Re: [Qemu-devel] [PATCH 1/5] lsi: use QTAILQ for lsi_queue

[Anthony Liguori <aliguori@redhat.com>]

On 01/06/2010 10:08 AM, Gerd Hoffmann wrote:
> Replace the funky array logic for queued commands with standard
> qemu list functions.  Also rename lsi_queue to lsi_request.
>
> Signed-off-by: Gerd Hoffmann<kraxel@redhat.com>
>    

Applied all.  Thanks.

Regards,

Anthony Liguori
> ---
>   hw/lsi53c895a.c |   68 ++++++++++++++++++++++--------------------------------
>   1 files changed, 28 insertions(+), 40 deletions(-)
>
> diff --git a/hw/lsi53c895a.c b/hw/lsi53c895a.c
> index e4033b1..71a95f5 100644
> --- a/hw/lsi53c895a.c
> +++ b/hw/lsi53c895a.c
> @@ -173,11 +173,12 @@ do { fprintf(stderr, "lsi_scsi: error: " fmt , ## __VA_ARGS__);} while (0)
>   /* Flag set if this is a tagged command.  */
>   #define LSI_TAG_VALID     (1<<  16)
>
> -typedef struct {
> +typedef struct lsi_request {
>       uint32_t tag;
>       uint32_t pending;
>       int out;
> -} lsi_queue;
> +    QTAILQ_ENTRY(lsi_request) next;
> +} lsi_request;
>
>   typedef struct {
>       PCIDevice dev;
> @@ -205,9 +206,7 @@ typedef struct {
>       uint32_t current_dma_len;
>       int command_complete;
>       uint8_t *dma_buf;
> -    lsi_queue *queue;
> -    int queue_len;
> -    int active_commands;
> +    QTAILQ_HEAD(, lsi_request) queue;
>
>       uint32_t dsa;
>       uint32_t temp;
> @@ -391,9 +390,9 @@ static void lsi_stop_script(LSIState *s)
>
>   static void lsi_update_irq(LSIState *s)
>   {
> -    int i;
>       int level;
>       static int last_level;
> +    lsi_request *p;
>
>       /* It's unclear whether the DIP/SIP bits should be cleared when the
>          Interrupt Status Registers are cleared or when istat0 is read.
> @@ -427,9 +426,9 @@ static void lsi_update_irq(LSIState *s)
>       if (!level&&  lsi_irq_on_rsl(s)&&  !(s->scntl1&  LSI_SCNTL1_CON)) {
>           DPRINTF("Handled IRQs&  disconnected, looking for pending "
>                   "processes\n");
> -        for (i = 0; i<  s->active_commands; i++) {
> -            if (s->queue[i].pending) {
> -                lsi_reselect(s, s->queue[i].tag);
> +        QTAILQ_FOREACH(p,&s->queue, next) {
> +            if (p->pending) {
> +                lsi_reselect(s, p->tag);
>                   break;
>               }
>           }
> @@ -563,14 +562,11 @@ static void lsi_do_dma(LSIState *s, int out)
>   /* Add a command to the queue.  */
>   static void lsi_queue_command(LSIState *s)
>   {
> -    lsi_queue *p;
> +    lsi_request *p;
>
>       DPRINTF("Queueing tag=0x%x\n", s->current_tag);
> -    if (s->queue_len == s->active_commands) {
> -        s->queue_len++;
> -        s->queue = qemu_realloc(s->queue, s->queue_len * sizeof(lsi_queue));
> -    }
> -    p =&s->queue[s->active_commands++];
> +    p = qemu_mallocz(sizeof(*p));
> +    QTAILQ_INSERT_TAIL(&s->queue, p, next);
>       p->tag = s->current_tag;
>       p->pending = 0;
>       p->out = (s->sstat1&  PHASE_MASK) == PHASE_DO;
> @@ -590,17 +586,14 @@ static void lsi_add_msg_byte(LSIState *s, uint8_t data)
>   /* Perform reselection to continue a command.  */
>   static void lsi_reselect(LSIState *s, uint32_t tag)
>   {
> -    lsi_queue *p;
> -    int n;
> +    lsi_request *p;
>       int id;
>
> -    p = NULL;
