nvme-pci: Use PCI bus address for data/queues in CMB

Currently, NVMe PCI host driver is programming CMB dma address as
I/O SQs addresses. This results in failures on systems where 1:1
outbound mapping is not used (example Broadcom iProc SOCs) because
CMB BAR will be progammed with PCI bus address but NVMe PCI EP will
try to access CMB using dma address.

To have CMB working on systems without 1:1 outbound mapping, we
program PCI bus address for I/O SQs instead of dma address. This
approach will work on systems with/without 1:1 outbound mapping.

Based on a report and previous patch from Abhishek Shah.

Fixes: 8ffaadf7 ("NVMe: Use CMB for the IO SQes if available")
Cc: stable@vger.kernel.org
Reported-by: Abhishek Shah <abhishek.shah@broadcom.com>
Tested-by: Abhishek Shah <abhishek.shah@broadcom.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/host/pci.c

@@ -94,7 +94,7 @@ struct nvme_dev {
 	struct mutex shutdown_lock;
 	bool subsystem;
 	void __iomem *cmb;
-	dma_addr_t cmb_dma_addr;
+	pci_bus_addr_t cmb_bus_addr;
 	u64 cmb_size;
 	u32 cmbsz;
 	u32 cmbloc;
@@ -1226,7 +1226,7 @@ static int nvme_alloc_sq_cmds(struct nvme_dev *dev, struct nvme_queue *nvmeq,
 	if (qid && dev->cmb && use_cmb_sqes && NVME_CMB_SQS(dev->cmbsz)) {
 		unsigned offset = (qid - 1) * roundup(SQ_SIZE(depth),
 						      dev->ctrl.page_size);
-		nvmeq->sq_dma_addr = dev->cmb_dma_addr + offset;
+		nvmeq->sq_dma_addr = dev->cmb_bus_addr + offset;
 		nvmeq->sq_cmds_io = dev->cmb + offset;
 	} else {
 		nvmeq->sq_cmds = dma_alloc_coherent(dev->dev, SQ_SIZE(depth),
@@ -1527,7 +1527,7 @@ static void __iomem *nvme_map_cmb(struct nvme_dev *dev)
 	resource_size_t bar_size;
 	struct pci_dev *pdev = to_pci_dev(dev->dev);
 	void __iomem *cmb;
-	dma_addr_t dma_addr;
+	int bar;
 
 	dev->cmbsz = readl(dev->bar + NVME_REG_CMBSZ);
 	if (!(NVME_CMB_SZ(dev->cmbsz)))
@@ -1540,7 +1540,8 @@ static void __iomem *nvme_map_cmb(struct nvme_dev *dev)
 	szu = (u64)1 << (12 + 4 * NVME_CMB_SZU(dev->cmbsz));
 	size = szu * NVME_CMB_SZ(dev->cmbsz);
 	offset = szu * NVME_CMB_OFST(dev->cmbloc);
-	bar_size = pci_resource_len(pdev, NVME_CMB_BIR(dev->cmbloc));
+	bar = NVME_CMB_BIR(dev->cmbloc);
+	bar_size = pci_resource_len(pdev, bar);
 
 	if (offset > bar_size)
 		return NULL;
@@ -1553,12 +1554,11 @@ static void __iomem *nvme_map_cmb(struct nvme_dev *dev)
 	if (size > bar_size - offset)
 		size = bar_size - offset;
 
-	dma_addr = pci_resource_start(pdev, NVME_CMB_BIR(dev->cmbloc)) + offset;
-	cmb = ioremap_wc(dma_addr, size);
+	cmb = ioremap_wc(pci_resource_start(pdev, bar) + offset, size);
 	if (!cmb)
 		return NULL;
 
-	dev->cmb_dma_addr = dma_addr;
+	dev->cmb_bus_addr = pci_bus_address(pdev, bar) + offset;
 	dev->cmb_size = size;
 	return cmb;
 }