From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Date: Tue, 17 Oct 2017 17:55:55 +0100
Subject: irqchip/gic: Make quirks matching conditional on init return value
Patch-mainline: v4.15-rc1
Git-commit: 9d111d49106b61f5a652d5418e85d8741b1a0427
References: bsc#1077761

As it turns out, the IIDR is not sufficient to distinguish between GICv3
implementations when it comes to enabling quirks. So update the prototype
of the init() hook to return a bool, and interpret a 'false' return value
as no match, in which case the 'enabling workaround' log message should
not be printed.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Alexander Graf <agraf@suse.de>
---
 drivers/irqchip/irq-gic-common.c |    5 +++--
 drivers/irqchip/irq-gic-common.h |    2 +-
 drivers/irqchip/irq-gic-v3-its.c |   12 +++++++++---
 3 files changed, 13 insertions(+), 6 deletions(-)

--- a/drivers/irqchip/irq-gic-common.c
+++ b/drivers/irqchip/irq-gic-common.c
@@ -40,8 +40,9 @@
 	for (; quirks->desc; quirks++) {
 		if (quirks->iidr != (quirks->mask & iidr))
 			continue;
-		quirks->init(data);
-		pr_info("GIC: enabling workaround for %s\n", quirks->desc);
+		if (quirks->init(data))
+			pr_info("GIC: enabling workaround for %s\n",
+				quirks->desc);
 	}
 }
 
--- a/drivers/irqchip/irq-gic-common.h
+++ b/drivers/irqchip/irq-gic-common.h
@@ -23,7 +23,7 @@
 
 struct gic_quirk {
 	const char *desc;
-	void (*init)(void *data);
+	bool (*init)(void *data);
 	u32 iidr;
 	u32 mask;
 };
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1578,28 +1578,34 @@
 	}
 }
 
-static void __maybe_unused its_enable_quirk_cavium_22375(void *data)
+static bool __maybe_unused its_enable_quirk_cavium_22375(void *data)
 {
 	struct its_node *its = data;
 
 	/* erratum 22375: only alloc 8MB table size */
 	its->device_ids = 0x14;		/* 20 bits, 8MB */
 	its->flags |= ITS_FLAGS_WORKAROUND_CAVIUM_22375;
+
+	return true;
 }
 
-static void __maybe_unused its_enable_quirk_cavium_23144(void *data)
+static bool __maybe_unused its_enable_quirk_cavium_23144(void *data)
 {
 	struct its_node *its = data;
 
 	its->flags |= ITS_FLAGS_WORKAROUND_CAVIUM_23144;
+
+	return true;
 }
 
-static void __maybe_unused its_enable_quirk_qdf2400_e0065(void *data)
+static bool __maybe_unused its_enable_quirk_qdf2400_e0065(void *data)
 {
 	struct its_node *its = data;
 
 	/* On QDF2400, the size of the ITE is 16Bytes */
 	its->ite_size = 16;
+
+	return true;
 }
 
 static const struct gic_quirk its_quirks[] = {