From 9663f2e6a6cf3f82b06d8fb699b11b80f92553ba Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Thu, 30 Oct 2008 19:38:18 -0700 Subject: resources: add io-mapping functions to dynamically map large device apertures Impact: add new generic io_map_*() APIs Graphics devices have large PCI apertures which would consume a significant fraction of a 32-bit address space if mapped during driver initialization. Using ioremap at runtime is impractical as it is too slow. This new set of interfaces uses atomic mappings on 32-bit processors and a large static mapping on 64-bit processors to provide reasonable 32-bit performance and optimal 64-bit performance. The current implementation sits atop the io_map_atomic fixmap-based mechanism for 32-bit processors. This includes some editorial suggestions from Randy Dunlap for Documentation/io-mapping.txt Signed-off-by: Keith Packard Signed-off-by: Eric Anholt Signed-off-by: Ingo Molnar --- include/linux/io-mapping.h | 118 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) create mode 100644 include/linux/io-mapping.h (limited to 'include/linux') diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h new file mode 100644 index 00000000000..1b566993db6 --- /dev/null +++ b/include/linux/io-mapping.h @@ -0,0 +1,118 @@ +/* + * Copyright © 2008 Keith Packard + * + * This file is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License + * 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, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#ifndef _LINUX_IO_MAPPING_H +#define _LINUX_IO_MAPPING_H + +#include +#include +#include +#include + +/* + * The io_mapping mechanism provides an abstraction for mapping + * individual pages from an io device to the CPU in an efficient fashion. + * + * See Documentation/io_mapping.txt + */ + +/* this struct isn't actually defined anywhere */ +struct io_mapping; + +#ifdef CONFIG_X86_64 + +/* Create the io_mapping object*/ +static inline struct io_mapping * +io_mapping_create_wc(unsigned long base, unsigned long size) +{ + return (struct io_mapping *) ioremap_wc(base, size); +} + +static inline void +io_mapping_free(struct io_mapping *mapping) +{ + iounmap(mapping); +} + +/* Atomic map/unmap */ +static inline void * +io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset) +{ + return ((char *) mapping) + offset; +} + +static inline void +io_mapping_unmap_atomic(void *vaddr) +{ +} + +/* Non-atomic map/unmap */ +static inline void * +io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset) +{ + return ((char *) mapping) + offset; +} + +static inline void +io_mapping_unmap(void *vaddr) +{ +} + +#endif /* CONFIG_X86_64 */ + +#ifdef CONFIG_X86_32 +static inline struct io_mapping * +io_mapping_create_wc(unsigned long base, unsigned long size) +{ + return (struct io_mapping *) base; +} + +static inline void +io_mapping_free(struct io_mapping *mapping) +{ +} + +/* Atomic map/unmap */ +static inline void * +io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset) +{ + offset += (unsigned long) mapping; + return iomap_atomic_prot_pfn(offset >> PAGE_SHIFT, KM_USER0, + __pgprot(__PAGE_KERNEL_WC)); +} + +static inline void +io_mapping_unmap_atomic(void *vaddr) +{ + iounmap_atomic(vaddr, KM_USER0); +} + +static inline void * +io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset) +{ + offset += (unsigned long) mapping; + return ioremap_wc(offset, PAGE_SIZE); +} + +static inline void +io_mapping_unmap(void *vaddr) +{ + iounmap(vaddr); +} +#endif /* CONFIG_X86_32 */ + +#endif /* _LINUX_IO_MAPPING_H */ -- cgit v1.2.3-70-g09d2 From e5beae16901795223d677f15aa2fe192976278ee Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Mon, 3 Nov 2008 18:21:45 +0100 Subject: io mapping: clean up #ifdefs Impact: cleanup clean up ifdefs: change #ifdef CONFIG_X86_32/64 to CONFIG_HAVE_ATOMIC_IOMAP. flip around the #ifdef sections to clean up the structure. Signed-off-by: Keith Packard Signed-off-by: Ingo Molnar --- arch/x86/Kconfig | 4 ++++ include/linux/io-mapping.h | 43 +++++++++++++++++++++++++------------------ 2 files changed, 29 insertions(+), 18 deletions(-) (limited to 'include/linux') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 6f20718d315..e60c59b81bd 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1894,6 +1894,10 @@ config SYSVIPC_COMPAT endmenu +config HAVE_ATOMIC_IOMAP + def_bool y + depends on X86_32 + source "net/Kconfig" source "drivers/Kconfig" diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h index 1b566993db6..82df31726a5 100644 --- a/include/linux/io-mapping.h +++ b/include/linux/io-mapping.h @@ -33,86 +33,93 @@ /* this struct isn't actually defined anywhere */ struct io_mapping; -#ifdef CONFIG_X86_64 +#ifdef CONFIG_HAVE_ATOMIC_IOMAP + +/* + * For small address space machines, mapping large objects + * into the kernel virtual space isn't practical. Where + * available, use fixmap support to dynamically map pages + * of the object at run time. + */ -/* Create the io_mapping object*/ static inline struct io_mapping * io_mapping_create_wc(unsigned long base, unsigned long size) { - return (struct io_mapping *) ioremap_wc(base, size); + return (struct io_mapping *) base; } static inline void io_mapping_free(struct io_mapping *mapping) { - iounmap(mapping); } /* Atomic map/unmap */ static inline void * io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset) { - return ((char *) mapping) + offset; + offset += (unsigned long) mapping; + return iomap_atomic_prot_pfn(offset >> PAGE_SHIFT, KM_USER0, + __pgprot(__PAGE_KERNEL_WC)); } static inline void io_mapping_unmap_atomic(void *vaddr) { + iounmap_atomic(vaddr, KM_USER0); } -/* Non-atomic map/unmap */ static inline void * io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset) { - return ((char *) mapping) + offset; + offset += (unsigned long) mapping; + return ioremap_wc(offset, PAGE_SIZE); } static inline void io_mapping_unmap(void *vaddr) { + iounmap(vaddr); } -#endif /* CONFIG_X86_64 */ +#else -#ifdef CONFIG_X86_32 +/* Create the io_mapping object*/ static inline struct io_mapping * io_mapping_create_wc(unsigned long base, unsigned long size) { - return (struct io_mapping *) base; + return (struct io_mapping *) ioremap_wc(base, size); } static inline void io_mapping_free(struct io_mapping *mapping) { + iounmap(mapping); } /* Atomic map/unmap */ static inline void * io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset) { - offset += (unsigned long) mapping; - return iomap_atomic_prot_pfn(offset >> PAGE_SHIFT, KM_USER0, - __pgprot(__PAGE_KERNEL_WC)); + return ((char *) mapping) + offset; } static inline void io_mapping_unmap_atomic(void *vaddr) { - iounmap_atomic(vaddr, KM_USER0); } +/* Non-atomic map/unmap */ static inline void * io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset) { - offset += (unsigned long) mapping; - return ioremap_wc(offset, PAGE_SIZE); + return ((char *) mapping) + offset; } static inline void io_mapping_unmap(void *vaddr) { - iounmap(vaddr); } -#endif /* CONFIG_X86_32 */ + +#endif /* HAVE_ATOMIC_IOMAP */ #endif /* _LINUX_IO_MAPPING_H */ -- cgit v1.2.3-70-g09d2