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

Bhushan Bharat-R65777
2013-07-02T05:15:24Z

> -----Original Message-----
> From: Linuxppc-dev [mailto:linuxppc-dev-
> bounces+bharat.bhushan=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
>
> #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
> 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
>
> /*
> @@ -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

Cannot we do this in arch/powerpc/kernel/asm/sections.h

>
> if (PHYSICAL_START == 0)
> return;
>
> src = (int *)(KERNELBASE + PHYSICAL_START);
> dest = (int *)KERNELBASE;
> +#ifdef CONFIG_PPC_BOOK3E
> + length = (interrupt_end_book3e - _stext) / sizeof(int);
> +#else
> length = (__end_interrupts - _stext) / sizeof(int);
> +#endif

can we keep same name in books and booke; __end_interrupts ? this way we can avoid such #ifdefs

-Bharat

>
> while (length--) {
> patch_instruction(dest, *src);
> --
> 1.7.9.5
>
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