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

tiejun.chen
2013-07-09T07:54:49Z

On 07/03/2013 07:52 PM, Sethi Varun-B16395 wrote:
>
>
>> -----Original Message-----
>> From: Linuxppc-dev [mailto:linuxppc-dev-
>> bounces+varun.sethi=freescale.com@lists.ozlabs.org] On Behalf Of Tiejun
>> Chen
>> Sent: Thursday, June 20, 2013 1:23 PM
>> To: benh@kernel.crashing.org
>> Cc: linuxppc-dev@lists.ozlabs.org; linux-kernel@vger.kernel.org
>> 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@windriver.com>
>> ---
>> 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