powerpc: Added PCI MSI support using the HSTA module

The PPC476GTR SoC supports message signalled interrupts (MSI) by writing
to special addresses within the High Speed Transfer Assist (HSTA) module.

This patch adds support for PCI MSI with a new system device. The DMA
window is also updated to allow access to the entire 42-bit address range
to allow PCI devices write access to the HSTA module.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 38 insertions, 23 deletions

diff --git a/arch/powerpc/boot/dts/akebono.dts b/arch/powerpc/boot/dts/akebono.dts
index 96ac13b2a02d..f92ecfed3d2f 100644
--- a/arch/powerpc/boot/dts/akebono.dts
+++ b/arch/powerpc/boot/dts/akebono.dts
@@ -82,6 +82,28 @@
 		ranges;
 		clock-frequency = <200000000>; // 200Mhz
 
+		HSTA0: hsta@310000e0000 {
+			compatible = "ibm,476gtr-hsta-msi", "ibm,hsta-msi";
+			reg = <0x310 0x000e0000 0x0 0xf0>;
+			interrupt-parent = <&MPIC>;
+			interrupts = <108 0
+				      109 0
+				      110 0
+				      111 0
+				      112 0
+				      113 0
+				      114 0
+				      115 0
+				      116 0
+				      117 0
+				      118 0
+				      119 0
+				      120 0
+				      121 0
+				      122 0
+				      123 0>;
+		};
+
 		MAL0: mcmal {
 			compatible = "ibm,mcmal-476gtr", "ibm,mcmal2";
 			dcr-reg = <0xc0000000 0x062>;
@@ -242,8 +264,10 @@
 			ranges = <0x02000000 0x00000000 0x80000000 0x00000110 0x80000000 0x0 0x80000000
 			          0x01000000 0x0        0x0        0x00000140 0x0        0x0 0x00010000>;
 
-			/* Inbound starting at 0 to memsize filled in by zImage */
-			dma-ranges = <0x42000000 0x0 0x0 0x0 0x0 0x0 0x0>;
+			/* Inbound starting at 0x0 to 0x40000000000. In order to use MSI
+			 * PCI devices must be able to write to the HSTA module.
+			 */
+			dma-ranges = <0x42000000 0x0 0x0 0x0 0x0 0x400 0x0>;
 
 			/* This drives busses 0 to 0xf */
 			bus-range = <0x0 0xf>;
@@ -280,8 +304,10 @@
 			ranges = <0x02000000 0x00000000 0x80000000 0x00000210 0x80000000 0x0 0x80000000
 			          0x01000000 0x0        0x0        0x00000240 0x0        0x0 0x00010000>;
 
-			/* Inbound starting at 0 to memsize filled in by zImage */
-			dma-ranges = <0x42000000 0x0 0x0 0x0 0x0 0x0 0x0>;
+			/* Inbound starting at 0x0 to 0x40000000000. In order to use MSI
+			 * PCI devices must be able to write to the HSTA module.
+			 */
+			dma-ranges = <0x42000000 0x0 0x0 0x0 0x0 0x400 0x0>;
 
 			/* This drives busses 0 to 0xf */
 			bus-range = <0x0 0xf>;
@@ -318,8 +344,10 @@
 			ranges = <0x02000000 0x00000000 0x80000000 0x00000190 0x80000000 0x0 0x80000000
 			          0x01000000 0x0        0x0        0x000001c0 0x0        0x0 0x00010000>;
 
-			/* Inbound starting at 0 to memsize filled in by zImage */
-			dma-ranges = <0x42000000 0x0 0x0 0x0 0x0 0x0 0x0>;
+			/* Inbound starting at 0x0 to 0x40000000000. In order to use MSI
+			 * PCI devices must be able to write to the HSTA module.
+			 */
+			dma-ranges = <0x42000000 0x0 0x0 0x0 0x0 0x400 0x0>;
 
 			/* This drives busses 0 to 0xf */
 			bus-range = <0x0 0xf>;
@@ -356,8 +384,10 @@
 			ranges = <0x02000000 0x00000000 0x80000000 0x00000290 0x80000000 0x0 0x80000000
 			          0x01000000 0x0        0x0        0x000002c0 0x0        0x0 0x00010000>;
 
-			/* Inbound starting at 0 to memsize filled in by zImage */
-			dma-ranges = <0x42000000 0x0 0x0 0x0 0x0 0x0 0x0>;
+			/* Inbound starting at 0x0 to 0x40000000000. In order to use MSI
+			 * PCI devices must be able to write to the HSTA module.
+			 */
+			dma-ranges = <0x42000000 0x0 0x0 0x0 0x0 0x400 0x0>;
 
 			/* This drives busses 0 to 0xf */
 			bus-range = <0x0 0xf>;
diff --git a/arch/powerpc/boot/treeboot-akebono.c b/arch/powerpc/boot/treeboot-akebono.c
index 070a20f2f5d1..b73174c34fe4 100644
--- a/arch/powerpc/boot/treeboot-akebono.c
+++ b/arch/powerpc/boot/treeboot-akebono.c
@@ -75,24 +75,9 @@ static void ibm_akebono_fixups(void)
 {
 	void *emac;
 	u32 reg;
-	void *devp = finddevice("/");
-	u32 dma_ranges[7];
 
 	dt_fixup_memory(0x0ULL,  ibm_akebono_memsize);
 
-	while ((devp = find_node_by_devtype(devp, "pci"))) {
-		if (getprop(devp, "dma-ranges", dma_ranges,
-			    sizeof(dma_ranges)) < 0) {
-			printf("%s: Failed to get dma-ranges\r\n", __func__);
-			continue;
-		}
-
-		dma_ranges[5] = ibm_akebono_memsize >> 32;
-		dma_ranges[6] = ibm_akebono_memsize & 0xffffffffUL;
-
-		setprop(devp, "dma-ranges", dma_ranges, sizeof(dma_ranges));
-	}
-
 	/* Fixup the SD timeout frequency */
 	mtdcrx(CCTL0_MCO4, 0x1);