MIPS: Loongson 3: Add HT-linked PCI support

Loongson family machines use Hyper-Transport bus for inter-core
connection and device connection. The PCI bus is a subordinate
linked at HT1.

With LEFI firmware interface, We don't need fixup for PCI irq routing
(except providing a VBIOS of the integrated GPU).

Signed-off-by: Huacai Chen <[e-mail]>
Signed-off-by: Hongliang Tao <[e-mail]>
Signed-off-by: Hua Yan <[e-mail]>
Tested-by: Alex Smith <[e-mail]>
Reviewed-by: Alex Smith <[e-mail]>
Cc: John Crispin <[e-mail]>
Cc: Steven J. Hill <[e-mail]>
Cc: Aurelien Jarno <[e-mail]>
Cc: [e-mail]
Cc: Fuxin Zhang <[e-mail]>
Cc: Zhangjin Wu <[e-mail]>
Patchwork: https://patchwork.linux-mips.org/patch/6633
Signed-off-by: Ralf Baechle <[e-mail]>

arch/mips/include/asm/mach-loongson/loongson.h

···
 #include <linux/init.h>
 #include <linux/irq.h>
 #include <linux/kconfig.h>
+#include <boot_param.h>
 
 /* loongson internal northbridge initialization */
 extern void bonito_irq_init(void);
···
 #define LOONGSON_PCICFG_BASE	0x1fe80000
 #define LOONGSON_PCICFG_SIZE	0x00000800	/* 2K */
 #define LOONGSON_PCICFG_TOP	(LOONGSON_PCICFG_BASE+LOONGSON_PCICFG_SIZE-1)
+
+#if defined(CONFIG_HT_PCI)
+#define LOONGSON_PCIIO_BASE	loongson_sysconf.pci_io_base
+#else
 #define LOONGSON_PCIIO_BASE	0x1fd00000
+#endif
+
 #define LOONGSON_PCIIO_SIZE	0x00100000	/* 1M */
 #define LOONGSON_PCIIO_TOP	(LOONGSON_PCIIO_BASE+LOONGSON_PCIIO_SIZE-1)
 

arch/mips/include/asm/mach-loongson/pci.h

···
 #else	/* loongson2f/32bit & loongson2e */
 
 /* this pci memory space is mapped by pcimap in pci.c */
+#ifdef CONFIG_CPU_LOONGSON3
+#define LOONGSON_PCI_MEM_START	0x40000000UL
+#define LOONGSON_PCI_MEM_END	0x7effffffUL
+#else
 #define LOONGSON_PCI_MEM_START	LOONGSON_PCILO1_BASE
 #define LOONGSON_PCI_MEM_END	(LOONGSON_PCILO1_BASE + 0x04000000 * 2)
+#endif
 /* this is an offset from mips_io_port_base */
 #define LOONGSON_PCI_IO_START	0x00004000UL
 

arch/mips/pci/Makefile

···
 obj-$(CONFIG_MIPS_COBALT)	+= fixup-cobalt.o
 obj-$(CONFIG_LEMOTE_FULOONG2E)	+= fixup-fuloong2e.o ops-loongson2.o
 obj-$(CONFIG_LEMOTE_MACH2F)	+= fixup-lemote2f.o ops-loongson2.o
+obj-$(CONFIG_LEMOTE_MACH3A)	+= fixup-loongson3.o ops-loongson3.o
 obj-$(CONFIG_MIPS_MALTA)	+= fixup-malta.o pci-malta.o
 obj-$(CONFIG_PMC_MSP7120_GW)	+= fixup-pmcmsp.o ops-pmcmsp.o
 obj-$(CONFIG_PMC_MSP7120_EVAL)	+= fixup-pmcmsp.o ops-pmcmsp.o

