Add ARM GICv2 driver

This patch adds a driver for ARM GICv2 systems, example GIC-400. Unlike
the existing GIC driver in `include/drivers/arm/arm_gic.h`, this driver
is optimised for GICv2 and does not support GICv3 systems in GICv2
compatibility mode. The driver interface has been implemented in
`drivers/arm/gic/v2/gicv2_main.c`. The corresponding header is in
`include/drivers/arm/gicv2.h`. Helper functions are implemented in
`drivers/arm/gic/v2/gicv2_helpers.c` and are accessible through the
`drivers/arm/gic/v2/gicv2_private.h` header.

Change-Id: I09fffa4e621fb99ba3c01204839894816cd89a2a

1 files changed, 230 insertions, 0 deletions

diff --git a/drivers/arm/gic/v2/gicv2_helpers.c b/drivers/arm/gic/v2/gicv2_helpers.c
new file mode 100644
index 00000000..1f904c51
--- /dev/null
+++ b/drivers/arm/gic/v2/gicv2_helpers.c
@@ -0,0 +1,230 @@
+/*
+ * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <arch.h>
+#include <arch_helpers.h>
+#include <assert.h>
+#include <debug.h>
+#include <gic_common.h>
+#include "gicv2_private.h"
+
+/*
+ * Accessor to read the GIC Distributor ITARGETSR corresponding to the
+ * interrupt `id`, 4 interrupt IDs at a time.
+ */
+unsigned int gicd_read_itargetsr(uintptr_t base, unsigned int id)
+{
+	unsigned n = id >> ITARGETSR_SHIFT;
+	return mmio_read_32(base + GICD_ITARGETSR + (n << 2));
+}
+
+/*
+ * Accessor to read the GIC Distributor CPENDSGIR corresponding to the
+ * interrupt `id`, 4 interrupt IDs at a time.
+ */
+unsigned int gicd_read_cpendsgir(uintptr_t base, unsigned int id)
+{
+	unsigned n = id >> CPENDSGIR_SHIFT;
+	return mmio_read_32(base + GICD_CPENDSGIR + (n << 2));
+}
+
+/*
+ * Accessor to read the GIC Distributor SPENDSGIR corresponding to the
+ * interrupt `id`, 4 interrupt IDs at a time.
+ */
+unsigned int gicd_read_spendsgir(uintptr_t base, unsigned int id)
+{
+	unsigned n = id >> SPENDSGIR_SHIFT;
+	return mmio_read_32(base + GICD_SPENDSGIR + (n << 2));
+}
+
+/*
+ * Accessor to write the GIC Distributor ITARGETSR corresponding to the
+ * interrupt `id`, 4 interrupt IDs at a time.
+ */
+void gicd_write_itargetsr(uintptr_t base, unsigned int id, unsigned int val)
+{
+	unsigned n = id >> ITARGETSR_SHIFT;
+	mmio_write_32(base + GICD_ITARGETSR + (n << 2), val);
+}
+
+/*
+ * Accessor to write the GIC Distributor CPENDSGIR corresponding to the
+ * interrupt `id`, 4 interrupt IDs at a time.
+ */
+void gicd_write_cpendsgir(uintptr_t base, unsigned int id, unsigned int val)
+{
+	unsigned n = id >> CPENDSGIR_SHIFT;
+	mmio_write_32(base + GICD_CPENDSGIR + (n << 2), val);
+}
+
+/*
+ * Accessor to write the GIC Distributor SPENDSGIR corresponding to the
+ * interrupt `id`, 4 interrupt IDs at a time.
+ */
+void gicd_write_spendsgir(uintptr_t base, unsigned int id, unsigned int val)
+{
+	unsigned n = id >> SPENDSGIR_SHIFT;
+	mmio_write_32(base + GICD_SPENDSGIR + (n << 2), val);
+}
+
+/*
+ * Accessor to write the GIC Distributor ITARGETSR corresponding to the
+ * interrupt `id`.
+ */
+void gicd_set_itargetsr(uintptr_t base, unsigned int id, unsigned int target)
+{
+	unsigned byte_off = id & ((1 << ITARGETSR_SHIFT) - 1);
+	unsigned int reg_val = gicd_read_itargetsr(base, id);
+
+	gicd_write_itargetsr(base, id, reg_val | (target << (byte_off << 3)));
+}
+
+/*******************************************************************************
+ * Get the current CPU bit mask from GICD_ITARGETSR0
+ ******************************************************************************/
+unsigned int gicv2_get_cpuif_id(uintptr_t base)
+{
+	unsigned int val;
+
+	val = gicd_read_itargetsr(base, 0);
+	return val & GIC_TARGET_CPU_MASK;
+}
+
+/*******************************************************************************
