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-rw-r--r--arch/powerpc/kernel/head_64.S98
1 files changed, 98 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 1b779560728f..4286775cbde9 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -40,6 +40,8 @@
#include <asm/kvm_book3s_asm.h>
#include <asm/ptrace.h>
#include <asm/hw_irq.h>
+#include <asm/cputhreads.h>
+#include <asm/ppc-opcode.h>
/* The physical memory is laid out such that the secondary processor
* spin code sits at 0x0000...0x00ff. On server, the vectors follow
@@ -181,6 +183,64 @@ exception_marker:
#endif
#ifdef CONFIG_PPC_BOOK3E
+/*
+ * The booting_thread_hwid holds the thread id we want to boot in cpu
+ * hotplug case. It is set by cpu hotplug code, and is invalid by default.
+ * The thread id is the same as the initial value of SPRN_PIR[THREAD_ID]
+ * bit field.
+ */
+ .globl booting_thread_hwid
+booting_thread_hwid:
+ .long INVALID_THREAD_HWID
+ .align 3
+/*
+ * start a thread in the same core
+ * input parameters:
+ * r3 = the thread physical id
+ * r4 = the entry point where thread starts
+ */
+_GLOBAL(book3e_start_thread)
+ LOAD_REG_IMMEDIATE(r5, MSR_KERNEL)
+ cmpi 0, r3, 0
+ beq 10f
+ cmpi 0, r3, 1
+ beq 11f
+ /* If the thread id is invalid, just exit. */
+ b 13f
+10:
+ MTTMR(TMRN_IMSR0, 5)
+ MTTMR(TMRN_INIA0, 4)
+ b 12f
+11:
+ MTTMR(TMRN_IMSR1, 5)
+ MTTMR(TMRN_INIA1, 4)
+12:
+ isync
+ li r6, 1
+ sld r6, r6, r3
+ mtspr SPRN_TENS, r6
+13:
+ blr
+
+/*
+ * stop a thread in the same core
+ * input parameter:
+ * r3 = the thread physical id
+ */
+_GLOBAL(book3e_stop_thread)
+ cmpi 0, r3, 0
+ beq 10f
+ cmpi 0, r3, 1
+ beq 10f
+ /* If the thread id is invalid, just exit. */
+ b 13f
+10:
+ li r4, 1
+ sld r4, r4, r3
+ mtspr SPRN_TENC, r4
+13:
+ blr
+
_GLOBAL(fsl_secondary_thread_init)
mfspr r4,SPRN_BUCSR
@@ -261,6 +321,44 @@ _GLOBAL(generic_secondary_smp_init)
mr r3,r24
mr r4,r25
bl book3e_secondary_core_init
+
+/*
+ * After common core init has finished, check if the current thread is the
+ * one we wanted to boot. If not, start the specified thread and stop the
+ * current thread.
+ */
+ LOAD_REG_ADDR(r4, booting_thread_hwid)
+ lwz r3, 0(r4)
+ li r5, INVALID_THREAD_HWID
+ cmpw r3, r5
+ beq 20f
+
+ /*
+ * The value of booting_thread_hwid has been stored in r3,
+ * so make it invalid.
+ */
+ stw r5, 0(r4)
+
+ /*
+ * Get the current thread id and check if it is the one we wanted.
+ * If not, start the one specified in booting_thread_hwid and stop
+ * the current thread.
+ */
+ mfspr r8, SPRN_TIR
+ cmpw r3, r8
+ beq 20f
+
+ /* start the specified thread */
+ LOAD_REG_ADDR(r5, fsl_secondary_thread_init)
+ ld r4, 0(r5)
+ bl book3e_start_thread
+
+ /* stop the current thread */
+ mr r3, r8
+ bl book3e_stop_thread
+10:
+ b 10b
+20:
#endif
generic_secondary_common_init: