diff options
Diffstat (limited to 'arch/ppc64/kernel/misc.S')
| -rw-r--r-- | arch/ppc64/kernel/misc.S | 175 |
1 files changed, 173 insertions, 2 deletions
diff --git a/arch/ppc64/kernel/misc.S b/arch/ppc64/kernel/misc.S index e3c73b3425dc01..f3dea0c5a88c20 100644 --- a/arch/ppc64/kernel/misc.S +++ b/arch/ppc64/kernel/misc.S @@ -680,6 +680,177 @@ _GLOBAL(kernel_thread) ld r30,-16(r1) blr +/* kexec_wait(phys_cpu) + * + * wait for the flag to change, indicating this kernel is going away but + * the slave code for the next one is at addresses 0 to 100. + * + * This is used by all slaves. + * + * Physical (hardware) cpu id should be in r3. + */ +_GLOBAL(kexec_wait) + bl 1f +1: mflr r5 + addi r5,r5,kexec_flag-1b + +99: HMT_LOW +#ifdef CONFIG_KEXEC /* use no memory without kexec */ + lwz r4,0(r5) + cmpwi 0,r4,0 + bnea 0x60 +#endif + b 99b + +/* this can be in text because we won't change it until we are + * running in real anyways + */ +kexec_flag: + .long 0 + + +#ifdef CONFIG_KEXEC + +/* kexec_smp_wait(void) + * + * call with interrupts off + * note: this is a terminal routine, it does not save lr + * + * get phys id from paca + * set paca id to -1 to say we got here + * switch to real mode + * join other cpus in kexec_wait(phys_id) + */ +_GLOBAL(kexec_smp_wait) + lhz r3,PACAHWCPUID(r13) + li r4,-1 + sth r4,PACAHWCPUID(r13) /* let others know we left */ + bl real_mode + b .kexec_wait + +/* + * switch to real mode (turn mmu off) + * we use the early kernel trick that the hardware ignores bits + * 0 and 1 (big endian) of the effective address in real mode + * + * don't overwrite r3 here, it is live for kexec_wait above. + */ +real_mode: /* assume normal blr return */ +1: li r9,MSR_RI + li r10,MSR_DR|MSR_IR + mflr r11 /* return address to SRR0 */ + mfmsr r12 + andc r9,r12,r9 + andc r10,r12,r10 + + mtmsrd r9,1 + mtspr SPRN_SRR1,r10 + mtspr SPRN_SRR0,r11 + rfid + + +/* + * kexec_sequence(newstack, start, image, control, clear_all()) + * + * does the grungy work with stack switching and real mode switches + * also does simple calls to other code + */ + +_GLOBAL(kexec_sequence) + mflr r0 + std r0,16(r1) + + /* switch stacks to newstack -- &kexec_stack.stack */ + stdu r1,THREAD_SIZE-112(r3) + mr r1,r3 + + li r0,0 + std r0,16(r1) + + /* save regs for local vars on new stack. + * yes, we won't go back, but ... + */ + std r31,-8(r1) + std r30,-16(r1) + std r29,-24(r1) + std r28,-32(r1) + std r27,-40(r1) + std r26,-48(r1) + std r25,-56(r1) + + stdu r1,-112-64(r1) + + /* save args into preserved regs */ + mr r31,r3 /* newstack (both) */ + mr r30,r4 /* start (real) */ + mr r29,r5 /* image (virt) */ + mr r28,r6 /* control, unused */ + mr r27,r7 /* clear_all() fn desc */ + mr r26,r8 /* spare */ + lhz r25,PACAHWCPUID(r13) /* get our phys cpu from paca */ + + /* disable interrupts, we are overwriting kernel data next */ + mfmsr r3 + rlwinm r3,r3,0,17,15 + mtmsrd r3,1 + + /* copy dest pages, flush whole dest image */ + mr r3,r29 + bl .kexec_copy_flush /* (image) */ + + /* turn off mmu */ + bl real_mode + + /* clear out hardware hash page table and tlb */ + ld r5,0(r27) /* deref function descriptor */ + mtctr r5 + bctrl /* ppc_md.hash_clear_all(void); */ + +/* + * kexec image calling is: + * the first 0x100 bytes of the entry point are copied to 0 + * + * all slaves branch to slave = 0x60 (absolute) + * slave(phys_cpu_id); + * + * master goes to start = entry point + * start(phys_cpu_id, start, 0); + * + * + * a wrapper is needed to call existing kernels, here is an approximate + * description of one method: + * + * v2: (2.6.10) + * start will be near the boot_block (maybe 0x100 bytes before it?) + * it will have a 0x60, which will b to boot_block, where it will wait + * and 0 will store phys into struct boot-block and load r3 from there, + * copy kernel 0-0x100 and tell slaves to back down to 0x60 again + * + * v1: (2.6.9) + * boot block will have all cpus scanning device tree to see if they + * are the boot cpu ????? + * other device tree differences (prop sizes, va vs pa, etc)... + */ + + /* copy 0x100 bytes starting at start to 0 */ + li r3,0 + mr r4,r30 + li r5,0x100 + li r6,0 + bl .copy_and_flush /* (dest, src, copy limit, start offset) */ +1: /* assume normal blr return */ + + /* release other cpus to the new kernel secondary start at 0x60 */ + mflr r5 + li r6,1 + stw r6,kexec_flag-1b(5) + mr r3,r25 # my phys cpu + mr r4,r30 # start, aka phys mem offset + mtlr 4 + li r5,0 + blr /* image->start(physid, image->start, 0); */ +#endif /* CONFIG_KEXEC */ + /* Why isn't this a) automatic, b) written in 'C'? */ .balign 8 _GLOBAL(sys_call_table32) @@ -951,7 +1122,7 @@ _GLOBAL(sys_call_table32) .llong .compat_sys_mq_timedreceive /* 265 */ .llong .compat_sys_mq_notify .llong .compat_sys_mq_getsetattr - .llong .sys_ni_syscall /* 268 reserved for sys_kexec_load */ + .llong .compat_sys_kexec_load .llong .sys32_add_key .llong .sys32_request_key .llong .compat_sys_keyctl @@ -1227,7 +1398,7 @@ _GLOBAL(sys_call_table) .llong .sys_mq_timedreceive /* 265 */ .llong .sys_mq_notify .llong .sys_mq_getsetattr - .llong .sys_ni_syscall /* 268 reserved for sys_kexec_load */ + .llong .sys_kexec_load .llong .sys_add_key .llong .sys_request_key /* 270 */ .llong .sys_keyctl |