clk_get_rate() returns unsigned long and currently this driver stores the
return value in u32 type, resulting the below warning:
Fixed smatch warnings:
drivers/scsi/ufs/ufs-exynos.c:286 exynos_ufs_get_clk_info()
warn: wrong type for 'ufs->mclk_rate' (should be 'ulong')
drivers/scsi/ufs/ufs-exynos.c:287 exynos_ufs_get_clk_info()
warn: wrong type for 'pclk_rate' (should be 'ulong')
Link: https://lore.kernel.org/r/20210819171131.55912-1-alim.akhtar@samsung.com
Fixes: 55f4b1f736 ("scsi: ufs: ufs-exynos: Add UFS host support for Exynos SoCs")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
In host control mode, eviction is perceived as an extreme measure. There
are several conditions that both the entering and exiting regions should
meet, so that eviction will take place.
The common case however, is that those conditions are rarely met, so it is
normal that the act of eviction fails. Therefore, do not report an error
in host control mode if eviction fails.
Link: https://lore.kernel.org/r/20210808090024.21721-5-avri.altman@wdc.com
Fixes: 6c59cb501b (scsi: ufs: ufshpb: Make eviction depend on region's reads)
Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
'num_inflight_map_req' should not be negative. It is incremented and
decremented without any protection, allowing it theoretically to be
negative, should some weird unbalanced count occur.
Verify that the those calls are properly serialized.
Link: https://lore.kernel.org/r/20210808090024.21721-4-avri.altman@wdc.com
Fixes: 33845a2d84 (scsi: ufs: ufshpb: Limit the number of in-flight map requests)
Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
In HPB2.0, if pre_req_min_tr_len < transfer_len < pre_req_max_tr_len, the
driver is expected to send a HPB-WRITE-BUFFER companion to HPB-READ.
The upper bound should fit into a single byte, regardless of bMAX_
DATA_SIZE_FOR_HPB_SINGLE_CMD which being an attribute (u32) can be
significantly larger.
To further illustrate the issue, consider the following scenario:
- SCSI_DEFAULT_MAX_SECTORS is 1024 limiting the I/O chunks to 512KB
- The OEM changes scsi_host_template .max_sectors to be 2048 which allows
for 1MB requests: transfer_len = 256
- pre_req_max_tr_len = HPB_MULTI_CHUNK_HIGH = 256
- ufshpb_is_supported_chunk() returns true (256 <= 256)
- WARN_ON_ONCE(256 > 256) doesn't warn
- ufshpb_set_hpb_read_to_upiu() casts transfer_len to u8: transfer_len = 0
- The command is failing with ILLEGAL REQUEST
Link: https://lore.kernel.org/r/20210808090024.21721-3-avri.altman@wdc.com
Fixes: 41d8a9333c (scsi: ufs: ufshpb: Add HPB 2.0 support)
Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Managed device links are deleted by device_del(). However it is possible to
add a device link to a consumer before device_add(), and then discovering
an error prevents the device from being used. In that case normally
references to the device would be dropped and the device would be deleted.
However the device link holds a reference to the device, so the device link
and device remain indefinitely (unless the supplier is deleted).
For UFSHCD, if a LUN fails to probe (e.g. absent BOOT WLUN), the device
will not have been registered but can still have a device link holding a
reference to the device. The unwanted device link will prevent runtime
suspend indefinitely.
Amend device link removal to accept removal of a link with an unregistered
consumer device (suggested by Rafael), and fix UFSHCD by explicitly
deleting the device link when SCSI destroys the SCSI device.
Link: https://lore.kernel.org/r/a1c9bac8-b560-b662-f0aa-58c7e000cbbd@intel.com
Fixes: b294ff3e34 ("scsi: ufs: core: Enable power management for wlun")
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Clearing a unit attention synchronously from inside the UFS error handler
may trigger the following deadlock:
- ufshcd_err_handler() calls ufshcd_err_handling_unprepare() and the
latter function calls ufshcd_clear_ua_wluns().
- ufshcd_clear_ua_wluns() submits a REQUEST SENSE command and that command
activates the SCSI error handler.
- The SCSI error handler calls ufshcd_host_reset_and_restore().
- ufshcd_host_reset_and_restore() executes the following code:
ufshcd_schedule_eh_work(hba); flush_work(&hba->eh_work);
This sequence results in a deadlock (circular wait). Fix this by requesting
sense data asynchronously.
Link: https://lore.kernel.org/r/20210722033439.26550-16-bvanassche@acm.org
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Stanley Chu <stanley.chu@mediatek.com>
Cc: Can Guo <cang@codeaurora.org>
Cc: Asutosh Das <asutoshd@codeaurora.org>
Cc: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Make the following changes in ufshcd_abort():
- Return FAILED instead of SUCCESS if the abort handler notices that a
SCSI command has already been completed. Returning SUCCESS in this case
triggers a use-after-free and may trigger a kernel crash.
