관리-도구

편집 파일: xip.h

/* SPDX-License-Identifier: GPL-2.0-only */ /* * MTD primitives for XIP support * * Author: Nicolas Pitre * Created: Nov 2, 2004 * Copyright: (C) 2004 MontaVista Software, Inc. * * This XIP support for MTD has been loosely inspired * by an earlier patch authored by David Woodhouse. */ #ifndef __LINUX_MTD_XIP_H__ #define __LINUX_MTD_XIP_H__ #ifdef CONFIG_MTD_XIP /* * We really don't want gcc to guess anything. * We absolutely _need_ proper inlining. */ #include <linux/compiler.h> /* * Function that are modifying the flash state away from array mode must * obviously not be running from flash. The __xipram is therefore marking * those functions so they get relocated to ram. */ #ifdef CONFIG_XIP_KERNEL #define __xipram noinline __section(".xiptext") #endif /* * Each architecture has to provide the following macros. They must access * the hardware directly and not rely on any other (XIP) functions since they * won't be available when used (flash not in array mode). * * xip_irqpending() * * return non zero when any hardware interrupt is pending. * * xip_currtime() * * return a platform specific time reference to be used with * xip_elapsed_since(). * * xip_elapsed_since(x) * * return in usecs the elapsed timebetween now and the reference x as * returned by xip_currtime(). * * note 1: conversion to usec can be approximated, as long as the * returned value is <= the real elapsed time. * note 2: this should be able to cope with a few seconds without * overflowing. * * xip_iprefetch() * * Macro to fill instruction prefetch * e.g. a series of nops: asm volatile (".rep 8; nop; .endr"); */ #include <asm/mtd-xip.h> #ifndef xip_irqpending #warning "missing IRQ and timer primitives for XIP MTD support" #warning "some of the XIP MTD support code will be disabled" #warning "your system will therefore be unresponsive when writing or erasing flash" #define xip_irqpending() (0) #define xip_currtime() (0) #define xip_elapsed_since(x) (0) #endif #ifndef xip_iprefetch #define xip_iprefetch() do { } while (0) #endif /* * xip_cpu_idle() is used when waiting for a delay equal or larger than * the system timer tick period. This should put the CPU into idle mode * to save power and to be woken up only when some interrupts are pending. * This should not rely upon standard kernel code. */ #ifndef xip_cpu_idle #define xip_cpu_idle() do { } while (0) #endif #endif /* CONFIG_MTD_XIP */ #ifndef __xipram #define __xipram #endif #endif /* __LINUX_MTD_XIP_H__ */