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

[Sethi Varun-B16395]

> -----Original Message-----
> From: Linuxppc-dev [mailto:linuxppc-dev-
> bounces+varun.sethi=freescale.com at lists.ozlabs.org] On Behalf Of Tiejun
> Chen
> Sent: Thursday, June 20, 2013 1:23 PM
> To: benh at kernel.crashing.org
> Cc: linuxppc-dev at lists.ozlabs.org; linux-kernel at 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 at 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 at l; 		\
>  	ori	r3,r3,interrupt_base_book3e at 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 at l;		\
> +	mtspr	SPRN_IVOR##vector_number,r3;
> +#endif
> 
[Sethi Varun-B16395] Please add a documentation note here.

>  #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 at h
>  	ori	r7,r7,MSR_KERNEL at 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. 

> 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 at 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.

>  /*
> @@ -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.

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

-Varun