drivers: add GIC support

The GIC is ARM's "Generic Interrupt Controller". This
change essentially implements the rudimentary support
for a GICv2 implementation that routes all interrupts
to Group1. This should also work for GICv1 with security
extensions.

BUG=chrome-os-partner:31945
BRANCH=None
TEST=Built and booted kernel using the code.

Change-Id: I9c9202c1309ca9e711e00d742085a6728552c54b
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: d1cd9b6b76035af107b7dc876f90777698162d34
Original-Change-Id: I4c5b84bfe888ac33fa01c8d64a3dffe1b5ddc823
Original-Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/217512
Original-Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: http://review.coreboot.org/9075
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <edward.ocallaghan@koparo.com>

7 files changed, 245 insertions, 0 deletions

diff --git a/src/drivers/Kconfig b/src/drivers/Kconfig
index 25dd59e1d9..435ed0e3bf 100644
--- a/src/drivers/Kconfig
+++ b/src/drivers/Kconfig
@@ -23,6 +23,7 @@ source src/drivers/dec/Kconfig
 source src/drivers/elog/Kconfig
 source src/drivers/emulation/Kconfig
 source src/drivers/generic/Kconfig
+source src/drivers/gic/Kconfig
 source src/drivers/i2c/Kconfig
 source src/drivers/ics/Kconfig
 source src/drivers/intel/Kconfig
diff --git a/src/drivers/Makefile.inc b/src/drivers/Makefile.inc
index 6e107cb910..11ec9205ae 100644
--- a/src/drivers/Makefile.inc
+++ b/src/drivers/Makefile.inc
@@ -22,6 +22,7 @@ subdirs-y += ati
 subdirs-y += dec
 subdirs-y += emulation
 subdirs-y += generic
+subdirs-y += gic
 subdirs-y += i2c
 subdirs-y += intel
 subdirs-y += lenovo
diff --git a/src/drivers/gic/Kconfig b/src/drivers/gic/Kconfig
new file mode 100644
index 0000000000..193311fc05
--- /dev/null
+++ b/src/drivers/gic/Kconfig
@@ -0,0 +1,4 @@
+config GIC
+	def_bool n
+	help
+	  This option enables GIC support, the ARM generic interrupt controller.
diff --git a/src/drivers/gic/Makefile.inc b/src/drivers/gic/Makefile.inc
new file mode 100644
index 0000000000..51e3e199e2
--- /dev/null
+++ b/src/drivers/gic/Makefile.inc
@@ -0,0 +1 @@
+ramstage-$(CONFIG_GIC) += gic.c
diff --git a/src/drivers/gic/gic.c b/src/drivers/gic/gic.c
new file mode 100644
index 0000000000..885d2216be
--- /dev/null
+++ b/src/drivers/gic/gic.c
@@ -0,0 +1,120 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2014 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <arch/cpu.h>
+#include <arch/io.h>
+#include <console/console.h>
+#include <gic.h>
+#include "gic.h"
+
+enum {
+	ENABLE_GRP0 = 0x1 << 0,
+	ENABLE_GRP1 = 0x1 << 1,
+};
+
+struct gic {
+	struct gicd_mmio *gicd;
+	struct gicc_mmio *gicc;
+	size_t num_interrupts;
+	unsigned int version;
+	unsigned int security_extensions;
+};
+
+static struct gic *gic_get(void)
+{
+	static struct gic gic;
+
+	if (gic.gicd == NULL) {
+		uint32_t typer;
