Add ARM GICv3 driver without support for legacy operation

This patch adds a driver for ARM GICv3 systems that need to run software
stacks where affinity routing is enabled across all privileged exception
levels for both security states. This driver is a partial implementation
of the ARM Generic Interrupt Controller Architecture Specification, GIC
architecture version 3.0 and version 4.0 (ARM IHI 0069A). The driver does
not cater for legacy support of interrupts and asymmetric configurations.

The existing GIC driver has been preserved unchanged. The common code for
GICv2 and GICv3 systems has been refactored into a new file,
`drivers/arm/gic/common/gic_common.c`. The corresponding header is in
`include/drivers/arm/gic_common.h`.

The driver interface is implemented in `drivers/arm/gic/v3/gicv3_main.c`.
The corresponding header is in `include/drivers/arm/gicv3.h`. Helper
functions are implemented in `drivers/arm/gic/v3/arm_gicv3_helpers.c`
and are accessible through the `drivers/arm/gic/v3/gicv3_private.h`
header.

Change-Id: I8c3c834a1d049d05b776b4dcb76b18ccb927444a
diff --git a/drivers/arm/gic/v3/gicv3_main.c b/drivers/arm/gic/v3/gicv3_main.c
new file mode 100644
index 0000000..06311e3
--- /dev/null
+++ b/drivers/arm/gic/v3/gicv3_main.c
@@ -0,0 +1,381 @@
+/*
+ * 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 <gicv3.h>
+#include "gicv3_private.h"
+
+static const gicv3_driver_data_t *driver_data;
+static unsigned int gicv2_compat;
+
+/*******************************************************************************
+ * This function initialises the ARM GICv3 driver in EL3 with provided platform
+ * inputs.
+ ******************************************************************************/
+void gicv3_driver_init(const gicv3_driver_data_t *plat_driver_data)
+{
+	unsigned int gic_version;
+
+	assert(plat_driver_data);
+	assert(plat_driver_data->gicd_base);
+	assert(plat_driver_data->gicr_base);
+	assert(plat_driver_data->rdistif_num);
+	assert(plat_driver_data->rdistif_base_addrs);
+
+	assert(IS_IN_EL3());
+
+	/*
+	 * The platform should provide a list of at least one type of
+	 * interrupts
+	 */
+	assert(plat_driver_data->g0_interrupt_array ||
+	       plat_driver_data->g1s_interrupt_array);
+
+	/*
+	 * If there are no interrupts of a particular type, then the number of
+	 * interrupts of that type should be 0 and vice-versa.
+	 */
+	assert(plat_driver_data->g0_interrupt_array ?
+	       plat_driver_data->g0_interrupt_num :
+	       plat_driver_data->g0_interrupt_num == 0);
+	assert(plat_driver_data->g1s_interrupt_array ?
+	       plat_driver_data->g1s_interrupt_num :
+	       plat_driver_data->g1s_interrupt_num == 0);
+
+	/* Check for system register support */
+	assert(read_id_aa64pfr0_el1() &
+			(ID_AA64PFR0_GIC_MASK << ID_AA64PFR0_GIC_SHIFT));
+
+	/* The GIC version should be 3.0 */
+	gic_version = gicd_read_pidr2(plat_driver_data->gicd_base);
+	gic_version >>=	PIDR2_ARCH_REV_SHIFT;
+	gic_version &= PIDR2_ARCH_REV_MASK;
+	assert(gic_version == ARCH_REV_GICV3);
+
+	/*
+	 * Find out whether the GIC supports the GICv2 compatibility mode. The
+	 * ARE_S bit resets to 0 if supported
+	 */
+	gicv2_compat = gicd_read_ctlr(plat_driver_data->gicd_base);
+	gicv2_compat >>= CTLR_ARE_S_SHIFT;
+	gicv2_compat = !(gicv2_compat & CTLR_ARE_S_MASK);
+
+	/*
+	 * Find the base address of each implemented Redistributor interface.
