GICv3: Enable multi socket GIC redistributor frame discovery

This patch provides declaration and definition of new GICv3 driver
API: gicv3_rdistif_probe().This function delegates the responsibility
of discovering the corresponding Redistributor base frame to each CPU
itself. It is a modified version of gicv3_rdistif_base_addrs_probe()
and is executed by each CPU in the platform unlike the previous
approach in which only the Primary CPU did the discovery of all the
Redistributor frames for every CPU.

The flush operations as part of gicv3_driver_init() function are
made necessary even for platforms with WARMBOOT_ENABLE_DCACHE_EARLY
because the GICv3 driver data structure contents are accessed by CPU
with D-Cache turned off during power down operations.

Change-Id: I1833e81d3974b32a3e4a3df4766a33d070982268
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>

drivers/arm/gic/v3/gicv3_main.c

@@ -16,7 +16,6 @@
 #include "gicv3_private.h"
 
 const gicv3_driver_data_t *gicv3_driver_data;
-static unsigned int gicv2_compat;
 
 /*
  * Spinlock to guard registers needing read-modify-write. APIs protected by this
@@ -60,51 +59,61 @@ static spinlock_t gic_lock;
 void __init gicv3_driver_init(const gicv3_driver_data_t *plat_driver_data)
 {
 	unsigned int gic_version;
+	unsigned int gicv2_compat;
 
 	assert(plat_driver_data != NULL);
 	assert(plat_driver_data->gicd_base != 0U);
-	assert(plat_driver_data->gicr_base != 0U);
 	assert(plat_driver_data->rdistif_num != 0U);
 	assert(plat_driver_data->rdistif_base_addrs != NULL);
 
 	assert(IS_IN_EL3());
 
-	assert(plat_driver_data->interrupt_props_num > 0 ?
-	       plat_driver_data->interrupt_props != NULL : 1);
+	assert((plat_driver_data->interrupt_props_num != 0U) ?
+	       (plat_driver_data->interrupt_props != NULL) : 1);
 
 	/* Check for system register support */
-#ifdef __aarch64__
+#ifndef __aarch64__
+	assert((read_id_pfr1() &
+			(ID_PFR1_GIC_MASK << ID_PFR1_GIC_SHIFT)) != 0U);
+#else
 	assert((read_id_aa64pfr0_el1() &
 			(ID_AA64PFR0_GIC_MASK << ID_AA64PFR0_GIC_SHIFT)) != 0U);
-#else
-	assert((read_id_pfr1() & (ID_PFR1_GIC_MASK << ID_PFR1_GIC_SHIFT)) != 0U);
-#endif /* __aarch64__ */
+#endif /* !__aarch64__ */
 
 	/* 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_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
+	 * 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);
-
+	gicv2_compat = gicv2_compat & CTLR_ARE_S_MASK;
+
+	if (plat_driver_data->gicr_base != 0U) {
+		/*
+		 * 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);
+#if !HW_ASSISTED_COHERENCY
+		/*
+		 * Flush the rdistif_base_addrs[] contents linked to the GICv3 driver.
+		 */
+		flush_dcache_range((uintptr_t)(plat_driver_data->rdistif_base_addrs),
+			plat_driver_data->rdistif_num *
+			sizeof(*(plat_driver_data->rdistif_base_addrs)));
+#endif
+	}
 	gicv3_driver_data = plat_driver_data;
 
 	/*
@@ -112,19 +121,19 @@ void __init gicv3_driver_init(const gicv3_driver_data_t *plat_driver_data)
 	 * enabled. When the secondary CPU boots up, it initializes the
 	 * GICC/GICR interface with the caches disabled. Hence flush the
 	 * driver data to ensure coherency. This is not required if the
-	 * platform has HW_ASSISTED_COHERENCY or WARMBOOT_ENABLE_DCACHE_EARLY
-	 * enabled.
+	 * platform has HW_ASSISTED_COHERENCY enabled.
 	 */
-#if !(HW_ASSISTED_COHERENCY || WARMBOOT_ENABLE_DCACHE_EARLY)
-	flush_dcache_range((uintptr_t) &gicv3_driver_data,
-			sizeof(gicv3_driver_data));
-	flush_dcache_range((uintptr_t) gicv3_driver_data,
-			sizeof(*gicv3_driver_data));
+#if !HW_ASSISTED_COHERENCY
+	flush_dcache_range((uintptr_t)&gicv3_driver_data,
+		sizeof(gicv3_driver_data));
+	flush_dcache_range((uintptr_t)gicv3_driver_data,
+		sizeof(*gicv3_driver_data));
 #endif
 
