On Tue, Nov 08, 2016 at 11:47:07AM +0800, zhichang.yuan wrote: > For arm64, there is no I/O space as other architectural platforms, such as > X86. Most I/O accesses are achieved based on MMIO. But for some arm64 SoCs, > such as Hip06, when accessing some legacy ISA devices connected to LPC, those > known port addresses are used to control the corresponding target devices, for > example, 0x2f8 is for UART, 0xe4 is for ipmi-bt. It is different from the > normal MMIO mode in using. > > To drive these devices, this patch introduces a method named indirect-IO. > In this method the in/out pair in arch/arm64/include/asm/io.h will be > redefined. When upper layer drivers call in/out with those known legacy port > addresses to access the peripherals, the hooking functions corrresponding to > those target peripherals will be called. Through this way, those upper layer > drivers which depend on in/out can run on Hip06 without any changes. > > Cc: Catalin Marinas <catalin.mari...@arm.com> > Cc: Will Deacon <will.dea...@arm.com> > Signed-off-by: zhichang.yuan <yuanzhich...@hisilicon.com> > Signed-off-by: Gabriele Paoloni <gabriele.paol...@huawei.com> > --- > arch/arm64/Kconfig | 6 +++ > arch/arm64/include/asm/extio.h | 94 > ++++++++++++++++++++++++++++++++++++++++++ > arch/arm64/include/asm/io.h | 29 +++++++++++++ > arch/arm64/kernel/Makefile | 1 + > arch/arm64/kernel/extio.c | 27 ++++++++++++ > 5 files changed, 157 insertions(+) > create mode 100644 arch/arm64/include/asm/extio.h > create mode 100644 arch/arm64/kernel/extio.c > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 969ef88..b44070b 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -163,6 +163,12 @@ config ARCH_MMAP_RND_COMPAT_BITS_MIN > config ARCH_MMAP_RND_COMPAT_BITS_MAX > default 16 > > +config ARM64_INDIRECT_PIO > + bool "access peripherals with legacy I/O port" > + help > + Support special accessors for ISA I/O devices. This is needed for > + SoCs that do not support standard read/write for the ISA range. > + > config NO_IOPORT_MAP > def_bool y if !PCI > > diff --git a/arch/arm64/include/asm/extio.h b/arch/arm64/include/asm/extio.h > new file mode 100644 > index 0000000..6ae0787 > --- /dev/null > +++ b/arch/arm64/include/asm/extio.h > @@ -0,0 +1,94 @@ > +/* > + * Copyright (C) 2016 Hisilicon Limited, All Rights Reserved. > + * Author: Zhichang Yuan <yuanzhich...@hisilicon.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. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see <http://www.gnu.org/licenses/>. > + */ > + > +#ifndef __LINUX_EXTIO_H > +#define __LINUX_EXTIO_H > + > +struct extio_ops { > + unsigned long start;/* inclusive, sys io addr */ > + unsigned long end;/* inclusive, sys io addr */ > + > + u64 (*pfin)(void *devobj, unsigned long ptaddr, size_t dlen); > + void (*pfout)(void *devobj, unsigned long ptaddr, u32 outval, > + size_t dlen); > + u64 (*pfins)(void *devobj, unsigned long ptaddr, void *inbuf, > + size_t dlen, unsigned int count); > + void (*pfouts)(void *devobj, unsigned long ptaddr, > + const void *outbuf, size_t dlen, > + unsigned int count); > + void *devpara; > +}; > + > +extern struct extio_ops *arm64_extio_ops; > + > +#define DECLARE_EXTIO(bw, type) > \ > +extern type in##bw(unsigned long addr); > \ > +extern void out##bw(type value, unsigned long addr); \ > +extern void ins##bw(unsigned long addr, void *buffer, unsigned int count);\ > +extern void outs##bw(unsigned long addr, const void *buffer, unsigned int > count); > + > +#define BUILD_EXTIO(bw, type) > \ > +type in##bw(unsigned long addr) > \ > +{ \ > + if (!arm64_extio_ops || arm64_extio_ops->start > addr || \ > + arm64_extio_ops->end < addr) \ > + return read##bw(PCI_IOBASE + addr); \ > + return arm64_extio_ops->pfin ? \ > + arm64_extio_ops->pfin(arm64_extio_ops->devpara, \ > + addr, sizeof(type)) : -1; \ > +} \ > + \ > +void out##bw(type value, unsigned long addr) \ > +{ \ > + if (!arm64_extio_ops || arm64_extio_ops->start > addr || \ > + arm64_extio_ops->end < addr) \ > + write##bw(value, PCI_IOBASE + addr); \ > + else \ > + if (arm64_extio_ops->pfout) \ > + arm64_extio_ops->pfout(arm64_extio_ops->devpara,\ > + addr, value, sizeof(type)); \ > +} \ > + \ > +void ins##bw(unsigned long addr, void *buffer, unsigned int count) \ > +{ \ > + if (!arm64_extio_ops || arm64_extio_ops->start > addr || \ > + arm64_extio_ops->end < addr) \ > + reads##bw(PCI_IOBASE + addr, buffer, count); \ > + else \ > + if (arm64_extio_ops->pfins) \ > + arm64_extio_ops->pfins(arm64_extio_ops->devpara,\ > + addr, buffer, sizeof(type), count); \ > +} \ > + \ > +void outs##bw(unsigned long addr, const void *buffer, unsigned int count) > \ > +{ \ > + if (!arm64_extio_ops || arm64_extio_ops->start > addr || \ > + arm64_extio_ops->end < addr) \ > + writes##bw(PCI_IOBASE + addr, buffer, count); \ > + else \ > + if (arm64_extio_ops->pfouts) \ > + arm64_extio_ops->pfouts(arm64_extio_ops->devpara,\ > + addr, buffer, sizeof(type), count); \ > +} > + > +static inline void arm64_set_extops(struct extio_ops *ops) > +{ > + if (ops) > + WRITE_ONCE(arm64_extio_ops, ops);
Why does this need to be WRITE_ONCE? You don't have READ_ONCE on the reader side. Also, what if multiple drivers want to set different ops for distinct address ranges? > +} > + > +#endif /* __LINUX_EXTIO_H*/ > diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h > index 0bba427..136735d 100644 > --- a/arch/arm64/include/asm/io.h > +++ b/arch/arm64/include/asm/io.h > @@ -31,6 +31,7 @@ > #include <asm/early_ioremap.h> > #include <asm/alternative.h> > #include <asm/cpufeature.h> > +#include <asm/extio.h> > > #include <xen/xen.h> > > @@ -149,6 +150,34 @@ static inline u64 __raw_readq(const volatile void > __iomem *addr) > #define IO_SPACE_LIMIT (PCI_IO_SIZE - 1) > #define PCI_IOBASE ((void __iomem *)PCI_IO_START) > > + > +/* > + * redefine the in(s)b/out(s)b for indirect-IO. > + */ > +#ifdef CONFIG_ARM64_INDIRECT_PIO > +#define inb inb > +#define outb outb > +#define insb insb > +#define outsb outsb > +/* external declaration */ > +DECLARE_EXTIO(b, u8) > + > +#define inw inw > +#define outw outw > +#define insw insw > +#define outsw outsw > + > +DECLARE_EXTIO(w, u16) > + > +#define inl inl > +#define outl outl > +#define insl insl > +#define outsl outsl > + > +DECLARE_EXTIO(l, u32) > +#endif > + > + > /* > * String version of I/O memory access operations. > */ > diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile > index 7d66bba..60e0482 100644 > --- a/arch/arm64/kernel/Makefile > +++ b/arch/arm64/kernel/Makefile > @@ -31,6 +31,7 @@ arm64-obj-$(CONFIG_COMPAT) += sys32.o kuser32.o > signal32.o \ > sys_compat.o entry32.o > arm64-obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o entry-ftrace.o > arm64-obj-$(CONFIG_MODULES) += arm64ksyms.o module.o > +arm64-obj-$(CONFIG_ARM64_INDIRECT_PIO) += extio.o > arm64-obj-$(CONFIG_ARM64_MODULE_PLTS) += module-plts.o > arm64-obj-$(CONFIG_PERF_EVENTS) += perf_regs.o perf_callchain.o > arm64-obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o > diff --git a/arch/arm64/kernel/extio.c b/arch/arm64/kernel/extio.c > new file mode 100644 > index 0000000..647b3fa > --- /dev/null > +++ b/arch/arm64/kernel/extio.c > @@ -0,0 +1,27 @@ > +/* > + * Copyright (C) 2016 Hisilicon Limited, All Rights Reserved. > + * Author: Zhichang Yuan <yuanzhich...@hisilicon.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. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see <http://www.gnu.org/licenses/>. > + */ > + > +#include <linux/io.h> > + > +struct extio_ops *arm64_extio_ops; > + > + > +BUILD_EXTIO(b, u8) > + > +BUILD_EXTIO(w, u16) > + > +BUILD_EXTIO(l, u32) Is there no way to make this slightly more generic, so that it can be re-used elsewhere? For example, if struct extio_ops was common, then you could have the singleton (which maybe should be an interval tree?), type definition, setter function and the BUILD_EXTIO invocations somewhere generic, rather than squirelled away in the arch backend. Will