+
+		gic.gicd = gicd_base();
+		gic.gicc = gicc_base();
+		typer = read32(&gic.gicd->typer);
+		gic.num_interrupts = 32 * ((typer & 0x1f) + 1);
+		gic.security_extensions = !!(typer & (1 << 10));
+		gic.version = (read32(&gic.gicd->icpidr2) & 0xf0) >> 4;
+
+		printk(BIOS_DEBUG, "GICv%d - %zu ints %s GICD=%p GICC=%p\n",
+			gic.version, gic.num_interrupts,
+			gic.security_extensions ? "SecExtn" : "",
+			gic.gicd, gic.gicc);
+	}
+
+	return &gic;
+}
+
+static inline void gic_write(uint32_t *base, uint32_t val)
+{
+	write32(val, base);
+}
+
+static void gic_write_regs(uint32_t *base, size_t num_regs, uint32_t val)
+{
+	size_t i;
+
+	for (i = 0; i < num_regs; i++)
+		gic_write(base++, val);
+}
+
+static void gic_write_banked_regs(uint32_t *base, size_t interrupts_per_reg,
+					uint32_t val)
+{
+	/* 1st 32 interrupts are banked per CPU. */
+	gic_write_regs(base, 32 / interrupts_per_reg, val);
+}
+
+void gic_init(void)
+{
+	struct gic *gic;
+	struct gicd_mmio *gicd;
+	struct gicc_mmio *gicc;
+	uint32_t cpu_mask;
+
+	gic = gic_get();
+	gicd = gic->gicd;
+	gicc = gic->gicc;
+
+	/* Enable Group 0 and Group 1 in GICD -- banked regs.  */
+	gic_write(&gicd->ctlr, ENABLE_GRP0 | ENABLE_GRP1);
+
+	/* Enable Group 0 and Group 1 in GICC and enable all priroity levels. */
+	gic_write(&gicc->ctlr, ENABLE_GRP0 | ENABLE_GRP1);
+	gic_write(&gicc->pmr, 1 << 7);
+
+	cpu_mask = 1 << smp_processor_id();
+	cpu_mask |= cpu_mask << 8;
+	cpu_mask |= cpu_mask << 16;
+
+	/* Only write banked registers for secondary CPUs. */
+	if (smp_processor_id()) {
+		gic_write_banked_regs(&gicd->itargetsr[0], 4, cpu_mask);
+		/* Put interrupts into Group 1. */
+		gic_write_banked_regs(&gicd->igroupr[0], 32, ~0x0);
+		/* Allow Non-secure access to everything. */
+		gic_write_banked_regs(&gicd->nsacr[0], 16, ~0x0);
+		return;
+	}
+
+	/* All interrupts routed to processors that execute this function. */
+	gic_write_regs(&gicd->itargetsr[0], gic->num_interrupts / 4, cpu_mask);
+	/* Put all interrupts into Gropup 1. */
+	gic_write_regs(&gicd->igroupr[0], gic->num_interrupts / 32, ~0x0);
+	/* Allow Non-secure access to everything. */
+	gic_write_regs(&gicd->nsacr[0], gic->num_interrupts / 16, ~0x0);
+}
diff --git a/src/drivers/gic/gic.h b/src/drivers/gic/gic.h
new file mode 100644
index 0000000000..d6f8d097cb
--- /dev/null
+++ b/src/drivers/gic/gic.h
@@ -0,0 +1,78 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2014 Google Inc
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef DRIVERS_GIC_H
+#define DRIVERS_GIC_H
+
+#include <stdint.h>
+
+#define NR(start, end) (((end) - (start)) / sizeof(uint32_t))
+
+struct gicd_mmio {
+	uint32_t ctlr;				/* 0x000 - 0x003 */
+	uint32_t typer;				/* 0x004 - 0x007 */
+	uint32_t iidr;				/* 0x008 - 0x00b */
+	uint32_t reserved_1[NR(0xc, 0x80)];	/* 0x00c - 0x07f */
