Refactor fvp gic code to be a generic driver

Refactor the FVP gic code in plat/fvp/fvp_gic.c to be a generic ARM
GIC driver in drivers/arm/gic/arm_gic.c. Provide the platform
specific inputs in the arm_gic_setup() function so that the driver
has no explicit dependency on platform code.

Provide weak implementations of the platform interrupt controller
API in a new file, plat/common/plat_gic.c. These simply call through
to the ARM GIC driver.

Move the only remaining FVP GIC function, fvp_gic_init() to
plat/fvp/aarch64/fvp_common.c and remove plat/fvp/fvp_gic.c

Fixes ARM-software/tf-issues#182

Change-Id: Iea82fe095fad62dd33ba9efbddd48c57717edd21

1 files changed, 428 insertions, 0 deletions

diff --git a/drivers/arm/gic/arm_gic.c b/drivers/arm/gic/arm_gic.c
new file mode 100644
index 0000000..636348b
--- /dev/null
+++ b/drivers/arm/gic/arm_gic.c
@@ -0,0 +1,428 @@
+/*
+ * Copyright (c) 2014, 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 <arm_gic.h>
+#include <assert.h>
+#include <bl_common.h>
+#include <debug.h>
+#include <gic_v2.h>
+#include <gic_v3.h>
+#include <interrupt_mgmt.h>
+#include <platform.h>
+#include <stdint.h>
+
+
+static unsigned int g_gicc_base;
+static unsigned int g_gicd_base;
+static unsigned long g_gicr_base;
+static const unsigned int *g_irq_sec_ptr;
+static unsigned int g_num_irqs;
+
+
+/*******************************************************************************
+ * This function does some minimal GICv3 configuration. The Firmware itself does
+ * not fully support GICv3 at this time and relies on GICv2 emulation as
+ * provided by GICv3. This function allows software (like Linux) in later stages
+ * to use full GICv3 features.
+ ******************************************************************************/
+static void gicv3_cpuif_setup(void)
+{
+	unsigned int scr_val, val;
+	uintptr_t base;
+
+	/*
+	 * When CPUs come out of reset they have their GICR_WAKER.ProcessorSleep
+	 * bit set. In order to allow interrupts to get routed to the CPU we
+	 * need to clear this bit if set and wait for GICR_WAKER.ChildrenAsleep
+	 * to clear (GICv3 Architecture specification 5.4.23).
+	 * GICR_WAKER is NOT banked per CPU, compute the correct base address
+	 * per CPU.
+	 */
+	assert(g_gicr_base);
+	base = gicv3_get_rdist(g_gicr_base, read_mpidr());
+	if (base == (uintptr_t)NULL) {
+		/* No re-distributor base address. This interface cannot be
+		 * configured.
+		 */
+		panic();
+	}
+
+	val = gicr_read_waker(base);
+
+	val &= ~WAKER_PS;
+	gicr_write_waker(base, val);
+	dsb();
+
+	/* We need to wait for ChildrenAsleep to clear. */
+	val = gicr_read_waker(base);
+	while (val & WAKER_CA)
+		val = gicr_read_waker(base);
+
+	/*
+	 * We need to set SCR_EL3.NS in order to see GICv3 non-secure state.
+	 * Restore SCR_EL3.NS again before exit.
+	 */
+	scr_val = read_scr();
+	write_scr(scr_val | SCR_NS_BIT);
+	isb();	/* ensure NS=1 takes effect before accessing ICC_SRE_EL2 */
+
+	/*
+	 * By default EL2 and NS-EL1 software should be able to enable GICv3
+	 * System register access without any configuration at EL3. But it turns
+	 * out that GICC PMR as set in GICv2 mode does not affect GICv3 mode. So
+	 * we need to set it here again. In order to do that we need to enable
+	 * register access. We leave it enabled as it should be fine and might
+	 * prevent problems with later software trying to access GIC System
+	 * Registers.
+	 */
+	val = read_icc_sre_el3();
+	write_icc_sre_el3(val | ICC_SRE_EN | ICC_SRE_SRE);
+
+	val = read_icc_sre_el2();
+	write_icc_sre_el2(val | ICC_SRE_EN | ICC_SRE_SRE);
+
+	write_icc_pmr_el1(GIC_PRI_MASK);
