Re: [PATCH v11 07/14] irqchip: Add RISC-V incoming MSI controller early driver

From: Thomas Gleixner
Date: Sat Oct 28 2023 - 14:41:47 EST


On Mon, Oct 23 2023 at 22:57, Anup Patel wrote:
> +#ifdef CONFIG_GENERIC_IRQ_DEBUGFS
> +void imsic_vector_debug_show(struct seq_file *m,
> + struct imsic_vector *vec, int ind)
> +{
> + unsigned int mcpu = 0, mlocal_id = 0;
> + struct imsic_local_priv *lpriv;
> + bool move_in_progress = false;
> + struct imsic_vector *mvec;
> + bool is_enabled = false;
> + unsigned long flags;
> +
> + lpriv = per_cpu_ptr(imsic->lpriv, vec->cpu);
> + if (WARN_ON(&lpriv->vectors[vec->local_id] != vec))
> + return;
> +
> + raw_spin_lock_irqsave(&lpriv->ids_lock, flags);
> + if (test_bit(vec->local_id, lpriv->ids_enabled_bitmap))
> + is_enabled = true;
> + mvec = lpriv->ids_move[vec->local_id];
> + if (mvec) {
> + move_in_progress = true;
> + mcpu = mvec->cpu;
> + mlocal_id = mvec->local_id;
> + }
> + raw_spin_unlock_irqrestore(&lpriv->ids_lock, flags);
> +
> + seq_printf(m, "%*starget_cpu : %5u\n", ind, "", vec->cpu);
> + seq_printf(m, "%*starget_local_id : %5u\n", ind, "", vec->local_id);
> + seq_printf(m, "%*sis_reserved : %5u\n", ind, "",
> + (vec->local_id <= IMSIC_IPI_ID) ? 1 : 0);
> + seq_printf(m, "%*sis_enabled : %5u\n", ind, "",
> + (move_in_progress) ? 1 : 0);
> + seq_printf(m, "%*sis_move_pending : %5u\n", ind, "",
> + (move_in_progress) ? 1 : 0);
> + if (move_in_progress) {
> + seq_printf(m, "%*smove_cpu : %5u\n", ind, "", mcpu);
> + seq_printf(m, "%*smove_local_id : %5u\n", ind, "", mlocal_id);
> + }
> +}
> +
> +void imsic_vector_debug_show_summary(struct seq_file *m, int ind)
> +{
> + unsigned int cpu, total_avail = 0, total_used = 0;
> + struct imsic_global_config *global = &imsic->global;
> + struct imsic_local_priv *lpriv;
> + unsigned long flags;
> +
> + for_each_possible_cpu(cpu) {
> + lpriv = per_cpu_ptr(imsic->lpriv, cpu);
> +
> + total_avail += global->nr_ids;
> +
> + raw_spin_lock_irqsave(&lpriv->ids_lock, flags);
> + total_used += bitmap_weight(lpriv->ids_used_bitmap,
> + global->nr_ids + 1) - 1;
> + raw_spin_unlock_irqrestore(&lpriv->ids_lock, flags);
> + }
> +
> + seq_printf(m, "%*stotal : %5u\n", ind, "", total_avail);
> + seq_printf(m, "%*sused : %5u\n", ind, "", total_used);
> + seq_printf(m, "%*s| CPU | tot | usd | vectors\n", ind, " ");
> +
> + cpus_read_lock();
> + for_each_online_cpu(cpu) {
> + lpriv = per_cpu_ptr(imsic->lpriv, cpu);
> +
> + raw_spin_lock_irqsave(&lpriv->ids_lock, flags);
> + total_used = bitmap_weight(lpriv->ids_used_bitmap,
> + global->nr_ids + 1) - 1;
> + seq_printf(m, "%*s %4d %4u %4u %*pbl\n", ind, " ",
> + cpu, global->nr_ids, total_used,
> + global->nr_ids + 1, lpriv->ids_used_bitmap);
> + raw_spin_unlock_irqrestore(&lpriv->ids_lock, flags);
> + }
> + cpus_read_unlock();

This looks very close to the matrix alocator information, just done differently.

> +static unsigned int imsic_vector_best_cpu(const struct cpumask *mask,
> + unsigned int order)
> +{
> + struct imsic_global_config *global = &imsic->global;
> + unsigned int cpu, best_cpu, free, maxfree = 0;
> + struct imsic_local_priv *lpriv;
> + unsigned long flags;
> +
> + best_cpu = UINT_MAX;
> + for_each_cpu(cpu, mask) {
> + if (!cpu_online(cpu))
> + continue;
> +
> + lpriv = per_cpu_ptr(imsic->lpriv, cpu);
> + raw_spin_lock_irqsave(&lpriv->ids_lock, flags);
> + free = bitmap_weight(lpriv->ids_used_bitmap,
> + global->nr_ids + 1);
> + free = (global->nr_ids + 1) - free;
> + raw_spin_unlock_irqrestore(&lpriv->ids_lock, flags);
> + if (free < BIT(order) || free <= maxfree)
> + continue;
> +
> + best_cpu = cpu;
> + maxfree = free;
> + }
> +
> + return best_cpu;

Looks very much like what the matrix allocator provides, right?

What's the actual reason that you can't use it?

Thanks,

tglx