arch/mips/pci/fixup-loongson3.c

···
+/*
+ * fixup-loongson3.c
+ *
+ * Copyright (C) 2012 Lemote, Inc.
+ * Author: Xiang Yu, [e-mail]
+ *         Chen Huacai, [e-mail]
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ * THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
+ * WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
+ * NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
+ * USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <linux/pci.h>
+#include <boot_param.h>
+
+static void print_fixup_info(const struct pci_dev *pdev)
+{
+	dev_info(&pdev->dev, "Device %x:%x, irq %d\n",
+			pdev->vendor, pdev->device, pdev->irq);
+}
+
+int __init pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
+{
+	print_fixup_info(dev);
+	return dev->irq;
+}
+
+static void pci_fixup_radeon(struct pci_dev *pdev)
+{
+	if (pdev->resource[PCI_ROM_RESOURCE].start)
+		return;
+
+	if (!loongson_sysconf.vgabios_addr)
+		return;
+
+	pdev->resource[PCI_ROM_RESOURCE].start =
+		loongson_sysconf.vgabios_addr;
+	pdev->resource[PCI_ROM_RESOURCE].end   =
+		loongson_sysconf.vgabios_addr + 256*1024 - 1;
+	pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_COPY;
+
+	dev_info(&pdev->dev, "BAR %d: assigned %pR for Radeon ROM\n",
+			PCI_ROM_RESOURCE, &pdev->resource[PCI_ROM_RESOURCE]);
+}
+
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_ATI, PCI_ANY_ID,
+				PCI_CLASS_DISPLAY_VGA, 8, pci_fixup_radeon);
+
+/* Do platform specific device initialization at pci_enable_device() time */
+int pcibios_plat_dev_init(struct pci_dev *dev)
+{
+	return 0;
+}

arch/mips/pci/ops-loongson3.c

···
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/kernel.h>
+
+#include <asm/mips-boards/bonito64.h>
+
+#include <loongson.h>
+
+#define PCI_ACCESS_READ  0
+#define PCI_ACCESS_WRITE 1
+
+#define HT1LO_PCICFG_BASE      0x1a000000
+#define HT1LO_PCICFG_BASE_TP1  0x1b000000
+
+static int loongson3_pci_config_access(unsigned char access_type,
+		struct pci_bus *bus, unsigned int devfn,
+		int where, u32 *data)
+{
+	unsigned char busnum = bus->number;
+	u_int64_t addr, type;
+	void *addrp;
+	int device = PCI_SLOT(devfn);
+	int function = PCI_FUNC(devfn);
+	int reg = where & ~3;
+
+	addr = (busnum << 16) | (device << 11) | (function << 8) | reg;
+	if (busnum == 0) {
+		if (device > 31)
+			return PCIBIOS_DEVICE_NOT_FOUND;
+		addrp = (void *)(TO_UNCAC(HT1LO_PCICFG_BASE) | (addr & 0xffff));
+		type = 0;
+
+	} else {
+		addrp = (void *)(TO_UNCAC(HT1LO_PCICFG_BASE_TP1) | (addr));
+		type = 0x10000;
+	}
+
+	if (access_type == PCI_ACCESS_WRITE)
+		writel(*data, addrp);
+	else {
+		*data = readl(addrp);
+		if (*data == 0xffffffff) {
+			*data = -1;
+			return PCIBIOS_DEVICE_NOT_FOUND;
+		}
+	}
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int loongson3_pci_pcibios_read(struct pci_bus *bus, unsigned int devfn,
+				 int where, int size, u32 *val)
+{
+	u32 data = 0;
+	int ret = loongson3_pci_config_access(PCI_ACCESS_READ,
+			bus, devfn, where, &data);
+
+	if (ret != PCIBIOS_SUCCESSFUL)
+		return ret;
+
+	if (size == 1)
+		*val = (data >> ((where & 3) << 3)) & 0xff;
+	else if (size == 2)
+		*val = (data >> ((where & 3) << 3)) & 0xffff;
+	else
+		*val = data;
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int loongson3_pci_pcibios_write(struct pci_bus *bus, unsigned int devfn,
+				  int where, int size, u32 val)
+{
+	u32 data = 0;
+	int ret;
+
+	if (size == 4)
+		data = val;
+	else {
+		ret = loongson3_pci_config_access(PCI_ACCESS_READ,
+				bus, devfn, where, &data);
+		if (ret != PCIBIOS_SUCCESSFUL)
+			return ret;
+
+		if (size == 1)
+			data = (data & ~(0xff << ((where & 3) << 3))) |
+			    (val << ((where & 3) << 3));
+		else if (size == 2)
+			data = (data & ~(0xffff << ((where & 3) << 3))) |
+			    (val << ((where & 3) << 3));
+	}
+
+	ret = loongson3_pci_config_access(PCI_ACCESS_WRITE,
+			bus, devfn, where, &data);
+
+	return ret;
+}
+
+struct pci_ops loongson_pci_ops = {
+	.read = loongson3_pci_pcibios_read,
+	.write = loongson3_pci_pcibios_write
+};