+	 * The number of interfaces should be equal to the number of CPUs in the
+	 * system. The memory for saving these addresses has to be allocated by
+	 * the platform port
+	 */
+	gicv3_rdistif_base_addrs_probe(plat_driver_data->rdistif_base_addrs,
+					   plat_driver_data->rdistif_num,
+					   plat_driver_data->gicr_base,
+					   plat_driver_data->mpidr_to_core_pos);
+
+	driver_data = plat_driver_data;
+
+	INFO("GICv3 %s legacy support detected."
+			" ARM GICV3 driver initialized in EL3\n",
+			gicv2_compat ? "with" : "without");
+}
+
+/*******************************************************************************
+ * This function initialises the GIC distributor interface based upon the data
+ * provided by the platform while initialising the driver.
+ ******************************************************************************/
+void gicv3_distif_init(void)
+{
+	assert(driver_data);
+	assert(driver_data->gicd_base);
+	assert(driver_data->g1s_interrupt_array);
+	assert(driver_data->g0_interrupt_array);
+
+	assert(IS_IN_EL3());
+
+	/*
+	 * Clear the "enable" bits for G0/G1S/G1NS interrupts before configuring
+	 * the ARE_S bit. The Distributor might generate a system error
+	 * otherwise.
+	 */
+	gicd_clr_ctlr(driver_data->gicd_base,
+		      CTLR_ENABLE_G0_BIT |
+		      CTLR_ENABLE_G1S_BIT |
+		      CTLR_ENABLE_G1NS_BIT,
+		      RWP_TRUE);
+
+	/* Set the ARE_S and ARE_NS bit now that interrupts have been disabled */
+	gicd_set_ctlr(driver_data->gicd_base,
+			CTLR_ARE_S_BIT | CTLR_ARE_NS_BIT, RWP_TRUE);
+
+	/* Set the default attribute of all SPIs */
+	gicv3_spis_configure_defaults(driver_data->gicd_base);
+
+	/* Configure the G1S SPIs */
+	gicv3_secure_spis_configure(driver_data->gicd_base,
+					driver_data->g1s_interrupt_num,
+					driver_data->g1s_interrupt_array,
+					INT_TYPE_G1S);
+
+	/* Configure the G0 SPIs */
+	gicv3_secure_spis_configure(driver_data->gicd_base,
+					driver_data->g0_interrupt_num,
+					driver_data->g0_interrupt_array,
+					INT_TYPE_G0);
+
+	/* Enable the secure SPIs now that they have been configured */
+	gicd_set_ctlr(driver_data->gicd_base,
+		      CTLR_ENABLE_G1S_BIT | CTLR_ENABLE_G0_BIT,
+		      RWP_TRUE);
+}
+
+/*******************************************************************************
+ * This function initialises the GIC Redistributor interface of the calling CPU
+ * (identified by the 'proc_num' parameter) based upon the data provided by the
+ * platform while initialising the driver.
+ ******************************************************************************/
+void gicv3_rdistif_init(unsigned int proc_num)
+{
+	uintptr_t gicr_base;
+
+	assert(driver_data);
+	assert(proc_num < driver_data->rdistif_num);
+	assert(driver_data->rdistif_base_addrs);
+	assert(driver_data->gicd_base);
+	assert(gicd_read_ctlr(driver_data->gicd_base) & CTLR_ARE_S_BIT);
+	assert(driver_data->g1s_interrupt_array);
+	assert(driver_data->g0_interrupt_array);
+
+	assert(IS_IN_EL3());
+
+	gicr_base = driver_data->rdistif_base_addrs[proc_num];
+
+	/* Set the default attribute of all SGIs and PPIs */
+	gicv3_ppi_sgi_configure_defaults(gicr_base);
+
+	/* Configure the G1S SGIs/PPIs */
+	gicv3_secure_ppi_sgi_configure(gicr_base,
+					   driver_data->g1s_interrupt_num,
+					   driver_data->g1s_interrupt_array,
+					   INT_TYPE_G1S);
+
+	/* Configure the G0 SGIs/PPIs */
+	gicv3_secure_ppi_sgi_configure(gicr_base,
+					   driver_data->g0_interrupt_num,
+					   driver_data->g0_interrupt_array,
+					   INT_TYPE_G0);
+}
+
+/*******************************************************************************
+ * This function enables the GIC CPU interface of the calling CPU using only
+ * system register accesses.
