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author | Ahmed S. Darwish <a.darwish@linutronix.de> | 2020-11-26 14:29:46 +0100 |
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committer | Martin K. Petersen <martin.petersen@oracle.com> | 2020-12-01 00:03:53 -0500 |
commit | 014aced18aff34d3b3ed3735b094d538b8c9f66e (patch) | |
tree | 2382c9fc9ca6ea64c806fd6d0a17d403597d7263 /drivers/scsi | |
parent | 3627668c2e2c9459cff874ad34b82d251038da48 (diff) | |
download | linux-stable-014aced18aff34d3b3ed3735b094d538b8c9f66e.tar.gz linux-stable-014aced18aff34d3b3ed3735b094d538b8c9f66e.tar.bz2 linux-stable-014aced18aff34d3b3ed3735b094d538b8c9f66e.zip |
scsi: qla4xxx: Remove in_interrupt() from qla4_82xx_rom_lock()
qla4_82xx_rom_lock() spins on a certain hardware state until it is
updated. At the end of each spin, if in_interrupt() is true, it does 20
loops of cpu_relax(). Otherwise, it yields the CPU.
While in_interrupt() is ill-defined and does not provide what the name
suggests, it is not needed here: qla4_82xx_rom_lock() is always called
from process context. Below is an analysis of its callers:
- ql4_nx.c: qla4_82xx_rom_fast_read(), all process context callers:
=> ql4_nx.c: qla4_82xx_pinit_from_rom(), GFP_KERNEL allocation
=> ql4_nx.c: qla4_82xx_load_from_flash(), msleep() in a loop
- ql4_nx.c: qla4_82xx_pinit_from_rom(), earlier discussed
- ql4_nx.c: qla4_82xx_rom_lock_recovery(), bound to "isp_operations"
->rom_lock_recovery() hook, which has one process context caller,
qla4_8xxx_device_bootstrap(), with callers:
=> ql4_83xx.c: qla4_83xx_need_reset_handler(), process, msleep()
=> ql4_nx.c: qla4_8xxx_device_state_handler(), multiple msleep()s
- ql4_nx.c: qla4_82xx_read_flash_data(), has cond_resched()
Remove the in_interrupt() check. Mark, qla4_82xx_rom_lock(), and the
->rom_lock_recovery() hook, with "Context: task, can sleep".
Change qla4_82xx_rom_lock() implementation to sleep 20ms, instead of a
schedule(), for each spin. This is more deterministic, and it matches
the other implementations bound to ->rom_lock_recovery().
Link: https://lore.kernel.org/r/20201126132952.2287996-9-bigeasy@linutronix.de
Cc: Nilesh Javali <njavali@marvell.com>
Cc: Manish Rangankar <mrangankar@marvell.com>
Cc: <GR-QLogic-Storage-Upstream@marvell.com>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi')
-rw-r--r-- | drivers/scsi/qla4xxx/ql4_def.h | 2 | ||||
-rw-r--r-- | drivers/scsi/qla4xxx/ql4_nx.c | 16 |
2 files changed, 7 insertions, 11 deletions
diff --git a/drivers/scsi/qla4xxx/ql4_def.h b/drivers/scsi/qla4xxx/ql4_def.h index 921054748388..031569c496e5 100644 --- a/drivers/scsi/qla4xxx/ql4_def.h +++ b/drivers/scsi/qla4xxx/ql4_def.h @@ -437,7 +437,7 @@ struct isp_operations { int (*wr_reg_indirect) (struct scsi_qla_host *, uint32_t, uint32_t); int (*idc_lock) (struct scsi_qla_host *); /* Context: task, can sleep */ void (*idc_unlock) (struct scsi_qla_host *); - void (*rom_lock_recovery) (struct scsi_qla_host *); + void (*rom_lock_recovery) (struct scsi_qla_host *); /* Context: task, can sleep */ void (*queue_mailbox_command) (struct scsi_qla_host *, uint32_t *, int); void (*process_mailbox_interrupt) (struct scsi_qla_host *, int); }; diff --git a/drivers/scsi/qla4xxx/ql4_nx.c b/drivers/scsi/qla4xxx/ql4_nx.c index 4362d0ebe0e1..fd30fbd0d33c 100644 --- a/drivers/scsi/qla4xxx/ql4_nx.c +++ b/drivers/scsi/qla4xxx/ql4_nx.c @@ -871,15 +871,18 @@ qla4_82xx_decode_crb_addr(unsigned long addr) static long rom_max_timeout = 100; static long qla4_82xx_rom_lock_timeout = 100; +/* + * Context: task, can_sleep + */ static int qla4_82xx_rom_lock(struct scsi_qla_host *ha) { - int i; int done = 0, timeout = 0; + might_sleep(); + while (!done) { /* acquire semaphore2 from PCI HW block */ - done = qla4_82xx_rd_32(ha, QLA82XX_PCIE_REG(PCIE_SEM2_LOCK)); if (done == 1) break; @@ -887,14 +890,7 @@ qla4_82xx_rom_lock(struct scsi_qla_host *ha) return -1; timeout++; - - /* Yield CPU */ - if (!in_interrupt()) - schedule(); - else { - for (i = 0; i < 20; i++) - cpu_relax(); /*This a nop instr on i386*/ - } + msleep(20); } qla4_82xx_wr_32(ha, QLA82XX_ROM_LOCK_ID, ROM_LOCK_DRIVER); return 0; |