+	isb();	/* commit ICC_* changes before setting NS=0 */
+
+	/* Restore SCR_EL3 */
+	write_scr(scr_val);
+	isb();	/* ensure NS=0 takes effect immediately */
+}
+
+/*******************************************************************************
+ * This function does some minimal GICv3 configuration when cores go
+ * down.
+ ******************************************************************************/
+static void gicv3_cpuif_deactivate(void)
+{
+	unsigned int val;
+	uintptr_t base;
+
+	/*
+	 * When taking CPUs down we need to set GICR_WAKER.ProcessorSleep and
+	 * wait for GICR_WAKER.ChildrenAsleep to get set.
+	 * (GICv3 Architecture specification 5.4.23).
+	 * GICR_WAKER is NOT banked per CPU, compute the correct base address
+	 * per CPU.
+	 */
+	assert(g_gicr_base);
+	base = gicv3_get_rdist(g_gicr_base, read_mpidr());
+	if (base == (uintptr_t)NULL) {
+		/* No re-distributor base address. This interface cannot be
+		 * configured.
+		 */
+		panic();
+	}
+
+	val = gicr_read_waker(base);
+	val |= WAKER_PS;
+	gicr_write_waker(base, val);
+	dsb();
+
+	/* We need to wait for ChildrenAsleep to set. */
+	val = gicr_read_waker(base);
+	while ((val & WAKER_CA) == 0)
+		val = gicr_read_waker(base);
+}
+
+
+/*******************************************************************************
+ * Enable secure interrupts and use FIQs to route them. Disable legacy bypass
+ * and set the priority mask register to allow all interrupts to trickle in.
+ ******************************************************************************/
+void arm_gic_cpuif_setup(void)
+{
+	unsigned int val;
+
+	assert(g_gicc_base);
+	val = gicc_read_iidr(g_gicc_base);
+
+	/*
+	 * If GICv3 we need to do a bit of additional setup. We want to
+	 * allow default GICv2 behaviour but allow the next stage to
+	 * enable full gicv3 features.
+	 */
+	if (((val >> GICC_IIDR_ARCH_SHIFT) & GICC_IIDR_ARCH_MASK) >= 3)
+		gicv3_cpuif_setup();
+
+	val = ENABLE_GRP0 | FIQ_EN | FIQ_BYP_DIS_GRP0;
+	val |= IRQ_BYP_DIS_GRP0 | FIQ_BYP_DIS_GRP1 | IRQ_BYP_DIS_GRP1;
+
+	gicc_write_pmr(g_gicc_base, GIC_PRI_MASK);
+	gicc_write_ctlr(g_gicc_base, val);
+}
+
+/*******************************************************************************
+ * Place the cpu interface in a state where it can never make a cpu exit wfi as
+ * as result of an asserted interrupt. This is critical for powering down a cpu
+ ******************************************************************************/
+void arm_gic_cpuif_deactivate(void)
+{
+	unsigned int val;
+
+	/* Disable secure, non-secure interrupts and disable their bypass */
+	assert(g_gicc_base);
+	val = gicc_read_ctlr(g_gicc_base);
+	val &= ~(ENABLE_GRP0 | ENABLE_GRP1);
+	val |= FIQ_BYP_DIS_GRP1 | FIQ_BYP_DIS_GRP0;
+	val |= IRQ_BYP_DIS_GRP0 | IRQ_BYP_DIS_GRP1;
+	gicc_write_ctlr(g_gicc_base, val);
+
+	val = gicc_read_iidr(g_gicc_base);
+
+	/*
+	 * If GICv3 we need to do a bit of additional setup. Make sure the
+	 * RDIST is put to sleep.
+	 */
+	if (((val >> GICC_IIDR_ARCH_SHIFT) & GICC_IIDR_ARCH_MASK) >= 3)
+		gicv3_cpuif_deactivate();
+}
+
+/*******************************************************************************
+ * Per cpu gic distributor setup which will be done by all cpus after a cold
+ * boot/hotplug. This marks out the secure interrupts & enables them.
+ ******************************************************************************/
+void arm_gic_pcpu_distif_setup(void)
+{
+	unsigned int index, irq_num;
+
+	assert(g_gicd_base);
+	gicd_write_igroupr(g_gicd_base, 0, ~0);
+
+	assert(g_irq_sec_ptr);
+	for (index = 0; index < g_num_irqs; index++) {
