Move GIC setup to a separate file

GIC setup code which used to be in bl31_plat_setup.c is now in fvp_gic.c
to simplify future changes to other bootloader stages.  This patch moves
code from bl31_plat_setup.c to fvp_gic.c, simplifies the include file
list for bl31_plat_setup.c, moves GIC declarations from the bl31.h header
file into the platform.h, and reworks files according to coding style
guide.

Change-Id: I48d82a4ba33e7114dcc88f9ca98767a06cf8f417

1 files changed, 274 insertions, 0 deletions

diff --git a/plat/fvp/fvp_gic.c b/plat/fvp/fvp_gic.c
new file mode 100644
index 0000000..cb3793d
--- /dev/null
+++ b/plat/fvp/fvp_gic.c
@@ -0,0 +1,274 @@
+/*
+ * Copyright (c) 2013, 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_helpers.h>
+#include <platform.h>
+#include <gic.h>
+
+
+/*******************************************************************************
+ * TODO: Revisit if priorities are being set such that no non-secure interrupt
+ * can have a higher priority than a secure one as recommended in the GICv2 spec
+ ******************************************************************************/
+
+/*******************************************************************************
+ * 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.
+ ******************************************************************************/
+void gicv3_cpuif_setup(void)
+{
+	unsigned int scr_val, val, 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.
+	 *
+	 * TODO:
+	 * For GICv4 we also need to adjust the Base address based on
+	 * GICR_TYPER.VLPIS
+	 */
+	base = BASE_GICR_BASE +
+		(platform_get_core_pos(read_mpidr()) << GICR_PCPUBASE_SHIFT);
+	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);
+
+	/*
+	 * 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(MAX_PRI_VAL);
+
+	/* Restore SCR_EL3 */
+	write_scr(scr_val);
+}
+
+/*******************************************************************************
+ * This function does some minimal GICv3 configuration when cores go
+ * down.
+ ******************************************************************************/
+void gicv3_cpuif_deactivate(void)
+{
+	unsigned int val, 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.
+	 *
+	 * TODO:
+	 * For GICv4 we also need to adjust the Base address based on
+	 * GICR_TYPER.VLPIS
+	 */
+	base = BASE_GICR_BASE +
+		(platform_get_core_pos(read_mpidr()) << GICR_PCPUBASE_SHIFT);
+	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 gic_cpuif_setup(unsigned int gicc_base)
+{
+	unsigned int val;
+
+	val = gicc_read_iidr(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(gicc_base, MAX_PRI_VAL);
+	gicc_write_ctlr(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 gic_cpuif_deactivate(unsigned int gicc_base)
+{
+	unsigned int val;
+
+	/* Disable secure, non-secure interrupts and disable their bypass */
+	val = gicc_read_ctlr(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(gicc_base, val);
+
+	val = gicc_read_iidr(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 gic_pcpu_distif_setup(unsigned int gicd_base)
+{
+	gicd_write_igroupr(gicd_base, 0, ~0);
+
+	gicd_clr_igroupr(gicd_base, IRQ_SEC_PHY_TIMER);
+	gicd_clr_igroupr(gicd_base, IRQ_SEC_SGI_0);
+	gicd_clr_igroupr(gicd_base, IRQ_SEC_SGI_1);
+	gicd_clr_igroupr(gicd_base, IRQ_SEC_SGI_2);
+	gicd_clr_igroupr(gicd_base, IRQ_SEC_SGI_3);
+	gicd_clr_igroupr(gicd_base, IRQ_SEC_SGI_4);
+	gicd_clr_igroupr(gicd_base, IRQ_SEC_SGI_5);
+	gicd_clr_igroupr(gicd_base, IRQ_SEC_SGI_6);
+	gicd_clr_igroupr(gicd_base, IRQ_SEC_SGI_7);
+
+	gicd_set_ipriorityr(gicd_base, IRQ_SEC_PHY_TIMER, MAX_PRI_VAL);
+	gicd_set_ipriorityr(gicd_base, IRQ_SEC_SGI_0, MAX_PRI_VAL);
+	gicd_set_ipriorityr(gicd_base, IRQ_SEC_SGI_1, MAX_PRI_VAL);
+	gicd_set_ipriorityr(gicd_base, IRQ_SEC_SGI_2, MAX_PRI_VAL);
+	gicd_set_ipriorityr(gicd_base, IRQ_SEC_SGI_3, MAX_PRI_VAL);
+	gicd_set_ipriorityr(gicd_base, IRQ_SEC_SGI_4, MAX_PRI_VAL);
+	gicd_set_ipriorityr(gicd_base, IRQ_SEC_SGI_5, MAX_PRI_VAL);
+	gicd_set_ipriorityr(gicd_base, IRQ_SEC_SGI_6, MAX_PRI_VAL);
+	gicd_set_ipriorityr(gicd_base, IRQ_SEC_SGI_7, MAX_PRI_VAL);
+
+	gicd_set_isenabler(gicd_base, IRQ_SEC_PHY_TIMER);
+	gicd_set_isenabler(gicd_base, IRQ_SEC_SGI_0);
+	gicd_set_isenabler(gicd_base, IRQ_SEC_SGI_1);
+	gicd_set_isenabler(gicd_base, IRQ_SEC_SGI_2);
+	gicd_set_isenabler(gicd_base, IRQ_SEC_SGI_3);
+	gicd_set_isenabler(gicd_base, IRQ_SEC_SGI_4);
+	gicd_set_isenabler(gicd_base, IRQ_SEC_SGI_5);
+	gicd_set_isenabler(gicd_base, IRQ_SEC_SGI_6);
+	gicd_set_isenabler(gicd_base, IRQ_SEC_SGI_7);
+}
+
+/*******************************************************************************
+ * 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.
+ ******************************************************************************/
+void gic_distif_setup(unsigned int gicd_base)
+{
+	unsigned int ctr, num_ints, ctlr;
+
+	/* Disable the distributor before going further */
+	ctlr = gicd_read_ctlr(gicd_base);
+	ctlr &= ~(ENABLE_GRP0 | ENABLE_GRP1);
+	gicd_write_ctlr(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(gicd_base) & IT_LINES_NO_MASK;
+	num_ints++;
+	for (ctr = 0; ctr < num_ints; ctr++)
+		gicd_write_igroupr(gicd_base, ctr << IGROUPR_SHIFT, ~0);
+
+	/* Configure secure interrupts now */
+	gicd_clr_igroupr(gicd_base, IRQ_TZ_WDOG);
+	gicd_set_ipriorityr(gicd_base, IRQ_TZ_WDOG, MAX_PRI_VAL);
+	gicd_set_itargetsr(gicd_base, IRQ_TZ_WDOG,
+			   platform_get_core_pos(read_mpidr()));
+	gicd_set_isenabler(gicd_base, IRQ_TZ_WDOG);
+	gic_pcpu_distif_setup(gicd_base);
+
+	gicd_write_ctlr(gicd_base, ctlr | ENABLE_GRP0);
+}
+
+void gic_setup(void)
+{
+	unsigned int gicd_base, gicc_base;
+
+	gicd_base = platform_get_cfgvar(CONFIG_GICD_ADDR);
+	gicc_base = platform_get_cfgvar(CONFIG_GICC_ADDR);
+
+	gic_cpuif_setup(gicc_base);
+	gic_distif_setup(gicd_base);
+}