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authorMarc Zyngier <marc.zyngier@arm.com>2014-06-30 16:01:30 +0100
committerJason Cooper <jason@lakedaemon.net>2014-07-08 21:49:14 +0000
commitd51d0af43b30dcae1ca13ea67fd717e03b37f153 (patch)
tree3c5b91f4ee3428130fe7276daf2a606f44182292 /drivers/irqchip/irq-gic-common.c
parent7171511eaec5bf23fb06078f59784a3a0626b38f (diff)
downloadlinux-d51d0af43b30dcae1ca13ea67fd717e03b37f153.tar.bz2
irqchip: gic: Move some bits of GICv2 to a library-type file
A few GICv2 low-level function are actually very useful to GICv3, and it makes some sense to share them across the two drivers. They end-up in their own file, with an additional parameter used to ensure an optional synchronization (unused on GICv2). Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Cooper <jason@lakedaemon.net> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Link: https://lkml.kernel.org/r/1404140510-5382-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Diffstat (limited to 'drivers/irqchip/irq-gic-common.c')
-rw-r--r--drivers/irqchip/irq-gic-common.c115
1 files changed, 115 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-gic-common.c b/drivers/irqchip/irq-gic-common.c
new file mode 100644
index 000000000000..60ac704d2090
--- /dev/null
+++ b/drivers/irqchip/irq-gic-common.c
@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2002 ARM Limited, All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqchip/arm-gic.h>
+
+#include "irq-gic-common.h"
+
+void gic_configure_irq(unsigned int irq, unsigned int type,
+ void __iomem *base, void (*sync_access)(void))
+{
+ u32 enablemask = 1 << (irq % 32);
+ u32 enableoff = (irq / 32) * 4;
+ u32 confmask = 0x2 << ((irq % 16) * 2);
+ u32 confoff = (irq / 16) * 4;
+ bool enabled = false;
+ u32 val;
+
+ /*
+ * Read current configuration register, and insert the config
+ * for "irq", depending on "type".
+ */
+ val = readl_relaxed(base + GIC_DIST_CONFIG + confoff);
+ if (type == IRQ_TYPE_LEVEL_HIGH)
+ val &= ~confmask;
+ else if (type == IRQ_TYPE_EDGE_RISING)
+ val |= confmask;
+
+ /*
+ * As recommended by the spec, disable the interrupt before changing
+ * the configuration
+ */
+ if (readl_relaxed(base + GIC_DIST_ENABLE_SET + enableoff) & enablemask) {
+ writel_relaxed(enablemask, base + GIC_DIST_ENABLE_CLEAR + enableoff);
+ if (sync_access)
+ sync_access();
+ enabled = true;
+ }
+
+ /*
+ * Write back the new configuration, and possibly re-enable
+ * the interrupt.
+ */
+ writel_relaxed(val, base + GIC_DIST_CONFIG + confoff);
+
+ if (enabled)
+ writel_relaxed(enablemask, base + GIC_DIST_ENABLE_SET + enableoff);
+
+ if (sync_access)
+ sync_access();
+}
+
+void __init gic_dist_config(void __iomem *base, int gic_irqs,
+ void (*sync_access)(void))
+{
+ unsigned int i;
+
+ /*
+ * Set all global interrupts to be level triggered, active low.
+ */
+ for (i = 32; i < gic_irqs; i += 16)
+ writel_relaxed(0, base + GIC_DIST_CONFIG + i / 4);
+
+ /*
+ * Set priority on all global interrupts.
+ */
+ for (i = 32; i < gic_irqs; i += 4)
+ writel_relaxed(0xa0a0a0a0, base + GIC_DIST_PRI + i);
+
+ /*
+ * Disable all interrupts. Leave the PPI and SGIs alone
+ * as they are enabled by redistributor registers.
+ */
+ for (i = 32; i < gic_irqs; i += 32)
+ writel_relaxed(0xffffffff, base + GIC_DIST_ENABLE_CLEAR + i / 8);
+
+ if (sync_access)
+ sync_access();
+}
+
+void gic_cpu_config(void __iomem *base, void (*sync_access)(void))
+{
+ int i;
+
+ /*
+ * Deal with the banked PPI and SGI interrupts - disable all
+ * PPI interrupts, ensure all SGI interrupts are enabled.
+ */
+ writel_relaxed(0xffff0000, base + GIC_DIST_ENABLE_CLEAR);
+ writel_relaxed(0x0000ffff, base + GIC_DIST_ENABLE_SET);
+
+ /*
+ * Set priority on PPI and SGI interrupts
+ */
+ for (i = 0; i < 32; i += 4)
+ writel_relaxed(0xa0a0a0a0, base + GIC_DIST_PRI + i * 4 / 4);
+
+ if (sync_access)
+ sync_access();
+}