- Fix the code for aborting SCSI commands submitted to a WLUN.
The current approach for aborting SCSI commands that have been submitted to
a WLUN and that timed out is as follows:
- Report to the SCSI core that the command has completed successfully.
Let the block layer free any data buffers associated with the command.
- Mark the command as outstanding in 'outstanding_reqs'.
- If the block layer tries to reuse the tag associated with the aborted
command, busy-wait until the tag is freed.
This approach can result in:
- Memory corruption if the controller accesses the data buffer after the
block layer has freed the associated data buffers.
- A race condition if ufshcd_queuecommand() or ufshcd_exec_dev_cmd()
checks the bit that corresponds to an aborted command in
'outstanding_reqs' after it has been cleared and before it is reset.
- High energy consumption if ufshcd_queuecommand() repeatedly returns
SCSI_MLQUEUE_HOST_BUSY.
Fix this by reporting to the SCSI error handler that aborting a SCSI
command failed if the SCSI command was submitted to a WLUN.
Link: https://lore.kernel.org/r/20210722033439.26550-15-bvanassche@acm.org
Fixes: 7a7e66c65d ("scsi: ufs: Fix a race condition between ufshcd_abort() and eh_work()")
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Stanley Chu <stanley.chu@mediatek.com>
Cc: Can Guo <cang@codeaurora.org>
Cc: Asutosh Das <asutoshd@codeaurora.org>
Cc: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
From arch/arm/include/asm/io.h
#define __iowmb() wmb()
[ ... ]
#define writel(v,c) ({ __iowmb(); writel_relaxed(v,c); })
From Documentation/memory-barriers.txt: "Note that, when using writel(), a
prior wmb() is not needed to guarantee that the cache coherent memory
writes have completed before writing to the MMIO region."
In other words, calling wmb() before writel() is not necessary. Hence
remove the wmb() calls that precede a writel() call. Remove the wmb() calls
that precede a ufshcd_send_command() call since the latter function uses
writel(). Remove the wmb() call from ufshcd_wait_for_dev_cmd() since the
following chain of events guarantees that the CPU will see up-to-date LRB
values:
- UFS controller writes to host memory.
- UFS controller posts completion interrupt after the memory writes from
the previous step are visible to the CPU.
- complete(hba->dev_cmd.complete) is called from the UFS interrupt handler.
- The wait_for_completion(hba->dev_cmd.complete) call in
ufshcd_wait_for_dev_cmd() returns.
Link: https://lore.kernel.org/r/20210722033439.26550-10-bvanassche@acm.org
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Stanley Chu <stanley.chu@mediatek.com>
Cc: Can Guo <cang@codeaurora.org>
Cc: Asutosh Das <asutoshd@codeaurora.org>
Cc: Avri Altman <avri.altman@wdc.com>
Tested-by: Avri altman <avri.altman@wdc.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Daejun Park <daejun7.park@samsung.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
In order not to hang on to "cold" regions, we inactivate a region that has
had no READ access for a predefined amount of time - READ_TO_MS. For that
purpose monitor the active regions list, polling it on every
POLLING_INTERVAL_MS. On timeout expiry add the region to the
"to-be-inactivated" list unless it is clean and did not exhaust its
READ_TO_EXPIRIES - another parameter.
None of this applies to pinned regions.
Link: https://lore.kernel.org/r/20210712095039.8093-9-avri.altman@wdc.com
Reviewed-by: Daejun Park <daejun7.park@samsung.com>
Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
In host control mode, reads are the major source of activation trials.
Keep track of those reads counters, for both active as well inactive
regions.
We reset the read counter upon write - we are only interested in "clean"
reads.
Keep those counters normalized, as we are using those reads as a
comparative score, to make various decisions. If during consecutive
normalizations an active region has exhaust its reads - inactivate it.
While at it, protect the {active,inactive}_count stats by adding them into
the applicable handler.
Link: https://lore.kernel.org/r/20210712095039.8093-5-avri.altman@wdc.com
Reviewed-by: Daejun Park <daejun7.park@samsung.com>
Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
In device control mode, the device may recommend the host to either
activate or inactivate a region, and the host should follow. Meaning those
are not actually recommendations, but more of instructions.
Conversely, in host control mode, the recommendation protocol is slightly
changed:
a) The device may only recommend the host to update a subregion of an
already-active region. And,
b) The device may *not* recommend to inactivate a region.
Furthermore, in host control mode, the host may choose not to follow any of
the device's recommendations. However, in case of a recommendation to
update an active and clean subregion, it is better to follow those
recommendation because otherwise the host has no other way to know that
some internal relocation took place.
Link: https://lore.kernel.org/r/20210712095039.8093-3-avri.altman@wdc.com
Reviewed-by: Daejun Park <daejun7.park@samsung.com>
Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Implement L2P map management in HPB.
The HPB divides logical addresses into several regions. A region consists
of several sub-regions. The sub-region is a basic unit where L2P mapping is
managed. The driver loads L2P mapping data of each sub-region. The loaded
sub-region is called active-state. The HPB driver unloads L2P mapping data
as region unit. The unloaded region is called inactive-state.
Sub-region/region candidates to be loaded and unloaded are delivered from
the UFS device. The UFS device delivers the recommended active sub-region
and inactivate region to the driver using sense data. The HPB module
performs L2P mapping management on the host through the delivered
information.
A pinned region is a preset region on the UFS device that is always
in activate-state.
The data structures for map data requests and L2P mappings use the mempool
API, minimizing allocation overhead while avoiding static allocation.
The mininum size of the memory pool used in the HPB is implemented
as a module parameter so that it can be configurable by the user.
To guarantee a minimum memory pool size of 4MB: ufshpb_host_map_kbytes=4096.
The map_work manages active/inactive via 2 "to-do" lists:
- hpb->lh_inact_rgn: regions to be inactivated
- hpb->lh_act_srgn: subregions to be activated
These lists are maintained on I/O completion.
[mkp: switch to REQ_OP_DRV_*]
Link: https://lore.kernel.org/r/20210712085859epcms2p36e420f19564f6cd0c4a45d54949619eb@epcms2p3
Tested-by: Bean Huo <beanhuo@micron.com>
Tested-by: Can Guo <cang@codeaurora.org>
Tested-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Acked-by: Avri Altman <Avri.Altman@wdc.com>
Signed-off-by: Daejun Park <daejun7.park@samsung.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Implement Host Performance Buffer (HPB) initialization and add function
calls to UFS core driver.
NAND flash-based storage devices, including UFS, have mechanisms to
translate logical addresses of I/O requests to the corresponding physical
addresses of the flash storage. In UFS, logical-to-physical-address (L2P)
map data, which is required to identify the physical address for the
requested I/Os, can only be partially stored in SRAM from NAND flash. Due
to this partial loading, accessing the flash address area, where the L2P
information for that address is not loaded in the SRAM, can result in
serious performance degradation.
The basic concept of HPB is to cache L2P mapping entries in host system
memory so that both physical block address (PBA) and logical block address
(LBA) can be delivered in HPB read command. The HPB read command allows to
read data faster than a regular read command in UFS since it provides the
physical address (HPB Entry) of the desired logical block in addition to
its logical address. The UFS device can access the physical block in NAND
directly without searching and uploading L2P mapping table. This improves
read performance because the NAND read operation for uploading L2P mapping
table is removed.
In HPB initialization, the host checks if the UFS device supports HPB
feature and retrieves related device capabilities. Then, HPB parameters are
configured in the device.
Total start-up time of popular applications was measured and the difference
observed between HPB being enabled and disabled. Popular applications are
12 game apps and 24 non-game apps. Each test cycle consists of running 36
applications in sequence. We repeated the cycle for observing performance
improvement by L2P mapping cache hit in HPB.
The following is the test environment:
- kernel version: 4.4.0
- RAM: 8GB
- UFS 2.1 (64GB)
Results:
+-------+----------+----------+-------+
| cycle | baseline | with HPB | diff |
+-------+----------+----------+-------+
| 1 | 272.4 | 264.9 | -7.5 |
| 2 | 250.4 | 248.2 | -2.2 |
| 3 | 226.2 | 215.6 | -10.6 |
| 4 | 230.6 | 214.8 | -15.8 |
| 5 | 232.0 | 218.1 | -13.9 |
| 6 | 231.9 | 212.6 | -19.3 |
+-------+----------+----------+-------+
We also measured HPB performance using iozone:
$ iozone -r 4k -+n -i2 -ecI -t 16 -l 16 -u 16 -s $IO_RANGE/16 -F \
mnt/tmp_1 mnt/tmp_2 mnt/tmp_3 mnt/tmp_4 mnt/tmp_5 mnt/tmp_6 mnt/tmp_7 \
mnt/tmp_8 mnt/tmp_9 mnt/tmp_10 mnt/tmp_11 mnt/tmp_12 mnt/tmp_13 \
mnt/tmp_14 mnt/tmp_15 mnt/tmp_16
Results:
+----------+--------+---------+
| IO range | HPB on | HPB off |
+----------+--------+---------+
| 1 GB | 294.8 | 300.87 |
| 4 GB | 293.51 | 179.35 |
| 8 GB | 294.85 | 162.52 |
| 16 GB | 293.45 | 156.26 |
| 32 GB | 277.4 | 153.25 |
+----------+--------+---------+
Link: https://lore.kernel.org/r/20210712085830epcms2p8c1288b7f7a81b044158a18232617b572@epcms2p8
Reported-by: kernel test robot <lkp@intel.com>
Tested-by: Bean Huo <beanhuo@micron.com>
Tested-by: Can Guo <cang@codeaurora.org>
Tested-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Acked-by: Avri Altman <Avri.Altman@wdc.com>
Signed-off-by: Daejun Park <daejun7.park@samsung.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
