Re: [Qemu-devel] [PATCH 1/5] target-ppc: Extend rtas-blob

[Alexey Kardashevskiy]

On 08/25/2014 11:45 PM, Aravinda Prasad wrote:
> Extend rtas-blob to accommodate error log. Error log
> structure is saved in rtas space upon a machine check
> exception.
> 
> Signed-off-by: Aravinda Prasad <address@hidden>
> ---
>  hw/ppc/spapr.c                  |   13 ++++++++++---
>  hw/ppc/spapr_rtas.c             |    4 ++--
>  include/hw/ppc/spapr.h          |    2 +-
>  pc-bios/spapr-rtas/spapr-rtas.S |   12 ++++++++++++
>  4 files changed, 25 insertions(+), 6 deletions(-)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index d01978f..1120988 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -85,6 +85,12 @@
>  
>  #define HTAB_SIZE(spapr)        (1ULL << ((spapr)->htab_shift))
>  
> +/*
> + * The rtas-entry-offset should match the value specified in
> + * spapr-rtas.S
> + */
> +#define RTAS_ENTRY_OFFSET       0x1000
> +
>  typedef struct sPAPRMachineState sPAPRMachineState;
>  
>  #define TYPE_SPAPR_MACHINE      "spapr-machine"
> @@ -670,7 +676,8 @@ static int spapr_populate_memory(sPAPREnvironment *spapr, 
> void *fdt)
>  static void spapr_finalize_fdt(sPAPREnvironment *spapr,
>                                 hwaddr fdt_addr,
>                                 hwaddr rtas_addr,
> -                               hwaddr rtas_size)
> +                               hwaddr rtas_size,
> +                               hwaddr rtas_entry)
>  {
>      int ret, i;
>      size_t cb = 0;
> @@ -705,7 +712,7 @@ static void spapr_finalize_fdt(sPAPREnvironment *spapr,
>      }
>  
>      /* RTAS */
> -    ret = spapr_rtas_device_tree_setup(fdt, rtas_addr, rtas_size);
> +    ret = spapr_rtas_device_tree_setup(fdt, rtas_addr, rtas_size, 
> rtas_entry);
>      if (ret < 0) {
>          fprintf(stderr, "Couldn't set up RTAS device tree properties\n");
>      }
> @@ -808,7 +815,7 @@ static void ppc_spapr_reset(void)
>  
>      /* Load the fdt */
>      spapr_finalize_fdt(spapr, spapr->fdt_addr, spapr->rtas_addr,
> -                       spapr->rtas_size);
> +                       spapr->rtas_size, spapr->rtas_addr + 
> RTAS_ENTRY_OFFSET);
>  
>      /* Set up the entry state */
>      first_ppc_cpu = POWERPC_CPU(first_cpu);
> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> index 9ba1ba6..02ddbf9 100644
> --- a/hw/ppc/spapr_rtas.c
> +++ b/hw/ppc/spapr_rtas.c
> @@ -328,7 +328,7 @@ void spapr_rtas_register(int token, const char *name, 
> spapr_rtas_fn fn)
>  }
>  
>  int spapr_rtas_device_tree_setup(void *fdt, hwaddr rtas_addr,
> -                                 hwaddr rtas_size)
> +                                 hwaddr rtas_size, hwaddr rtas_entry)
>  {
>      int ret;
>      int i;
> @@ -349,7 +349,7 @@ int spapr_rtas_device_tree_setup(void *fdt, hwaddr 
> rtas_addr,
>      }
>  
>      ret = qemu_fdt_setprop_cell(fdt, "/rtas", "linux,rtas-entry",
> -                                rtas_addr);
> +                                rtas_entry);
>      if (ret < 0) {
>          fprintf(stderr, "Couldn't add linux,rtas-entry property: %s\n",
>                  fdt_strerror(ret));
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index bbba51a..dedfa67 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -436,7 +436,7 @@ target_ulong spapr_rtas_call(PowerPCCPU *cpu, 
> sPAPREnvironment *spapr,
>                               uint32_t token, uint32_t nargs, target_ulong 
> args,
>                               uint32_t nret, target_ulong rets);
>  int spapr_rtas_device_tree_setup(void *fdt, hwaddr rtas_addr,
> -                                 hwaddr rtas_size);
> +                                 hwaddr rtas_size, hwaddr rtas_entry);
>  
>  #define SPAPR_TCE_PAGE_SHIFT   12
>  #define SPAPR_TCE_PAGE_SIZE    (1ULL << SPAPR_TCE_PAGE_SHIFT)
> diff --git a/pc-bios/spapr-rtas/spapr-rtas.S b/pc-bios/spapr-rtas/spapr-rtas.S
> index 903bec2..8c9b17e 100644
> --- a/pc-bios/spapr-rtas/spapr-rtas.S
> +++ b/pc-bios/spapr-rtas/spapr-rtas.S
> @@ -30,6 +30,18 @@
>  
>  .globl       _start
>  _start:
> +     /*
> +      * Reserve space for error log in RTAS blob.
> +      *
> +      * Either we can reserve initial bytes for error log followed by
> +      * rtas-entry or space can be reserved after rtas-entry. I prefer
> +      * former, as we already have rtas-base and rtas-entry (currently
> +      * both pointing to rtas-base) defined in qemu and we can update
> +      * rtas-entry to point to an offset from rtas-base. This avoids
> +      * unnecessary definition of rtas-error-offset while keeping
> +      * rtas-entry redundant.
> +      */
> +     . = 0x1000


Why not this (and not changing spapr-rtas.S)?

--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -875,7 +875,8 @@ static void ppc_spapr_reset(void)
                        spapr->rtas_size);

     /* Copy RTAS over */
-    cpu_physical_memory_write(spapr->rtas_addr, spapr->rtas_blob,
+    cpu_physical_memory_write(spapr->rtas_addr + RTAS_ENTRY_OFFSET,
+                              spapr->rtas_blob,
                               spapr->rtas_size);




>       mr      4,3
>       lis     3,address@hidden
>       ori     3,3,address@hidden
> 


-- 
Alexey Kardashevskiy
IBM OzLabs, LTC Team

e-mail: address@hidden
notes: Alexey Kardashevskiy/Australia/IBM