+		irq_num = g_irq_sec_ptr[index];
+		if (irq_num < MIN_SPI_ID) {
+			/* We have an SGI or a PPI */
+			gicd_clr_igroupr(g_gicd_base, irq_num);
+			gicd_set_ipriorityr(g_gicd_base, irq_num,
+				GIC_HIGHEST_SEC_PRIORITY);
+			gicd_set_isenabler(g_gicd_base, irq_num);
+		}
+	}
+}
+
+/*******************************************************************************
+ * Global gic distributor setup which will be done by the primary cpu after a
+ * cold boot. It marks out the secure SPIs, PPIs & SGIs and enables them. It
+ * then enables the secure GIC distributor interface.
+ ******************************************************************************/
+static void arm_gic_distif_setup(void)
+{
+	unsigned int num_ints, ctlr, index, irq_num;
+
+	/* Disable the distributor before going further */
+	assert(g_gicd_base);
+	ctlr = gicd_read_ctlr(g_gicd_base);
+	ctlr &= ~(ENABLE_GRP0 | ENABLE_GRP1);
+	gicd_write_ctlr(g_gicd_base, ctlr);
+
+	/*
+	 * Mark out non-secure interrupts. Calculate number of
+	 * IGROUPR registers to consider. Will be equal to the
+	 * number of IT_LINES
+	 */
+	num_ints = gicd_read_typer(g_gicd_base) & IT_LINES_NO_MASK;
+	num_ints++;
+	for (index = 0; index < num_ints; index++)
+		gicd_write_igroupr(g_gicd_base, index << IGROUPR_SHIFT, ~0);
+
+	/* Configure secure interrupts now */
+	assert(g_irq_sec_ptr);
+	for (index = 0; index < g_num_irqs; index++) {
+		irq_num = g_irq_sec_ptr[index];
+		if (irq_num >= MIN_SPI_ID) {
+			/* We have an SPI */
+			gicd_clr_igroupr(g_gicd_base, irq_num);
+			gicd_set_ipriorityr(g_gicd_base, irq_num,
+				GIC_HIGHEST_SEC_PRIORITY);
+			gicd_set_itargetsr(g_gicd_base, irq_num,
+					platform_get_core_pos(read_mpidr()));
+			gicd_set_isenabler(g_gicd_base, irq_num);
+		}
+	}
+	arm_gic_pcpu_distif_setup();
+
+	gicd_write_ctlr(g_gicd_base, ctlr | ENABLE_GRP0);
+}
+
+/*******************************************************************************
+ * Initialize the ARM GIC driver with the provided platform inputs
+******************************************************************************/
+void arm_gic_init(unsigned int gicc_base,
+		unsigned int gicd_base,
+		unsigned long gicr_base,
+		const unsigned int *irq_sec_ptr,
+		unsigned int num_irqs
+		)
+{
+	assert(gicc_base);
+	assert(gicd_base);
+	assert(gicr_base);
+	assert(irq_sec_ptr);
+	g_gicc_base = gicc_base;
+	g_gicd_base = gicd_base;
+	g_gicr_base = gicr_base;
+	g_irq_sec_ptr = irq_sec_ptr;
+	g_num_irqs = num_irqs;
+}
+
+/*******************************************************************************
+ * Setup the ARM GIC CPU and distributor interfaces.
+******************************************************************************/
+void arm_gic_setup(void)
+{
+	arm_gic_cpuif_setup();
+	arm_gic_distif_setup();
+}
+
+/*******************************************************************************
+ * An ARM processor signals interrupt exceptions through the IRQ and FIQ pins.
+ * The interrupt controller knows which pin/line it uses to signal a type of
+ * interrupt. This function provides a common implementation of
+ * plat_interrupt_type_to_line() in an ARM GIC environment for optional re-use
+ * across platforms. It lets the interrupt management framework determine
+ * for a type of interrupt and security state, which line should be used in the
+ * SCR_EL3 to control its routing to EL3. The interrupt line is represented as
+ * the bit position of the IRQ or FIQ bit in the SCR_EL3.
+ ******************************************************************************/
+uint32_t arm_gic_interrupt_type_to_line(uint32_t type,
+				uint32_t security_state)
