Add support for Ariane FPGA SoC

This patch adds support for Ariane platform.
We needed to enable PLIC interrupts early(like on BBL) due to some issue of the design.
Otherwise, Linux would not get any external interrupts.

Signed-off-by: Panagiotis Peristerakis <perister@ics.forth.gr>

platform/ariane-fpga/config.mk

@@ -0,0 +1,41 @@
+#
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2019 FORTH-ICS/CARV
+#		Panagiotis Peristerakis <perister@ics.forth.gr>
+#
+
+#for more infos, check out /platform/template/config.mk
+
+PLATFORM_RISCV_XLEN = 64
+
+# Common drivers to enable
+PLATFORM_SERIAL_UART8250=y
+PLATFORM_IRQCHIP_PLIC=y
+PLATFORM_SYS_CLINT=y
+
+# Blobs to build
+FW_TEXT_START=0x80000000
+FW_JUMP=n
+
+ifeq ($(PLATFORM_RISCV_XLEN), 32)
+ # This needs to be 4MB aligned for 32-bit support
+ FW_JUMP_ADDR=0x80400000
+ else
+ # This needs to be 2MB aligned for 64-bit support
+ FW_JUMP_ADDR=0x80200000
+ endif
+FW_JUMP_FDT_ADDR=0x82200000
+
+# Firmware with payload configuration.
+FW_PAYLOAD=y
+
+ifeq ($(PLATFORM_RISCV_XLEN), 32)
+# This needs to be 4MB aligned for 32-bit support
+  FW_PAYLOAD_OFFSET=0x400000
+else
+# This needs to be 2MB aligned for 64-bit support
+  FW_PAYLOAD_OFFSET=0x200000
+endif
+FW_PAYLOAD_FDT_ADDR=0x82200000
+FW_PAYLOAD_ALIGN=0x1000

platform/ariane-fpga/objects.mk

@@ -0,0 +1,8 @@
+#
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2019 FORTH-ICS/CARV
+#		Panagiotis Peristerakis <perister@ics.forth.gr>
+#
+
+platform-objs-y += platform.o

