For "User Mode Linux", it may enable 'MMU', but not need implement ioremap and iounmap, so "include/asm-generic/io.h" need notice this case to keep itself 'generic'. The related error (with allmodconfig, without pcap): CC [M] drivers/ptp/ptp_pch.o drivers/ptp/ptp_pch.c: In function ‘pch_remove’: drivers/ptp/ptp_pch.c:571:3: error: implicit declaration of function ‘iounmap’ [-Werror=implicit-function-declaration] drivers/ptp/ptp_pch.c: In function ‘pch_probe’: drivers/ptp/ptp_pch.c:621:2: error: implicit declaration of function ‘ioremap’ [-Werror=implicit-function-declaration] drivers/ptp/ptp_pch.c:621:13: warning: assignment makes pointer from integer without a cast [enabled by default] cc1: some warnings being treated as errors Signed-off-by: Chen Gang <gang.chen@xxxxxxxxxxx> --- arch/um/include/asm/Kbuild | 1 + include/asm-generic/io.h | 6 +++--- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild index b30f34a..a34ea5d 100644 --- a/arch/um/include/asm/Kbuild +++ b/arch/um/include/asm/Kbuild @@ -3,3 +3,4 @@ generic-y += hw_irq.h irq_regs.h kdebug.h percpu.h sections.h topology.h xor.h generic-y += ftrace.h pci.h io.h param.h delay.h mutex.h current.h exec.h generic-y += switch_to.h clkdev.h generic-y += trace_clock.h +generic-y += io.h diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h index d5afe96..e80331d 100644 --- a/include/asm-generic/io.h +++ b/include/asm-generic/io.h @@ -303,10 +303,10 @@ static inline void *phys_to_virt(unsigned long address) /* * Change "struct page" to physical address. * - * This implementation is for the no-MMU case only... if you have an MMU + * This implementation is for the no-MMU or UML case only... if you have an MMU * you'll need to provide your own definitions. */ -#ifndef CONFIG_MMU +#if !CONFIG_MMU || CONFIG_UML static inline void __iomem *ioremap(phys_addr_t offset, unsigned long size) { return (void __iomem*) (unsigned long)offset; @@ -325,7 +325,7 @@ static inline void __iomem *ioremap(phys_addr_t offset, unsigned long size) static inline void iounmap(void __iomem *addr) { } -#endif /* CONFIG_MMU */ +#endif /* !CONFIG_MMU || CONFIG_UML */ #ifdef CONFIG_HAS_IOPORT #ifndef CONFIG_GENERIC_IOMAP -- 1.7.7.6 -- 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