[v3][PATCH 2/8] powerpc/book3e: support CONFIG_RELOCATABLE

From: Tiejun Chen
Date: Tue Jul 09 2013 - 04:06:09 EST


book3e is different with book3s since 3s includes the exception
vectors code in head_64.S as it relies on absolute addressing
which is only possible within this compilation unit. So we have
to get that label address with got.

And when boot a relocated kernel, we should reset ipvr properly again
after .relocate.

Signed-off-by: Tiejun Chen <tiejun.chen@xxxxxxxxxxxxx>
---
arch/powerpc/include/asm/exception-64e.h | 11 +++++++++++
arch/powerpc/kernel/exceptions-64e.S | 18 +++++++++++++++++-
arch/powerpc/kernel/head_64.S | 25 +++++++++++++++++++++++++
3 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/exception-64e.h b/arch/powerpc/include/asm/exception-64e.h
index 51fa43e..371a77f 100644
--- a/arch/powerpc/include/asm/exception-64e.h
+++ b/arch/powerpc/include/asm/exception-64e.h
@@ -214,10 +214,21 @@ exc_##label##_book3e:
#define TLB_MISS_STATS_SAVE_INFO_BOLTED
#endif

+#ifndef CONFIG_RELOCATABLE
#define SET_IVOR(vector_number, vector_offset) \
li r3,vector_offset@l; \
ori r3,r3,interrupt_base_book3e@l; \
mtspr SPRN_IVOR##vector_number,r3;
+#else /* !CONFIG_RELOCATABLE */
+/* In relocatable case the value of the constant expression 'expr' is only
+ * offset. So instead, we should loads the address of label 'name'.
+ */
+#define SET_IVOR(vector_number, vector_offset) \
+ LOAD_REG_ADDR(r3,interrupt_base_book3e);\
+ rlwinm r3,r3,0,15,0; \
+ ori r3,r3,vector_offset@l; \
+ mtspr SPRN_IVOR##vector_number,r3;
+#endif /* CONFIG_RELOCATABLE */

#endif /* _ASM_POWERPC_EXCEPTION_64E_H */

diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index a518e48..be3b4b1 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -1097,7 +1097,15 @@ skpinv: addi r6,r6,1 /* Increment */
* r4 = MAS0 w/TLBSEL & ESEL for the temp mapping
*/
/* Now we branch the new virtual address mapped by this entry */
+#ifdef CONFIG_RELOCATABLE
+ /* We have to find out address from lr. */
+ bl 1f /* Find our address */
+1: mflr r6
+ addi r6,r6,(2f - 1b)
+ tovirt(r6,r6)
+#else
LOAD_REG_IMMEDIATE(r6,2f)
+#endif
lis r7,MSR_KERNEL@h
ori r7,r7,MSR_KERNEL@l
mtspr SPRN_SRR0,r6
@@ -1348,9 +1356,17 @@ _GLOBAL(book3e_secondary_thread_init)
mflr r28
b 3b

-_STATIC(init_core_book3e)
+_GLOBAL(init_core_book3e)
/* Establish the interrupt vector base */
+#ifdef CONFIG_RELOCATABLE
+/* In relocatable case the value of the constant expression 'expr' is only
+ * offset. So instead, we should loads the address of label 'name'.
+ */
+ tovirt(r2,r2)
+ LOAD_REG_ADDR(r3, interrupt_base_book3e)
+#else
LOAD_REG_IMMEDIATE(r3, interrupt_base_book3e)
+#endif
mtspr SPRN_IVPR,r3
sync
blr
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index b61363d..550f8fb 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -414,12 +414,25 @@ _STATIC(__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) /* Restore for the remains. */
+#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)
+ /* In relocatable case we always have to load the address of label 'name'
+ * to set IVPR. So after .relocate we have to update IVPR with current
+ * address of label.
+ */
+ bl .init_core_book3e
+#endif
#endif

/*
@@ -447,12 +460,24 @@ _STATIC(__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)
+#if defined(CONFIG_PPC_BOOK3E)
+ tophys(r26,r26) /* Restore for the remains. */
+#endif
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
--
1.7.9.5

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