[PATCH 07/10] irqchip/gic-v3-its: Split probing from its node initialization

[Robert Richter]

To initialize the its nodes at a later point during boot, we need to
split probing from initialization. Collect all information required
for initialization in struct its_node. We can then use the its node
list for initialization.

Signed-off-by: Robert Richter <rrichter@xxxxxxxxxx>
---
 drivers/irqchip/irq-gic-v3-its.c   | 135 +++++++++++++++++++++++--------------
 drivers/irqchip/irq-gic-v3.c       |   2 +-
 include/linux/irqchip/arm-gic-v3.h |   4 +-
 3 files changed, 87 insertions(+), 54 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 4033f71f5181..c28f4158ff70 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -103,6 +103,7 @@ struct its_node {
 	struct list_head	entry;
 	void __iomem		*base;
 	phys_addr_t		phys_base;
+	phys_addr_t		phys_size;
 	struct its_cmd_block	*cmd_base;
 	struct its_cmd_block	*cmd_write;
 	struct its_baser	tables[GITS_BASER_NR_REGS];
@@ -3375,7 +3376,7 @@ static struct syscore_ops its_syscore_ops = {
 	.resume = its_restore_enable,
 };
 
-static int its_init_domain(struct fwnode_handle *handle, struct its_node *its)
+static int its_init_domain(struct its_node *its)
 {
 	struct irq_domain *inner_domain;
 	struct msi_domain_info *info;
@@ -3384,7 +3385,8 @@ static int its_init_domain(struct fwnode_handle *handle, struct its_node *its)
 	if (!info)
 		return -ENOMEM;
 
-	inner_domain = irq_domain_create_tree(handle, &its_domain_ops, its);
+	inner_domain = irq_domain_create_tree(its->fwnode_handle,
+					&its_domain_ops, its);
 	if (!inner_domain) {
 		kfree(info);
 		return -ENOMEM;
@@ -3441,8 +3443,7 @@ static int its_init_vpe_domain(void)
 	return 0;
 }
 
-static int __init its_compute_its_list_map(struct resource *res,
-					   void __iomem *its_base)
+static int __init its_compute_its_list_map(struct its_node *its)
 {
 	int its_number;
 	u32 ctlr;
@@ -3456,15 +3457,15 @@ static int __init its_compute_its_list_map(struct resource *res,
 	its_number = find_first_zero_bit(&its_list_map, GICv4_ITS_LIST_MAX);
 	if (its_number >= GICv4_ITS_LIST_MAX) {
 		pr_err("ITS@%pa: No ITSList entry available!\n",
-		       &res->start);
+		       &its->phys_base);
 		return -EINVAL;
 	}
 
-	ctlr = readl_relaxed(its_base + GITS_CTLR);
+	ctlr = readl_relaxed(its->base + GITS_CTLR);
 	ctlr &= ~GITS_CTLR_ITS_NUMBER;
 	ctlr |= its_number << GITS_CTLR_ITS_NUMBER_SHIFT;
-	writel_relaxed(ctlr, its_base + GITS_CTLR);
-	ctlr = readl_relaxed(its_base + GITS_CTLR);
+	writel_relaxed(ctlr, its->base + GITS_CTLR);
+	ctlr = readl_relaxed(its->base + GITS_CTLR);
 	if ((ctlr & GITS_CTLR_ITS_NUMBER) != (its_number << GITS_CTLR_ITS_NUMBER_SHIFT)) {
 		its_number = ctlr & GITS_CTLR_ITS_NUMBER;
 		its_number >>= GITS_CTLR_ITS_NUMBER_SHIFT;
@@ -3472,83 +3473,110 @@ static int __init its_compute_its_list_map(struct resource *res,
 
 	if (test_and_set_bit(its_number, &its_list_map)) {
 		pr_err("ITS@%pa: Duplicate ITSList entry %d\n",
-		       &res->start, its_number);
+		       &its->phys_base, its_number);
 		return -EINVAL;
 	}
 