+ ******************************************************************************/
+void gicv3_cpuif_enable(unsigned int proc_num)
+{
+	uintptr_t gicr_base;
+	unsigned int scr_el3;
+	unsigned int icc_sre_el3;
+
+	assert(driver_data);
+	assert(proc_num < driver_data->rdistif_num);
+	assert(driver_data->rdistif_base_addrs);
+	assert(IS_IN_EL3());
+
+	/* Mark the connected core as awake */
+	gicr_base = driver_data->rdistif_base_addrs[proc_num];
+	gicv3_rdistif_mark_core_awake(gicr_base);
+
+	/* Disable the legacy interrupt bypass */
+	icc_sre_el3 = ICC_SRE_DIB_BIT | ICC_SRE_DFB_BIT;
+
+	/*
+	 * Enable system register access for EL3 and allow lower exception
+	 * levels to configure the same for themselves. If the legacy mode is
+	 * not supported, the SRE bit is RAO/WI
+	 */
+	icc_sre_el3 |= (ICC_SRE_EN_BIT | ICC_SRE_SRE_BIT);
+	write_icc_sre_el3(read_icc_sre_el3() | icc_sre_el3);
+
+	scr_el3 = read_scr_el3();
+
+	/*
+	 * Switch to NS state to write Non secure ICC_SRE_EL1 and
+	 * ICC_SRE_EL2 registers.
+	 */
+	write_scr_el3(scr_el3 | SCR_NS_BIT);
+	isb();
+
+	write_icc_sre_el2(read_icc_sre_el2() | icc_sre_el3);
+	write_icc_sre_el1(ICC_SRE_SRE_BIT);
+	isb();
+
+	/* Switch to secure state. */
+	write_scr_el3(scr_el3 & (~SCR_NS_BIT));
+	isb();
+
+	/* Program the idle priority in the PMR */
+	write_icc_pmr_el1(GIC_PRI_MASK);
+
+	/* Enable Group0 interrupts */
+	write_icc_igrpen0_el1(IGRPEN1_EL1_ENABLE_G0_BIT);
+
+	/* Enable Group1 Secure interrupts */
+	write_icc_igrpen1_el3(read_icc_igrpen1_el3() |
+				IGRPEN1_EL3_ENABLE_G1S_BIT);
+
+	/* Write the secure ICC_SRE_EL1 register */
+	write_icc_sre_el1(ICC_SRE_SRE_BIT);
+	isb();
+}
+
+/*******************************************************************************
+ * This function disables the GIC CPU interface of the calling CPU using
+ * only system register accesses.
+ ******************************************************************************/
+void gicv3_cpuif_disable(unsigned int proc_num)
+{
+	uintptr_t gicr_base;
+
+	assert(driver_data);
+	assert(proc_num < driver_data->rdistif_num);
+	assert(driver_data->rdistif_base_addrs);
+
+	assert(IS_IN_EL3());
+
+	/* Disable legacy interrupt bypass */
+	write_icc_sre_el3(read_icc_sre_el3() |
+			  (ICC_SRE_DIB_BIT | ICC_SRE_DFB_BIT));
+
+	/* Disable Group0 interrupts */
+	write_icc_igrpen0_el1(read_icc_igrpen0_el1() &
+			      ~IGRPEN1_EL1_ENABLE_G0_BIT);
+
+	/* Disable Group1 Secure interrupts */
+	write_icc_igrpen1_el3(read_icc_igrpen1_el3() &
+			      ~IGRPEN1_EL3_ENABLE_G1S_BIT);
+
+	/* Synchronise accesses to group enable registers */
+	isb();
+
+	/* Mark the connected core as asleep */
+	gicr_base = driver_data->rdistif_base_addrs[proc_num];
+	gicv3_rdistif_mark_core_asleep(gicr_base);
+}
+
+/*******************************************************************************
+ * This function returns the id of the highest priority pending interrupt at
+ * the GIC cpu interface.
