[PATCH] pci: Fix configuring io/memory base and limit registers of PCI bridges

Pali Rohár pali at kernel.org
Fri Sep 10 13:33:35 CEST 2021


Lower 4 bits of PCI_MEMORY_BASE and PCI_MEMORY_LIMIT registers are reserved
and should be zero. So do not set them to non-zero value.

Lower 4 bits of PCI_PREF_MEMORY_BASE and PCI_PREF_MEMORY_LIMIT registers
contain information if 64-bit memory addressing is supported. So preserve
this information when overwriting these registers.

Lower 4 bits of PCI_IO_BASE and PCI_IO_LIMIT register contain information
if 32-bit io addressing is supported. So preserve this information and do
not try to configure 32-bit io addressing (via PCI_IO_BASE_UPPER16 and
PCI_IO_LIMIT_UPPER16 registers) when it is unsupported.

Signed-off-by: Pali Rohár <pali at kernel.org>
---
 drivers/pci/pci_auto.c | 39 +++++++++++++++++++++++++++++----------
 1 file changed, 29 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/pci_auto.c b/drivers/pci/pci_auto.c
index b128a05dd380..7b6e629cae70 100644
--- a/drivers/pci/pci_auto.c
+++ b/drivers/pci/pci_auto.c
@@ -165,6 +165,7 @@ void dm_pciauto_prescan_setup_bridge(struct udevice *dev, int sub_bus)
 	struct pci_region *pci_prefetch;
 	struct pci_region *pci_io;
 	u16 cmdstat, prefechable_64;
+	u8 io_32;
 	struct udevice *ctlr = pci_get_controller(dev);
 	struct pci_controller *ctlr_hose = dev_get_uclass_priv(ctlr);
 
@@ -175,6 +176,8 @@ void dm_pciauto_prescan_setup_bridge(struct udevice *dev, int sub_bus)
 	dm_pci_read_config16(dev, PCI_COMMAND, &cmdstat);
 	dm_pci_read_config16(dev, PCI_PREF_MEMORY_BASE, &prefechable_64);
 	prefechable_64 &= PCI_PREF_RANGE_TYPE_MASK;
+	dm_pci_read_config8(dev, PCI_IO_LIMIT, &io_32);
+	io_32 &= PCI_IO_RANGE_TYPE_MASK;
 
 	/* Configure bus number registers */
 	dm_pci_write_config8(dev, PCI_PRIMARY_BUS,
@@ -191,7 +194,8 @@ void dm_pciauto_prescan_setup_bridge(struct udevice *dev, int sub_bus)
 		 * I/O space
 		 */
 		dm_pci_write_config16(dev, PCI_MEMORY_BASE,
-				      (pci_mem->bus_lower & 0xfff00000) >> 16);
+				      ((pci_mem->bus_lower & 0xfff00000) >> 16) &
+				      PCI_MEMORY_RANGE_MASK);
 
 		cmdstat |= PCI_COMMAND_MEMORY;
 	}
@@ -205,7 +209,8 @@ void dm_pciauto_prescan_setup_bridge(struct udevice *dev, int sub_bus)
 		 * I/O space
 		 */
 		dm_pci_write_config16(dev, PCI_PREF_MEMORY_BASE,
-				(pci_prefetch->bus_lower & 0xfff00000) >> 16);
+				(((pci_prefetch->bus_lower & 0xfff00000) >> 16) &
+				PCI_PREF_RANGE_MASK) | prefechable_64);
 		if (prefechable_64 == PCI_PREF_RANGE_TYPE_64)
 #ifdef CONFIG_SYS_PCI_64BIT
 			dm_pci_write_config32(dev, PCI_PREF_BASE_UPPER32,
@@ -217,8 +222,10 @@ void dm_pciauto_prescan_setup_bridge(struct udevice *dev, int sub_bus)
 		cmdstat |= PCI_COMMAND_MEMORY;
 	} else {
 		/* We don't support prefetchable memory for now, so disable */
-		dm_pci_write_config16(dev, PCI_PREF_MEMORY_BASE, 0x1000);
-		dm_pci_write_config16(dev, PCI_PREF_MEMORY_LIMIT, 0x0);
+		dm_pci_write_config16(dev, PCI_PREF_MEMORY_BASE, 0x1000 |
+								prefechable_64);
+		dm_pci_write_config16(dev, PCI_PREF_MEMORY_LIMIT, 0x0 |
+								prefechable_64);
 		if (prefechable_64 == PCI_PREF_RANGE_TYPE_64) {
 			dm_pci_write_config16(dev, PCI_PREF_BASE_UPPER32, 0x0);
 			dm_pci_write_config16(dev, PCI_PREF_LIMIT_UPPER32, 0x0);
@@ -230,8 +237,10 @@ void dm_pciauto_prescan_setup_bridge(struct udevice *dev, int sub_bus)
 		pciauto_region_align(pci_io, 0x1000);
 
