Re: [Qemu-devel] [PATCH 3/3] m25p80: change cur_addr to 32 bit integer

[Cédric Le Goater]

On 06/28/2016 10:39 AM, Paolo Bonzini wrote:
> The maximum amount of storage that can be addressed by the m25p80 command
> set is 4 GiB.  However, cur_addr is currently a 64-bit integer.  To avoid
> further problems related to sign extension of signed 32-bit integer
> expressions, change cur_addr to a 32 bit integer.  Preserve migration
> format by adding a dummy 4-byte field in place of the (big-endian)
> high four bytes in the formerly 64-bit cur_addr field.

I do not think that migration ever worked before. did it ? 

> Signed-off-by: Paolo Bonzini <address@hidden>

Reviewed-by: Cédric Le Goater <address@hidden>

> ---
>  hw/block/m25p80.c | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
> 
> diff --git a/hw/block/m25p80.c b/hw/block/m25p80.c
> index 76a9bcf..7668b22 100644
> --- a/hw/block/m25p80.c
> +++ b/hw/block/m25p80.c
> @@ -389,7 +389,7 @@ typedef struct Flash {
>      uint32_t pos;
>      uint8_t needed_bytes;
>      uint8_t cmd_in_progress;
> -    uint64_t cur_addr;
> +    uint32_t cur_addr;
>      uint32_t nonvolatile_cfg;
>      /* Configuration register for Macronix */
>      uint32_t volatile_cfg;
> @@ -535,9 +535,9 @@ static inline void flash_sync_dirty(Flash *s, int64_t 
> newpage)
>  }
>  
>  static inline
> -void flash_write8(Flash *s, uint64_t addr, uint8_t data)
> +void flash_write8(Flash *s, uint32_t addr, uint8_t data)
>  {
> -    int64_t page = addr / s->pi->page_size;
> +    uint32_t page = addr / s->pi->page_size;
>      uint8_t prev = s->storage[s->cur_addr];

This routine needs a cleanup. It takes an 'addr' parameter (it is called 
with s->cur_addr) and uses s->cur_addr at the same time. 

C.

>      if (!s->write_enable) {
> @@ -545,7 +545,7 @@ void flash_write8(Flash *s, uint64_t addr, uint8_t data)
>      }
>  
>      if ((prev ^ data) & data) {
> -        DB_PRINT_L(1, "programming zero to one! addr=%" PRIx64 "  %" PRIx8
> +        DB_PRINT_L(1, "programming zero to one! addr=%" PRIx32 "  %" PRIx8
>                     " -> %" PRIx8 "\n", addr, prev, data);
>      }
>  
> @@ -1094,7 +1094,7 @@ static uint32_t m25p80_transfer8(SSISlave *ss, uint32_t 
> tx)
>      switch (s->state) {
>  
>      case STATE_PAGE_PROGRAM:
> -        DB_PRINT_L(1, "page program cur_addr=%#" PRIx64 " data=%" PRIx8 "\n",
> +        DB_PRINT_L(1, "page program cur_addr=%#" PRIx32 " data=%" PRIx8 "\n",
>                     s->cur_addr, (uint8_t)tx);
>          flash_write8(s, s->cur_addr, (uint8_t)tx);
>          s->cur_addr = (s->cur_addr + 1) & (s->size - 1);
> @@ -1102,7 +1102,7 @@ static uint32_t m25p80_transfer8(SSISlave *ss, uint32_t 
> tx)
>  
>      case STATE_READ:
>          r = s->storage[s->cur_addr];
> -        DB_PRINT_L(1, "READ 0x%" PRIx64 "=%" PRIx8 "\n", s->cur_addr,
> +        DB_PRINT_L(1, "READ 0x%" PRIx32 "=%" PRIx8 "\n", s->cur_addr,
>                     (uint8_t)r);
>          s->cur_addr = (s->cur_addr + 1) & (s->size - 1);
>          break;
> @@ -1199,7 +1199,8 @@ static const VMStateDescription vmstate_m25p80 = {
>          VMSTATE_UINT32(pos, Flash),
>          VMSTATE_UINT8(needed_bytes, Flash),
>          VMSTATE_UINT8(cmd_in_progress, Flash),
> -        VMSTATE_UINT64(cur_addr, Flash),
> +        VMSTATE_UNUSED(4),
> +        VMSTATE_UINT32(cur_addr, Flash),
>          VMSTATE_BOOL(write_enable, Flash),
>          VMSTATE_BOOL_V(reset_enable, Flash, 2),
>          VMSTATE_UINT8_V(ear, Flash, 2),
>