On Fri, 2014-09-12 at 15:34 +0200, Tomas Henzl wrote: > On 09/12/2014 09:29 AM, Ching Huang wrote: > > From: Ching Huang <ching2048@xxxxxxxxxxxx> > > > > This patch is to modify previous patch 13/17 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. for readability, rename firstindex to getIndex, rename lastindex to putIndex > For some reason, the names head+tail areusual for a circular buffer. > But let us ignore the names, I don't care. > > 2. define ARCMSR_API_DATA_BUFLEN as 1032 > > 3. simplify ioctl data read by macro CIRC_CNT_TO_END and CIRC_CNT > It's definitely better when you post renames and other non-functional changes in separate > patches, it's easier for the reviewer. > > > > Signed-off-by: Ching Huang <ching2048@xxxxxxxxxxxx> > > --- > > > > diff -uprN a/drivers/scsi/arcmsr/arcmsr_attr.c b/drivers/scsi/arcmsr/arcmsr_attr.c > > --- a/drivers/scsi/arcmsr/arcmsr_attr.c 2014-08-21 12:14:27.000000000 +0800 > > +++ b/drivers/scsi/arcmsr/arcmsr_attr.c 2014-09-12 15:18:46.659125000 +0800 > > @@ -50,6 +50,7 @@ > > #include <linux/errno.h> > > #include <linux/delay.h> > > #include <linux/pci.h> > > +#include <linux/circ_buf.h> > > > > #include <scsi/scsi_cmnd.h> > > #include <scsi/scsi_device.h> > > @@ -68,7 +69,7 @@ static ssize_t arcmsr_sysfs_iop_message_ > > struct device *dev = container_of(kobj,struct device,kobj); > > struct Scsi_Host *host = class_to_shost(dev); > > struct AdapterControlBlock *acb = (struct AdapterControlBlock *) host->hostdata; > > - uint8_t *pQbuffer,*ptmpQbuffer; > > + uint8_t *ptmpQbuffer; > > int32_t allxfer_len = 0; > > unsigned long flags; > > > > @@ -78,57 +79,22 @@ static ssize_t arcmsr_sysfs_iop_message_ > > /* do message unit read. */ > > ptmpQbuffer = (uint8_t *)buf; > > spin_lock_irqsave(&acb->rqbuffer_lock, flags); > > - if (acb->rqbuf_firstindex != acb->rqbuf_lastindex) { > > - pQbuffer = &acb->rqbuffer[acb->rqbuf_firstindex]; > > - if (acb->rqbuf_firstindex > acb->rqbuf_lastindex) { > > - if ((ARCMSR_MAX_QBUFFER - acb->rqbuf_firstindex) >= 1032) { > > - memcpy(ptmpQbuffer, pQbuffer, 1032); > > - acb->rqbuf_firstindex += 1032; > > - acb->rqbuf_firstindex %= ARCMSR_MAX_QBUFFER; > > - allxfer_len = 1032; > > - } else { > > - if (((ARCMSR_MAX_QBUFFER - acb->rqbuf_firstindex) > > - + acb->rqbuf_lastindex) > 1032) { > > - memcpy(ptmpQbuffer, pQbuffer, > > - ARCMSR_MAX_QBUFFER > > - - acb->rqbuf_firstindex); > > - ptmpQbuffer += ARCMSR_MAX_QBUFFER > > - - acb->rqbuf_firstindex; > > - memcpy(ptmpQbuffer, acb->rqbuffer, 1032 > > - - (ARCMSR_MAX_QBUFFER - > > - acb->rqbuf_firstindex)); > > - acb->rqbuf_firstindex = 1032 - > > - (ARCMSR_MAX_QBUFFER - > > - acb->rqbuf_firstindex); > > - allxfer_len = 1032; > > - } else { > > - memcpy(ptmpQbuffer, pQbuffer, > > - ARCMSR_MAX_QBUFFER - > > - acb->rqbuf_firstindex); > > - ptmpQbuffer += ARCMSR_MAX_QBUFFER - > > - acb->rqbuf_firstindex; > > - memcpy(ptmpQbuffer, acb->rqbuffer, > > - acb->rqbuf_lastindex); > > - allxfer_len = ARCMSR_MAX_QBUFFER - > > - acb->rqbuf_firstindex + > > - acb->rqbuf_lastindex; > > - acb->rqbuf_firstindex = > > - acb->rqbuf_lastindex; > > - } > > - } > > - } else { > > - if ((acb->rqbuf_lastindex - acb->rqbuf_firstindex) > 1032) { > > - memcpy(ptmpQbuffer, pQbuffer, 1032); > > - acb->rqbuf_firstindex += 1032; > > - allxfer_len = 1032; > > - } else { > > - memcpy(ptmpQbuffer, pQbuffer, acb->rqbuf_lastindex > > - - acb->rqbuf_firstindex); > > - allxfer_len = acb->rqbuf_lastindex - > > - acb->rqbuf_firstindex; > > - acb->rqbuf_firstindex = acb->rqbuf_lastindex; > > - } > > + if (acb->rqbuf_getIndex != acb->rqbuf_putIndex) { > > + unsigned int tail = acb->rqbuf_getIndex; > > + unsigned int head = acb->rqbuf_putIndex; > > + unsigned int cnt_to_end = CIRC_CNT_TO_END(head, tail, ARCMSR_MAX_QBUFFER); > > + > > + allxfer_len = CIRC_CNT(head, tail, ARCMSR_MAX_QBUFFER); > > + if (allxfer_len > ARCMSR_API_DATA_BUFLEN) > > + allxfer_len = ARCMSR_API_DATA_BUFLEN; > > + > > + if (allxfer_len <= cnt_to_end) > > + memcpy(ptmpQbuffer, acb->rqbuffer + tail, allxfer_len); > > + else { > > + memcpy(ptmpQbuffer, acb->rqbuffer + tail, cnt_to_end); > > + memcpy(ptmpQbuffer + cnt_to_end, acb->rqbuffer, allxfer_len - cnt_to_end); > > } > > + acb->rqbuf_getIndex = (acb->rqbuf_getIndex + allxfer_len) % ARCMSR_MAX_QBUFFER; > > } > > if (acb->acb_flags & ACB_F_IOPDATA_OVERFLOW) { > > struct QBUFFER __iomem *prbuffer; > > @@ -150,33 +116,32 @@ static ssize_t arcmsr_sysfs_iop_message_ > > struct device *dev = container_of(kobj,struct device,kobj); > > struct Scsi_Host *host = class_to_shost(dev); > > struct AdapterControlBlock *acb = (struct AdapterControlBlock *) host->hostdata; > > - int32_t my_empty_len, user_len, wqbuf_firstindex, wqbuf_lastindex; > > + int32_t my_empty_len, user_len, wqbuf_getIndex, wqbuf_putIndex; > > uint8_t *pQbuffer, *ptmpuserbuffer; > > unsigned long flags; > > > > if (!capable(CAP_SYS_ADMIN)) > > return -EACCES; > > - if (count > 1032) > > + if (count > ARCMSR_API_DATA_BUFLEN) > > return -EINVAL; > > /* do message unit write. */ > > ptmpuserbuffer = (uint8_t *)buf; > > user_len = (int32_t)count; > > spin_lock_irqsave(&acb->wqbuffer_lock, flags); > > - wqbuf_lastindex = acb->wqbuf_lastindex; > > - wqbuf_firstindex = acb->wqbuf_firstindex; > > - if (wqbuf_lastindex != wqbuf_firstindex) { > > + wqbuf_putIndex = acb->wqbuf_putIndex; > > + wqbuf_getIndex = acb->wqbuf_getIndex; > > + if (wqbuf_putIndex != wqbuf_getIndex) { > > arcmsr_write_ioctldata2iop(acb); > > spin_unlock_irqrestore(&acb->wqbuffer_lock, flags); > > return 0; /*need retry*/ > > } else { > > - my_empty_len = (wqbuf_firstindex-wqbuf_lastindex - 1) > > - &(ARCMSR_MAX_QBUFFER - 1); > > + my_empty_len = ARCMSR_MAX_QBUFFER - 1; > This^ doesn't look like like an rename can you explain? It is just a code simplification. > > Let us stop here, or we end in an endless loop of corrections. The original 13/17 > you are trying to improve here was at least without bugs (better said I haven't noticed) so > improving it now only complicates the process. > My suggestion is -let us skip this patch and focus only on fixing the spinlock problem found in 16/17. > OKay? Agree. > > Cheers, > Tomas > -- 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
