freebsd-dev/sys/dev/mmc/mmcbr_if.m
Marius Strobl aca38eab8a o Add support for eMMC HS200 and HS400 bus speed modes at 200 MHz to
sdhci(4), mmc(4) and mmcsd(4). For the most part, this consists of:
  - Correcting and extending the infrastructure for negotiating and
    enabling post-DDR52 modes already added as part of r315598. In
    fact, HS400ES now should work as well but hasn't been activated
    due to lack of corresponding hardware.
  - Adding support executing standard SDHCI initial tuning as well
    as re-tuning as required for eMMC HS200/HS400 and the fast UHS-I
    SD card modes. Currently, corresponding methods are only hooked
    up to the ACPI and PCI front-ends of sdhci(4), though. Moreover,
    sdhci(4) won't offer any modes requiring (re-)tuning to the MMC/SD
    layer in order to not break operations with other sdhci(4) front-
    ends. Likewise, sdhci(4) now no longer offers modes requiring the
    set_uhs_timing method introduced in r315598 to be implemented/
    hooked up (previously, this method was used with DDR52 only, which
    in turn is only available with Intel controllers so far, i. e. no
    such limitation was necessary before). Similarly for 1.2/1.8 V VCCQ
    support and the switch_vccq method.
  - Addition of locking to the IOCTL half of mmcsd(4) to prevent races
    with detachment and suspension, especially since it's required to
    immediately switch away from RPMB partitions again after an access
    to these (so re-tuning can take place anew, given that the current
    eMMC specification v5.1 doesn't allow tuning commands to be issued
    with a RPMB partition selected). Therefore, the existing part_mtx
    lock in the mmcsd(4) softc is additionally renamed to disk_mtx in
    order to denote that it only refers to the disk(9) half, likewise
    for corresponding macros.

  On the system where the addition of DDR52 support increased the read
  throughput to ~80 MB/s (from ~45 MB/s at high speed), HS200 yields
  ~154 MB/s and HS400 ~187 MB/s, i. e. performance now has more than
  quadrupled compared to pre-r315598.

  Also, with the advent of (re-)tuning support, most infrastructure
  necessary for SD card UHS-I modes up to SDR104 now is also in place.
  Note, though, that the standard SDHCI way of (re-)tuning is special
  in several ways, which also is why sending the actual tuning requests
  to the device is part of sdhci(4). SDHCI implementations not following
  the specification, MMC and non-SDHCI SD card controllers likely will
  use a generic implementation in the MMC/SD layer for executing tuning,
  which hasn't been written so far, though.

  However, in fact this isn't a feature-only change; there are boards
  based on Intel Bay Trail where DDR52 is problematic and the suggested
  workaround is to use HS200 mode instead. So far exact details are
  unknown, however, i. e. whether that's due to a defect in these SoCs
  or on the boards.

  Moreover, due to the above changes requiring to be aware of possible
  MMC siblings in the fast path of mmc(4), corresponding information
  now is cached in mmc_softc. As a side-effect, mmc_calculate_clock(),
  mmc_delete_cards(), mmc_discover_cards() and mmc_rescan_cards() now
  all are guaranteed to operate on the same set of devices as there no
  longer is any use of device_get_children(9), which can fail in low
  memory situations. Likewise, mmc_calculate_clock() now longer will
  trigger a panic due to the latter.

o Fix a bug in the failure reporting of mmcsd_delete(); in case of an
  error when the starting block of a previously stored erase request
  is used (in order to be able to erase a full erase sector worth of
  data), the starting block of the newly supplied bio_pblkno has to be
  returned for indicating no progress. Otherwise, upper layers might
  be told that a negative number of BIOs have been completed, leading
  to a panic.

o Fix 2 bugs on resume:
  - Things done in fork1(9) like the acquisition of an SX lock or the
    sleepable memory allocation are incompatible with a MTX_DEF taken.
    Thus, mmcsd_resume() must not call kproc_create(9), which in turn
    uses fork1(9), with the disk_mtx (formerly part_mtx) held.
  - In mmc_suspend(), the bus is powered down, which in the typical
    case of a device being selected at the time of suspension, causes
    the device deselection as part of the bus acquisition by mmc(4) in
    mmc_scan() to fail as the bus isn't powered up again before later
    in mmc_go_discovery(). Thus, power down with the bus acquired in
    mmc_suspend(), which will trigger the deselection up-front.

o Fix a memory leak in mmcsd_ioctl() in case copyin(9) fails. [1]

o Fix missing variable initialization in mmc_switch_status(). [2]

o Fix R1_SWITCH_ERROR detection in mmc_switch_status(). [3]

o Handle the case of device_add_child(9) failing, for example due to
  a memory shortage, gracefully in mmc(4) and sdhci(4), including not
  leaking memory for the instance variables in case of mmc(4) (which
  might or might not fix [4] as the latter problem has been discovered
  independently).

o Handle the case of an unknown SD CSD version in mmc_decode_csd_sd()
  gracefully instead of calling panic(9).

o Again, check and handle the return values of some additional function
  calls in mmc(4) instead of assuming that everything went right or mark
  non-fatal errors by casting the return value to void.

o Correct a typo in the Linux IOCTL compatibility; it should have been
  MMC_IOC_MULTI_CMD rather than MMC_IOC_CMD_MULTI.

o Now that we are reaching ever faster speeds (more improvement in this
  regard is to be expected when adding ADMA support to sdhci(4)), apply
  a few micro-optimizations like predicting mmc(4) and sdhci(4) debugging
  to be off or caching erase sector and maximum data sizes as well support
  of block addressing in mmsd(4) (instead of doing 2 indirections on every
  read/write request for determining the maximum data size for example).

Reported by:	Coverity
CID:		1372612 [1], 1372624 [2], 1372594 [3], 1007069 [4]
2017-07-23 16:11:47 +00:00

167 lines
5.0 KiB
Objective-C

#-
# Copyright (c) 2006 M. Warner Losh
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#
# Portions of this software may have been developed with reference to
# the SD Simplified Specification. The following disclaimer may apply:
#
# The following conditions apply to the release of the simplified
# specification ("Simplified Specification") by the SD Card Association and
# the SD Group. The Simplified Specification is a subset of the complete SD
# Specification which is owned by the SD Card Association and the SD
# Group. This Simplified Specification is provided on a non-confidential
# basis subject to the disclaimers below. Any implementation of the
# Simplified Specification may require a license from the SD Card
# Association, SD Group, SD-3C LLC or other third parties.
#
# Disclaimers:
#
# The information contained in the Simplified Specification is presented only
# as a standard specification for SD Cards and SD Host/Ancillary products and
# is provided "AS-IS" without any representations or warranties of any
# kind. No responsibility is assumed by the SD Group, SD-3C LLC or the SD
# Card Association for any damages, any infringements of patents or other
# right of the SD Group, SD-3C LLC, the SD Card Association or any third
# parties, which may result from its use. No license is granted by
# implication, estoppel or otherwise under any patent or other rights of the
# SD Group, SD-3C LLC, the SD Card Association or any third party. Nothing
# herein shall be construed as an obligation by the SD Group, the SD-3C LLC
# or the SD Card Association to disclose or distribute any technical
# information, know-how or other confidential information to any third party.
#
# $FreeBSD$
#
#include <sys/types.h>
#include <dev/mmc/mmcreg.h>
#
# This is the interface that a mmc bridge chip gives to the mmc bus
# that attaches to the mmc bridge.
#
INTERFACE mmcbr;
#
# Default implementations of some methods.
#
CODE {
static int
null_switch_vccq(device_t brdev __unused, device_t reqdev __unused)
{
return (0);
}
static int
null_retune(device_t brdev __unused, device_t reqdev __unused,
bool reset __unused)
{
return (0);
}
static int
null_tune(device_t brdev __unused, device_t reqdev __unused,
bool hs400 __unused)
{
return (0);
}
};
#
# Called by the mmcbus to set up the IO pins correctly, the common/core
# supply voltage (VDD/VCC) to use for the device, the clock frequency, the
# type of SPI chip select, power mode and bus width.
#
METHOD int update_ios {
device_t brdev;
device_t reqdev;
};
#
# Called by the mmcbus to switch the signaling voltage (VCCQ).
#
METHOD int switch_vccq {
device_t brdev;
device_t reqdev;
} DEFAULT null_switch_vccq;
#
# Called by the mmcbus with the bridge claimed to execute initial tuning.
#
METHOD int tune {
device_t brdev;
device_t reqdev;
bool hs400;
} DEFAULT null_tune;
#
# Called by the mmcbus with the bridge claimed to execute re-tuning.
#
METHOD int retune {
device_t brdev;
device_t reqdev;
bool reset;
} DEFAULT null_retune;
#
# Called by the mmcbus or its children to schedule a mmc request. These
# requests are queued. Time passes. The bridge then gets notification
# of the status of the request, who then notifies the requesting device
# by calling the completion function supplied as part of the request.
# Requires the bridge to be claimed.
#
METHOD int request {
device_t brdev;
device_t reqdev;
struct mmc_request *req;
};
#
# Called by mmcbus to get the read only status bits.
#
METHOD int get_ro {
device_t brdev;
device_t reqdev;
};
#
# Claim the current bridge, blocking the current thread until the host
# is no longer busy.
#
METHOD int acquire_host {
device_t brdev;
device_t reqdev;
};
#
# Release the current bridge.
#
METHOD int release_host {
device_t brdev;
device_t reqdev;
};