+ * Helper function to configure the default attributes of SPIs.
+ ******************************************************************************/
+void gicv2_spis_configure_defaults(uintptr_t gicd_base)
+{
+	unsigned int index, num_ints;
+
+	num_ints = gicd_read_typer(gicd_base);
+	num_ints &= TYPER_IT_LINES_NO_MASK;
+	num_ints = (num_ints + 1) << 5;
+
+	/*
+	 * Treat all SPIs as G1NS by default. The number of interrupts is
+	 * calculated as 32 * (IT_LINES + 1). We do 32 at a time.
+	 */
+	for (index = MIN_SPI_ID; index < num_ints; index += 32)
+		gicd_write_igroupr(gicd_base, index, ~0U);
+
+	/* Setup the default SPI priorities doing four at a time */
+	for (index = MIN_SPI_ID; index < num_ints; index += 4)
+		gicd_write_ipriorityr(gicd_base,
+				      index,
+				      GICD_IPRIORITYR_DEF_VAL);
+
+	/* Treat all SPIs as level triggered by default, 16 at a time */
+	for (index = MIN_SPI_ID; index < num_ints; index += 16)
+		gicd_write_icfgr(gicd_base, index, 0);
+}
+
+/*******************************************************************************
+ * Helper function to configure secure G0 SPIs.
+ ******************************************************************************/
+void gicv2_secure_spis_configure(uintptr_t gicd_base,
+				     unsigned int num_ints,
+				     const unsigned int *sec_intr_list)
+{
+	unsigned int index, irq_num;
+
+	/* If `num_ints` is not 0, ensure that `sec_intr_list` is not NULL */
+	assert(num_ints ? (uintptr_t)sec_intr_list : 1);
+
+	for (index = 0; index < num_ints; index++) {
+		irq_num = sec_intr_list[index];
+		if (irq_num >= MIN_SPI_ID) {
+			/* Configure this interrupt as a secure interrupt */
+			gicd_clr_igroupr(gicd_base, irq_num);
+
+			/* Set the priority of this interrupt */
+			gicd_write_ipriorityr(gicd_base,
+					      irq_num,
+					      GIC_HIGHEST_SEC_PRIORITY);
+
+			/* Target the secure interrupts to primary CPU */
+			gicd_set_itargetsr(gicd_base, irq_num,
+					gicv2_get_cpuif_id(gicd_base));
+
+			/* Enable this interrupt */
+			gicd_set_isenabler(gicd_base, irq_num);
+		}
+	}
+
+}
+
+/*******************************************************************************
+ * Helper function to configure secure G0 SGIs and PPIs.
+ ******************************************************************************/
+void gicv2_secure_ppi_sgi_setup(uintptr_t gicd_base,
+					unsigned int num_ints,
+					const unsigned int *sec_intr_list)
+{
+	unsigned int index, irq_num, sec_ppi_sgi_mask = 0;
+
+	/* If `num_ints` is not 0, ensure that `sec_intr_list` is not NULL */
+	assert(num_ints ? (uintptr_t)sec_intr_list : 1);
+
+	/*
+	 * Disable all SGIs (imp. def.)/PPIs before configuring them. This is a
+	 * more scalable approach as it avoids clearing the enable bits in the
+	 * GICD_CTLR.
+	 */
+	gicd_write_icenabler(gicd_base, 0, ~0);
+
+	/* Setup the default PPI/SGI priorities doing four at a time */
+	for (index = 0; index < MIN_SPI_ID; index += 4)
+		gicd_write_ipriorityr(gicd_base,
+				      index,
+				      GICD_IPRIORITYR_DEF_VAL);
+
+	for (index = 0; index < num_ints; index++) {
+		irq_num = sec_intr_list[index];
+		if (irq_num < MIN_SPI_ID) {
+			/* We have an SGI or a PPI. They are Group0 at reset */
+			sec_ppi_sgi_mask |= 1U << irq_num;
+
+			/* Set the priority of this interrupt */
+			gicd_write_ipriorityr(gicd_base,
+					    irq_num,
+					    GIC_HIGHEST_SEC_PRIORITY);
+		}
+	}
+
+	/*
+	 * Invert the bitmask to create a mask for non-secure PPIs and
+	 * SGIs. Program the GICD_IGROUPR0 with this bit mask.
+	 */
+	gicd_write_igroupr(gicd_base, 0, ~sec_ppi_sgi_mask);
+
+	/* Enable the Group 0 SGIs and PPIs */
+	gicd_write_isenabler(gicd_base, 0, sec_ppi_sgi_mask);
+}