This patch introduces support for the PIO mapping API on the ARM architecture. It is currently only meant as an example for discussions and it can be further optimised. Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> Cc: Russell King <rmk@xxxxxxxxxxxxxxxx> --- arch/arm/Kconfig | 3 ++ arch/arm/include/asm/pio-mapping.h | 66 ++++++++++++++++++++++++++++++++++++ 2 files changed, 69 insertions(+), 0 deletions(-) create mode 100644 arch/arm/include/asm/pio-mapping.h diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 4c33ca8..e48adcf 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -161,6 +161,9 @@ config ARCH_MTD_XIP config GENERIC_HARDIRQS_NO__DO_IRQ def_bool y +config HAVE_ARCH_PIO + def_bool y + if OPROFILE config OPROFILE_ARMV6 diff --git a/arch/arm/include/asm/pio-mapping.h b/arch/arm/include/asm/pio-mapping.h new file mode 100644 index 0000000..28d5834 --- /dev/null +++ b/arch/arm/include/asm/pio-mapping.h @@ -0,0 +1,66 @@ +/* + * include/linux/pio-mapping.h + * + * Copyright (C) 2010 ARM Ltd. + * Written by Catalin Marinas <catalin.marinas@xxxxxxx> + * + * 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, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifndef ASM_PIO_MAPPING_H +#define ASM_PIO_MAPPING_H + +#include <asm/cacheflush.h> +#include <asm/fixmap.h> + +static inline void *pio_kmap(struct page *page, enum dma_data_direction dir) +{ + return kmap(page); +} + +static inline void pio_kunmap(struct page *page, enum dma_data_direction dir) +{ + if (dir == DMA_FROM_DEVICE) + flush_dcache_page(page); + kunmap(page); +} + +static inline void *pio_kmap_atomic(struct page *page, enum km_type idx, + enum dma_data_direction dir) +{ + return kmap_atomic(page, idx); +} + +static inline void pio_kunmap_atomic(void *addr, enum km_type idx, + enum dma_data_direction dir) +{ + /* address higher than FIXADDR_START are flushed in kunmap_atomic */ + if (dir == DMA_FROM_DEVICE && addr < (void *)FIXADDR_START) + __cpuc_flush_dcache_area(addr, PAGE_SIZE); + kunmap_atomic(addr, idx); +} + +static inline void pio_begin(void *addr, size_t size, + enum dma_data_direction dir) +{ +} + +static inline void pio_end(void *addr, size_t size, + enum dma_data_direction dir) +{ + if (dir == DMA_FROM_DEVICE) + __cpuc_flush_dcache_area(addr, size); +} + +#endif /* ASM_PIO_MAPPING_H */ -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html