Re: [Qemu-devel] [PATCH 2/3] hw/sd.c: add SD card save/load support

[Peter Maydell]

On 26 December 2011 10:03, Mitsyanko Igor <address@hidden> wrote:
> We couldn't properly implement save/restore functionality of SD host 
> controllers
> states without SD card's state VMStateDescription implementation. This patch
> updates SD card emulation to support save/load of card's state.
>
> Signed-off-by: Mitsyanko Igor <address@hidden>

Ah, cool. I'd had a quick go at adding save/restore to sd.c but
ran aground on the wp_groups array issue.

(cc'd Juan as vmstate/migration expert)

> ---
>  hw/milkymist-memcard.c |    2 +
>  hw/sd.c                |  115 
> +++++++++++++++++++++++++++++++++---------------
>  hw/sd.h                |    1 +
>  3 files changed, 82 insertions(+), 36 deletions(-)
>
> diff --git a/hw/milkymist-memcard.c b/hw/milkymist-memcard.c
> index 865a46c..6e8b0e4 100644
> --- a/hw/milkymist-memcard.c
> +++ b/hw/milkymist-memcard.c
> @@ -266,6 +266,8 @@ static const VMStateDescription vmstate_milkymist_memcard 
> = {
>     .minimum_version_id = 1,
>     .minimum_version_id_old = 1,
>     .fields      = (VMStateField[]) {
> +        VMSTATE_STRUCT_POINTER(card, MilkymistMemcardState, sd_vmstate,
> +                SDState *),

This doesn't seem like the right approach to me -- the migration state
for the controller shouldn't have to include all the state for the card.
Instead I think it would be better for sd.c to register a vmstate struct
(by calling vmstate_register in sd_init) and thus handle its own
saving/loading. Then if/when we make sd.c a proper qemu object we
won't need to change the migration state for all the controllers.

>         VMSTATE_INT32(command_write_ptr, MilkymistMemcardState),
>         VMSTATE_INT32(response_read_ptr, MilkymistMemcardState),
>         VMSTATE_INT32(response_len, MilkymistMemcardState),
> diff --git a/hw/sd.c b/hw/sd.c
> index 07eb263..2b489d3 100644
> --- a/hw/sd.c
> +++ b/hw/sd.c
> @@ -54,24 +54,28 @@ typedef enum {
>     sd_illegal = -2,
>  } sd_rsp_type_t;
>
> +enum {
> +    sd_inactive,
> +    sd_card_identification_mode,
> +    sd_data_transfer_mode,
> +};
> +
> +enum {
> +    sd_inactive_state = -1,
> +    sd_idle_state = 0,
> +    sd_ready_state,
> +    sd_identification_state,
> +    sd_standby_state,
> +    sd_transfer_state,
> +    sd_sendingdata_state,
> +    sd_receivingdata_state,
> +    sd_programming_state,
> +    sd_disconnect_state,
> +};
> +
>  struct SDState {
> -    enum {
> -        sd_inactive,
> -        sd_card_identification_mode,
> -        sd_data_transfer_mode,
> -    } mode;
> -    enum {
> -        sd_inactive_state = -1,
> -        sd_idle_state = 0,
> -        sd_ready_state,
> -        sd_identification_state,
> -        sd_standby_state,
> -        sd_transfer_state,
> -        sd_sendingdata_state,
> -        sd_receivingdata_state,
> -        sd_programming_state,
> -        sd_disconnect_state,
> -    } state;
> +    uint32_t mode;
> +    int32_t state;
>     uint32_t ocr;
>     uint8_t scr[8];
>     uint8_t cid[16];
> @@ -81,22 +85,22 @@ struct SDState {
>     uint8_t sd_status[64];
>     uint32_t vhs;
>     int wp_switch;
> -    int *wp_groups;
> +    uint8_t *wp_groups;
>     uint64_t size;
> -    int blk_len;
> +    uint32_t blk_len;
>     uint32_t erase_start;
>     uint32_t erase_end;
>     uint8_t pwd[16];
> -    int pwd_len;
> -    int function_group[6];
> +    uint32_t pwd_len;
> +    uint8_t function_group[6];
>
> -    int spi;
> -    int current_cmd;
> +    uint8_t spi;
> +    uint8_t current_cmd;
>     /* True if we will handle the next command as an ACMD. Note that this does
>      * *not* track the APP_CMD status bit!
>      */
> -    int expecting_acmd;
> -    int blk_written;
> +    bool expecting_acmd;

