Re: [v2][PATCH 1/7] powerpc/book3e: support CONFIG_RELOCATABLE

From: tiejun.chen
Date: Tue Jul 09 2013 - 03:54:52 EST


On 07/03/2013 07:52 PM, Sethi Varun-B16395 wrote:


-----Original Message-----
From: Linuxppc-dev [mailto:linuxppc-dev-
bounces+varun.sethi=freescale.com@xxxxxxxxxxxxxxxx] On Behalf Of Tiejun
Chen
Sent: Thursday, June 20, 2013 1:23 PM
To: benh@xxxxxxxxxxxxxxxxxxx
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Subject: [v2][PATCH 1/7] powerpc/book3e: support CONFIG_RELOCATABLE

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 | 8 ++++++++
arch/powerpc/kernel/exceptions-64e.S | 15 ++++++++++++++-
arch/powerpc/kernel/head_64.S | 22 ++++++++++++++++++++++
arch/powerpc/lib/feature-fixups.c | 7 +++++++
4 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/exception-64e.h
b/arch/powerpc/include/asm/exception-64e.h
index 51fa43e..89e940d 100644
--- a/arch/powerpc/include/asm/exception-64e.h
+++ b/arch/powerpc/include/asm/exception-64e.h
@@ -214,10 +214,18 @@ 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
+#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

[Sethi Varun-B16395] Please add a documentation note here.

Okay.


#endif /* _ASM_POWERPC_EXCEPTION_64E_H */

diff --git a/arch/powerpc/kernel/exceptions-64e.S
b/arch/powerpc/kernel/exceptions-64e.S
index 645170a..4b23119 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 +1356,14 @@ _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
+ 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
[Sethi Varun-B16395] Please add a documentation note here as well.

Okay.


diff --git a/arch/powerpc/kernel/head_64.S
b/arch/powerpc/kernel/head_64.S index b61363d..0942f3a 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -414,12 +414,22 @@ _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)
+ /* We should set ivpr again after .relocate. */
+ bl .init_core_book3e
+#endif
#endif

[Sethi Varun-B16395] A more detailed note over here would be useful.

Okay.


/*
@@ -447,12 +457,24 @@ _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, interrupt_end_book3e)
+ 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
diff --git a/arch/powerpc/lib/feature-fixups.c
b/arch/powerpc/lib/feature-fixups.c
index 7a8a748..13f20ed 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -135,13 +135,20 @@ void do_final_fixups(void) #if
defined(CONFIG_PPC64) && defined(CONFIG_RELOCATABLE)
int *src, *dest;
unsigned long length;
+#ifdef CONFIG_PPC_BOOK3E
+ extern char interrupt_end_book3e[];
+#endif
[Sethi Varun-B16395] You can simply move this to sections.h and remove the ifdefs.

I would replace interrupt_end_book3e with __end_interrupts then we can have a unique label for book3e and book3s as Bharat mentioned previously.

Thanks

Tiejun

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