[PATCH] NVMe: Fix compilation on architecturs without readq/writeq

[Matthew Wilcox <matthew.r.wilcox@intel.com>]

The only places that uses readq/writeq are in the initialisation
path.  Since they're not performance critical, always use readl/writel.

Reported-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
---
 drivers/block/nvme.c |   20 +++++++++++++++++---
 1 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/drivers/block/nvme.c b/drivers/block/nvme.c
index c1dc4d8..f27deec 100644
--- a/drivers/block/nvme.c
+++ b/drivers/block/nvme.c
@@ -972,6 +972,20 @@ static __devinit struct nvme_queue *nvme_create_queue(struct nvme_dev *dev,
 	return ERR_PTR(result);
 }
 
+static inline unsigned long long nvme_readq(const volatile void __iomem *addr)
+{
+	unsigned long long result = readl(addr);
+	result |= (unsigned long long)readl(addr + 4) << 32;
+	return result;
+}
+
+static inline void
+nvme_writeq(unsigned long long val, volatile void __iomem *addr)
+{
+	writel(val, addr);
+	writel(val >> 32, addr + 4);
+}
+
 static int __devinit nvme_configure_admin_queue(struct nvme_dev *dev)
 {
 	int result;
@@ -996,11 +1010,11 @@ static int __devinit nvme_configure_admin_queue(struct nvme_dev *dev)
 
 	writel(0, &dev->bar->cc);
 	writel(aqa, &dev->bar->aqa);
-	writeq(nvmeq->sq_dma_addr, &dev->bar->asq);
-	writeq(nvmeq->cq_dma_addr, &dev->bar->acq);
+	nvme_writeq(nvmeq->sq_dma_addr, &dev->bar->asq);
+	nvme_writeq(nvmeq->cq_dma_addr, &dev->bar->acq);
 	writel(dev->ctrl_config, &dev->bar->cc);
 
-	cap = readq(&dev->bar->cap);
+	cap = nvme_readq(&dev->bar->cap);
 	timeout = ((NVME_CAP_TIMEOUT(cap) + 1) * HZ / 2) + jiffies;
 	dev->db_stride = NVME_CAP_STRIDE(cap);
 
-- 
1.7.7.3