RE: [PATCH] scsi/mpt2sas: fix unsafe preempt setting for ioc

From: Nandigama, Nagalakshmi
Date: Tue Apr 10 2012 - 01:57:46 EST


This patch seem to be fine. Please consider this patch as Acked-by: "Nandigama, Nagalakshmi" <Nagalakshmi.Nandigama@xxxxxxx>

Regards,
Nagalakshmi


-----Original Message-----
From: Alex Shi [mailto:alex.shi@xxxxxxxxx]
Sent: Monday, March 26, 2012 11:50 AM
To: JBottomley@xxxxxxxxxxxxx
Cc: Nandigama, Nagalakshmi; linux-scsi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Subject: [PATCH] scsi/mpt2sas: fix unsafe preempt setting for ioc

commit 911ae943 add a new function:
+_base_get_msix_index(struct MPT2SAS_ADAPTER *ioc)
+{
+ return ioc->cpu_msix_table[smp_processor_id()];
+}
Here smp_processor_id() need be used in preempt safe condition. but
caller did not give this assurance. So fix this in caller.

Signed-off-by: Alex Shi <alex.shi@xxxxxxxxx>
---
drivers/scsi/mpt2sas/mpt2sas_base.c | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.c b/drivers/scsi/mpt2sas/mpt2sas_base.c
index a78036f..55a368e 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_base.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_base.c
@@ -1803,6 +1803,7 @@ mpt2sas_base_put_smid_scsi_io(struct MPT2SAS_ADAPTER *ioc, u16 smid, u16 handle)
u64 *request = (u64 *)&descriptor;


+ preempt_disable();
descriptor.SCSIIO.RequestFlags = MPI2_REQ_DESCRIPT_FLAGS_SCSI_IO;
descriptor.SCSIIO.MSIxIndex = _base_get_msix_index(ioc);
descriptor.SCSIIO.SMID = cpu_to_le16(smid);
@@ -1810,6 +1811,7 @@ mpt2sas_base_put_smid_scsi_io(struct MPT2SAS_ADAPTER *ioc, u16 smid, u16 handle)
descriptor.SCSIIO.LMID = 0;
_base_writeq(*request, &ioc->chip->RequestDescriptorPostLow,
&ioc->scsi_lookup_lock);
+ preempt_enable();
}


@@ -1849,6 +1851,7 @@ mpt2sas_base_put_smid_default(struct MPT2SAS_ADAPTER *ioc, u16 smid)
Mpi2RequestDescriptorUnion_t descriptor;
u64 *request = (u64 *)&descriptor;

+ preempt_disable();
descriptor.Default.RequestFlags = MPI2_REQ_DESCRIPT_FLAGS_DEFAULT_TYPE;
descriptor.Default.MSIxIndex = _base_get_msix_index(ioc);
descriptor.Default.SMID = cpu_to_le16(smid);
@@ -1856,6 +1859,7 @@ mpt2sas_base_put_smid_default(struct MPT2SAS_ADAPTER *ioc, u16 smid)
descriptor.Default.DescriptorTypeDependent = 0;
_base_writeq(*request, &ioc->chip->RequestDescriptorPostLow,
&ioc->scsi_lookup_lock);
+ preempt_enable();
}

/**
@@ -1873,6 +1877,7 @@ mpt2sas_base_put_smid_target_assist(struct MPT2SAS_ADAPTER *ioc, u16 smid,
Mpi2RequestDescriptorUnion_t descriptor;
u64 *request = (u64 *)&descriptor;

+ preempt_disable();
descriptor.SCSITarget.RequestFlags =
MPI2_REQ_DESCRIPT_FLAGS_SCSI_TARGET;
descriptor.SCSITarget.MSIxIndex = _base_get_msix_index(ioc);
@@ -1881,6 +1886,7 @@ mpt2sas_base_put_smid_target_assist(struct MPT2SAS_ADAPTER *ioc, u16 smid,
descriptor.SCSITarget.IoIndex = cpu_to_le16(io_index);
_base_writeq(*request, &ioc->chip->RequestDescriptorPostLow,
&ioc->scsi_lookup_lock);
+ preempt_enable();
}

/**
--
1.7.5.4

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