Re: [PATCH v6 1/2] PCI support added to ARC

[Bjorn Helgaas]

Hi Joao,

Trivial nits below; I wouldn't even mention them if you weren't making
a few updates to the other patch.

On Thu, Jan 14, 2016 at 11:04:32AM +0000, Joao Pinto wrote:
> This patch adds PCI support to ARC and updates drivers/pci Makefile
> enabling the ARC arch to use the generic PCI setup functions.
> 
> Signed-off-by: Joao Pinto <jpinto@xxxxxxxxxxxx>
> ---
> Change v5 -> v6 (Vineet Gupta):
> - Removed EXPORT_SYMBOL(pcibios_fixup_bus) from pcibios.c
> Change v4 -> v5 (Vineet Gupta):
> - pcibios.c unused functions, variables and includes were removed
> - ioremap.c has no need for changes (no patch is necessary)
> - pci.h unused functions and variables were removed
> Change v3 -> v4:
> - Nothing changed (just to keep up with patch set version).
> Change v2 -> v3 (Bjorn Helgaas):
> - arch/arc/kernel/pcibios.c unused functions were removed and also the
> arch/arc/include/asm/mach/pci.h was removed because was no longer necessary
> Change v1 -> v2:
> - In arch/arc/Kconfig, the new menu entry (Bus Configuration) was moved to the
> slot between sourcing of drivers/Kconfig and fs/Kconfig (Vineet Gupta)
> - In arch/arc/plat-axs10x/Kconfig the "select MIGHT_HAVE_PCI" option was placed
> in order as suggested (Vineet Gupta)
> - ioport_map() and ioport_unmap() were static inlined and included in
> the io.h (Vineet Gupta)
> - pcibios_min_io and pcibios_min_mem declaration moved to
> pcibios.c (Vineet Gupta)
> - pr_err() replaced by dev_err() in pcibios_enable_device() (Bjorn Helgaas)
> - string simplified in pcibios_enable_device() (Vineet Gupta)
> - pci_host_bridge_window structure was replaced by resource_entry structure, and
> list_for_each_entry() for resource_list_for_each_entry() in pcibios.c
> 
>  arch/arc/Kconfig             | 23 +++++++++++++++++++++++
>  arch/arc/include/asm/dma.h   |  5 +++++
>  arch/arc/include/asm/io.h    |  9 +++++++++
>  arch/arc/include/asm/pci.h   | 31 +++++++++++++++++++++++++++++++
>  arch/arc/kernel/Makefile     |  1 +
>  arch/arc/kernel/pcibios.c    | 23 ++++++++++++++++++++++++
>  arch/arc/plat-axs10x/Kconfig |  1 +
>  drivers/pci/Makefile         |  1 +
>  8 files changed, 95 insertions(+)
>  create mode 100644 arch/arc/include/asm/pci.h
>  create mode 100644 arch/arc/kernel/pcibios.c
> 
> diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
> index 2c2ac3f..98b32c1 100644
> --- a/arch/arc/Kconfig
> +++ b/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
>  
> @@ -570,6 +574,25 @@ 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 have 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"
> diff --git a/arch/arc/include/asm/dma.h b/arch/arc/include/asm/dma.h
> index ca7c451..37942fa 100644
> --- a/arch/arc/include/asm/dma.h
> +++ b/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)

No parens needed around "0".

> +#endif
>  
>  #endif
> diff --git a/arch/arc/include/asm/io.h b/arch/arc/include/asm/io.h
> index 694ece8..947bf0c 100644
> --- a/arch/arc/include/asm/io.h
> +++ b/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)
> diff --git a/arch/arc/include/asm/pci.h b/arch/arc/include/asm/pci.h
> new file mode 100644
> index 0000000..2f091e1
> --- /dev/null
> +++ b/arch/arc/include/asm/pci.h
> @@ -0,0 +1,31 @@
> +/*
> + * 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 <asm-generic/pci-dma-compat.h>
> +#include <asm-generic/pci-bridge.h>
> +
> +#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)

Or around "1".

> +
> +#endif /* __KERNEL__ */
> +
> +#endif /* _ASM_ARC_PCI_H */
> diff --git a/arch/arc/kernel/Makefile b/arch/arc/kernel/Makefile
> index e7f3625..1bc2036 100644
> --- a/arch/arc/kernel/Makefile
> +++ b/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-$(CONFIG_SMP) 			+= smp.o
> diff --git a/arch/arc/kernel/pcibios.c b/arch/arc/kernel/pcibios.c
> new file mode 100644
> index 0000000..12ea45a
> --- /dev/null
> +++ b/arch/arc/kernel/pcibios.c
> @@ -0,0 +1,23 @@
> +/*
> + * Copyright (C) 2014-2015 Synopsys, Inc. (www.synopsys.com)
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + */
> +
> +#include <linux/pci.h>
> +
> +/*
> + * We don't have to worry about legacy ISA devices, so nothing to do here
> + */
> +resource_size_t pcibios_align_resource(void *data, const struct resource *res,
> +				resource_size_t size, resource_size_t align)
> +{
> +	return res->start;
> +}
> +
> +void pcibios_fixup_bus(struct pci_bus *bus)
> +{
> +}
> diff --git a/arch/arc/plat-axs10x/Kconfig b/arch/arc/plat-axs10x/Kconfig
> index d475f9d..426ac4b 100644
> --- a/arch/arc/plat-axs10x/Kconfig
> +++ b/arch/arc/plat-axs10x/Kconfig
> @@ -11,6 +11,7 @@ menuconfig ARC_PLAT_AXS10X
>  	select DW_APB_ICTL
>  	select GPIO_DWAPB
>  	select OF_GPIO
> +	select MIGHT_HAVE_PCI
>  	select GENERIC_IRQ_CHIP
>  	select ARCH_REQUIRE_GPIOLIB
>  	help
> diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
> index be3f631..2154092 100644
> --- a/drivers/pci/Makefile
> +++ b/drivers/pci/Makefile
> @@ -32,6 +32,7 @@ obj-$(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
> -- 
> 1.8.1.5