Subject: Re: [PATCH v4 02/16] powerpc/cell: Move data segment faulting code out of cell platform

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Thu, 09 Oct 2014 20:34:26 +0530

Michael Neuling <[email-masked]> writes:

> From: Ian Munsie <[email-masked]>
>
> __spu_trap_data_seg() currently contains code to determine the VSID and ESID
> required for a particular EA and mm struct.
>
> This code is generically useful for other co-processors. This moves the code of
> the cell platform so it can be used by other powerpc code. It also adds 1TB
> segment handling which Cell didn't support.  The new function is called
> copro_calculate_slb().
>
> This also moves the internal struct spu_slb to a generic struct copro_slb which
> is now used in the Cell and copro code.  We use this new struct instead of
> passing around esid and vsid parameters.
>

Reviewed-by: Aneesh Kumar K.V <[email-masked]>

> Signed-off-by: Ian Munsie <[email-masked]>
> Signed-off-by: Michael Neuling <[email-masked]>
> ---
>  arch/powerpc/include/asm/copro.h       |  7 +++++
>  arch/powerpc/include/asm/mmu-hash64.h  |  7 +++++
>  arch/powerpc/mm/copro_fault.c          | 46 ++++++++++++++++++++++++++++
>  arch/powerpc/mm/slb.c                  |  3 --
>  arch/powerpc/platforms/cell/spu_base.c | 55 ++++++----------------------------
>  5 files changed, 69 insertions(+), 49 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/copro.h b/arch/powerpc/include/asm/copro.h
> index 51cae85..b0e6a18 100644
> --- a/arch/powerpc/include/asm/copro.h
> +++ b/arch/powerpc/include/asm/copro.h
> @@ -10,7 +10,14 @@
>  #ifndef _ASM_POWERPC_COPRO_H
>  #define _ASM_POWERPC_COPRO_H
>  
> +struct copro_slb
> +{
> +	u64 esid, vsid;
> +};
> +
>  int copro_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
>  			  unsigned long dsisr, unsigned *flt);
>  
> +int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb);
> +
>  #endif /* _ASM_POWERPC_COPRO_H */
> diff --git a/arch/powerpc/include/asm/mmu-hash64.h b/arch/powerpc/include/asm/mmu-hash64.h
> index d765144..aeabd02 100644
> --- a/arch/powerpc/include/asm/mmu-hash64.h
> +++ b/arch/powerpc/include/asm/mmu-hash64.h
> @@ -190,6 +190,13 @@ static inline unsigned int mmu_psize_to_shift(unsigned int mmu_psize)
>  
>  #ifndef __ASSEMBLY__
>  
> +static inline int slb_vsid_shift(int ssize)
> +{
> +	if (ssize == MMU_SEGSIZE_256M)
> +		return SLB_VSID_SHIFT;
> +	return SLB_VSID_SHIFT_1T;
> +}
> +
>  static inline int segment_shift(int ssize)
>  {
>  	if (ssize == MMU_SEGSIZE_256M)
> diff --git a/arch/powerpc/mm/copro_fault.c b/arch/powerpc/mm/copro_fault.c
> index ba7df14..a15a23e 100644
> --- a/arch/powerpc/mm/copro_fault.c
> +++ b/arch/powerpc/mm/copro_fault.c
> @@ -24,6 +24,7 @@
>  #include <linux/mm.h>
>  #include <linux/export.h>
>  #include <asm/reg.h>
> +#include <asm/copro.h>
>  
>  /*
>   * This ought to be kept in sync with the powerpc specific do_page_fault
> @@ -90,3 +91,48 @@ out_unlock:
>  	return ret;
>  }
>  EXPORT_SYMBOL_GPL(copro_handle_mm_fault);
> +
> +int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb)
> +{
> +	u64 vsid;
> +	int psize, ssize;
> +
> +	slb->esid = (ea & ESID_MASK) | SLB_ESID_V;
> +
> +	switch (REGION_ID(ea)) {
> +	case USER_REGION_ID:
> +		pr_devel("%s: 0x%llx -- USER_REGION_ID\n", __func__, ea);
> +		psize = get_slice_psize(mm, ea);
> +		ssize = user_segment_size(ea);
> +		vsid = get_vsid(mm->context.id, ea, ssize);
> +		break;
> +	case VMALLOC_REGION_ID:
> +		pr_devel("%s: 0x%llx -- VMALLOC_REGION_ID\n", __func__, ea);
> +		if (ea < VMALLOC_END)
> +			psize = mmu_vmalloc_psize;
> +		else
> +			psize = mmu_io_psize;
> +		ssize = mmu_kernel_ssize;
> +		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
> +		break;
> +	case KERNEL_REGION_ID:
> +		pr_devel("%s: 0x%llx -- KERNEL_REGION_ID\n", __func__, ea);
> +		psize = mmu_linear_psize;
> +		ssize = mmu_kernel_ssize;
> +		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
> +		break;
> +	default:
> +		pr_debug("%s: invalid region access at %016llx\n", __func__, ea);
> +		return 1;
> +	}
> +
> +	vsid = (vsid << slb_vsid_shift(ssize)) | SLB_VSID_USER;
> +
> +	vsid |= mmu_psize_defs[psize].sllp |
> +		((ssize == MMU_SEGSIZE_1T) ? SLB_VSID_B_1T : 0);
> +

s/0/SLB_VSID_B_256M/ 

> +	slb->vsid = vsid;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(copro_calculate_slb);
> diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
> index 0399a67..6e450ca 100644
> --- a/arch/powerpc/mm/slb.c
> +++ b/arch/powerpc/mm/slb.c
> @@ -46,9 +46,6 @@ static inline unsigned long mk_esid_data(unsigned long ea, int ssize,
>  	return (ea & slb_esid_mask(ssize)) | SLB_ESID_V | slot;
>  }
>  
> -#define slb_vsid_shift(ssize)	\
> -	((ssize) == MMU_SEGSIZE_256M? SLB_VSID_SHIFT: SLB_VSID_SHIFT_1T)
> -
>  static inline unsigned long mk_vsid_data(unsigned long ea, int ssize,
>  					 unsigned long flags)
>  {
> diff --git a/arch/powerpc/platforms/cell/spu_base.c b/arch/powerpc/platforms/cell/spu_base.c
> index 2930d1e..ffcbd24 100644
> --- a/arch/powerpc/platforms/cell/spu_base.c
> +++ b/arch/powerpc/platforms/cell/spu_base.c
> @@ -76,10 +76,6 @@ static LIST_HEAD(spu_full_list);
>  static DEFINE_SPINLOCK(spu_full_list_lock);
>  static DEFINE_MUTEX(spu_full_list_mutex);
>  
> -struct spu_slb {
> -	u64 esid, vsid;
> -};
> -
>  void spu_invalidate_slbs(struct spu *spu)
>  {
>  	struct spu_priv2 __iomem *priv2 = spu->priv2;
> @@ -149,7 +145,7 @@ static void spu_restart_dma(struct spu *spu)
>  	}
>  }
>  
> -static inline void spu_load_slb(struct spu *spu, int slbe, struct spu_slb *slb)
> +static inline void spu_load_slb(struct spu *spu, int slbe, struct copro_slb *slb)
>  {
>  	struct spu_priv2 __iomem *priv2 = spu->priv2;
>  
> @@ -167,45 +163,12 @@ static inline void spu_load_slb(struct spu *spu, int slbe, struct spu_slb *slb)
>  
>  static int __spu_trap_data_seg(struct spu *spu, unsigned long ea)
>  {
> -	struct mm_struct *mm = spu->mm;
> -	struct spu_slb slb;
> -	int psize;
> -
> -	pr_debug("%s\n", __func__);
> -
> -	slb.esid = (ea & ESID_MASK) | SLB_ESID_V;
> +	struct copro_slb slb;
> +	int ret;
>  
> -	switch(REGION_ID(ea)) {
> -	case USER_REGION_ID:
> -#ifdef CONFIG_PPC_MM_SLICES
> -		psize = get_slice_psize(mm, ea);
> -#else
> -		psize = mm->context.user_psize;
> -#endif
> -		slb.vsid = (get_vsid(mm->context.id, ea, MMU_SEGSIZE_256M)
> -				<< SLB_VSID_SHIFT) | SLB_VSID_USER;
> -		break;
> -	case VMALLOC_REGION_ID:
> -		if (ea < VMALLOC_END)
> -			psize = mmu_vmalloc_psize;
> -		else
> -			psize = mmu_io_psize;
> -		slb.vsid = (get_kernel_vsid(ea, MMU_SEGSIZE_256M)
> -				<< SLB_VSID_SHIFT) | SLB_VSID_KERNEL;
> -		break;
> -	case KERNEL_REGION_ID:
> -		psize = mmu_linear_psize;
> -		slb.vsid = (get_kernel_vsid(ea, MMU_SEGSIZE_256M)
> -				<< SLB_VSID_SHIFT) | SLB_VSID_KERNEL;
> -		break;
> -	default:
> -		/* Future: support kernel segments so that drivers
> -		 * can use SPUs.
> -		 */
> -		pr_debug("invalid region access at %016lx\n", ea);
> -		return 1;
> -	}
> -	slb.vsid |= mmu_psize_defs[psize].sllp;
> +	ret = copro_calculate_slb(spu->mm, ea, &slb);
> +	if (ret)
> +		return ret;
>  
>  	spu_load_slb(spu, spu->slb_replace, &slb);
>  
> @@ -253,7 +216,7 @@ static int __spu_trap_data_map(struct spu *spu, unsigned long ea, u64 dsisr)
>  	return 0;
>  }
>  
> -static void __spu_kernel_slb(void *addr, struct spu_slb *slb)
> +static void __spu_kernel_slb(void *addr, struct copro_slb *slb)
>  {
>  	unsigned long ea = (unsigned long)addr;
>  	u64 llp;
> @@ -272,7 +235,7 @@ static void __spu_kernel_slb(void *addr, struct spu_slb *slb)
>   * Given an array of @nr_slbs SLB entries, @slbs, return non-zero if the
>   * address @new_addr is present.
>   */
> -static inline int __slb_present(struct spu_slb *slbs, int nr_slbs,
> +static inline int __slb_present(struct copro_slb *slbs, int nr_slbs,
>  		void *new_addr)
>  {
>  	unsigned long ea = (unsigned long)new_addr;
> @@ -297,7 +260,7 @@ static inline int __slb_present(struct spu_slb *slbs, int nr_slbs,
>  void spu_setup_kernel_slbs(struct spu *spu, struct spu_lscsa *lscsa,
>  		void *code, int code_size)
>  {
> -	struct spu_slb slbs[4];
> +	struct copro_slb slbs[4];
>  	int i, nr_slbs = 0;
>  	/* start and end addresses of both mappings */
>  	void *addrs[] = {
> -- 
> 1.9.1
>
> --
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