 	return its_number;
 }
 
+static void its_free(struct its_node *its)
+{
+	raw_spin_lock(&its_lock);
+	list_del(&its->entry);
+	raw_spin_unlock(&its_lock);
+
+	kfree(its);
+}
+
+static int __init its_init_one(struct its_node *its);
+
 static int __init its_probe_one(struct resource *res,
 				struct fwnode_handle *handle, int numa_node)
 {
 	struct its_node *its;
+	int err;
+
+	its = kzalloc(sizeof(*its), GFP_KERNEL);
+	if (!its)
+		return -ENOMEM;
+
+	raw_spin_lock_init(&its->lock);
+	INIT_LIST_HEAD(&its->entry);
+	INIT_LIST_HEAD(&its->its_device_list);
+	its->fwnode_handle = handle;
+	its->phys_base = res->start;
+	its->phys_size = resource_size(res);
+	its->numa_node = numa_node;
+
+	raw_spin_lock(&its_lock);
+	list_add_tail(&its->entry, &its_nodes);
+	raw_spin_unlock(&its_lock);
+
+	pr_info("ITS %pR\n", res);
+
+	err = its_init_one(its);
+	if (err)
+		its_free(its);
+
+	return err;
+}
+
+static int __init its_init_one(struct its_node *its)
+{
 	void __iomem *its_base;
 	u32 val, ctlr;
 	u64 baser, tmp, typer;
 	int err;
 
-	its_base = ioremap(res->start, resource_size(res));
+	its_base = ioremap(its->phys_base, its->phys_size);
 	if (!its_base) {
-		pr_warn("ITS@%pa: Unable to map ITS registers\n", &res->start);
-		return -ENOMEM;
+		pr_warn("ITS@%pa: Unable to map ITS registers\n", &its->phys_base);
+		err = -ENOMEM;
+		goto fail;
 	}
 
 	val = readl_relaxed(its_base + GITS_PIDR2) & GIC_PIDR2_ARCH_MASK;
 	if (val != 0x30 && val != 0x40) {
-		pr_warn("ITS@%pa: No ITS detected, giving up\n", &res->start);
+		pr_warn("ITS@%pa: No ITS detected, giving up\n", &its->phys_base);
 		err = -ENODEV;
 		goto out_unmap;
 	}
 
 	err = its_force_quiescent(its_base);
 	if (err) {
-		pr_warn("ITS@%pa: Failed to quiesce, giving up\n", &res->start);
+		pr_warn("ITS@%pa: Failed to quiesce, giving up\n", &its->phys_base);
 		goto out_unmap;
 	}
 
-	pr_info("ITS %pR\n", res);
-
-	its = kzalloc(sizeof(*its), GFP_KERNEL);
-	if (!its) {
-		err = -ENOMEM;
-		goto out_unmap;
-	}
-
-	raw_spin_lock_init(&its->lock);
-	INIT_LIST_HEAD(&its->entry);
-	INIT_LIST_HEAD(&its->its_device_list);
 	typer = gic_read_typer(its_base + GITS_TYPER);
 	its->base = its_base;
-	its->phys_base = res->start;
 	its->ite_size = GITS_TYPER_ITT_ENTRY_SIZE(typer);
 	its->device_ids = GITS_TYPER_DEVBITS(typer);
 	its->is_v4 = !!(typer & GITS_TYPER_VLPIS);
 	if (its->is_v4) {
 		if (!(typer & GITS_TYPER_VMOVP)) {
-			err = its_compute_its_list_map(res, its_base);
+			err = its_compute_its_list_map(its);
 			if (err < 0)
-				goto out_free_its;
+				goto out_unmap;
 
 			its->list_nr = err;
 
 			pr_info("ITS@%pa: Using ITS number %d\n",
-				&res->start, err);
+				&its->phys_base, err);
 		} else {
-			pr_info("ITS@%pa: Single VMOVP capable\n", &res->start);
+			pr_info("ITS@%pa: Single VMOVP capable\n",
+				&its->phys_base);
 		}
 	}
 
-	its->numa_node = numa_node;
-
 	its->cmd_base = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
 						get_order(ITS_CMD_QUEUE_SZ));
 	if (!its->cmd_base) {
 		err = -ENOMEM;
-		goto out_free_its;
+		goto out_unmap;
 	}
 	its->cmd_write = its->cmd_base;
-	its->fwnode_handle = handle;
 	its->get_msi_base = its_irq_get_msi_base;
 	its->msi_domain_flags = IRQ_DOMAIN_FLAG_MSI_REMAP;
 
