[PATCH V14 00/24] mmc: Add Command Queue support

Adrian Hunter
2017-11-21T13:42:26Z

Hi

Here is V14 of the hardware command queue patches without the software
command queue patches, now using blk-mq and now with blk-mq support for
non-CQE I/O.

V14 includes a number of fixes to existing code, changes to default to
blk-mq, and adds patches to remove legacy code.

HW CMDQ offers 25% - 50% better random multi-threaded I/O. I see a slight
2% drop in sequential read speed but no change to sequential write.

Non-CQE blk-mq showed a 3% decrease in sequential read performance. This
seemed to be coming from the inferior latency of running work items compared
with a dedicated thread. Hacking blk-mq workqueue to be unbound reduced the
performance degradation from 3% to 1%.

While we should look at changing blk-mq to give better workqueue performance,
a bigger gain is likely to be made by adding a new host API to enable the
next already-prepared request to be issued directly from within ->done()
callback of the current request.

Changes since V13:
mmc: block: Fix missing blk_put_request()
New patch.
mmc: block: Check return value of blk_get_request()
New patch.
mmc: core: Do not leave the block driver in a suspended state
New patch.
mmc: block: Ensure that debugfs files are removed
New patch.
mmc: block: No need to export mmc_cleanup_queue()
New patch.
mmc: block: Simplify cleaning up the queue
New patch.
mmc: block: Use data timeout in card_busy_detect()
New patch.
mmc: block: Check for transfer state in card_busy_detect()
New patch.
mmc: block: Make card_busy_detect() accumulate all response error bits
New patch.
mmc: core: Make mmc_pre_req() and mmc_post_req() available
New patch.
mmc: core: Add parameter use_blk_mq
Default to y
mmc: block: Add blk-mq support
Wrap blk_mq_end_request / blk_end_request_all
Rename mmc_blk_rw_recovery -> mmc_blk_mq_rw_recovery
Additional parentheses to '==' expressions
Use mmc_pre_req() / mmc_post_req()
Fix missing tuning release on error after mmc_start_request()
Expand comment about timeouts
Allow for possibility that the queue is quiesced when removing
Ensure complete_work is flushed when removing
mmc: block: Add CQE support
Additional parentheses to '==' expressions
mmc: block: blk-mq: Check error bits and save the exception bit when polling card busy
Replaces patch "Stop using card_busy_detect()" retaining card_busy_detect()
mmc: block: blk-mq: Stop using legacy recovery
Allow for SPI
mmc: mmc_test: Do not use mmc_start_areq() anymore
New patch.
mmc: core: Remove option not to use blk-mq
New patch.
mmc: block: Remove code no longer needed after the switch to blk-mq
New patch.
mmc: core: Remove code no longer needed after the switch to blk-mq
New patch.

Changes since V12:
mmc: block: Add error-handling comments
New patch.
mmc: block: Add blk-mq support
Use legacy error handling
mmc: block: Add CQE support
Re-base
mmc: block: blk-mq: Add support for direct completion
New patch.
mmc: block: blk-mq: Separate card polling from recovery
New patch.
mmc: block: blk-mq: Stop using card_busy_detect()
New patch.
mmc: block: blk-mq: Stop using legacy recovery
New patch.

Changes since V11:
Split "mmc: block: Add CQE and blk-mq support" into 2 patches

Changes since V10:
mmc: core: Remove unnecessary host claim
mmc: core: Introduce host claiming by context
mmc: core: Add support for handling CQE requests
mmc: mmc: Enable Command Queuing
mmc: mmc: Enable CQE's
mmc: block: Use local variables in mmc_blk_data_prep()
mmc: block: Prepare CQE data
mmc: block: Factor out mmc_setup_queue()
mmc: core: Add parameter use_blk_mq
mmc: core: Export mmc_start_bkops()
mmc: core: Export mmc_start_request()
mmc: core: Export mmc_retune_hold_now() and mmc_retune_release()
Dropped because they have been applied
mmc: block: Add CQE and blk-mq support
Extend blk-mq support for asynchronous read / writes to all host
controllers including those that require polling. The direct
completion path is still available but depends on a new capability
flag.
Drop blk-mq support for synchronous read / writes.

