
mmc_card_set_blockaddr(card);
switch (ext_csd[EXT_CSD_CARD_TYPE]) {
case EXT_CSD_CARD_TYPE_52 | EXT_CSD_CARD_TYPE_26:
card->ext_csd.hs_max_dtr = 52000000;
break;
case EXT_CSD_CARD_TYPE_26:
card->ext_csd.hs_max_dtr = 26000000;
break;
default:
/* MMC v4 spec says this cannot happen */
printk(KERN_WARNING "%s: card is mmc v4 but doesn't "
"support any high-speed modes.\n",
mmc_hostname(card->host));
goto out;
}
out:
kfree(ext_csd);
return err;
}
/*
* Handle the detection and initialisation of a card.
*
* In the case of a resume, "curcard" will contain the card
* we're trying to reinitialise.
*/
static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
struct mmc_card *oldcard)
{
struct mmc_card *card;
int err;
u32 cid[4];
unsigned int max_dtr;
BUG_ON(!host);
BUG_ON(!host->claimed);
/*
* Since we're changing the OCR value, we seem to
* need to tell some cards to go back to the idle
* state. We wait 1ms to give cards time to
* respond.
*/
mmc_go_idle(host);
/* The extra bit indicates that we support high capacity */
err = mmc_send_op_cond(host, ocr | (1 << 30), NULL);
if (err != MMC_ERR_NONE)
goto err;
/*
* Fetch CID from card.
*/
err = mmc_all_send_cid(host, cid);
if (err != MMC_ERR_NONE)
goto err;
if (oldcard) {
if (memcmp(cid, oldcard->raw_cid, sizeof(cid)) != 0)
goto err;
card = oldcard;
} else {
/*
* Allocate card structure.
*/
card = mmc_alloc_card(host);
if (IS_ERR(card))
goto err;
card->type = MMC_TYPE_MMC;
card->rca = 1;
memcpy(card->raw_cid, cid, sizeof(card->raw_cid));
}
/*
* Set card RCA.
*/
err = mmc_set_relative_addr(card);
if (err != MMC_ERR_NONE)
goto free_card;
mmc_set_bus_mode(host, MMC_BUSMODE_PUSHPULL);
if (!oldcard) {
/*
* Fetch CSD from card.
*/
err = mmc_send_csd(card, card->raw_csd);
if (err != MMC_ERR_NONE)
goto free_card;
mmc_decode_csd(card);
mmc_decode_cid(card);
}
/*
* Select card, as all following commands rely on that.
*/
err = mmc_select_card(card);
if (err != MMC_ERR_NONE)
goto free_card;
if (!oldcard) {
/*
* Fetch and process extened CSD.
*/
err = mmc_read_ext_csd(card);
if (err != MMC_ERR_NONE)
goto free_card;
}
/*
* Activate high speed (if supported)
*/
if ((card->ext_csd.hs_max_dtr != 0) &&
(host->caps & MMC_CAP_MMC_HIGHSPEED)) {
err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_HS_TIMING, 1);
if (err != MMC_ERR_NONE)
goto free_card;
mmc_card_set_highspeed(card);
mmc_set_timing(card->host, MMC_TIMING_MMC_HS);
}
/*
* Compute bus speed.
*/
max_dtr = (unsigned int)-1;
if (mmc_card_highspeed(card)) {
if (max_dtr > card->ext_csd.hs_max_dtr)
max_dtr = card->ext_csd.hs_max_dtr;
} else if (max_dtr > card->csd.max_dtr) {
max_dtr = card->csd.max_dtr;
}
mmc_set_clock(host, max_dtr);
/*
* Activate wide bus (if supported).
*/
if ((card->csd.mmca_vsn >= CSD_SPEC_VER_4) &&
(host->caps & MMC_CAP_4_BIT_DATA)) {
err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_BUS_WIDTH, EXT_CSD_BUS_WIDTH_4);
if (err != MMC_ERR_NONE)
goto free_card;
mmc_set_bus_width(card->host, MMC_BUS_WIDTH_4);
}
if (!oldcard)
host->card = card;
return MMC_ERR_NONE;
free_card:
if (!oldcard)
mmc_remove_card(card);
err:
return MMC_ERR_FAILED;
}
/*
* Host is being removed. Free up the current card.
*/
static void mmc_remove(struct mmc_host *host)
{
BUG_ON(!host);
BUG_ON(!host->card);
mmc_remove_card(host->card);
host->card = NULL;
}
/*
* Card detection callback from host.
*/
static void mmc_detect(struct mmc_host *host)
{
int err;
BUG_ON(!host);
BUG_ON(!host->card);
mmc_claim_host(host);
/*
* Just check if our card has been removed.
*/
err = mmc_send_status(host->card, NULL);
mmc_release_host(host);
if (err != MMC_ERR_NONE) {
mmc_remove_card(host->card);
host->card = NULL;
mmc_claim_host(host);
mmc_detach_bus(host);
mmc_release_host(host);
}
}
#ifdef CONFIG_MMC_UNSAFE_RESUME
/*
* Suspend callback from host.
*/
static void mmc_suspend(struct mmc_host *host)
{
BUG_ON(!host);
BUG_ON(!host->card);
mmc_claim_host(host);
mmc_deselect_cards(host);
host->card->state &= ~MMC_STATE_HIGHSPEED;
mmc_release_host(host);
}
/*
* Resume callback from host.
*
* This function tries to determine if the same card is still present
* and, if so, restore all state to it.
*/
static void mmc_resume(struct mmc_host *host)
{
int err;
BUG_ON(!host);
BUG_ON(!host->card);
mmc_claim_host(host);
err = mmc_sd_init_card(host, host->ocr, host->card);
if (err != MMC_ERR_NONE) {
mmc_remove_card(host->card);
host->card = NULL;
mmc_detach_bus(host);
}
mmc_release_host(host);
}
#else
#define mmc_suspend NULL
#define mmc_resume NULL
#endif
static const struct mmc_bus_ops mmc_ops = {
.remove = mmc_remove,
.detect = mmc_detect,
.suspend = mmc_suspend,
.resume = mmc_resume,
};
/*
* Starting point for MMC card init.
*/
int mmc_attach_mmc(struct mmc_host *host, u32 ocr)
{
int err;
BUG_ON(!host);
BUG_ON(!host->claimed);
mmc_attach_bus(host, &mmc_ops);
/*
* Sanity check the voltages that the card claims to
* support.
*/
if (ocr & 0x7F) {
printk(KERN_WARNING "%s: card claims to support voltages "
"below the defined range. These will be ignored.\n",
mmc_hostname(host));
ocr &= ~0x7F;
}
host->ocr = mmc_select_voltage(host, ocr);
/*
* Can we support the voltage of the card?
*/
if (!host->ocr)
goto err;
/*
* Detect and init the card.
*/
err = mmc_sd_init_card(host, host->ocr, NULL);
if (err != MMC_ERR_NONE)
goto err;
mmc_release_host(host);
err = mmc_register_card(host->card);
if (err)
goto reclaim_host;
return 0;
reclaim_host:
mmc_claim_host(host);
mmc_remove_card(host->card);
host->card = NULL;
err:
mmc_detach_bus(host);
mmc_release_host(host);
return 0;
}
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