irqchip/gicv3: Handle resource request failure consistently

Due to a silly oversight on my part, making the simple switch to
of_io_request_and_map() in the DT path inadvertently introduced
divergent behaviour, whereby failng to request an iomem region now
becomes fatal for DT, vs. being silently ignored for ACPI.

Refactor a bit harder, so that request errors are non-fatal in both
paths as intended, but also consistently reported as well.

Reported-by: Matt Ranostay <mranostay@ti.com>
Fixes: 2b2cd74a06c3 ("irqchip/gic-v3: Claim iomem resources")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/5f2b57a0131f3082fae9d3002d360bf784ccb092.1655387206.git.robin.murphy@arm.com

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 5c1cf90..2d25bca 100644 (file)
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -2042,15 +2042,40 @@ static void __init gic_of_setup_kvm_info(struct device_node *node)
        vgic_set_kvm_info(&gic_v3_kvm_info);
 }
 
+static void gic_request_region(resource_size_t base, resource_size_t size,
+                              const char *name)
+{
+       if (!request_mem_region(base, size, name))
+               pr_warn_once(FW_BUG "%s region %pa has overlapping address\n",
+                            name, &base);
+}
+
+static void __iomem *gic_of_iomap(struct device_node *node, int idx,
+                                 const char *name, struct resource *res)
+{
+       void __iomem *base;
+       int ret;
+
+       ret = of_address_to_resource(node, idx, res);
+       if (ret)
+               return IOMEM_ERR_PTR(ret);
+
+       gic_request_region(res->start, resource_size(res), name);
+       base = of_iomap(node, idx);
+
+       return base ?: IOMEM_ERR_PTR(-ENOMEM);
+}
+
 static int __init gic_of_init(struct device_node *node, struct device_node *parent)
 {
        void __iomem *dist_base;
        struct redist_region *rdist_regs;
+       struct resource res;
        u64 redist_stride;
        u32 nr_redist_regions;
        int err, i;
 
-       dist_base = of_io_request_and_map(node, 0, "GICD");
+       dist_base = gic_of_iomap(node, 0, "GICD", &res);
        if (IS_ERR(dist_base)) {
                pr_err("%pOF: unable to map gic dist registers\n", node);
                return PTR_ERR(dist_base);
@@ -2073,12 +2098,8 @@ static int __init gic_of_init(struct device_node *node, struct device_node *pare
        }
 
        for (i = 0; i < nr_redist_regions; i++) {
-               struct resource res;
-               int ret;
-
-               ret = of_address_to_resource(node, 1 + i, &res);
-               rdist_regs[i].redist_base = of_io_request_and_map(node, 1 + i, "GICR");
-               if (ret || IS_ERR(rdist_regs[i].redist_base)) {
+               rdist_regs[i].redist_base = gic_of_iomap(node, 1 + i, "GICR", &res);
+               if (IS_ERR(rdist_regs[i].redist_base)) {
                        pr_err("%pOF: couldn't map region %d\n", node, i);
                        err = -ENODEV;
                        goto out_unmap_rdist;
@@ -2151,7 +2172,7 @@ gic_acpi_parse_madt_redist(union acpi_subtable_headers *header,
                pr_err("Couldn't map GICR region @%llx\n", redist->base_address);
                return -ENOMEM;
        }
-       request_mem_region(redist->base_address, redist->length, "GICR");
+       gic_request_region(redist->base_address, redist->length, "GICR");
 
        gic_acpi_register_redist(redist->base_address, redist_base);
        return 0;
@@ -2174,7 +2195,7 @@ gic_acpi_parse_madt_gicc(union acpi_subtable_headers *header,
        redist_base = ioremap(gicc->gicr_base_address, size);
        if (!redist_base)
                return -ENOMEM;
-       request_mem_region(gicc->gicr_base_address, size, "GICR");
+       gic_request_region(gicc->gicr_base_address, size, "GICR");
 
        gic_acpi_register_redist(gicc->gicr_base_address, redist_base);
        return 0;
@@ -2376,7 +2397,7 @@ gic_acpi_init(union acpi_subtable_headers *header, const unsigned long end)
                pr_err("Unable to map GICD registers\n");
                return -ENOMEM;
        }
-       request_mem_region(dist->base_address, ACPI_GICV3_DIST_MEM_SIZE, "GICD");
+       gic_request_region(dist->base_address, ACPI_GICV3_DIST_MEM_SIZE, "GICD");
 
        err = gic_validate_dist_version(acpi_data.dist_base);
        if (err) {