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-rw-r--r--arch/ppc64/kernel/misc.S175
1 files changed, 173 insertions, 2 deletions
diff --git a/arch/ppc64/kernel/misc.S b/arch/ppc64/kernel/misc.S
index e3c73b3425d..f3dea0c5a88 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