From 7d5f5fa276efbbe45f0ed270b3f4e4a2816398c2 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 20 Aug 2013 22:51:47 +0200 Subject: m68k: Add kexec support Signed-off-by: Geert Uytterhoeven diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig index 75f25a8..178dffa 100644 --- a/arch/m68k/Kconfig +++ b/arch/m68k/Kconfig @@ -87,6 +87,23 @@ config MMU_SUN3 bool depends on MMU && !MMU_MOTOROLA && !MMU_COLDFIRE +config KEXEC + bool "kexec system call" + depends on M68KCLASSIC + help + kexec is a system call that implements the ability to shutdown your + current kernel, and to start another kernel. It is like a reboot + but it is independent of the system firmware. And like a reboot + you can start any kernel with it, not just Linux. + + The name comes from the similarity to the exec system call. + + It is an ongoing process to be certain the hardware in a machine + is properly shutdown, so do not be surprised if this code does not + initially work for you. As of this writing the exact hardware + interface is strongly in flux, so no good recommendation can be + made. + menu "Platform setup" source arch/m68k/Kconfig.cpu diff --git a/arch/m68k/include/asm/kexec.h b/arch/m68k/include/asm/kexec.h new file mode 100644 index 0000000..3df97ab --- /dev/null +++ b/arch/m68k/include/asm/kexec.h @@ -0,0 +1,29 @@ +#ifndef _ASM_M68K_KEXEC_H +#define _ASM_M68K_KEXEC_H + +#ifdef CONFIG_KEXEC + +/* Maximum physical address we can use pages from */ +#define KEXEC_SOURCE_MEMORY_LIMIT (-1UL) +/* Maximum address we can reach in physical address mode */ +#define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL) +/* Maximum address we can use for the control code buffer */ +#define KEXEC_CONTROL_MEMORY_LIMIT (-1UL) + +#define KEXEC_CONTROL_PAGE_SIZE 4096 + +#define KEXEC_ARCH KEXEC_ARCH_68K + +#ifndef __ASSEMBLY__ + +static inline void crash_setup_regs(struct pt_regs *newregs, + struct pt_regs *oldregs) +{ + /* Dummy implementation for now */ +} + +#endif /* __ASSEMBLY__ */ + +#endif /* CONFIG_KEXEC */ + +#endif /* _ASM_M68K_KEXEC_H */ diff --git a/arch/m68k/kernel/Makefile b/arch/m68k/kernel/Makefile index 655347d..7ee5f00 100644 --- a/arch/m68k/kernel/Makefile +++ b/arch/m68k/kernel/Makefile @@ -22,3 +22,5 @@ obj-$(CONFIG_PCI) += pcibios.o obj-$(CONFIG_HAS_DMA) += dma.o +obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o + diff --git a/arch/m68k/kernel/asm-offsets.c b/arch/m68k/kernel/asm-offsets.c index 8b7b228..3a38634 100644 --- a/arch/m68k/kernel/asm-offsets.c +++ b/arch/m68k/kernel/asm-offsets.c @@ -98,6 +98,9 @@ int main(void) DEFINE(CIABBASE, &ciab); DEFINE(C_PRA, offsetof(struct CIA, pra)); DEFINE(ZTWOBASE, zTwoBase); + + /* enum m68k_fixup_type */ + DEFINE(M68K_FIXUP_MEMOFFSET, m68k_fixup_memoffset); #endif return 0; diff --git a/arch/m68k/kernel/machine_kexec.c b/arch/m68k/kernel/machine_kexec.c new file mode 100644 index 0000000..d4affc9 --- /dev/null +++ b/arch/m68k/kernel/machine_kexec.c @@ -0,0 +1,58 @@ +/* + * machine_kexec.c - handle transition of Linux booting another kernel + */ +#include +#include +#include +#include + +#include +#include +#include + +extern const unsigned char relocate_new_kernel[]; +extern const size_t relocate_new_kernel_size; + +int machine_kexec_prepare(struct kimage *kimage) +{ + return 0; +} + +void machine_kexec_cleanup(struct kimage *kimage) +{ +} + +void machine_shutdown(void) +{ +} + +void machine_crash_shutdown(struct pt_regs *regs) +{ +} + +typedef void (*relocate_kernel_t)(unsigned long ptr, + unsigned long start, + unsigned long cpu_mmu_flags) __noreturn; + +void machine_kexec(struct kimage *image) +{ + void *reboot_code_buffer; + unsigned long cpu_mmu_flags; + + reboot_code_buffer = page_address(image->control_code_page); + + memcpy(reboot_code_buffer, relocate_new_kernel, + relocate_new_kernel_size); + + /* + * we do not want to be bothered. + */ + local_irq_disable(); + + pr_info("Will call new kernel at 0x%08lx. Bye...