[U-Boot] [PATCH] PCI: add 64-bit prefetchable memory support

[fenghua at phytium.com.cn]

From: David Feng <fenghua at phytium.com.cn>

PCI specification allow prefetchable memory to be 32-bit or 64-bit.
PCI express specification states that all memmory bars for prefetchable
memory must be implemented as 64-bit. They all require that 64 bit
prefetchble memory are suported especially when u-boot is ported to
more and more 64bit processors.

Signed-off-by: David Feng <fenghua at phytium.com.cn>
---
 drivers/pci/pci_auto.c |   36 +++++++++++++++++++++++++++++++++++-
 1 file changed, 35 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pci_auto.c b/drivers/pci/pci_auto.c
index ed92857..5ddb0b8 100644
--- a/drivers/pci/pci_auto.c
+++ b/drivers/pci/pci_auto.c
@@ -223,9 +223,12 @@ void pciauto_prescan_setup_bridge(struct pci_controller *hose,
 	struct pci_region *pci_mem = hose->pci_mem;
 	struct pci_region *pci_prefetch = hose->pci_prefetch;
 	struct pci_region *pci_io = hose->pci_io;
-	u16 cmdstat;
+	u16 cmdstat, prefechable_64;
 
 	pci_hose_read_config_word(hose, dev, PCI_COMMAND, &cmdstat);
+	pci_hose_read_config_word(hose, dev, PCI_PREF_MEMORY_BASE,
+				&prefechable_64);
+	prefechable_64 &= 0x1;
 
 	/* Configure bus number registers */
 	pci_hose_write_config_byte(hose, dev, PCI_PRIMARY_BUS,
@@ -252,12 +255,26 @@ void pciauto_prescan_setup_bridge(struct pci_controller *hose,
 		/* Set up memory and I/O filter limits, assume 32-bit I/O space */
 		pci_hose_write_config_word(hose, dev, PCI_PREF_MEMORY_BASE,
 					(pci_prefetch->bus_lower & 0xfff00000) >> 16);
+		if (prefechable_64)
+#ifdef CONFIG_SYS_PCI_64BIT
+			pci_hose_write_config_dword(hose, dev,
+					PCI_PREF_BASE_UPPER32,
+					pci_prefetch->bus_lower >> 32);
+#else
+			pci_hose_write_config_dword(hose, dev,
+					PCI_PREF_BASE_UPPER32,
+					0x0);
+#endif
 
 		cmdstat |= PCI_COMMAND_MEMORY;
 	} else {
 		/* We don't support prefetchable memory for now, so disable */
 		pci_hose_write_config_word(hose, dev, PCI_PREF_MEMORY_BASE, 0x1000);
 		pci_hose_write_config_word(hose, dev, PCI_PREF_MEMORY_LIMIT, 0x0);
+		if (prefechable_64) {
+			pci_hose_write_config_word(hose, dev, PCI_PREF_BASE_UPPER32, 0x0);
+			pci_hose_write_config_word(hose, dev, PCI_PREF_LIMIT_UPPER32, 0x0);
+		}
 	}
 
 	if (pci_io) {
@@ -297,11 +314,28 @@ void pciauto_postscan_setup_bridge(struct pci_controller *hose,
 	}
 
 	if (pci_prefetch) {
+		u16 prefechable_64;
+
+		pci_hose_read_config_word(hose, dev,
+					PCI_PREF_MEMORY_LIMIT,
+					&prefechable_64);
+		prefechable_64 &= 0x1;
+
 		/* Round memory allocator to 1MB boundary */
 		pciauto_region_align(pci_prefetch, 0x100000);
 
 		pci_hose_write_config_word(hose, dev, PCI_PREF_MEMORY_LIMIT,
 				(pci_prefetch->bus_lower - 1) >> 16);
+		if (prefechable_64)
+#ifdef CONFIG_SYS_PCI_64BIT
+			pci_hose_write_config_dword(hose, dev,
+					PCI_PREF_LIMIT_UPPER32,
+					(pci_prefetch->bus_lower - 1) >> 32);
+#else
+			pci_hose_write_config_dword(hose, dev,
+					PCI_PREF_LIMIT_UPPER32,
+					0x0);
+#endif
 	}
 
 	if (pci_io) {
-- 
1.7.9.5