platform/ariane-fpga/platform.c

@@ -0,0 +1,201 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019 FORTH-ICS/CARV
+ *				Panagiotis Peristerakis <perister@ics.forth.gr>
+ */
+
+#include <sbi/riscv_encoding.h>
+#include <sbi/sbi_const.h>
+#include <sbi/sbi_platform.h>
+#include <sbi_utils/irqchip/plic.h>
+#include <sbi_utils/serial/uart8250.h>
+#include <sbi_utils/sys/clint.h>
+#include <sbi/sbi_console.h>
+#include <sbi/sbi_hart.h>
+#include <libfdt.h>
+#include <fdt.h>
+#include <sbi_utils/irqchip/plic.h>
+#include <sbi/riscv_io.h>
+
+#define ARIANE_UART_ADDR			0x10000000
+#define ARIANE_UART_FREQ			50000000
+#define ARIANE_UART_BAUDRATE			115200
+#define ARIANE_UART_REG_SHIFT			2
+#define ARIANE_UART_REG_WIDTH			4
+#define ARIANE_PLIC_ADDR			0xc000000
+#define ARIANE_PLIC_NUM_SOURCES			3
+#define ARIANE_HART_COUNT			1
+#define ARIANE_CLINT_ADDR 0x2000000
+#define PLIC_ENABLE_BASE		0x2000
+#define PLIC_ENABLE_STRIDE		0x80
+#define PLIC_CONTEXT_BASE		0x200000
+#define PLIC_CONTEXT_STRIDE		0x1000
+
+#define SBI_ARIANE_FEATURES	\
+	(SBI_PLATFORM_HAS_TIMER_VALUE | \
+	 SBI_PLATFORM_HAS_SCOUNTEREN | \
+	 SBI_PLATFORM_HAS_MCOUNTEREN | \
+	 SBI_PLATFORM_HAS_MFAULTS_DELEGATION)
+
+
+/*
+ * Ariane platform early initialization.
+ */
+static int ariane_early_init(bool cold_boot)
+{
+	/* For now nothing to do. */
+	return 0;
+}
+
+/*
+ * Ariane platform final initialization.
+ */
+static int ariane_final_init(bool cold_boot)
+{
+	void *fdt;
+
+	if (!cold_boot)
+		return 0;
+	fdt = sbi_scratch_thishart_arg1_ptr();
+	plic_fdt_fixup(fdt, "riscv,plic0");
+	return 0;
+}
+
+/*
+ * Initialize the ariane console.
+ */
+static int ariane_console_init(void)
+{
+	return uart8250_init(ARIANE_UART_ADDR,
+						 ARIANE_UART_FREQ,
+						 ARIANE_UART_BAUDRATE,
+						ARIANE_UART_REG_SHIFT,
+						ARIANE_UART_REG_WIDTH);
+}
+
+static int plic_ariane_warm_irqchip_init(u32 target_hart,
+			   int m_cntx_id, int s_cntx_id)
+{
+	size_t i, ie_words = ARIANE_PLIC_NUM_SOURCES / 32 + 1;
+
+	if (ARIANE_HART_COUNT <= target_hart)
+		return -1;
+	/* By default, enable all IRQs for M-mode of target HART */
+	if (m_cntx_id > -1) {
+		for (i = 0; i < ie_words; i++)
+			plic_set_ie(m_cntx_id, i, 1);
+	}
+	/* Enable all IRQs for S-mode of target HART */
+	if (s_cntx_id > -1) {
+		for (i = 0; i < ie_words; i++)
+			plic_set_ie(s_cntx_id, i, 1);
+	}
+	/* By default, enable M-mode threshold */
+	if (m_cntx_id > -1)
+		plic_set_thresh(m_cntx_id, 1);
+	/* By default, disable S-mode threshold */
+	if (s_cntx_id > -1)
+		plic_set_thresh(s_cntx_id, 0);
+
+	return 0;
+}
+
+/*
+ * Initialize the ariane interrupt controller for current HART.
+ */
+static int ariane_irqchip_init(bool cold_boot)
+{
+	u32 hartid = sbi_current_hartid();
+	int ret;
+
+	if (cold_boot) {
+		ret = plic_cold_irqchip_init(ARIANE_PLIC_ADDR,
+					     ARIANE_PLIC_NUM_SOURCES,
+					     ARIANE_HART_COUNT);
+		if (ret)
+			return ret;
+	}
+	return plic_ariane_warm_irqchip_init(hartid,
+					2 * hartid, 2 * hartid + 1);
+}
+
+/*
+ * Initialize IPI for current HART.
+ */
+static int ariane_ipi_init(bool cold_boot)
+{
+	int ret;
+
+	if (cold_boot) {
+		ret = clint_cold_ipi_init(ARIANE_CLINT_ADDR,
+					  ARIANE_HART_COUNT);
+		if (ret)
+			return ret;
+	}
+
+	return clint_warm_ipi_init();
+}
+
+/*
+ * Initialize ariane timer for current HART.
+ */
+static int ariane_timer_init(bool cold_boot)
+{
+	int ret;
+
+	if (cold_boot) {
+		ret = clint_cold_timer_init(ARIANE_CLINT_ADDR,
+							ARIANE_HART_COUNT);
+		if (ret)
+			return ret;
+	}
+
+	return clint_warm_timer_init();
+}
+
+/*
+ * Reboot the ariane.
+ */
+static int ariane_system_reboot(u32 type)
+{
+	/* For now nothing to do. */
+	sbi_printf("System reboot\n");
+	return 0;
+}
+
+/*
+ * Shutdown or poweroff the ariane.
+ */
+static int ariane_system_shutdown(u32 type)
+{
+	/* For now nothing to do. */
+	sbi_printf("System shutdown\n");
+	return 0;
+}
+
+/*
+ * Platform descriptor.
+ */
+const struct sbi_platform platform = {
+	.name = "ARIANE RISC-V",
+	.features = SBI_ARIANE_FEATURES,
+	.hart_count = ARIANE_HART_COUNT,
+	.hart_stack_size = 4096,
+	.disabled_hart_mask = 0,
+	.early_init = ariane_early_init,
+	.final_init = ariane_final_init,
+	.console_init = ariane_console_init,
+	.console_putc = uart8250_putc,
+	.console_getc = uart8250_getc,
+	.irqchip_init = ariane_irqchip_init,
+	.ipi_init = ariane_ipi_init,
+	.ipi_send = clint_ipi_send,
+	.ipi_sync = clint_ipi_sync,
+	.ipi_clear = clint_ipi_clear,
+	.timer_init = ariane_timer_init,
+	.timer_value = clint_timer_value,
+	.timer_event_start = clint_timer_event_start,
+	.timer_event_stop = clint_timer_event_stop,
+	.system_reboot = ariane_system_reboot,
+	.system_shutdown = ariane_system_shutdown
+};