PCI: Add pci_bus_addr_t

David Ahern reported that d63e2e1f3df9 ("sparc/PCI: Clip bridge windows
to fit in upstream windows") fails to boot on sparc/T5-8:

  pci 0000:06:00.0: reg 0x184: can't handle BAR above 4GB (bus address 0x110204000)

The problem is that sparc64 assumed that dma_addr_t only needed to hold DMA
addresses, i.e., bus addresses returned via the DMA API (dma_map_single(),
etc.), while the PCI core assumed dma_addr_t could hold *any* bus address,
including raw BAR values.  On sparc64, all DMA addresses fit in 32 bits, so
dma_addr_t is a 32-bit type.  However, BAR values can be 64 bits wide, so
they don't fit in a dma_addr_t.  d63e2e1f3df9 added new checking that
tripped over this mismatch.

Add pci_bus_addr_t, which is wide enough to hold any PCI bus address,
including both raw BAR values and DMA addresses.  This will be 64 bits
on 64-bit platforms and on platforms with a 64-bit dma_addr_t.  Then
dma_addr_t only needs to be wide enough to hold addresses from the DMA API.

[bhelgaas: changelog, bugzilla, Kconfig to ensure pci_bus_addr_t is at
least as wide as dma_addr_t, documentation]
Fixes: d63e2e1f3df9 ("sparc/PCI: Clip bridge windows to fit in upstream windows")
Fixes: 23b13bc76f35 ("PCI: Fail safely if we can't handle BARs larger than 4GB")
Link: http://lkml.kernel.org/r/CAE9FiQU1gJY1LYrxs+ma5LCTEEe4xmtjRG0aXJ9K_Tsu+m9Wuw@mail.gmail.com
Link: http://lkml.kernel.org/r/1427857069-6789-1-git-send-email-yinghai@kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=96231
Reported-by: David Ahern <david.ahern@oracle.com>
Tested-by: David Ahern <david.ahern@oracle.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: David S. Miller <davem@davemloft.net>
CC: stable@vger.kernel.org	# v3.19+

3 files changed, 15 insertions, 11 deletions

diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 7a8f1c5e65af..73de4efcbe6e 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -1,6 +1,10 @@
 #
 # PCI configuration
 #
+config PCI_BUS_ADDR_T_64BIT
+	def_bool y if (ARCH_DMA_ADDR_T_64BIT || 64BIT)
+	depends on PCI
+
 config PCI_MSI
 	bool "Message Signaled Interrupts (MSI and MSI-X)"
 	depends on PCI
diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index 90fa3a78fb7c..6fbd3f2b5992 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -92,11 +92,11 @@ void pci_bus_remove_resources(struct pci_bus *bus)
 }
 
 static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL};
-#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+#ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
 static struct pci_bus_region pci_64_bit = {0,
-				(dma_addr_t) 0xffffffffffffffffULL};
-static struct pci_bus_region pci_high = {(dma_addr_t) 0x100000000ULL,
-				(dma_addr_t) 0xffffffffffffffffULL};
+				(pci_bus_addr_t) 0xffffffffffffffffULL};
+static struct pci_bus_region pci_high = {(pci_bus_addr_t) 0x100000000ULL,
+				(pci_bus_addr_t) 0xffffffffffffffffULL};
 #endif
 
 /*
@@ -200,7 +200,7 @@ int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
 					  resource_size_t),
 		void *alignf_data)
 {
-#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+#ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
 	int rc;
 
 	if (res->flags & IORESOURCE_MEM_64) {
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 6675a7a1b9fc..c91185721345 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -254,8 +254,8 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
 	}
 
 	if (res->flags & IORESOURCE_MEM_64) {
-		if ((sizeof(dma_addr_t) < 8 || sizeof(resource_size_t) < 8) &&
-		    sz64 > 0x100000000ULL) {
+		if ((sizeof(pci_bus_addr_t) < 8 || sizeof(resource_size_t) < 8)
+		    && sz64 > 0x100000000ULL) {
 			res->flags |= IORESOURCE_UNSET | IORESOURCE_DISABLED;
 			res->start = 0;
 			res->end = 0;
@@ -264,7 +264,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
 			goto out;
 		}
 
-		if ((sizeof(dma_addr_t) < 8) && l) {
+		if ((sizeof(pci_bus_addr_t) < 8) && l) {
 			/* Above 32-bit boundary; try to reallocate */
 			res->flags |= IORESOURCE_UNSET;
 			res->start = 0;
@@ -399,7 +399,7 @@ static void pci_read_bridge_mmio_pref(struct pci_bus *child)
 	struct pci_dev *dev = child->self;
 	u16 mem_base_lo, mem_limit_lo;
 	u64 base64, limit64;
-	dma_addr_t base, limit;
+	pci_bus_addr_t base, limit;
 	struct pci_bus_region region;
 	struct resource *res;
 
@@ -426,8 +426,8 @@ static void pci_read_bridge_mmio_pref(struct pci_bus *child)
 		}
 	}
 
-	base = (dma_addr_t) base64;
-	limit = (dma_addr_t) limit64;
+	base = (pci_bus_addr_t) base64;
+	limit = (pci_bus_addr_t) limit64;
 
 	if (base != base64) {
 		dev_err(&dev->dev, "can't handle bridge window above 4GB (bus address %#010llx)\n",