Venkat Gopalakrishnan (1):
mmc: cqhci: support for command queue enabled host

Changes since V9:
mmc: block: Add CQE and blk-mq support
- reinstate mq support for REQ_OP_DRV_IN/OUT that was removed because
it was incorrectly assumed to be handled by the rpmb character device
- don't check for rpmb block device anymore
mmc: cqhci: support for command queue enabled host
Fix cqhci_set_irqs() as per Haibo Chen

Changes since V8:
Re-based
mmc: core: Introduce host claiming by context
Slightly simplified as per Ulf
mmc: core: Export mmc_retune_hold_now() and mmc_retune_release()
New patch.
mmc: block: Add CQE and blk-mq support
Fix missing ->post_req() on the error path

Changes since V7:
Re-based
mmc: core: Introduce host claiming by context
Slightly simplified
mmc: core: Add parameter use_blk_mq
New patch.
mmc: core: Remove unnecessary host claim
New patch.
mmc: core: Export mmc_start_bkops()
New patch.
mmc: core: Export mmc_start_request()
New patch.
mmc: block: Add CQE and blk-mq support
Add blk-mq support for non_CQE requests

Changes since V6:
mmc: core: Introduce host claiming by context
New patch.
mmc: core: Move mmc_start_areq() declaration
Dropped because it has been applied
mmc: block: Fix block status codes
Dropped because it has been applied
mmc: host: Add CQE interface
Dropped because it has been applied
mmc: core: Turn off CQE before sending commands
Dropped because it has been applied
mmc: block: Factor out mmc_setup_queue()
New patch.
mmc: block: Add CQE support
Drop legacy support and add blk-mq support

Changes since V5:
Re-based
mmc: core: Add mmc_retune_hold_now()
Dropped because it has been applied
mmc: core: Add members to mmc_request and mmc_data for CQE's
Dropped because it has been applied
mmc: core: Move mmc_start_areq() declaration
New patch at Ulf's request
mmc: block: Fix block status codes
Another un-related patch
mmc: host: Add CQE interface
Move recovery_notifier() callback to struct mmc_request
mmc: core: Add support for handling CQE requests
Roll __mmc_cqe_request_done() into mmc_cqe_request_done()
Move function declarations requested by Ulf
mmc: core: Remove unused MMC_CAP2_PACKED_CMD
Dropped because it has been applied
mmc: block: Add CQE support
Add explanation to commit message
Adjustment for changed recovery_notifier() callback
mmc: cqhci: support for command queue enabled host
Adjustment for changed recovery_notifier() callback
mmc: sdhci-pci: Add CQHCI support for Intel GLK
Add DCMD capability for Intel controllers except GLK

Changes since V4:
mmc: core: Add mmc_retune_hold_now()
Add explanation to commit message.
mmc: host: Add CQE interface
Add comments to callback declarations.
mmc: core: Turn off CQE before sending commands
Add explanation to commit message.
mmc: core: Add support for handling CQE requests
Add comments as requested by Ulf.
mmc: core: Remove unused MMC_CAP2_PACKED_CMD
New patch.
mmc: mmc: Enable Command Queuing
Adjust for removal of MMC_CAP2_PACKED_CMD.
Add a comment about Packed Commands.
mmc: mmc: Enable CQE's
Remove un-necessary check for MMC_CAP2_CQE
mmc: block: Use local variables in mmc_blk_data_prep()
New patch.
mmc: block: Prepare CQE data
Adjust due to "mmc: block: Use local variables in mmc_blk_data_prep()"
Remove priority setting.
Add explanation to commit message.
mmc: cqhci: support for command queue enabled host
Fix transfer descriptor setting in cqhci_set_tran_desc() for 32-bit DMA

Changes since V3:
Adjusted ...blk_end_request...() for new block status codes
Fixed CQHCI transaction descriptor for "no DCMD" case

Changes since V2:
Dropped patches that have been applied.
Re-based
Added "mmc: sdhci-pci: Add CQHCI support for Intel GLK"

Changes since V1:

"Share mmc request array between partitions" is dependent
on changes in "Introduce queue semantics", so added that
and block fixes:

Added "Fix is_waiting_last_req set incorrectly"
Added "Fix cmd error reset failure path"
Added "Use local var for mqrq_cur"
Added "Introduce queue semantics"

Changes since RFC:

Re-based on next.
Added comment about command queue priority.
Added some acks and reviews.

Adrian Hunter (9):
mmc: core: Add parameter use_blk_mq
mmc: block: Add error-handling comments
mmc: block: Add blk-mq support
mmc: block: Add CQE support
mmc: sdhci-pci: Add CQHCI support for Intel GLK
mmc: block: blk-mq: Add support for direct completion
mmc: block: blk-mq: Separate card polling from recovery
mmc: block: blk-mq: Stop using card_busy_detect()
mmc: block: blk-mq: Stop using legacy recovery

