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author | Ahmed S. Darwish <a.darwish@linutronix.de> | 2020-11-26 14:29:41 +0100 |
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committer | Martin K. Petersen <martin.petersen@oracle.com> | 2020-12-01 00:03:52 -0500 |
commit | a93c3835319849f0226b9a7101284aeb60a5ed8e (patch) | |
tree | f62d0e9cce74600bece44e4f6cfca53d9763407c | |
parent | 18577cdcaeeb7a1ca5c3adc4d92ed2ba75699625 (diff) | |
download | linux-stable-a93c3835319849f0226b9a7101284aeb60a5ed8e.tar.gz linux-stable-a93c3835319849f0226b9a7101284aeb60a5ed8e.tar.bz2 linux-stable-a93c3835319849f0226b9a7101284aeb60a5ed8e.zip |
scsi: qla4xxx: Remove in_interrupt()
qla4_82xx_crb_win_lock() spins on a certain hardware state until it's
updated. At the end of each spin, if in_interrupt() is true, it does 20
loops of cpu_relax(). Otherwise, it yields the CPU.
The in_interrupt() macro is ill-defined as it does not provide what the
name suggests, and it does not catch the intended use-case here.
qla4_82xx_crb_win_lock() is always invoked with scsi_qla_host::hw_lock
acquired, with disabled interrupts. If the caller is in process context, as
in qla4_82xx_need_reset_handler(), then in_interrupt() will return false
even though it is not allowed to call schedule().
Remove the in_interrupt() check.
Change qla4_82xx_crb_win_lock() specification to a purely atomic
function. Mark it as static, remove its forward declaration, and move it
above its callers. To avoid hammering the PCI bus while spinning, use a 10
micro-second delay instead of cpu_relax().
Link: https://lore.kernel.org/r/20201126132952.2287996-4-bigeasy@linutronix.de
Fixes: f4f5df23bf72 ("[SCSI] qla4xxx: Added support for ISP82XX")
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>
-rw-r--r-- | drivers/scsi/qla4xxx/ql4_glbl.h | 1 | ||||
-rw-r--r-- | drivers/scsi/qla4xxx/ql4_nx.c | 63 |
2 files changed, 29 insertions, 35 deletions
diff --git a/drivers/scsi/qla4xxx/ql4_glbl.h b/drivers/scsi/qla4xxx/ql4_glbl.h index b8f02210aeb0..ea60057b2e20 100644 --- a/drivers/scsi/qla4xxx/ql4_glbl.h +++ b/drivers/scsi/qla4xxx/ql4_glbl.h @@ -114,7 +114,6 @@ irqreturn_t qla4_82xx_intr_handler(int irq, void *dev_id); void qla4_82xx_queue_iocb(struct scsi_qla_host *ha); void qla4_82xx_complete_iocb(struct scsi_qla_host *ha); -int qla4_82xx_crb_win_lock(struct scsi_qla_host *); void qla4_82xx_crb_win_unlock(struct scsi_qla_host *); int qla4_82xx_pci_get_crb_addr_2M(struct scsi_qla_host *, ulong *); void qla4_82xx_wr_32(struct scsi_qla_host *, ulong, u32); diff --git a/drivers/scsi/qla4xxx/ql4_nx.c b/drivers/scsi/qla4xxx/ql4_nx.c index f1767b21076f..da903a545b2c 100644 --- a/drivers/scsi/qla4xxx/ql4_nx.c +++ b/drivers/scsi/qla4xxx/ql4_nx.c @@ -375,6 +375,35 @@ qla4_82xx_pci_set_crbwindow_2M(struct scsi_qla_host *ha, ulong *off) *off = (*off & MASK(16)) + CRB_INDIRECT_2M + ha->nx_pcibase; } +#define CRB_WIN_LOCK_TIMEOUT 100000000 + +/* + * Context: atomic + */ +static int qla4_82xx_crb_win_lock(struct scsi_qla_host *ha) +{ + int done = 0, timeout = 0; + + while (!done) { + /* acquire semaphore3 from PCI HW block */ + done = qla4_82xx_rd_32(ha, QLA82XX_PCIE_REG(PCIE_SEM7_LOCK)); + if (done == 1) + break; + if (timeout >= CRB_WIN_LOCK_TIMEOUT) + return -1; + + timeout++; + udelay(10); + } + qla4_82xx_wr_32(ha, QLA82XX_CRB_WIN_LOCK_ID, ha->func_num); + return 0; +} + +void qla4_82xx_crb_win_unlock(struct scsi_qla_host *ha) +{ + qla4_82xx_rd_32(ha, QLA82XX_PCIE_REG(PCIE_SEM7_UNLOCK)); +} + void qla4_82xx_wr_32(struct scsi_qla_host *ha, ulong off, u32 data) { @@ -475,40 +504,6 @@ int qla4_82xx_md_wr_32(struct scsi_qla_host *ha, uint32_t off, uint32_t data) return rval; } -#define CRB_WIN_LOCK_TIMEOUT 100000000 - -int qla4_82xx_crb_win_lock(struct scsi_qla_host *ha) -{ - int i; - int done = 0, timeout = 0; - - while (!done) { - /* acquire semaphore3 from PCI HW block */ - done = qla4_82xx_rd_32(ha, QLA82XX_PCIE_REG(PCIE_SEM7_LOCK)); - if (done == 1) - break; - if (timeout >= CRB_WIN_LOCK_TIMEOUT) - return -1; - - timeout++; - - /* Yield CPU */ - if (!in_interrupt()) - schedule(); - else { - for (i = 0; i < 20; i++) - cpu_relax(); /*This a nop instr on i386*/ - } - } - qla4_82xx_wr_32(ha, QLA82XX_CRB_WIN_LOCK_ID, ha->func_num); - return 0; -} - -void qla4_82xx_crb_win_unlock(struct scsi_qla_host *ha) -{ - qla4_82xx_rd_32(ha, QLA82XX_PCIE_REG(PCIE_SEM7_UNLOCK)); -} - #define IDC_LOCK_TIMEOUT 100000000 /** |