> -    for (n = 0; n<  s->active_commands; n++) {
> -        p =&s->queue[n];
> +    QTAILQ_FOREACH(p,&s->queue, next) {
>           if (p->tag == tag)
>               break;
>       }
> -    if (n == s->active_commands) {
> +    if (p == NULL) {
>           BADF("Reselected non-existant command tag=0x%x\n", tag);
>           return;
>       }
> @@ -624,10 +617,8 @@ static void lsi_reselect(LSIState *s, uint32_t tag)
>           lsi_add_msg_byte(s, tag&  0xff);
>       }
>
> -    s->active_commands--;
> -    if (n != s->active_commands) {
> -        s->queue[n] = s->queue[s->active_commands];
> -    }
> +    QTAILQ_REMOVE(&s->queue, p, next);
> +    qemu_free(p);
>
>       if (lsi_irq_on_rsl(s)) {
>           lsi_script_scsi_interrupt(s, LSI_SIST0_RSL, 0);
> @@ -638,10 +629,9 @@ static void lsi_reselect(LSIState *s, uint32_t tag)
>      the device was reselected, nonzero if the IO is deferred.  */
>   static int lsi_queue_tag(LSIState *s, uint32_t tag, uint32_t arg)
>   {
> -    lsi_queue *p;
> -    int i;
> -    for (i = 0; i<  s->active_commands; i++) {
> -        p =&s->queue[i];
> +    lsi_request *p;
> +
> +    QTAILQ_FOREACH(p,&s->queue, next) {
>           if (p->tag == tag) {
>               if (p->pending) {
>                   BADF("Multiple IO pending for tag %d\n", tag);
> @@ -659,7 +649,7 @@ static int lsi_queue_tag(LSIState *s, uint32_t tag, uint32_t arg)
>                   lsi_reselect(s, tag);
>                   return 0;
>               } else {
> -               DPRINTF("Queueing IO tag=0x%x\n", tag);
> +                DPRINTF("Queueing IO tag=0x%x\n", tag);
>                   p->pending = arg;
>                   return 1;
>               }
> @@ -905,13 +895,15 @@ static void lsi_memcpy(LSIState *s, uint32_t dest, uint32_t src, int count)
>
>   static void lsi_wait_reselect(LSIState *s)
>   {
> -    int i;
> +    lsi_request *p;
> +
>       DPRINTF("Wait Reselect\n");
>       if (s->current_dma_len)
>           BADF("Reselect with pending DMA\n");
> -    for (i = 0; i<  s->active_commands; i++) {
> -        if (s->queue[i].pending) {
> -            lsi_reselect(s, s->queue[i].tag);
> +
> +    QTAILQ_FOREACH(p,&s->queue, next) {
> +        if (p->pending) {
> +            lsi_reselect(s, p->tag);
>               break;
>           }
>       }
> @@ -2008,7 +2000,7 @@ static void lsi_pre_save(void *opaque)
>
>       assert(s->dma_buf == NULL);
>       assert(s->current_dma_len == 0);
> -    assert(s->active_commands == 0);
> +    assert(QTAILQ_EMPTY(&s->queue));
>   }
>
>   static const VMStateDescription vmstate_lsi_scsi = {
> @@ -2101,8 +2093,6 @@ static int lsi_scsi_uninit(PCIDevice *d)
>       cpu_unregister_io_memory(s->mmio_io_addr);
>       cpu_unregister_io_memory(s->ram_io_addr);
>
> -    qemu_free(s->queue);
> -
>       return 0;
>   }
>
> @@ -2138,9 +2128,7 @@ static int lsi_scsi_init(PCIDevice *dev)
>                              PCI_BASE_ADDRESS_SPACE_MEMORY, lsi_mmio_mapfunc);
>       pci_register_bar((struct PCIDevice *)s, 2, 0x2000,
>                              PCI_BASE_ADDRESS_SPACE_MEMORY, lsi_ram_mapfunc);
> -    s->queue = qemu_malloc(sizeof(lsi_queue));
> -    s->queue_len = 1;
> -    s->active_commands = 0;
> +    QTAILQ_INIT(&s->queue);
>
>       lsi_soft_reset(s);
>
>