irqchip/gic-v5: Split IRS probing into OF and generic portions

Split the IRS driver code into OF specific and generic portions in order
to pave the way for adding ACPI firmware bindings support.

Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Acked-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260115-gicv5-host-acpi-v3-3-c13a9a150388@kernel.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: Lorenzo Pieralisi

drivers/irqchip/irq-gic-v5-irs.c

@@ -545,15 +545,13 @@ int gicv5_irs_register_cpu(int cpuid)
 
 static void __init gicv5_irs_init_bases(struct gicv5_irs_chip_data *irs_data,
 					void __iomem *irs_base,
-					struct fwnode_handle *handle)
+					bool noncoherent)
 {
-	struct device_node *np = to_of_node(handle);
 	u32 cr0, cr1;
 
-	irs_data->fwnode = handle;
 	irs_data->irs_base = irs_base;
 
-	if (of_property_read_bool(np, "dma-noncoherent")) {
+	if (noncoherent) {
 		/*
 		 * A non-coherent IRS implies that some cache levels cannot be
 		 * used coherently by the cores and GIC. Our only option is to mark
@@ -678,12 +676,52 @@ static void irs_setup_pri_bits(u32 idr1)
 	}
 }
 
-static int __init gicv5_irs_init(struct device_node *node)
+static int __init gicv5_irs_init(struct gicv5_irs_chip_data *irs_data)
+{
+	u32 spi_count, idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR2);
+
+	if (WARN(!FIELD_GET(GICV5_IRS_IDR2_LPI, idr),
+		 "LPI support not available - no IPIs, can't proceed\n")) {
+		return -ENODEV;
+	}
+
+	idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR7);
+	irs_data->spi_min = FIELD_GET(GICV5_IRS_IDR7_SPI_BASE, idr);
+
+	idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR6);
+	irs_data->spi_range = FIELD_GET(GICV5_IRS_IDR6_SPI_IRS_RANGE, idr);
+
+	/*
+	 * Do the global setting only on the first IRS.
+	 * Global properties (iaffid_bits, global spi count) are guaranteed to
+	 * be consistent across IRSes by the architecture.
+	 */
+	if (list_empty(&irs_nodes)) {
+
+		idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR1);
+		irs_setup_pri_bits(idr);
+
+		idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR5);
+
+		spi_count = FIELD_GET(GICV5_IRS_IDR5_SPI_RANGE, idr);
+		gicv5_global_data.global_spi_count = spi_count;
+
+		gicv5_init_lpi_domain();
+
+		pr_debug("Detected %u SPIs globally\n", spi_count);
+	}
+
+	list_add_tail(&irs_data->entry, &irs_nodes);
+
+	return 0;
+}
+
+static int __init gicv5_irs_of_init(struct device_node *node)
 {
 	struct gicv5_irs_chip_data *irs_data;
 	void __iomem *irs_base;
-	u32 idr, spi_count;
 	u8 iaffid_bits;
+	u32 idr;
 	int ret;
 
 	irs_data = kzalloc(sizeof(*irs_data), GFP_KERNEL);
@@ -705,7 +743,8 @@ static int __init gicv5_irs_init(struct device_node *node)
 		goto out_err;
 	}
 
-	gicv5_irs_init_bases(irs_data, irs_base, &node->fwnode);
+	irs_data->fwnode = of_fwnode_handle(node);
+	gicv5_irs_init_bases(irs_data, irs_base, of_property_read_bool(node, "dma-noncoherent"));
 
 	idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR1);
 	iaffid_bits = FIELD_GET(GICV5_IRS_IDR1_IAFFID_BITS, idr) + 1;
@@ -716,18 +755,9 @@ static int __init gicv5_irs_init(struct device_node *node)
 		goto out_iomem;
 	}
 
-	idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR2);
-	if (WARN(!FIELD_GET(GICV5_IRS_IDR2_LPI, idr),
-		 "LPI support not available - no IPIs, can't proceed\n")) {
-		ret = -ENODEV;
+	ret = gicv5_irs_init(irs_data);
+	if (ret)
 		goto out_iomem;
-	}
-
-	idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR7);
-	irs_data->spi_min = FIELD_GET(GICV5_IRS_IDR7_SPI_BASE, idr);
-
-	idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR6);
-	irs_data->spi_range = FIELD_GET(GICV5_IRS_IDR6_SPI_IRS_RANGE, idr);
 
 	if (irs_data->spi_range) {
 		pr_info("%s detected SPI range [%u-%u]\n",
@@ -737,29 +767,7 @@ static int __init gicv5_irs_init(struct device_node *node)
 						irs_data->spi_range - 1);
 	}
 
-	/*
-	 * Do the global setting only on the first IRS.
-	 * Global properties (iaffid_bits, global spi count) are guaranteed to
-	 * be consistent across IRSes by the architecture.
-	 */
-	if (list_empty(&irs_nodes)) {
-
-		idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR1);
-		irs_setup_pri_bits(idr);
-
-		idr = irs_readl_relaxed(irs_data, GICV5_IRS_IDR5);
-
-		spi_count = FIELD_GET(GICV5_IRS_IDR5_SPI_RANGE, idr);
-		gicv5_global_data.global_spi_count = spi_count;
-
-		gicv5_init_lpi_domain();
-
-		pr_debug("Detected %u SPIs globally\n", spi_count);
-	}
-
-	list_add_tail(&irs_data->entry, &irs_nodes);
-
-	return 0;
+	return ret;
 
 out_iomem:
 	iounmap(irs_base);
@@ -818,7 +826,7 @@ int __init gicv5_irs_of_probe(struct device_node *parent)
 		if (!of_device_is_compatible(np, "arm,gic-v5-irs"))
 			continue;
 
-		ret = gicv5_irs_init(np);
+		ret = gicv5_irs_of_init(np);
 		if (ret)
 			pr_err("Failed to init IRS %s\n", np->full_name);
 	}