 		dm_pci_write_config8(dev, PCI_IO_BASE,
-				     (pci_io->bus_lower & 0x0000f000) >> 8);
-		dm_pci_write_config16(dev, PCI_IO_BASE_UPPER16,
+				     (((pci_io->bus_lower & 0x0000f000) >> 8) &
+				     PCI_IO_RANGE_MASK) | io_32);
+		if (io_32 == PCI_IO_RANGE_TYPE_32)
+			dm_pci_write_config16(dev, PCI_IO_BASE_UPPER16,
 				      (pci_io->bus_lower & 0xffff0000) >> 16);
 
 		cmdstat |= PCI_COMMAND_IO;
@@ -261,7 +270,8 @@ void dm_pciauto_postscan_setup_bridge(struct udevice *dev, int sub_bus)
 		pciauto_region_align(pci_mem, 0x100000);
 
 		dm_pci_write_config16(dev, PCI_MEMORY_LIMIT,
-				      (pci_mem->bus_lower - 1) >> 16);
+				      ((pci_mem->bus_lower - 1) >> 16) &
+				      PCI_MEMORY_RANGE_MASK);
 	}
 
 	if (pci_prefetch) {
@@ -275,7 +285,8 @@ void dm_pciauto_postscan_setup_bridge(struct udevice *dev, int sub_bus)
 		pciauto_region_align(pci_prefetch, 0x100000);
 
 		dm_pci_write_config16(dev, PCI_PREF_MEMORY_LIMIT,
-				      (pci_prefetch->bus_lower - 1) >> 16);
+				      (((pci_prefetch->bus_lower - 1) >> 16) &
+				       PCI_PREF_RANGE_MASK) | prefechable_64);
 		if (prefechable_64 == PCI_PREF_RANGE_TYPE_64)
 #ifdef CONFIG_SYS_PCI_64BIT
 			dm_pci_write_config32(dev, PCI_PREF_LIMIT_UPPER32,
@@ -286,12 +297,20 @@ void dm_pciauto_postscan_setup_bridge(struct udevice *dev, int sub_bus)
 	}
 
 	if (pci_io) {
+		u8 io_32;
+
+		dm_pci_read_config8(dev, PCI_IO_LIMIT,
+				     &io_32);
+		io_32 &= PCI_IO_RANGE_TYPE_MASK;
+
 		/* Round I/O allocator to 4KB boundary */
 		pciauto_region_align(pci_io, 0x1000);
 
 		dm_pci_write_config8(dev, PCI_IO_LIMIT,
-				((pci_io->bus_lower - 1) & 0x0000f000) >> 8);
-		dm_pci_write_config16(dev, PCI_IO_LIMIT_UPPER16,
+				((((pci_io->bus_lower - 1) & 0x0000f000) >> 8) &
+				PCI_IO_RANGE_MASK) | io_32);
+		if (io_32 == PCI_IO_RANGE_TYPE_32)
+			dm_pci_write_config16(dev, PCI_IO_LIMIT_UPPER16,
 				((pci_io->bus_lower - 1) & 0xffff0000) >> 16);
 	}
 }
-- 
2.20.1



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