irqchip/gic-v4.1: Map the ITS SGIR register page

One of the new features of GICv4.1 is to allow virtual SGIs to be
directly signaled to a VPE. For that, the ITS has grown a new
64kB page containing only a single register that is used to
signal a SGI to a given VPE.

Add a second mapping covering this new 64kB range, and take this
opportunity to limit the original mapping to 64kB, which is enough
to cover the span of the ITS registers.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20200304203330.4967-8-maz@kernel.org

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index bcc1a09..54d6fdf 100644 (file)
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -96,6 +96,7 @@ struct its_node {
        struct mutex            dev_alloc_lock;
        struct list_head        entry;
        void __iomem            *base;
+       void __iomem            *sgir_base;
        phys_addr_t             phys_base;
        struct its_cmd_block    *cmd_base;
        struct its_cmd_block    *cmd_write;
@@ -4456,7 +4457,7 @@ static int __init its_probe_one(struct resource *res,
        struct page *page;
        int err;
 
-       its_base = ioremap(res->start, resource_size(res));
+       its_base = ioremap(res->start, SZ_64K);
        if (!its_base) {
                pr_warn("ITS@%pa: Unable to map ITS registers\n", &res->start);
                return -ENOMEM;
@@ -4507,6 +4508,13 @@ static int __init its_probe_one(struct resource *res,
 
                if (is_v4_1(its)) {
                        u32 svpet = FIELD_GET(GITS_TYPER_SVPET, typer);
+
+                       its->sgir_base = ioremap(res->start + SZ_128K, SZ_64K);
+                       if (!its->sgir_base) {
+                               err = -ENOMEM;
+                               goto out_free_its;
+                       }
+
                        its->mpidr = readl_relaxed(its_base + GITS_MPIDR);
 
                        pr_info("ITS@%pa: Using GICv4.1 mode %08x %08x\n",
@@ -4520,7 +4528,7 @@ static int __init its_probe_one(struct resource *res,
                                get_order(ITS_CMD_QUEUE_SZ));
        if (!page) {
                err = -ENOMEM;
-               goto out_free_its;
+               goto out_unmap_sgir;
        }
        its->cmd_base = (void *)page_address(page);
        its->cmd_write = its->cmd_base;
@@ -4587,6 +4595,9 @@ out_free_tables:
        its_free_tables(its);
 out_free_cmd:
        free_pages((unsigned long)its->cmd_base, get_order(ITS_CMD_QUEUE_SZ));
+out_unmap_sgir:
+       if (its->sgir_base)
+               iounmap(its->sgir_base);
 out_free_its:
        kfree(its);
 out_unmap: