Subject: [PATCH] powerpc: make U4 PCIe work (#2)

From: Benjamin Herrenschmidt <[email-masked]>
Date: Fri, 06 Oct 2006 15:40:01 +1000

The Maple support code was missing code for U4/CPC945 PCIe. This adds
it, enabling it to work on tigerwood boards, and possibly also js21
using SLOF. Also disable an obsolete firmware workaround.

Signed-off-by: Benjamin Herrenschmidt <[email-masked]>

Index: linux-work/arch/powerpc/platforms/maple/pci.c
===================================================================
--- linux-work.orig/arch/powerpc/platforms/maple/pci.c	2006-10-05 16:00:29.000000000 +1000
+++ linux-work/arch/powerpc/platforms/maple/pci.c	2006-10-06 15:38:38.000000000 +1000
@@ -8,7 +8,7 @@
  * 2 of the License, or (at your option) any later version.
  */
 
-#define DEBUG
+#undef DEBUG
 
 #include <linux/kernel.h>
 #include <linux/pci.h>
@@ -16,6 +16,7 @@
 #include <linux/string.h>
 #include <linux/init.h>
 #include <linux/bootmem.h>
+#include <linux/irq.h>
 
 #include <asm/sections.h>
 #include <asm/io.h>
@@ -33,7 +34,7 @@
 #define DBG(x...)
 #endif
 
-static struct pci_controller *u3_agp, *u3_ht;
+static struct pci_controller *u3_agp, *u3_ht, *u4_pcie;
 
 static int __init fixup_one_level_bus_range(struct device_node *node, int higher)
 {
@@ -287,6 +288,113 @@ static struct pci_ops u3_ht_pci_ops =
 	u3_ht_write_config
 };
 
+static unsigned int u4_pcie_cfa0(u8 devfn, u8 off)
+{
+	return (1 << ((unsigned int)PCI_SLOT(devfn))) 	|
+		(((unsigned int)PCI_FUNC(devfn)) << 8) |
+		((((unsigned int)(off)) >> 8) << 28) 	|
+		(((unsigned int)(off)) & 0xfcu);
+}
+
+static unsigned int u4_pcie_cfa1(u8 bus, u8 devfn, u8 off)
+{
+        return (((unsigned int)(bus)) << 16)		|
+		(((unsigned int)(devfn)) << 8)		|
+		((((unsigned int)(off)) >> 8) << 28)	|
+		(((unsigned int)(off)) & 0xfcU)| 1u;
+}
+
+static volatile void __iomem *u4_pcie_cfg_access(struct pci_controller* hose,
+                                        u8 bus, u8 dev_fn, int offset)
+{
+        unsigned int caddr;
+
+        if (bus == hose->first_busno)
+                caddr = u4_pcie_cfa0(dev_fn, offset);
+        else
+                caddr = u4_pcie_cfa1(bus, dev_fn, offset);
+
+        /* Uninorth will return garbage if we don't read back the value ! */
+        do {
+                out_le32(hose->cfg_addr, caddr);
+        } while (in_le32(hose->cfg_addr) != caddr);
+
+        offset &= 0x03;
+        return hose->cfg_data + offset;
+}
+
+static int u4_pcie_read_config(struct pci_bus *bus, unsigned int devfn,
+                               int offset, int len, u32 *val)
+{
+        struct pci_controller *hose;
+        volatile void __iomem *addr;
+
+        hose = pci_bus_to_host(bus);
+        if (hose == NULL)
+                return PCIBIOS_DEVICE_NOT_FOUND;
+        if (offset >= 0x1000)
+                return  PCIBIOS_BAD_REGISTER_NUMBER;
+        addr = u4_pcie_cfg_access(hose, bus->number, devfn, offset);
+        if (!addr)
+                return PCIBIOS_DEVICE_NOT_FOUND;
+        /*
+         * Note: the caller has already checked that offset is
+         * suitably aligned and that len is 1, 2 or 4.
+         */
+        switch (len) {
+        case 1:
+                *val = in_8(addr);
+                break;
+        case 2:
+                *val = in_le16(addr);
+                break;
+        default:
+                *val = in_le32(addr);
+                break;
+        }
+        return PCIBIOS_SUCCESSFUL;
+}
+static int u4_pcie_write_config(struct pci_bus *bus, unsigned int devfn,
+                                int offset, int len, u32 val)
+{
+        struct pci_controller *hose;
+        void __iomem *addr;
+
+        hose = pci_bus_to_host(bus);
+        if (hose == NULL)
+                return PCIBIOS_DEVICE_NOT_FOUND;
+        if (offset >= 0x1000)
+                return  PCIBIOS_BAD_REGISTER_NUMBER;
+        addr = u4_pcie_cfg_access(hose, bus->number, devfn, offset);
+        if (!addr)
+                return PCIBIOS_DEVICE_NOT_FOUND;
+        /*
+         * Note: the caller has already checked that offset is
+         * suitably aligned and that len is 1, 2 or 4.
+         */
+        switch (len) {
+        case 1:
+                out_8(addr, val);
+                (void) in_8(addr);
+                break;
+        case 2:
+                out_le16(addr, val);
+                (void) in_le16(addr);
+                break;
+        default:
+                out_le32(addr, val);
+                (void) in_le32(addr);
+                break;
+        }
+        return PCIBIOS_SUCCESSFUL;
+}
+
+static struct pci_ops u4_pcie_pci_ops =
+{
+        u4_pcie_read_config,
+        u4_pcie_write_config
+};
+
 static void __init setup_u3_agp(struct pci_controller* hose)
 {
 	/* On G5, we move AGP up to high bus number so we don't need
@@ -307,6 +415,26 @@ static void __init setup_u3_agp(struct p
 	u3_agp = hose;
 }
 
