Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq core updates from Thomas Gleixner:
 "A rather large update for the interrupt core code and the irq chip drivers:

   - Add a new bitmap matrix allocator and supporting changes, which is
     used to replace the x86 vector allocator which comes with separate
     pull request. This allows to replace the convoluted nested loop
     allocation function in x86 with a facility which supports the
     recently added property of managed interrupts proper and allows to
     switch to a best effort vector reservation scheme, which addresses
     problems with vector exhaustion.

   - A large update to the ARM GIC-V3-ITS driver adding support for
     range selectors.

   - New interrupt controllers:
       - Meson and Meson8 GPIO
       - BCM7271 L2
       - Socionext EXIU

     If you expected that this will stop at some point, I have to
     disappoint you. There are new ones posted already. Sigh!

   - STM32 interrupt controller support for new platforms.

   - A pile of fixes, cleanups and updates to the MIPS GIC driver

   - The usual small fixes, cleanups and updates all over the place.
     Most visible one is to move the irq chip drivers Kconfig switches
     into a separate Kconfig menu"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
  genirq: Fix type of shifting literal 1 in __setup_irq()
  irqdomain: Drop pointless NULL check in virq_debug_show_one
  genirq/proc: Return proper error code when irq_set_affinity() fails
  irq/work: Use llist_for_each_entry_safe
  irqchip: mips-gic: Print warning if inherited GIC base is used
  irqchip/mips-gic: Add pr_fmt and reword pr_* messages
  irqchip/stm32: Move the wakeup on interrupt mask
  irqchip/stm32: Fix initial values
  irqchip/stm32: Add stm32h7 support
  dt-bindings/interrupt-controllers: Add compatible string for stm32h7
  irqchip/stm32: Add multi-bank management
  irqchip/stm32: Select GENERIC_IRQ_CHIP
  irqchip/exiu: Add support for Socionext Synquacer EXIU controller
  dt-bindings: Add description of Socionext EXIU interrupt controller
  irqchip/gic-v3-its: Fix VPE activate callback return value
  irqchip: mips-gic: Make IPI bitmaps static
  irqchip: mips-gic: Share register writes in gic_set_type()
  irqchip: mips-gic: Remove gic_vpes variable
  irqchip: mips-gic: Use num_possible_cpus() to reserve IPIs
  irqchip: mips-gic: Configure EIC when CPUs come online
  ...

1 files changed, 62 insertions, 9 deletions

diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 651d726e8b12..f641e8e2c78d 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -1256,6 +1256,19 @@ static void gic_teardown(struct gic_chip_data *gic)
 
 #ifdef CONFIG_OF
 static int gic_cnt __initdata;
+static bool gicv2_force_probe;
+
+static int __init gicv2_force_probe_cfg(char *buf)
+{
+	return strtobool(buf, &gicv2_force_probe);
+}
+early_param("irqchip.gicv2_force_probe", gicv2_force_probe_cfg);
+
+static bool gic_check_gicv2(void __iomem *base)
+{
+	u32 val = readl_relaxed(base + GIC_CPU_IDENT);
+	return (val & 0xff0fff) == 0x02043B;
+}
 
 static bool gic_check_eoimode(struct device_node *node, void __iomem **base)
 {
@@ -1265,20 +1278,60 @@ static bool gic_check_eoimode(struct device_node *node, void __iomem **base)
 
 	if (!is_hyp_mode_available())
 		return false;
-	if (resource_size(&cpuif_res) < SZ_8K)
-		return false;
-	if (resource_size(&cpuif_res) == SZ_128K) {
-		u32 val_low, val_high;
+	if (resource_size(&cpuif_res) < SZ_8K) {
+		void __iomem *alt;
+		/*
+		 * Check for a stupid firmware that only exposes the
+		 * first page of a GICv2.
+		 */
+		if (!gic_check_gicv2(*base))
+			return false;
 
+		if (!gicv2_force_probe) {
+			pr_warn("GIC: GICv2 detected, but range too small and irqchip.gicv2_force_probe not set\n");
+			return false;
+		}
+
+		alt = ioremap(cpuif_res.start, SZ_8K);
+		if (!alt)
+			return false;
+		if (!gic_check_gicv2(alt + SZ_4K)) {
+			/*
+			 * The first page was that of a GICv2, and
+			 * the second was *something*. Let's trust it
+			 * to be a GICv2, and update the mapping.
+			 */
+			pr_warn("GIC: GICv2 at %pa, but range is too small (broken DT?), assuming 8kB\n",
+				&cpuif_res.start);
+			iounmap(*base);
+			*base = alt;
+			return true;
+		}
+
+		/*
+		 * We detected *two* initial GICv2 pages in a
+		 * row. Could be a GICv2 aliased over two 64kB
+		 * pages. Update the resource, map the iospace, and
+		 * pray.
+		 */
+		iounmap(alt);
+		alt = ioremap(cpuif_res.start, SZ_128K);
+		if (!alt)
+			return false;
+		pr_warn("GIC: Aliased GICv2 at %pa, trying to find the canonical range over 128kB\n",
+			&cpuif_res.start);
+		cpuif_res.end = cpuif_res.start + SZ_128K -1;
+		iounmap(*base);
+		*base = alt;
+	}
+	if (resource_size(&cpuif_res) == SZ_128K) {
 		/*
-		 * Verify that we have the first 4kB of a GIC400
+		 * Verify that we have the first 4kB of a GICv2
 		 * aliased over the first 64kB by checking the
 		 * GICC_IIDR register on both ends.
 		 */
-		val_low = readl_relaxed(*base + GIC_CPU_IDENT);
-		val_high = readl_relaxed(*base + GIC_CPU_IDENT + 0xf000);
-		if ((val_low & 0xffff0fff) != 0x0202043B ||
-		    val_low != val_high)
+		if (!gic_check_gicv2(*base) ||
+		    !gic_check_gicv2(*base + 0xf000))
 			return false;
 
 		/*