Why have you changed expecting_acmd and enable to bool, but spi
to a uint8_t and wp_groups[] to a uint8_t[] ? This isn't very
consistent. (I'm vaguely against bool because you then end up
making other changes to change '1' to 'true' and so on.)

> +    uint32_t blk_written;
>     uint64_t data_start;
>     uint32_t data_offset;
>     uint8_t data[512];
> @@ -105,7 +109,7 @@ struct SDState {
>     BlockDriverState *bdrv;
>     uint8_t *buf;
>
> -    int enable;
> +    bool enable;
>  };
>
>  static void sd_set_mode(SDState *sd)
> @@ -415,14 +419,14 @@ static void sd_reset(SDState *sd, BlockDriverState 
> *bdrv)
>     if (sd->wp_groups)
>         g_free(sd->wp_groups);
>     sd->wp_switch = bdrv ? bdrv_is_read_only(bdrv) : 0;
> -    sd->wp_groups = (int *) g_malloc0(sizeof(int) * sect);
> -    memset(sd->function_group, 0, sizeof(int) * 6);
> +    sd->wp_groups = (uint8_t *)g_malloc0(sect);
> +    memset(sd->function_group, 0, 6);

Since you're touching this line anyway, can we have
sizeof(sd->function_group) rather than that hardcoded 6 ?

>     sd->erase_start = 0;
>     sd->erase_end = 0;
>     sd->size = size;
>     sd->blk_len = 0x200;
>     sd->pwd_len = 0;
> -    sd->expecting_acmd = 0;
> +    sd->expecting_acmd = false;
>  }
>
>  static void sd_cardchange(void *opaque, bool load)
> @@ -451,7 +455,7 @@ SDState *sd_init(BlockDriverState *bs, int is_spi)
>     sd = (SDState *) g_malloc0(sizeof(SDState));
>     sd->buf = qemu_blockalign(bs, 512);
>     sd->spi = is_spi;
> -    sd->enable = 1;
> +    sd->enable = true;
>     sd_reset(sd, bs);
>     if (sd->bdrv) {
>         bdrv_attach_dev_nofail(sd->bdrv, sd);
> @@ -534,7 +538,7 @@ static void sd_function_switch(SDState *sd, uint32_t arg)
>     sd->data[66] = crc & 0xff;
>  }
>
> -static inline int sd_wp_addr(SDState *sd, uint32_t addr)
> +static inline uint8_t sd_wp_addr(SDState *sd, uint32_t addr)
>  {
>     return sd->wp_groups[addr >>
>             (HWBLOCK_SHIFT + SECTOR_SHIFT + WPGROUP_SHIFT)];
> @@ -560,7 +564,7 @@ static void sd_lock_command(SDState *sd)
>             sd->card_status |= LOCK_UNLOCK_FAILED;
>             return;
>         }
> -        memset(sd->wp_groups, 0, sizeof(int) * (sd->size >>
> +        memset(sd->wp_groups, 0, (sd->size >>
>                         (HWBLOCK_SHIFT + SECTOR_SHIFT + WPGROUP_SHIFT)));
>         sd->csd[14] &= ~0x10;
>         sd->card_status &= ~CARD_IS_LOCKED;
> @@ -1125,7 +1129,7 @@ static sd_rsp_type_t sd_normal_command(SDState *sd,
>         if (sd->rca != rca)
>             return sd_r0;
>
> -        sd->expecting_acmd = 1;
> +        sd->expecting_acmd = true;
>         sd->card_status |= APP_CMD;
>         return sd_r1;
>
> @@ -1307,7 +1311,7 @@ int sd_do_command(SDState *sd, SDRequest *req,
>     if (sd->card_status & CARD_IS_LOCKED) {
>         if (!cmd_valid_while_locked(sd, req)) {
>             sd->card_status |= ILLEGAL_COMMAND;
> -            sd->expecting_acmd = 0;
> +            sd->expecting_acmd = false;
>             fprintf(stderr, "SD: Card is locked\n");
>             rtype = sd_illegal;
>             goto send_response;
> @@ -1318,7 +1322,7 @@ int sd_do_command(SDState *sd, SDRequest *req,
>     sd_set_mode(sd);
>
>     if (sd->expecting_acmd) {
> -        sd->expecting_acmd = 0;
> +        sd->expecting_acmd = false;
>         rtype = sd_app_command(sd, *req);
>     } else {
>         rtype = sd_normal_command(sd, *req);
> @@ -1706,5 +1710,44 @@ int sd_data_ready(SDState *sd)
>
>  void sd_enable(SDState *sd, int enable)
>  {
> -    sd->enable = enable;
> +    sd->enable = enable ? true : false;