@@ -3597,13 +3625,11 @@ static int __init its_probe_one(struct resource *res,
 	if (GITS_TYPER_HCC(typer))
 		its->flags |= ITS_FLAGS_SAVE_SUSPEND_STATE;
 
-	err = its_init_domain(handle, its);
+	err = its_init_domain(its);
 	if (err)
 		goto out_free_tables;
 
-	raw_spin_lock(&its_lock);
-	list_add_tail(&its->entry, &its_nodes);
-	raw_spin_unlock(&its_lock);
+	pr_info("ITS@%pa: ITS node added\n", &its->phys_base);
 
 	return 0;
 
@@ -3611,11 +3637,10 @@ static int __init its_probe_one(struct resource *res,
 	its_free_tables(its);
 out_free_cmd:
 	free_pages((unsigned long)its->cmd_base, get_order(ITS_CMD_QUEUE_SZ));
-out_free_its:
-	kfree(its);
 out_unmap:
 	iounmap(its_base);
-	pr_err("ITS@%pa: failed probing (%d)\n", &res->start, err);
+fail:
+	pr_err("ITS@%pa: failed probing (%d)\n", &its->phys_base, err);
 	return err;
 }
 
@@ -3888,13 +3913,12 @@ static void __init its_acpi_probe(void)
 static void __init its_acpi_probe(void) { }
 #endif
 
-int __init its_init(struct fwnode_handle *handle, struct rdists *rdists,
-		    struct irq_domain *parent_domain)
+static int __init its_init(void);
+
+int __init its_probe(struct fwnode_handle *handle, struct rdists *rdists,
+		     struct irq_domain *parent_domain)
 {
 	struct device_node *of_node;
-	struct its_node *its;
-	bool has_v4 = false;
-	int err;
 
 	its_parent = parent_domain;
 	of_node = to_of_node(handle);
@@ -3903,13 +3927,22 @@ int __init its_init(struct fwnode_handle *handle, struct rdists *rdists,
 	else
 		its_acpi_probe();
 
+	gic_rdists = rdists;
+
+	return its_init();
+}
+
+static int __init its_init(void)
+{
+	struct its_node *its;
+	bool has_v4 = false;
+	int err;
+
 	if (list_empty(&its_nodes)) {
 		pr_warn("ITS: No ITS available, not enabling LPIs\n");
 		return -ENXIO;
 	}
 
-	gic_rdists = rdists;
-
 	err = allocate_lpi_tables();
 	if (err)
 		return err;
@@ -3917,10 +3950,10 @@ int __init its_init(struct fwnode_handle *handle, struct rdists *rdists,
 	list_for_each_entry(its, &its_nodes, entry)
 		has_v4 |= its->is_v4;
 
-	if (has_v4 & rdists->has_vlpis) {
+	if (has_v4 & gic_rdists->has_vlpis) {
 		if (its_init_vpe_domain() ||
-		    its_init_v4(parent_domain, &its_vpe_domain_ops)) {
-			rdists->has_vlpis = false;
+		    its_init_v4(its_parent, &its_vpe_domain_ops)) {
+			gic_rdists->has_vlpis = false;
 			pr_err("ITS: Disabling GICv4 support\n");
 		}
 	}
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 8f87f40c9460..e04108b7c6b7 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -1132,7 +1132,7 @@ static int __init gic_init_bases(void __iomem *dist_base,
 	gic_cpu_pm_init();
 
 	if (gic_dist_supports_lpis()) {
-		its_init(handle, &gic_data.rdists, gic_data.domain);
+		its_probe(handle, &gic_data.rdists, gic_data.domain);
 		its_cpu_init();
 	}
 
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index 071b4cbdf010..a6fdb2910f73 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -603,8 +603,8 @@ struct rdists {
 struct irq_domain;
 struct fwnode_handle;
 int its_cpu_init(void);
-int its_init(struct fwnode_handle *handle, struct rdists *rdists,
-	     struct irq_domain *domain);
+int its_probe(struct fwnode_handle *handle, struct rdists *rdists,
+	      struct irq_domain *domain);
 int mbi_init(struct fwnode_handle *fwnode, struct irq_domain *parent);
 
 static inline bool gic_enable_sre(void)
-- 
2.11.0