u32 device_id;
};
+static struct {
+ raw_spinlock_t lock;
+ struct its_device *dev;
+ struct its_vpe **vpes;
+ int next_victim;
+} vpe_proxy;
+
static LIST_HEAD(its_nodes);
static DEFINE_SPINLOCK(its_lock);
static struct rdists *gic_rdists;
msi_info = msi_get_domain_info(domain);
its = msi_info->data;
+ if (!gic_rdists->has_direct_lpi &&
+ vpe_proxy.dev &&
+ vpe_proxy.dev->its == its &&
+ dev_id == vpe_proxy.dev->device_id) {
+ /* Bad luck. Get yourself a better implementation */
+ WARN_ONCE(1, "DevId %x clashes with GICv4 VPE proxy device\n",
+ dev_id);
+ return -EINVAL;
+ }
+
its_dev = its_find_device(its, dev_id);
if (its_dev) {
/*
.deactivate = its_irq_domain_deactivate,
};
+/*
+ * This is insane.
+ *
+ * If a GICv4 doesn't implement Direct LPIs (which is extremely
+ * likely), the only way to perform an invalidate is to use a fake
+ * device to issue an INV command, implying that the LPI has first
+ * been mapped to some event on that device. Since this is not exactly
+ * cheap, we try to keep that mapping around as long as possible, and
+ * only issue an UNMAP if we're short on available slots.
+ *
+ * Broken by design(tm).
+ */
+static void its_vpe_db_proxy_unmap_locked(struct its_vpe *vpe)
+{
+ /* Already unmapped? */
+ if (vpe->vpe_proxy_event == -1)
+ return;
+
+ its_send_discard(vpe_proxy.dev, vpe->vpe_proxy_event);
+ vpe_proxy.vpes[vpe->vpe_proxy_event] = NULL;
+
+ /*
+ * We don't track empty slots at all, so let's move the
+ * next_victim pointer if we can quickly reuse that slot
+ * instead of nuking an existing entry. Not clear that this is
+ * always a win though, and this might just generate a ripple
+ * effect... Let's just hope VPEs don't migrate too often.
+ */
+ if (vpe_proxy.vpes[vpe_proxy.next_victim])
+ vpe_proxy.next_victim = vpe->vpe_proxy_event;
+
+ vpe->vpe_proxy_event = -1;
+}
+
+static void its_vpe_db_proxy_unmap(struct its_vpe *vpe)
+{
+ if (!gic_rdists->has_direct_lpi) {
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&vpe_proxy.lock, flags);
+ its_vpe_db_proxy_unmap_locked(vpe);
+ raw_spin_unlock_irqrestore(&vpe_proxy.lock, flags);
+ }
+}
+
+static void its_vpe_db_proxy_map_locked(struct its_vpe *vpe)
+{
+ /* Already mapped? */
+ if (vpe->vpe_proxy_event != -1)
+ return;
+
+ /* This slot was already allocated. Kick the other VPE out. */
+ if (vpe_proxy.vpes[vpe_proxy.next_victim])
+ its_vpe_db_proxy_unmap_locked(vpe_proxy.vpes[vpe_proxy.next_victim]);
+
+ /* Map the new VPE instead */
+ vpe_proxy.vpes[vpe_proxy.next_victim] = vpe;
+ vpe->vpe_proxy_event = vpe_proxy.next_victim;
+ vpe_proxy.next_victim = (vpe_proxy.next_victim + 1) % vpe_proxy.dev->nr_ites;
+
+ vpe_proxy.dev->event_map.col_map[vpe->vpe_proxy_event] = vpe->col_idx;
+ its_send_mapti(vpe_proxy.dev, vpe->vpe_db_lpi, vpe->vpe_proxy_event);
+}
+
static int its_vpe_set_affinity(struct irq_data *d,
const struct cpumask *mask_val,
bool force)
/*
* Changing affinity is mega expensive, so let's be as lazy as
- * we can and only do it if we really have to.
+ * we can and only do it if we really have to. Also, if mapped
+ * into the proxy device, we need to nuke that mapping.
*/
if (vpe->col_idx != cpu) {
+ its_vpe_db_proxy_unmap(vpe);
vpe->col_idx = cpu;
its_send_vmovp(vpe);
}
}
}
+static void its_vpe_send_cmd(struct its_vpe *vpe,
+ void (*cmd)(struct its_device *, u32))
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&vpe_proxy.lock, flags);
+
+ its_vpe_db_proxy_map_locked(vpe);
+ cmd(vpe_proxy.dev, vpe->vpe_proxy_event);
+
+ raw_spin_unlock_irqrestore(&vpe_proxy.lock, flags);
+}
+
static void its_vpe_send_inv(struct irq_data *d)
{
struct its_vpe *vpe = irq_data_get_irq_chip_data(d);
- void __iomem *rdbase;
- rdbase = per_cpu_ptr(gic_rdists->rdist, vpe->col_idx)->rd_base;
- gic_write_lpir(vpe->vpe_db_lpi, rdbase + GICR_INVLPIR);
- while (gic_read_lpir(rdbase + GICR_SYNCR) & 1)
- cpu_relax();
+ if (gic_rdists->has_direct_lpi) {
+ void __iomem *rdbase;
+
+ rdbase = per_cpu_ptr(gic_rdists->rdist, vpe->col_idx)->rd_base;
+ gic_write_lpir(vpe->vpe_db_lpi, rdbase + GICR_INVLPIR);
+ while (gic_read_lpir(rdbase + GICR_SYNCR) & 1)
+ cpu_relax();
+ } else {
+ its_vpe_send_cmd(vpe, its_send_inv);
+ }
}
static void its_vpe_mask_irq(struct irq_data *d)
vpe->vpe_id = vpe_id;
vpe->vpt_page = vpt_page;
+ vpe->vpe_proxy_event = -1;
return 0;
}
static void its_vpe_teardown(struct its_vpe *vpe)
{
+ its_vpe_db_proxy_unmap(vpe);
its_vpe_id_free(vpe->vpe_id);
its_free_pending_table(vpe->vpt_page);
}
static int its_init_vpe_domain(void)
{
+ struct its_node *its;
+ u32 devid;
+ int entries;
+
+ if (gic_rdists->has_direct_lpi) {
+ pr_info("ITS: Using DirectLPI for VPE invalidation\n");
+ return 0;
+ }
+
+ /* Any ITS will do, even if not v4 */
+ its = list_first_entry(&its_nodes, struct its_node, entry);
+
+ entries = roundup_pow_of_two(nr_cpu_ids);
+ vpe_proxy.vpes = kzalloc(sizeof(*vpe_proxy.vpes) * entries,
+ GFP_KERNEL);
+ if (!vpe_proxy.vpes) {
+ pr_err("ITS: Can't allocate GICv4 proxy device array\n");
+ return -ENOMEM;
+ }
+
+ /* Use the last possible DevID */
+ devid = GENMASK(its->device_ids - 1, 0);
+ vpe_proxy.dev = its_create_device(its, devid, entries, false);
+ if (!vpe_proxy.dev) {
+ kfree(vpe_proxy.vpes);
+ pr_err("ITS: Can't allocate GICv4 proxy device\n");
+ return -ENOMEM;
+ }
+
+ BUG_ON(entries != vpe_proxy.dev->nr_ites);
+
+ raw_spin_lock_init(&vpe_proxy.lock);
+ vpe_proxy.next_victim = 0;
+ pr_info("ITS: Allocated DevID %x as GICv4 proxy device (%d slots)\n",
+ devid, vpe_proxy.dev->nr_ites);
+
return 0;
}
projects / linux.git / commitdiff