+ ******************************************************************************/
+unsigned int gicv3_get_pending_interrupt_id(void)
+{
+	unsigned int id;
+
+	assert(IS_IN_EL3());
+	id = read_icc_hppir0_el1() & HPPIR0_EL1_INTID_MASK;
+
+	/*
+	 * If the ID is special identifier corresponding to G1S or G1NS
+	 * interrupt, then read the highest pending group 1 interrupt.
+	 */
+	if ((id == PENDING_G1S_INTID) || (id == PENDING_G1NS_INTID))
+		return read_icc_hppir1_el1() & HPPIR1_EL1_INTID_MASK;
+
+	return id;
+}
+
+/*******************************************************************************
+ * This function returns the type of the highest priority pending interrupt at
+ * the GIC cpu interface. The return values can be one of the following :
+ *   PENDING_G1S_INTID  : The interrupt type is secure Group 1.
+ *   PENDING_G1NS_INTID : The interrupt type is non secure Group 1.
+ *   0 - 1019           : The interrupt type is secure Group 0.
+ *   GIC_SPURIOUS_INTERRUPT : there is no pending interrupt with
+ *                            sufficient priority to be signaled
+ ******************************************************************************/
+unsigned int gicv3_get_pending_interrupt_type(void)
+{
+	assert(IS_IN_EL3());
+	return read_icc_hppir0_el1() & HPPIR0_EL1_INTID_MASK;
+}
+
+/*******************************************************************************
+ * 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 Secure / Non Secure. The return value can be one of the
+ * following :
+ *    INT_TYPE_G0  : The interrupt type is a Secure Group 0 interrupt
+ *    INT_TYPE_G1S : The interrupt type is a Secure Group 1 secure interrupt
+ *    INT_TYPE_G1NS: The interrupt type is a Secure Group 1 non secure
+ *                   interrupt.
+ ******************************************************************************/
+unsigned int gicv3_get_interrupt_type(unsigned int id,
+					  unsigned int proc_num)
+{
+	unsigned int igroup, grpmodr;
+	uintptr_t gicr_base;
+
+	assert(IS_IN_EL3());
+	assert(driver_data);
+
+	/* Ensure the parameters are valid */
+	assert(id < PENDING_G1S_INTID || id >= MIN_LPI_ID);
+	assert(proc_num < driver_data->rdistif_num);
+
+	/* All LPI interrupts are Group 1 non secure */
+	if (id >= MIN_LPI_ID)
+		return INT_TYPE_G1NS;
+
+	if (id < MIN_SPI_ID) {
+		assert(driver_data->rdistif_base_addrs);
+		gicr_base = driver_data->rdistif_base_addrs[proc_num];
+		igroup = gicr_get_igroupr0(gicr_base, id);
+		grpmodr = gicr_get_igrpmodr0(gicr_base, id);
+	} else {
+		assert(driver_data->gicd_base);
+		igroup = gicd_get_igroupr(driver_data->gicd_base, id);
+		grpmodr = gicd_get_igrpmodr(driver_data->gicd_base, id);
+	}
+
+	/*
+	 * If the IGROUP bit is set, then it is a Group 1 Non secure
+	 * interrupt
+	 */
+	if (igroup)
+		return INT_TYPE_G1NS;
+
+	/* If the GRPMOD bit is set, then it is a Group 1 Secure interrupt */
+	if (grpmodr)
+		return INT_TYPE_G1S;
+
+	/* Else it is a Group 0 Secure interrupt */
+	return INT_TYPE_G0;
+}