ARC: Add PCI support

Add PCI support to ARC and update drivers/pci Makefile enabling the ARC
arch to use the generic PCI setup functions.

[bhelgaas: fold in Joao's pci-dma-compat.h & pci-bridge.h build fix (I
should have caught this myself, sorry]
Signed-off-by: Joao Pinto <jpinto@synopsys.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/Kconfig

@@ -19,6 +19,7 @@ config ARC
 	select GENERIC_FIND_FIRST_BIT
 	# for now, we don't need GENERIC_IRQ_PROBE, CONFIG_GENERIC_IRQ_CHIP
 	select GENERIC_IRQ_SHOW
+	select GENERIC_PCI_IOMAP
 	select GENERIC_PENDING_IRQ if SMP
 	select GENERIC_SMP_IDLE_THREAD
 	select HAVE_ARCH_KGDB
@@ -39,6 +40,9 @@ config ARC
 	select PERF_USE_VMALLOC
 	select HAVE_DEBUG_STACKOVERFLOW
 
+config MIGHT_HAVE_PCI
+	bool
+
 config TRACE_IRQFLAGS_SUPPORT
 	def_bool y
 
@@ -568,6 +572,28 @@ endmenu	 # "ARC Architecture Configuration"
 source "mm/Kconfig"
 source "net/Kconfig"
 source "drivers/Kconfig"
+
+menu "Bus Support"
+
+config PCI
+	bool "PCI support" if MIGHT_HAVE_PCI
+	help
+	  PCI is the name of a bus system, i.e., the way the CPU talks to
+	  the other stuff inside your box.  Find out if your board/platform
+	  has PCI.
+
+	  Note: PCIe support for Synopsys Device will be available only
+	  when HAPS DX is configured with PCIe RC bitmap. If you have PCI,
+	  say Y, otherwise N.
+
+config PCI_SYSCALL
+	def_bool PCI
+
+source "drivers/pci/Kconfig"
+source "drivers/pci/pcie/Kconfig"
+
+endmenu
+
 source "fs/Kconfig"
 source "arch/arc/Kconfig.debug"
 source "security/Kconfig"

arch/arc/include/asm/dma.h

@@ -10,5 +10,10 @@
 #define ASM_ARC_DMA_H
 
 #define MAX_DMA_ADDRESS 0xC0000000
+#ifdef CONFIG_PCI
+extern int isa_dma_bridge_buggy;
+#else
+#define isa_dma_bridge_buggy	0
+#endif
 
 #endif

arch/arc/include/asm/io.h

@@ -16,6 +16,15 @@
 extern void __iomem *ioremap(unsigned long physaddr, unsigned long size);
 extern void __iomem *ioremap_prot(phys_addr_t offset, unsigned long size,
 				  unsigned long flags);
+static inline void __iomem *ioport_map(unsigned long port, unsigned int nr)
+{
+	return (void __iomem *)port;
+}
+
+static inline void ioport_unmap(void __iomem *addr)
+{
+}
+
 extern void iounmap(const void __iomem *addr);
 
 #define ioremap_nocache(phy, sz)	ioremap(phy, sz)

arch/arc/include/asm/pci.h

+/*
+ * Copyright (C) 2015-2016 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _ASM_ARC_PCI_H
+#define _ASM_ARC_PCI_H
+
+#ifdef __KERNEL__
+#include <linux/ioport.h>
+
+#define PCIBIOS_MIN_IO 0x100
+#define PCIBIOS_MIN_MEM 0x100000
+
+#define pcibios_assign_all_busses()	1
+/*
+ * The PCI address space does equal the physical memory address space.
+ * The networking and block device layers use this boolean for bounce
+ * buffer decisions.
+ */
+#define PCI_DMA_BUS_IS_PHYS	1
+
+#endif /* __KERNEL__ */
+
+#endif /* _ASM_ARC_PCI_H */

arch/arc/kernel/Makefile

@@ -12,6 +12,7 @@ obj-y	:= arcksyms.o setup.o irq.o time.o reset.o ptrace.o process.o devtree.o
 obj-y	+= signal.o traps.o sys.o troubleshoot.o stacktrace.o disasm.o clk.o
 obj-$(CONFIG_ISA_ARCOMPACT)		+= entry-compact.o intc-compact.o
 obj-$(CONFIG_ISA_ARCV2)			+= entry-arcv2.o intc-arcv2.o
+obj-$(CONFIG_PCI)  			+= pcibios.o
 
 obj-$(CONFIG_MODULES)			+= arcksyms.o module.o
 obj-$(CONFIG_SMP) 			+= smp.o

arch/arc/kernel/pcibios.c

+/*
+ * Copyright (C) 2014-2015 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/pci.h>
+
+/*
+ * We don't have to worry about legacy ISA devices, so nothing to do here
+ */
+resource_size_t pcibios_align_resource(void *data, const struct resource *res,
+				resource_size_t size, resource_size_t align)
+{
+	return res->start;
+}
+
+void pcibios_fixup_bus(struct pci_bus *bus)
+{
+}

arch/arc/plat-axs10x/Kconfig

@@ -11,6 +11,7 @@ menuconfig ARC_PLAT_AXS10X
 	select DW_APB_ICTL
 	select GPIO_DWAPB
 	select OF_GPIO
+	select MIGHT_HAVE_PCI
 	select GENERIC_IRQ_CHIP
 	select ARCH_REQUIRE_GPIOLIB
 	help

drivers/pci/Makefile

@@ -32,6 +32,7 @@ obj-$(CONFIG_PCI_IOV) += iov.o
 # Some architectures use the generic PCI setup functions
 #
 obj-$(CONFIG_ALPHA) += setup-irq.o
+obj-$(CONFIG_ARC) += setup-irq.o
 obj-$(CONFIG_ARM) += setup-irq.o
 obj-$(CONFIG_ARM64) += setup-irq.o
 obj-$(CONFIG_UNICORE32) += setup-irq.o