Re: [Qemu-devel] [PATCH] hw/block/pflash_cfi01: Report correct size info for parallel configs

[Peter Crosthwaite]

On Wed, Jun 11, 2014 at 12:03 AM, Peter Maydell
<address@hidden> wrote:
> If the flash device is configured with a device-width which is
> not equal to the bank-width, indicating that it is actually several
> narrow flash devices in parallel, the CFI table should report the
> number of blocks and the size of a single device, not of the whole
> combined setup. This stops Linux from complaining:
> "NOR chip too large to fit in mapping. Attempting to cope..."
>
> As usual, we retain the old broken but backwards compatible behaviour
> when the device-width is not specified.
>
> Signed-off-by: Peter Maydell <address@hidden>

Reviewed-by: Peter Crosthwaite <address@hidden>

> ---
> At the moment vexpress is the only board which properly sets device-width
> rather than using the back-compat misemulated behaviour...
>
>  hw/block/pflash_cfi01.c | 20 +++++++++++++++++---
>  1 file changed, 17 insertions(+), 3 deletions(-)
>
> diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c
> index 0c95d53..f9507b4 100644
> --- a/hw/block/pflash_cfi01.c
> +++ b/hw/block/pflash_cfi01.c
> @@ -748,9 +748,18 @@ static void pflash_cfi01_realize(DeviceState *dev, Error 
> **errp)
>      pflash_t *pfl = CFI_PFLASH01(dev);
>      uint64_t total_len;
>      int ret;
> +    uint64_t blocks_per_device, device_len;
> +    int num_devices;
>
>      total_len = pfl->sector_len * pfl->nb_blocs;
>
> +    /* These are only used to expose the parameters of each device
> +     * in the cfi_table[].
> +     */
> +    num_devices = pfl->device_width ? (pfl->bank_width / pfl->device_width) 
> : 1;
> +    blocks_per_device = pfl->nb_blocs / num_devices;
> +    device_len = pfl->sector_len * blocks_per_device;
> +
>      /* XXX: to be fixed */
>  #if 0
>      if (total_len != (8 * 1024 * 1024) && total_len != (16 * 1024 * 1024) &&
> @@ -838,7 +847,7 @@ static void pflash_cfi01_realize(DeviceState *dev, Error 
> **errp)
>      /* Max timeout for chip erase */
>      pfl->cfi_table[0x26] = 0x00;
>      /* Device size */
> -    pfl->cfi_table[0x27] = ctz32(total_len); // + 1;
> +    pfl->cfi_table[0x27] = ctz32(device_len); /* + 1; */
>      /* Flash device interface (8 & 16 bits) */
>      pfl->cfi_table[0x28] = 0x02;
>      pfl->cfi_table[0x29] = 0x00;
> @@ -854,8 +863,8 @@ static void pflash_cfi01_realize(DeviceState *dev, Error 
> **errp)
>      /* Number of erase block regions (uniform) */
>      pfl->cfi_table[0x2C] = 0x01;
>      /* Erase block region 1 */
> -    pfl->cfi_table[0x2D] = pfl->nb_blocs - 1;
> -    pfl->cfi_table[0x2E] = (pfl->nb_blocs - 1) >> 8;
> +    pfl->cfi_table[0x2D] = blocks_per_device - 1;
> +    pfl->cfi_table[0x2E] = (blocks_per_device - 1) >> 8;
>      pfl->cfi_table[0x2F] = pfl->sector_len >> 8;
>      pfl->cfi_table[0x30] = pfl->sector_len >> 16;
>
> @@ -882,6 +891,11 @@ static void pflash_cfi01_realize(DeviceState *dev, Error 
> **errp)
>
>  static Property pflash_cfi01_properties[] = {
>      DEFINE_PROP_DRIVE("drive", struct pflash_t, bs),
> +    /* num-blocks is the number of blocks actually visible to the guest,
> +     * ie the total size of the device divided by the sector length.
> +     * If we're emulating flash devices wired in parallel the actual
> +     * number of blocks per indvidual device will differ.
> +     */
>      DEFINE_PROP_UINT32("num-blocks", struct pflash_t, nb_blocs, 0),
>      DEFINE_PROP_UINT64("sector-length", struct pflash_t, sector_len, 0),
>      /* width here is the overall width of this QEMU device in bytes.
> --
> 1.9.2
>
>