[PATCH v3 7/8] lib: sbi: Implement SBI debug trigger extension

[Himanshu Chauhan]

This patch adds functions to register ecalls for debug triggers
and handler to handle the debug trigger function IDs.

Signed-off-by: Himanshu Chauhan <hchauhan at ventanamicro.com>
Reviewed-by: Anup Patel <anup at brainfault.org>
---
 lib/sbi/Kconfig          |  4 +++
 lib/sbi/objects.mk       |  3 ++
 lib/sbi/sbi_ecall_dbtr.c | 73 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 80 insertions(+)
 create mode 100644 lib/sbi/sbi_ecall_dbtr.c

diff --git a/lib/sbi/Kconfig b/lib/sbi/Kconfig
index 477775e..81dd2db 100644
--- a/lib/sbi/Kconfig
+++ b/lib/sbi/Kconfig
@@ -46,4 +46,8 @@ config SBI_ECALL_VENDOR
 	bool "Platform-defined vendor extensions"
 	default y
 
+config SBI_ECALL_DBTR
+	bool "Debug Trigger Extension"
+	default y
+
 endmenu
diff --git a/lib/sbi/objects.mk b/lib/sbi/objects.mk
index c7de150..0a50e95 100644
--- a/lib/sbi/objects.mk
+++ b/lib/sbi/objects.mk
@@ -52,6 +52,9 @@ libsbi-objs-$(CONFIG_SBI_ECALL_LEGACY) += sbi_ecall_legacy.o
 carray-sbi_ecall_exts-$(CONFIG_SBI_ECALL_VENDOR) += ecall_vendor
 libsbi-objs-$(CONFIG_SBI_ECALL_VENDOR) += sbi_ecall_vendor.o
 
+carray-sbi_ecall_exts-$(CONFIG_SBI_ECALL_DBTR) += ecall_dbtr
+libsbi-objs-$(CONFIG_SBI_ECALL_DBTR) += sbi_ecall_dbtr.o
+
 libsbi-objs-y += sbi_bitmap.o
 libsbi-objs-y += sbi_bitops.o
 libsbi-objs-y += sbi_console.o
diff --git a/lib/sbi/sbi_ecall_dbtr.c b/lib/sbi/sbi_ecall_dbtr.c
new file mode 100644
index 0000000..2765320
--- /dev/null
+++ b/lib/sbi/sbi_ecall_dbtr.c
@@ -0,0 +1,73 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2023 Ventana Micro Systems Inc.
+ *
+ * Author(s):
+ *   Himanshu Chauhan <hchauhan at ventanamicro.com>
+ */
+
+#include <sbi/sbi_ecall.h>
+#include <sbi/sbi_ecall_interface.h>
+#include <sbi/sbi_error.h>
+#include <sbi/sbi_trap.h>
+#include <sbi/sbi_domain.h>
+#include <sbi/sbi_dbtr.h>
+
+static int sbi_ecall_dbtr_handler(unsigned long extid, unsigned long funcid,
+				  struct sbi_trap_regs *regs,
+				  struct sbi_ecall_return *out)
+{
+	unsigned long smode = (csr_read(CSR_MSTATUS) & MSTATUS_MPP) >>
+			MSTATUS_MPP_SHIFT;
+	const struct sbi_domain *dom = sbi_domain_thishart_ptr();
+	int ret = 0;
+
+	switch (funcid) {
+	case SBI_EXT_DBTR_NUM_TRIGGERS:
+		ret = sbi_dbtr_num_trig(regs->a0, &out->value);
+		break;
+	case SBI_EXT_DBTR_SETUP_SHMEM:
+		ret = sbi_dbtr_setup_shmem(dom, smode, regs->a0, regs->a1);
+		break;
+	case SBI_EXT_DBTR_TRIGGER_READ:
+		ret = sbi_dbtr_read_trig(dom, smode, regs->a0, regs->a1);
+		break;
+	case SBI_EXT_DBTR_TRIGGER_INSTALL:
+		ret = sbi_dbtr_install_trig(dom, smode, regs->a0, &out->value);
+		break;
+	case SBI_EXT_DBTR_TRIGGER_UNINSTALL:
+		ret = sbi_dbtr_uninstall_trig(regs->a0, regs->a1);
+		break;
+	case SBI_EXT_DBTR_TRIGGER_ENABLE:
+		ret = sbi_dbtr_enable_trig(regs->a0, regs->a1);
+		break;
+	case SBI_EXT_DBTR_TRIGGER_UPDATE:
+		ret = sbi_dbtr_update_trig(dom, smode, regs->a0, regs->a1);
+		break;
+	case SBI_EXT_DBTR_TRIGGER_DISABLE:
+		ret = sbi_dbtr_disable_trig(regs->a0, regs->a1);
+		break;
+	default:
+		ret = SBI_ENOTSUPP;
+	};
+
+	return ret;
+}
+
+struct sbi_ecall_extension ecall_dbtr;
+
+static int sbi_ecall_dbtr_register_extensions(void)
+{
+	if (sbi_dbtr_get_total_triggers() == 0)
+		return 0;
+
+	return sbi_ecall_register_extension(&ecall_dbtr);
+}
+
+struct sbi_ecall_extension ecall_dbtr = {
+	.extid_start = SBI_EXT_DBTR,
+	.extid_end = SBI_EXT_DBTR,
+	.handle = sbi_ecall_dbtr_handler,
+	.register_extensions = sbi_ecall_dbtr_register_extensions,
+};
-- 
2.34.1