Linux-libre 4.4-gnupck-4.4-gnu

1 files changed, 39 insertions, 4 deletions

diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index d48125d0c..1b7795607 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -182,6 +182,8 @@ exception_marker:
 
 #ifdef CONFIG_PPC_BOOK3E
 _GLOBAL(fsl_secondary_thread_init)
+	mfspr	r4,SPRN_BUCSR
+
 	/* Enable branch prediction */
 	lis     r3,BUCSR_INIT@h
 	ori     r3,r3,BUCSR_INIT@l
@@ -196,10 +198,24 @@ _GLOBAL(fsl_secondary_thread_init)
 	 * number.  There are two threads per core, so shift everything
 	 * but the low bit right by two bits so that the cpu numbering is
 	 * continuous.
+	 *
+	 * If the old value of BUCSR is non-zero, this thread has run
+	 * before.  Thus, we assume we are coming from kexec or a similar
+	 * scenario, and PIR is already set to the correct value.  This
+	 * is a bit of a hack, but there are limited opportunities for
+	 * getting information into the thread and the alternatives
+	 * seemed like they'd be overkill.  We can't tell just by looking
+	 * at the old PIR value which state it's in, since the same value
+	 * could be valid for one thread out of reset and for a different
+	 * thread in Linux.
 	 */
+
 	mfspr	r3, SPRN_PIR
+	cmpwi	r4,0
+	bne	1f
 	rlwimi	r3, r3, 30, 2, 30
 	mtspr	SPRN_PIR, r3
+1:
 #endif
 
 _GLOBAL(generic_secondary_thread_init)
@@ -441,12 +457,22 @@ __after_prom_start:
 	/* process relocations for the final address of the kernel */
 	lis	r25,PAGE_OFFSET@highest	/* compute virtual base of kernel */
 	sldi	r25,r25,32
+#if defined(CONFIG_PPC_BOOK3E)
+	tovirt(r26,r26)		/* on booke, we already run at PAGE_OFFSET */
+#endif
 	lwz	r7,__run_at_load-_stext(r26)
+#if defined(CONFIG_PPC_BOOK3E)
+	tophys(r26,r26)
+#endif
 	cmplwi	cr0,r7,1	/* flagged to stay where we are ? */
 	bne	1f
 	add	r25,r25,r26
 1:	mr	r3,r25
 	bl	relocate
+#if defined(CONFIG_PPC_BOOK3E)
+	/* IVPR needs to be set after relocation. */
+	bl	init_core_book3e
+#endif
 #endif
 
 /*
@@ -458,15 +484,15 @@ __after_prom_start:
  */
 	li	r3,0			/* target addr */
 #ifdef CONFIG_PPC_BOOK3E
-	tovirt(r3,r3)			/* on booke, we already run at PAGE_OFFSET */
+	tovirt(r3,r3)		/* on booke, we already run at PAGE_OFFSET */
 #endif
 	mr.	r4,r26			/* In some cases the loader may  */
+#if defined(CONFIG_PPC_BOOK3E)
+	tovirt(r4,r4)
+#endif
 	beq	9f			/* have already put us at zero */
 	li	r6,0x100		/* Start offset, the first 0x100 */
 					/* bytes were copied earlier.	 */
-#ifdef CONFIG_PPC_BOOK3E
-	tovirt(r6,r6)			/* on booke, we already run at PAGE_OFFSET */
-#endif
 
 #ifdef CONFIG_RELOCATABLE
 /*
@@ -474,12 +500,21 @@ __after_prom_start:
  * variable __run_at_load, if it is set the kernel is treated as relocatable
  * kernel, otherwise it will be moved to PHYSICAL_START
  */
+#if defined(CONFIG_PPC_BOOK3E)
+	tovirt(r26,r26)		/* on booke, we already run at PAGE_OFFSET */
+#endif
 	lwz	r7,__run_at_load-_stext(r26)
 	cmplwi	cr0,r7,1
 	bne	3f
 
+#ifdef CONFIG_PPC_BOOK3E
+	LOAD_REG_ADDR(r5, __end_interrupts)
+	LOAD_REG_ADDR(r11, _stext)
+	sub	r5,r5,r11
+#else
 	/* just copy interrupts */
 	LOAD_REG_IMMEDIATE(r5, __end_interrupts - _stext)
+#endif
 	b	5f
 3:
 #endif