Venkat Gopalakrishnan (1):
mmc: cqhci: support for command queue enabled host

drivers/mmc/Kconfig | 11 +
drivers/mmc/core/block.c | 850 ++++++++++++++++++++++++++-
drivers/mmc/core/block.h | 12 +
drivers/mmc/core/core.c | 7 +
drivers/mmc/core/core.h | 2 +
drivers/mmc/core/host.c | 2 +
drivers/mmc/core/host.h | 4 +
drivers/mmc/core/queue.c | 426 +++++++++++++-
drivers/mmc/core/queue.h | 56 ++
drivers/mmc/host/Kconfig | 14 +
drivers/mmc/host/Makefile | 1 +
drivers/mmc/host/cqhci.c | 1150 +++++++++++++++++++++++++++++++++++++
drivers/mmc/host/cqhci.h | 240 ++++++++
drivers/mmc/host/sdhci-pci-core.c | 155 ++++-
include/linux/mmc/host.h | 2 +
15 files changed, 2900 insertions(+), 32 deletions(-)
create mode 100644 drivers/mmc/host/cqhci.c
create mode 100644 drivers/mmc/host/cqhci.h

Adrian Hunter (4):
mmc: core: Add parameter use_blk_mq
mmc: block: Add blk-mq support
mmc: block: Add CQE support
mmc: sdhci-pci: Add CQHCI support for Intel GLK

Venkat Gopalakrishnan (1):
mmc: cqhci: support for command queue enabled host

drivers/mmc/Kconfig | 11 +
drivers/mmc/core/block.c | 801 +++++++++++++++++++++++++-
drivers/mmc/core/block.h | 12 +
drivers/mmc/core/core.c | 7 +
drivers/mmc/core/core.h | 2 +
drivers/mmc/core/host.c | 2 +
drivers/mmc/core/host.h | 4 +
drivers/mmc/core/queue.c | 426 +++++++++++++-
drivers/mmc/core/queue.h | 56 ++
drivers/mmc/host/Kconfig | 14 +
drivers/mmc/host/Makefile | 1 +
drivers/mmc/host/cqhci.c | 1150 +++++++++++++++++++++++++++++++++++++
drivers/mmc/host/cqhci.h | 240 ++++++++
drivers/mmc/host/sdhci-pci-core.c | 155 ++++-
include/linux/mmc/host.h | 2 +
15 files changed, 2852 insertions(+), 31 deletions(-)
create mode 100644 drivers/mmc/host/cqhci.c
create mode 100644 drivers/mmc/host/cqhci.h

Adrian Hunter (23):
mmc: block: Fix missing blk_put_request()
mmc: block: Check return value of blk_get_request()
mmc: core: Do not leave the block driver in a suspended state
mmc: block: Ensure that debugfs files are removed
mmc: block: No need to export mmc_cleanup_queue()
mmc: block: Simplify cleaning up the queue
mmc: block: Use data timeout in card_busy_detect()
mmc: block: Check for transfer state in card_busy_detect()
mmc: block: Make card_busy_detect() accumulate all response error bits
mmc: core: Make mmc_pre_req() and mmc_post_req() available
mmc: block: Add error-handling comments
mmc: core: Add parameter use_blk_mq
mmc: block: Add blk-mq support
mmc: block: Add CQE support
mmc: sdhci-pci: Add CQHCI support for Intel GLK
mmc: block: blk-mq: Add support for direct completion
mmc: block: blk-mq: Separate card polling from recovery
mmc: block: blk-mq: Check error bits and save the exception bit when polling card busy
mmc: block: blk-mq: Stop using legacy recovery
mmc: mmc_test: Do not use mmc_start_areq() anymore
mmc: core: Remove option not to use blk-mq
mmc: block: Remove code no longer needed after the switch to blk-mq
mmc: core: Remove code no longer needed after the switch to blk-mq

Venkat Gopalakrishnan (1):
mmc: cqhci: support for command queue enabled host

drivers/mmc/core/block.c | 1396 +++++++++++++++++++++----------------
drivers/mmc/core/block.h | 12 +-
drivers/mmc/core/bus.c | 5 +-
drivers/mmc/core/core.c | 216 +-----
drivers/mmc/core/core.h | 39 +-
drivers/mmc/core/debugfs.c | 1 +
drivers/mmc/core/host.h | 4 +
drivers/mmc/core/mmc_test.c | 122 ++--
drivers/mmc/core/queue.c | 493 ++++++++-----
drivers/mmc/core/queue.h | 69 +-
drivers/mmc/host/Kconfig | 14 +
drivers/mmc/host/Makefile | 1 +
drivers/mmc/host/cqhci.c | 1150 ++++++++++++++++++++++++++++++
drivers/mmc/host/cqhci.h | 240 +++++++
drivers/mmc/host/sdhci-pci-core.c | 155 +++-
include/linux/mmc/host.h | 5 +-
16 files changed, 2840 insertions(+), 1082 deletions(-)
create mode 100644 drivers/mmc/host/cqhci.c
create mode 100644 drivers/mmc/host/cqhci.h

Regards
Adrian