-	INFO("GICv3 %s legacy support detected."
-			" ARM GICV3 driver initialized in EL3\n",
-			gicv2_compat ? "with" : "without");
+	INFO("GICv3 with%s legacy support detected."
+			" ARM GICv3 driver initialized in EL3\n",
+			(gicv2_compat == 0U) ? "" : "out");
+
 }
 
 /*******************************************************************************
@@ -192,6 +201,7 @@ void gicv3_rdistif_init(unsigned int proc_num)
 	gicv3_rdistif_on(proc_num);
 
 	gicr_base = gicv3_driver_data->rdistif_base_addrs[proc_num];
+	assert(gicr_base != 0U);
 
 	/* Set the default attribute of all SGIs and PPIs */
 	gicv3_ppi_sgi_config_defaults(gicr_base);
@@ -313,6 +323,7 @@ void gicv3_cpuif_disable(unsigned int proc_num)
 
 	/* Mark the connected core as asleep */
 	gicr_base = gicv3_driver_data->rdistif_base_addrs[proc_num];
+	assert(gicr_base != 0U);
 	gicv3_rdistif_mark_core_asleep(gicr_base);
 }
 
@@ -1081,3 +1092,71 @@ unsigned int gicv3_set_pmr(unsigned int mask)
 
 	return old_mask;
 }
+
+/*******************************************************************************
+ * This function delegates the responsibility of discovering the corresponding
+ * Redistributor frames to each CPU itself. It is a modified version of
+ * gicv3_rdistif_base_addrs_probe() and is executed by each CPU in the platform
+ * unlike the previous way in which only the Primary CPU did the discovery of
+ * all the Redistributor frames for every CPU. It also handles the scenario in
+ * which the frames of various CPUs are not contiguous in physical memory.
+ ******************************************************************************/
+int gicv3_rdistif_probe(const uintptr_t gicr_frame)
+{
+	u_register_t mpidr;
+	unsigned int proc_num, proc_self;
+	uint64_t typer_val;
+	uintptr_t rdistif_base;
+	bool gicr_frame_found = false;
+
+	assert(gicv3_driver_data->gicr_base == 0U);
+
+	/* Ensure this function is called with Data Cache enabled */
+#ifndef __aarch64__
+	assert((read_sctlr() & SCTLR_C_BIT) != 0U);
+#else
+	assert((read_sctlr_el3() & SCTLR_C_BIT) != 0U);
+#endif /* !__aarch64__ */
+
+	proc_self = gicv3_driver_data->mpidr_to_core_pos(read_mpidr_el1());
+	rdistif_base = gicr_frame;
+	do {
+		typer_val = gicr_read_typer(rdistif_base);
+		if (gicv3_driver_data->mpidr_to_core_pos != NULL) {
+			mpidr = mpidr_from_gicr_typer(typer_val);
+			proc_num = gicv3_driver_data->mpidr_to_core_pos(mpidr);
+		} else {
+			proc_num = (unsigned int)(typer_val >> TYPER_PROC_NUM_SHIFT) &
+					TYPER_PROC_NUM_MASK;
+		}
+		if (proc_num == proc_self) {
+			/* The base address doesn't need to be initialized on
+			 * every warm boot.
+			 */
+			if (gicv3_driver_data->rdistif_base_addrs[proc_num] != 0U)
+				return 0;
+			gicv3_driver_data->rdistif_base_addrs[proc_num] =
+			rdistif_base;
+			gicr_frame_found = true;
+			break;
+		}
+		rdistif_base += (uintptr_t)(ULL(1) << GICR_PCPUBASE_SHIFT);
+	} while ((typer_val & TYPER_LAST_BIT) == 0U);
+
+	if (!gicr_frame_found)
+		return -1;
+
+	/*
+	 * Flush the driver data to ensure coherency. This is
+	 * not required if platform has HW_ASSISTED_COHERENCY
+	 * enabled.
+	 */
+#if !HW_ASSISTED_COHERENCY
+	/*
+	 * Flush the rdistif_base_addrs[] contents linked to the GICv3 driver.
+	 */
+	flush_dcache_range((uintptr_t)&(gicv3_driver_data->rdistif_base_addrs[proc_num]),
+		sizeof(*(gicv3_driver_data->rdistif_base_addrs)));
+#endif
+	return 0; /* Found matching GICR frame */
+}

include/drivers/arm/gicv3.h

 /*
- * Copyright (c) 2015-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -366,6 +366,7 @@ typedef struct gicv3_its_ctx {
  * GICv3 EL3 driver API
  ******************************************************************************/
 void gicv3_driver_init(const gicv3_driver_data_t *plat_driver_data);
+int gicv3_rdistif_probe(const uintptr_t gicr_frame);
 void gicv3_distif_init(void);
 void gicv3_rdistif_init(unsigned int proc_num);
 void gicv3_rdistif_on(unsigned int proc_num);