+	uint32_t igroupr[NR(0x80, 0x100)];	/* 0x080 - 0x0ff */
+	uint32_t isenabler[NR(0x100, 0x180)];	/* 0x100 - 0x17f */
+	uint32_t icenabler[NR(0x180, 0x200)];	/* 0x180 - 0x1ff */
+	uint32_t ispendr[NR(0x200, 0x280)];	/* 0x200 - 0x27f */
+	uint32_t icpendr[NR(0x280, 0x300)];	/* 0x280 - 0x2ff */
+	uint32_t isactiver[NR(0x300, 0x380)];	/* 0x300 - 0x37f */
+	uint32_t icactiver[NR(0x380, 0x400)];	/* 0x380 - 0x3ff */
+	uint32_t ipriorityr[NR(0x400, 0x7fc)];	/* 0x400 - 0x7fb */
+	uint32_t reserved_2[NR(0x7fc, 0x800)];	/* 0x7fc - 0x7ff */
+	uint32_t itargetsr[NR(0x800, 0xbfc)];	/* 0x800 - 0xbfb */
+	uint32_t reserved_3[NR(0xbfc, 0xc00)];	/* 0xbfc - 0x2ff */
+	uint32_t icfgr[NR(0xc00, 0xd00)];	/* 0xc00 - 0xcff */
+	uint32_t reserved_4[NR(0xd00, 0xe00)];	/* 0xd00 - 0xdff */
+	uint32_t nsacr[NR(0xe00, 0xf00)];	/* 0xe00 - 0xeff */
+	uint32_t sgir;				/* 0xf00 - 0xf03 */
+	uint32_t reserved_5[NR(0xf04, 0xf10)];	/* 0xf04 - 0xf0f */
+	uint32_t cpendsgir[NR(0xf10, 0xf20)];	/* 0xf10 - 0xf1f */
+	uint32_t spendsgir[NR(0xf20, 0xf30)];	/* 0xf20 - 0xf2f */
+	uint32_t reserved_6[NR(0xf30, 0xfe8)];	/* 0xf30 - 0xfe7 */
+	uint32_t icpidr2;			/* 0xfe8 - 0xfeb */
+	uint32_t reserved_7[NR(0xfec, 0x1000)];	/* 0xfec - 0xfff */
+};
+
+struct gicc_mmio {
+	uint32_t ctlr;				/* 0x000 - 0x003 */
+	uint32_t pmr;				/* 0x004 - 0x007 */
+	uint32_t bpr;				/* 0x008 - 0x00b */
+	uint32_t iar;				/* 0x00c - 0x00f */
+	uint32_t eoir;				/* 0x010 - 0x013 */
+	uint32_t rpr;				/* 0x014 - 0x017 */
+	uint32_t hppir;				/* 0x018 - 0x01b */
+	uint32_t apbr;				/* 0x01c - 0x01f */
+	uint32_t aiar;				/* 0x020 - 0x023 */
+	uint32_t aeoir;				/* 0x024 - 0x027 */
+	uint32_t ahppir;			/* 0x028 - 0x02b */
+	uint32_t resered_1[NR(0x2c, 0xd0)];	/* 0x02c - 0x0cf */
+	uint32_t apr[NR(0xd0, 0xe0)];		/* 0x0d0 - 0x0df */
+	uint32_t nsapr[NR(0xe0, 0xf0)];		/* 0x0e0 - 0x0ef */
+	uint32_t resered_2[NR(0xf0, 0xfc)];	/* 0x0f0 - 0x0fb */
+	uint32_t iidr;				/* 0x0fc - 0x0ff */
+	uint32_t reserved_3[NR(0x100, 0x1000)];	/* 0x100 - 0xfff */
+	uint32_t dir;				/* 0x1000 - 0x1003 */
+};
+
+#undef NR
+
+#endif /* DRIVERS_GIC_H */
diff --git a/src/include/gic.h b/src/include/gic.h
new file mode 100644
index 0000000000..22c5631473
--- /dev/null
+++ b/src/include/gic.h
@@ -0,0 +1,40 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2014 Google Inc
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef GIC_H
+#define GIC_H
+
+#if IS_ENABLED(CONFIG_GIC)
+
+/* Initialize the GIC on the currently processor, including GICD and GICC. */
+void gic_init(void);
+
+/* Return a pointer to the base of the GIC distributor mmio region. */
+void *gicd_base(void);
+
+/* Return a pointer to the base of the GIC cpu mmio region. */
+void *gicc_base(void);
+
+#else /* CONFIG_GIC */
+
+static inline void gic_init(void) {}
+
+#endif /* CONFIG_GIC */
+
+#endif /* GIC_H */