This kind of thing is why I don't like bool :-)

> +}
> +
> +static int sd_vmstate_get_wpgroups_size(void *opaque, int version_id)
> +{
> +    SDState *sd = (SDState *)opaque;
> +    return sd->size >> (HWBLOCK_SHIFT + SECTOR_SHIFT + WPGROUP_SHIFT);
>  }
> +
> +const VMStateDescription sd_vmstate = {
> +    .name = "sd_card",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .fields      = (VMStateField[]) {
> +        VMSTATE_UINT32(mode, SDState),
> +        VMSTATE_INT32(state, SDState),
> +        VMSTATE_UINT8_ARRAY(cid, SDState, 16),
> +        VMSTATE_UINT8_ARRAY(csd, SDState, 16),
> +        VMSTATE_UINT16(rca, SDState),
> +        VMSTATE_UINT32(card_status, SDState),
> +        VMSTATE_PARTIAL_BUFFER(sd_status, SDState, 1),
> +        VMSTATE_UINT32(vhs, SDState),
> +        VMSTATE_VBUFFER_CALCSIZE(wp_groups, SDState,
> +              1, NULL, 0, sd_vmstate_get_wpgroups_size),
> +        VMSTATE_UINT32(blk_len, SDState),
> +        VMSTATE_UINT32(erase_start, SDState),
> +        VMSTATE_UINT32(erase_end, SDState),
> +        VMSTATE_UINT8_ARRAY(pwd, SDState, 16),
> +        VMSTATE_UINT32(pwd_len, SDState),
> +        VMSTATE_UINT8_ARRAY(function_group, SDState, 6),
> +        VMSTATE_UINT8(current_cmd, SDState),
> +        VMSTATE_BOOL(expecting_acmd, SDState),
> +        VMSTATE_UINT32(blk_written, SDState),
> +        VMSTATE_UINT64(data_start, SDState),
> +        VMSTATE_UINT32(data_offset, SDState),
> +        VMSTATE_UINT8_ARRAY(data, SDState, 512),
> +        VMSTATE_BUFFER_UNSAFE(buf, SDState, 1, 512),
> +        VMSTATE_BOOL(enable, SDState),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> diff --git a/hw/sd.h b/hw/sd.h
> index ac4b7c4..a2489c6 100644
> --- a/hw/sd.h
> +++ b/hw/sd.h
> @@ -66,6 +66,7 @@ typedef struct {
>  } SDRequest;
>
>  typedef struct SDState SDState;
> +extern const VMStateDescription sd_vmstate;
>
>  SDState *sd_init(BlockDriverState *bs, int is_spi);
>  int sd_do_command(SDState *sd, SDRequest *req,
> --
> 1.7.4.1

-- PMM