On 09/12/2014 10:22 AM, Ching Huang wrote: > From: Ching Huang <ching2048@xxxxxxxxxxxx> > > This patch is to modify previous patch 16/17 and it is relative to > http://git.infradead.org/users/hch/scsi-queue.git/tree/arcmsr-for-3.18:/drivers/scsi/arcmsr > > change in v4: > 1. clean up of duplicate variable declaration in switch. > 2. simplify of updating doneq_index and postq_index > 3. fix spin_lock area in arcmsr_hbaD_polling_ccbdone The intention of the doneq_lock is to protect the pmu->doneq_index and the associated buffer, right? Why is the spinlock not used on other places accessing the doneq_index like arcmsr_done4abort_postqueue or arcmsr_hbaD_postqueue_isr ? And in arcmsr_hbaD_polling_ccbdone the code looks so: spin_unlock_irqrestore(&acb->doneq_lock, flags); doneq_index = pmu->doneq_index; flag_ccb = pmu->done_qbuffer[doneq_index & 0xFFF].addressLow; you unlock^ and after that is the value read and used Seems to me that I probably don't understand what the spinlock should protect. Could you explain ? Thanks, Tomas > > Signed-off-by: Ching Huang <ching2048@xxxxxxxxxxxx> > --- > > diff -uprN a/drivers/scsi/arcmsr/arcmsr_hba.c b/drivers/scsi/arcmsr/arcmsr_hba.c > --- a/drivers/scsi/arcmsr/arcmsr_hba.c 2014-09-12 12:43:16.956653000 +0800 > +++ b/drivers/scsi/arcmsr/arcmsr_hba.c 2014-09-12 15:00:23.516069000 +0800 > @@ -1121,7 +1121,7 @@ static void arcmsr_drain_donequeue(struc > static void arcmsr_done4abort_postqueue(struct AdapterControlBlock *acb) > { > int i = 0; > - uint32_t flag_ccb; > + uint32_t flag_ccb, ccb_cdb_phy; > struct ARCMSR_CDB *pARCMSR_CDB; > bool error; > struct CommandControlBlock *pCCB; > @@ -1165,10 +1165,6 @@ static void arcmsr_done4abort_postqueue( > break; > case ACB_ADAPTER_TYPE_C: { > struct MessageUnit_C __iomem *reg = acb->pmuC; > - struct ARCMSR_CDB *pARCMSR_CDB; > - uint32_t flag_ccb, ccb_cdb_phy; > - bool error; > - struct CommandControlBlock *pCCB; > while ((readl(®->host_int_status) & ARCMSR_HBCMU_OUTBOUND_POSTQUEUE_ISR) && (i++ < ARCMSR_MAX_OUTSTANDING_CMD)) { > /*need to do*/ > flag_ccb = readl(®->outbound_queueport_low); > @@ -1182,10 +1178,8 @@ static void arcmsr_done4abort_postqueue( > break; > case ACB_ADAPTER_TYPE_D: { > struct MessageUnit_D *pmu = acb->pmuD; > - uint32_t ccb_cdb_phy, outbound_write_pointer; > - uint32_t doneq_index, index_stripped, addressLow, residual; > - bool error; > - struct CommandControlBlock *pCCB; > + uint32_t outbound_write_pointer; > + uint32_t doneq_index, index_stripped, addressLow, residual, toggle; > > outbound_write_pointer = pmu->done_qbuffer[0].addressLow + 1; > doneq_index = pmu->doneq_index; > @@ -1193,23 +1187,11 @@ static void arcmsr_done4abort_postqueue( > for (i = 0; i < residual; i++) { > while ((doneq_index & 0xFFF) != > (outbound_write_pointer & 0xFFF)) { > - if (doneq_index & 0x4000) { > - index_stripped = doneq_index & 0xFFF; > - index_stripped += 1; > - index_stripped %= > - ARCMSR_MAX_ARC1214_DONEQUEUE; > - pmu->doneq_index = index_stripped ? > - (index_stripped | 0x4000) : > - (index_stripped + 1); > - } else { > - index_stripped = doneq_index; > - index_stripped += 1; > - index_stripped %= > - ARCMSR_MAX_ARC1214_DONEQUEUE; > - pmu->doneq_index = index_stripped ? > - index_stripped : > - ((index_stripped | 0x4000) + 1); > - } > + toggle = doneq_index & 0x4000; > + index_stripped = (doneq_index & 0xFFF) + 1; > + index_stripped %= ARCMSR_MAX_ARC1214_DONEQUEUE; > + pmu->doneq_index = index_stripped ? (index_stripped | toggle) : > + ((toggle ^ 0x4000) + 1); > doneq_index = pmu->doneq_index; > addressLow = pmu->done_qbuffer[doneq_index & > 0xFFF].addressLow; > @@ -1461,7 +1443,7 @@ static void arcmsr_post_ccb(struct Adapt > case ACB_ADAPTER_TYPE_D: { > struct MessageUnit_D *pmu = acb->pmuD; > u16 index_stripped; > - u16 postq_index; > + u16 postq_index, toggle; > unsigned long flags; > struct InBound_SRB *pinbound_srb; > > @@ -1472,19 +1454,11 @@ static void arcmsr_post_ccb(struct Adapt > pinbound_srb->addressLow = dma_addr_lo32(cdb_phyaddr); > pinbound_srb->length = ccb->arc_cdb_size >> 2; > arcmsr_cdb->msgContext = dma_addr_lo32(cdb_phyaddr); > - if (postq_index & 0x4000) { > - index_stripped = postq_index & 0xFF; > - index_stripped += 1; > - index_stripped %= ARCMSR_MAX_ARC1214_POSTQUEUE; > - pmu->postq_index = index_stripped ? > - (index_stripped | 0x4000) : index_stripped; > - } else { > - index_stripped = postq_index; > - index_stripped += 1; > - index_stripped %= ARCMSR_MAX_ARC1214_POSTQUEUE; > - pmu->postq_index = index_stripped ? index_stripped : > - (index_stripped | 0x4000); > - } > + toggle = postq_index & 0x4000; > + index_stripped = postq_index + 1; > + index_stripped &= (ARCMSR_MAX_ARC1214_POSTQUEUE - 1); > + pmu->postq_index = index_stripped ? (index_stripped | toggle) : > + (toggle ^ 0x4000); > writel(postq_index, pmu->inboundlist_write_pointer); > spin_unlock_irqrestore(&acb->postq_lock, flags); > break; > @@ -1999,7 +1973,7 @@ static void arcmsr_hbaC_postqueue_isr(st > > static void arcmsr_hbaD_postqueue_isr(struct AdapterControlBlock *acb) > { > - u32 outbound_write_pointer, doneq_index, index_stripped; > + u32 outbound_write_pointer, doneq_index, index_stripped, toggle; > uint32_t addressLow, ccb_cdb_phy; > int error; > struct MessageUnit_D *pmu; > @@ -2013,21 +1987,11 @@ static void arcmsr_hbaD_postqueue_isr(st > doneq_index = pmu->doneq_index; > if ((doneq_index & 0xFFF) != (outbound_write_pointer & 0xFFF)) { > do { > - if (doneq_index & 0x4000) { > - index_stripped = doneq_index & 0xFFF; > - index_stripped += 1; > - index_stripped %= ARCMSR_MAX_ARC1214_DONEQUEUE; > - pmu->doneq_index = index_stripped > - ? (index_stripped | 0x4000) : > - (index_stripped + 1); > - } else { > - index_stripped = doneq_index; > - index_stripped += 1; > - index_stripped %= ARCMSR_MAX_ARC1214_DONEQUEUE; > - pmu->doneq_index = index_stripped > - ? index_stripped : > - ((index_stripped | 0x4000) + 1); > - } > + toggle = doneq_index & 0x4000; > + index_stripped = (doneq_index & 0xFFF) + 1; > + index_stripped %= ARCMSR_MAX_ARC1214_DONEQUEUE; > + pmu->doneq_index = index_stripped ? (index_stripped | toggle) : > + ((toggle ^ 0x4000) + 1); > doneq_index = pmu->doneq_index; > addressLow = pmu->done_qbuffer[doneq_index & > 0xFFF].addressLow; > @@ -2843,7 +2807,7 @@ static bool arcmsr_hbaD_get_config(struc > char __iomem *iop_firm_version; > char __iomem *iop_device_map; > u32 count; > - struct MessageUnit_D *reg ; > + struct MessageUnit_D *reg; > void *dma_coherent2; > dma_addr_t dma_coherent_handle2; > struct pci_dev *pdev = acb->pdev; > @@ -3176,7 +3140,7 @@ static int arcmsr_hbaD_polling_ccbdone(s > { > bool error; > uint32_t poll_ccb_done = 0, poll_count = 0, flag_ccb, ccb_cdb_phy; > - int rtn, doneq_index, index_stripped, outbound_write_pointer; > + int rtn, doneq_index, index_stripped, outbound_write_pointer, toggle; > unsigned long flags; > struct ARCMSR_CDB *arcmsr_cdb; > struct CommandControlBlock *pCCB; > @@ -3185,9 +3149,11 @@ static int arcmsr_hbaD_polling_ccbdone(s > polling_hbaD_ccb_retry: > poll_count++; > while (1) { > + spin_lock_irqsave(&acb->doneq_lock, flags); > outbound_write_pointer = pmu->done_qbuffer[0].addressLow + 1; > doneq_index = pmu->doneq_index; > if ((outbound_write_pointer & 0xFFF) == (doneq_index & 0xFFF)) { > + spin_unlock_irqrestore(&acb->doneq_lock, flags); > if (poll_ccb_done) { > rtn = SUCCESS; > break; > @@ -3200,21 +3166,11 @@ polling_hbaD_ccb_retry: > goto polling_hbaD_ccb_retry; > } > } > - spin_lock_irqsave(&acb->doneq_lock, flags); > - if (doneq_index & 0x4000) { > - index_stripped = doneq_index & 0xFFF; > - index_stripped += 1; > - index_stripped %= ARCMSR_MAX_ARC1214_DONEQUEUE; > - pmu->doneq_index = index_stripped ? > - (index_stripped | 0x4000) : > - (index_stripped + 1); > - } else { > - index_stripped = doneq_index; > - index_stripped += 1; > - index_stripped %= ARCMSR_MAX_ARC1214_DONEQUEUE; > - pmu->doneq_index = index_stripped ? index_stripped : > - ((index_stripped | 0x4000) + 1); > - } > + toggle = doneq_index & 0x4000; > + index_stripped = (doneq_index & 0xFFF) + 1; > + index_stripped %= ARCMSR_MAX_ARC1214_DONEQUEUE; > + pmu->doneq_index = index_stripped ? (index_stripped | toggle) : > + ((toggle ^ 0x4000) + 1); > spin_unlock_irqrestore(&acb->doneq_lock, flags); > doneq_index = pmu->doneq_index; > flag_ccb = pmu->done_qbuffer[doneq_index & 0xFFF].addressLow; > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-scsi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
