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| author | Sumit.Saxena@avagotech.com <Sumit.Saxena@avagotech.com> | 2014-09-12 17:27:18 +0400 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2014-09-16 20:14:22 +0400 |
| commit | 0756040952582c4e7c2f23ff2af882c0f0c7a516 (patch) | |
| tree | 5323de07a6b316457de0c6c453b8921eae229715 /drivers/scsi/megaraid | |
| parent | 07e38d94ef3646ccee4f222ae1f3033bb37f7fa0 (diff) | |
| download | linux-0756040952582c4e7c2f23ff2af882c0f0c7a516.tar.xz | |
megaraid_sas : Use writeq for 64bit pci write to avoid spinlock overhead
Resending the patch. Addressed the review comments from Tomas Henzl.
Reduce the assingment for u64 req_data variable.
Use writeq() for 64bit PCI write instead of writel() to avoid additional lock overhead.
Signed-off-by: Sumit Saxena <sumit.saxena@avagotech.com>
Signed-off-by: Kashyap Desai <kashyap.desai@avagotech.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'drivers/scsi/megaraid')
| -rw-r--r-- | drivers/scsi/megaraid/megaraid_sas_fusion.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c index 57b47fe69072..8898817eaf8b 100644 --- a/drivers/scsi/megaraid/megaraid_sas_fusion.c +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c @@ -1065,6 +1065,11 @@ megasas_fire_cmd_fusion(struct megasas_instance *instance, u32 req_desc_hi, struct megasas_register_set __iomem *regs) { +#if defined(writeq) && defined(CONFIG_64BIT) + u64 req_data = (((u64)req_desc_hi << 32) | (u32)req_desc_lo); + + writeq(le64_to_cpu(req_data), &(regs)->inbound_low_queue_port); +#else unsigned long flags; spin_lock_irqsave(&instance->hba_lock, flags); @@ -1072,6 +1077,7 @@ megasas_fire_cmd_fusion(struct megasas_instance *instance, writel(le32_to_cpu(req_desc_lo), &(regs)->inbound_low_queue_port); writel(le32_to_cpu(req_desc_hi), &(regs)->inbound_high_queue_port); spin_unlock_irqrestore(&instance->hba_lock, flags); +#endif } /** |