Re: [Qemu-devel] [PATCH v7 07/20] hw/arm/smmuv3: Queue helpers

[Peter Maydell]

On 1 September 2017 at 18:21, Eric Auger <address@hidden> wrote:
> We introduce helpers to read/write into the circular queues.
> smmuv3_read_cmdq and smmuv3_write_evtq will become static
> later on.
>
> Signed-off-by: Eric Auger <address@hidden>

See comments on a previous patch where I suggest a better
way to implement the queue increment/wrapping handling.

> +typedef enum {
> +    CMD_Q_EMPTY,
> +    CMD_Q_FULL,
> +    CMD_Q_PARTIALLY_FILLED,
> +} SMMUQStatus;
> +
> +#define Q_ENTRY(q, idx)  (q->base + q->ent_size * idx)
> +#define Q_WRAP(q, pc)    ((pc) >> (q)->shift)
> +#define Q_IDX(q, pc)     ((pc) & ((1 << (q)->shift) - 1))
> +
> +static inline SMMUQStatus __smmu_queue_status(SMMUV3State *s, SMMUQueue *q)

No __ prefixes, please.

> +{
> +    uint32_t prod = Q_IDX(q, q->prod);
> +    uint32_t cons = Q_IDX(q, q->cons);
> +
> +    if ((prod == cons) && (q->wrap.prod != q->wrap.cons)) {
> +        return CMD_Q_FULL;
> +    } else if ((prod == cons) && (q->wrap.prod == q->wrap.cons)) {
> +        return CMD_Q_EMPTY;
> +    }
> +    return CMD_Q_PARTIALLY_FILLED;
> +}
> +#define smmu_is_q_full(s, q) (__smmu_queue_status(s, q) == CMD_Q_FULL)
> +#define smmu_is_q_empty(s, q) (__smmu_queue_status(s, q) == CMD_Q_EMPTY)
> +
> +static inline int __smmu_q_enabled(SMMUV3State *s, uint32_t q)
> +{
> +    return smmu_read32_reg(s, SMMU_REG_CR0) & q;
> +}
> +#define smmu_cmd_q_enabled(s) __smmu_q_enabled(s, SMMU_CR0_CMDQ_ENABLE)
> +#define smmu_evt_q_enabled(s) __smmu_q_enabled(s, SMMU_CR0_EVTQ_ENABLE)

This code seems to be rather macro-happy.

thanks
-- PMM