+{
+	assert(type == INTR_TYPE_S_EL1 ||
+	       type == INTR_TYPE_EL3 ||
+	       type == INTR_TYPE_NS);
+
+	assert(security_state == NON_SECURE || security_state == SECURE);
+
+	/*
+	 * We ignore the security state parameter under the assumption that
+	 * both normal and secure worlds are using ARM GICv2. This parameter
+	 * will be used when the secure world starts using GICv3.
+	 */
+#if ARM_GIC_ARCH == 2
+	return gicv2_interrupt_type_to_line(g_gicc_base, type);
+#else
+#error "Invalid ARM GIC architecture version specified for platform port"
+#endif /* ARM_GIC_ARCH */
+}
+
+#if ARM_GIC_ARCH == 2
+/*******************************************************************************
+ * This function returns the type of the highest priority pending interrupt at
+ * the GIC cpu interface. INTR_TYPE_INVAL is returned when there is no
+ * interrupt pending.
+ ******************************************************************************/
+uint32_t arm_gic_get_pending_interrupt_type(void)
+{
+	uint32_t id;
+
+	assert(g_gicc_base);
+	id = gicc_read_hppir(g_gicc_base);
+
+	/* Assume that all secure interrupts are S-EL1 interrupts */
+	if (id < 1022)
+		return INTR_TYPE_S_EL1;
+
+	if (id == GIC_SPURIOUS_INTERRUPT)
+		return INTR_TYPE_INVAL;
+
+	return INTR_TYPE_NS;
+}
+
+/*******************************************************************************
+ * This function returns the id of the highest priority pending interrupt at
+ * the GIC cpu interface. INTR_ID_UNAVAILABLE is returned when there is no
+ * interrupt pending.
+ ******************************************************************************/
+uint32_t arm_gic_get_pending_interrupt_id(void)
+{
+	uint32_t id;
+
+	assert(g_gicc_base);
+	id = gicc_read_hppir(g_gicc_base);
+
+	if (id < 1022)
+		return id;
+
+	if (id == 1023)
+		return INTR_ID_UNAVAILABLE;
+
+	/*
+	 * Find out which non-secure interrupt it is under the assumption that
+	 * the GICC_CTLR.AckCtl bit is 0.
+	 */
+	return gicc_read_ahppir(g_gicc_base);
+}
+
+/*******************************************************************************
+ * This functions reads the GIC cpu interface Interrupt Acknowledge register
+ * to start handling the pending interrupt. It returns the contents of the IAR.
+ ******************************************************************************/
+uint32_t arm_gic_acknowledge_interrupt(void)
+{
+	assert(g_gicc_base);
+	return gicc_read_IAR(g_gicc_base);
+}
+
+/*******************************************************************************
+ * This functions writes the GIC cpu interface End Of Interrupt register with
+ * the passed value to finish handling the active interrupt
+ ******************************************************************************/
+void arm_gic_end_of_interrupt(uint32_t id)
+{
+	assert(g_gicc_base);
+	gicc_write_EOIR(g_gicc_base, id);
+}
+
+/*******************************************************************************
+ * This function returns the type of the interrupt id depending upon the group
+ * this interrupt has been configured under by the interrupt controller i.e.
+ * group0 or group1.
+ ******************************************************************************/
+uint32_t arm_gic_get_interrupt_type(uint32_t id)
+{
+	uint32_t group;
+
+	assert(g_gicd_base);
+	group = gicd_get_igroupr(g_gicd_base, id);
+
+	/* Assume that all secure interrupts are S-EL1 interrupts */
+	if (group == GRP0)
+		return INTR_TYPE_S_EL1;
+	else
+		return INTR_TYPE_NS;
+}
+
+#else
+#error "Invalid ARM GIC architecture version specified for platform port"
+#endif /* ARM_GIC_ARCH */