+static void __init setup_u4_pcie(struct pci_controller* hose)
+{
+        /* We currently only implement the "non-atomic" config space, to
+         * be optimised later.
+         */
+        hose->ops = &u4_pcie_pci_ops;
+        hose->cfg_addr = ioremap(0xf0000000 + 0x800000, 0x1000);
+        hose->cfg_data = ioremap(0xf0000000 + 0xc00000, 0x1000);
+
+        /* The bus contains a bridge from root -> device, we need to
+         * make it visible on bus 0 so that we pick the right type
+         * of config cycles. If we didn't, we would have to force all
+         * config cycles to be type 1. So we override the "bus-range"
+         * property here
+         */
+        hose->first_busno = 0x00;
+        hose->last_busno = 0xff;
+        u4_pcie = hose;
+}
+
 static void __init setup_u3_ht(struct pci_controller* hose)
 {
 	hose->ops = &u3_ht_pci_ops;
@@ -354,6 +482,10 @@ static int __init add_bridge(struct devi
 		setup_u3_ht(hose);
 		disp_name = "U3-HT";
 		primary = 1;
+        } else if (device_is_compatible(dev, "u4-pcie")) {
+                setup_u4_pcie(hose);
+                disp_name = "U4-PCIE";
+                primary = 0;
 	}
 	printk(KERN_INFO "Found %s PCI host bridge. Firmware bus number: %d->%d\n",
 		disp_name, hose->first_busno, hose->last_busno);
@@ -361,7 +493,6 @@ static int __init add_bridge(struct devi
 	/* Interpret the "ranges" property */
 	/* This also maps the I/O region and sets isa_io/mem_base */
 	pci_process_bridge_OF_ranges(hose, dev, primary);
-	pci_setup_phb_io(hose, primary);
 
 	/* Fixup "bus-range" OF property */
 	fixup_bus_range(dev);
@@ -376,8 +507,17 @@ void __init maple_pcibios_fixup(void)
 
 	DBG(" -> maple_pcibios_fixup\n");
 
-	for_each_pci_dev(dev)
-		pci_read_irq_line(dev);
+	for_each_pci_dev(dev) {
+		/* Fixup IRQ for PCIe host */
+		if (u4_pcie != NULL && dev->bus->number == 0 &&
+		    pci_bus_to_host(dev->bus) == u4_pcie) {
+			printk(KERN_DEBUG "Fixup U4 PCIe IRQ\n");
+			dev->irq = irq_create_mapping(NULL, 1);
+			if (dev->irq != NO_IRQ)
+				set_irq_type(dev->irq, IRQ_TYPE_LEVEL_LOW);
+		} else
+			pci_read_irq_line(dev);
+	}
 
 	DBG(" <- maple_pcibios_fixup\n");
 }
@@ -388,8 +528,10 @@ static void __init maple_fixup_phb_resou
 	
 	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
 		unsigned long offset = (unsigned long)hose->io_base_virt - pci_io_base;
+
 		hose->io_resource.start += offset;
 		hose->io_resource.end += offset;
+
 		printk(KERN_INFO "PCI Host %d, io start: %llx; io end: %llx\n",
 		       hose->global_number,
 		       (unsigned long long)hose->io_resource.start,
@@ -431,6 +573,19 @@ void __init maple_pci_init(void)
 	if (ht && add_bridge(ht) != 0)
 		of_node_put(ht);
 
+        /*
+         * We need to call pci_setup_phb_io for the HT bridge first
+         * so it gets the I/O port numbers starting at 0, and we
+         * need to call it for the AGP bridge after that so it gets
+         * small positive I/O port numbers.
+         */
+        if (u3_ht)
+                pci_setup_phb_io(u3_ht, 1);
+        if (u3_agp)
+                pci_setup_phb_io(u3_agp, 0);
+        if (u4_pcie)
+                pci_setup_phb_io(u4_pcie, 0);
+
 	/* Fixup the IO resources on our host bridges as the common code
 	 * does it only for childs of the host bridges
 	 */
@@ -465,8 +620,11 @@ int maple_pci_get_legacy_ide_irq(struct 
 		return defirq;
 
 	np = pci_device_to_OF_node(pdev);
-	if (np == NULL)
+	if (np == NULL) {
+		printk("Failed to locate OF node for IDE %s\n",
+		       pci_name(pdev));
 		return defirq;
+	}
 	irq = irq_of_parse_and_map(np, channel & 0x1);
 	if (irq == NO_IRQ) {
 		printk("Failed to map onboard IDE interrupt for channel %d\n",
@@ -479,6 +637,9 @@ int maple_pci_get_legacy_ide_irq(struct 
 /* XXX: To remove once all firmwares are ok */
 static void fixup_maple_ide(struct pci_dev* dev)
 {
+	if (!machine_is(maple))
+		return;
+
 #if 0 /* Enable this to enable IDE port 0 */
 	{
 		u8 v;
@@ -495,7 +656,7 @@ static void fixup_maple_ide(struct pci_d
 	dev->resource[4].start = 0xcc00;
 	dev->resource[4].end = 0xcc10;
 #endif
-#if 1 /* Enable this to fixup IDE sense/polarity of irqs in IO-APICs */
+#if 0 /* Enable this to fixup IDE sense/polarity of irqs in IO-APICs */
 	{
 		struct pci_dev *apicdev;
 		u32 v;