Re: [Qemu-devel] [PATCH v2] target-ppc: Eliminate redundant and incorrect function booke206_page_size_to_tlb

[David Gibson]

On Tue, Jun 28, 2016 at 06:50:05AM -0700, Aaron Larson wrote:
> 
> Eliminate redundant and incorrect booke206_page_size_to_tlb function
> from ppce500_spin.c in preference to previously existing but newly
> exported definition from e500.c
> 
> Defect analysis:
> 
> The booke206_page_size_to_tlb function in e500.c was updated in commit
> 2bd9543 "ppc: booke206: use MAV=2.0 TSIZE definition, fix 4G pages" to
> reflect a change in the definition of MAS1_TSIZE_SHIFT from 8
> (corresponding to a min TLB page size of 4kb) to a value of 7 (TLB
> page size 2k).  The booke206_page_size_to_tlb() function defined in
> ppce500_spin.c was never updated to reflect the change in
> MAS1_TSIZE_SHIFT.
> 
> In http://lists.nongnu.org/archive/html/qemu-ppc/2016-06/msg00533.html,
> Scott Wood suggested this "root cause" explanation:
> 
> SW> The patch that changed MAS1_TSIZE_SHIFT from 8 to 7 was around the
> SW> same time as the patch that added this code, which is probably why
> SW> adjusting it got missed.  Commit 2bd9543cd3 did update the
> SW> equivalent code in ppce500_mpc8544ds.c, which now resides in
> SW> hw/ppc/e500.c and has been changed to not assume a power-of-2
> SW> size.  The ppce500_spin version should be eliminated.
> 
> Signed-off-by: Aaron Larson <address@hidden>

Applied to pppc-for-2.7, thanks.

> ---
>  hw/ppc/e500.c         | 2 +-
>  hw/ppc/e500.h         | 2 ++
>  hw/ppc/ppce500_spin.c | 7 +------
>  3 files changed, 4 insertions(+), 7 deletions(-)
> 
> diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c
> index ee1c60b..0cd534d 100644
> --- a/hw/ppc/e500.c
> +++ b/hw/ppc/e500.c
> @@ -601,7 +601,7 @@ static int ppce500_prep_device_tree(MachineState *machine,
>  }
>  
>  /* Create -kernel TLB entries for BookE.  */
> -static inline hwaddr booke206_page_size_to_tlb(uint64_t size)
> +hwaddr booke206_page_size_to_tlb(uint64_t size)
>  {
>      return 63 - clz64(size >> 10);
>  }
> diff --git a/hw/ppc/e500.h b/hw/ppc/e500.h
> index ef224ea..70ba1d8 100644
> --- a/hw/ppc/e500.h
> +++ b/hw/ppc/e500.h
> @@ -26,4 +26,6 @@ typedef struct PPCE500Params {
>  
>  void ppce500_init(MachineState *machine, PPCE500Params *params);
>  
> +hwaddr booke206_page_size_to_tlb(uint64_t size);
> +
>  #endif
> diff --git a/hw/ppc/ppce500_spin.c b/hw/ppc/ppce500_spin.c
> index 225177b..22c584e 100644
> --- a/hw/ppc/ppce500_spin.c
> +++ b/hw/ppc/ppce500_spin.c
> @@ -32,6 +32,7 @@
>  #include "sysemu/sysemu.h"
>  #include "hw/sysbus.h"
>  #include "sysemu/kvm.h"
> +#include "e500.h"
>  
>  #define MAX_CPUS 32
>  
> @@ -72,12 +73,6 @@ static void spin_reset(void *opaque)
>      }
>  }
>  
> -/* Create -kernel TLB entries for BookE, linearly spanning 256MB.  */
> -static inline hwaddr booke206_page_size_to_tlb(uint64_t size)
> -{
> -    return ctz32(size >> 10) >> 1;
> -}
> -
>  static void mmubooke_create_initial_mapping(CPUPPCState *env,
>                                       target_ulong va,
>                                       hwaddr pa,

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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