\n", image->start); + __flush_cache_all(); + cpu_mmu_flags = m68k_cputype | m68k_mmutype << 8; + ((relocate_kernel_t) reboot_code_buffer)(image->head & PAGE_MASK, + image->start, + cpu_mmu_flags); +} diff --git a/arch/m68k/kernel/relocate_kernel.S b/arch/m68k/kernel/relocate_kernel.S new file mode 100644 index 0000000..3e09a89 --- /dev/null +++ b/arch/m68k/kernel/relocate_kernel.S @@ -0,0 +1,159 @@ +#include + +#include +#include +#include + + +#define MMU_BASE 8 /* MMU flags base in cpu_mmu_flags */ + +.text + +ENTRY(relocate_new_kernel) + movel %sp@(4),%a0 /* a0 = ptr */ + movel %sp@(8),%a1 /* a1 = start */ + movel %sp@(12),%d1 /* d1 = cpu_mmu_flags */ + movew #PAGE_MASK,%d2 /* d2 = PAGE_MASK */ + + /* Disable MMU */ + + btst #MMU_BASE + MMUB_68851,%d1 + jeq 3f + +1: /* 68851 or 68030 */ + + lea %pc@(.Lcopy),%a4 +2: addl #0x00000000,%a4 /* virt_to_phys() */ + + .section ".m68k_fixup","aw" + .long M68K_FIXUP_MEMOFFSET, 2b+2 + .previous + + .chip 68030 + pmove %tc,%d0 /* Disable MMU */ + bclr #7,%d0 + pmove %d0,%tc + jmp %a4@ /* Jump to physical .Lcopy */ + .chip 68k + +3: + btst #MMU_BASE + MMUB_68030,%d1 + jne 1b + + btst #MMU_BASE + MMUB_68040,%d1 + jeq 6f + +4: /* 68040 or 68060 */ + + lea %pc@(.Lcont040),%a4 +5: addl #0x00000000,%a4 /* virt_to_phys() */ + + .section ".m68k_fixup","aw" + .long M68K_FIXUP_MEMOFFSET, 5b+2 + .previous + + movel %a4,%d0 + andl #0xff000000,%d0 + orw #0xe020,%d0 /* Map 16 MiB, enable, cacheable */ + .chip 68040 + movec %d0,%itt0 + movec %d0,%dtt0 + .chip 68k + jmp %a4@ /* Jump to physical .Lcont040 */ + +.Lcont040: + moveq #0,%d0 + .chip 68040 + movec %d0,%tc /* Disable MMU */ + movec %d0,%itt0 + movec %d0,%itt1 + movec %d0,%dtt0 + movec %d0,%dtt1 + .chip 68k + jra .Lcopy + +6: + btst #MMU_BASE + MMUB_68060,%d1 + jne 4b + +.Lcopy: + movel %a0@+,%d0 /* d0 = entry = *ptr */ + jeq .Lflush + + btst #2,%d0 /* entry & IND_DONE? */ + jne .Lflush + + btst #1,%d0 /* entry & IND_INDIRECTION? */ + jeq 1f + andw %d2,%d0 + movel %d0,%a0 /* ptr = entry & PAGE_MASK */ + jra .Lcopy + +1: + btst #0,%d0 /* entry & IND_DESTINATION? */ + jeq 2f + andw %d2,%d0 + movel %d0,%a2 /* a2 = dst = entry & PAGE_MASK */ + jra .Lcopy + +2: + btst #3,%d0 /* entry & IND_SOURCE? */ + jeq .Lcopy + + andw %d2,%d0 + movel %d0,%a3 /* a3 = src = entry & PAGE_MASK */ + movew #PAGE_SIZE/32 - 1,%d0 /* d0 = PAGE_SIZE/32 - 1 */ +3: + movel %a3@+,%a2@+ /* *dst++ = *src++ */ + movel %a3@+,%a2@+ /* *dst++ = *src++ */ + movel %a3@+,%a2@+ /* *dst++ = *src++ */ + movel %a3@+,%a2@+ /* *dst++ = *src++ */ + movel %a3@+,%a2@+ /* *dst++ = *src++ */ + movel %a3@+,%a2@+ /* *dst++ = *src++ */ + movel %a3@+,%a2@+ /* *dst++ = *src++ */ + movel %a3@+,%a2@+ /* *dst++ = *src++ */ + dbf %d0, 3b + jra .Lcopy + +.Lflush: + /* Flush all caches */ + + btst #CPUB_68020,%d1 + jeq 2f + +1: /* 68020 or 68030 */ + .chip 68030 + movec %cacr,%d0 + orw #0x808,%d0 + movec %d0,%cacr + .chip 68k + jra .Lreincarnate + +2: + btst #CPUB_68030,%d1 + jne 1b + + btst #CPUB_68040,%d1 + jeq 4f + +3: /* 68040 or 68060 */ + .chip 68040 + nop + cpusha %bc + nop + cinva %bc + nop + .chip 68k + jra .Lreincarnate + +4: + btst #CPUB_68060,%d1 + jne 3b + +.Lreincarnate: + jmp %a1@ + +relocate_new_kernel_end: + +ENTRY(relocate_new_kernel_size) + .long relocate_new_kernel_end - relocate_new_kernel diff --git a/include/uapi/linux/kexec.h b/include/uapi/linux/kexec.h index 104838f..d6629d4 100644 --- a/include/uapi/linux/kexec.h +++ b/include/uapi/linux/kexec.h @@ -18,6 +18,7 @@ */ #define KEXEC_ARCH_DEFAULT ( 0 << 16) #define KEXEC_ARCH_386 ( 3 << 16) +#define KEXEC_ARCH_68K ( 4 << 16) #define KEXEC_ARCH_X86_64 (62 << 16) #define KEXEC_ARCH_PPC (20 << 16) #define KEXEC_ARCH_PPC64 (21 << 16) -- cgit v0.10.2