[RFC PATCH 1/2] riscv: Add SBI debug trigger extension and function ids

[Himanshu Chauhan <hchauhan@ventanamicro.com>]

Debug trigger extension is a proposed SBI extension to support
native debugging in S-mode and VS-mode.

The proposal for the extension can be found at:
https://lists.riscv.org/g/sig-hypervisors/message/361

This patch adds the extension and the function IDs defined
by the extension.

Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
---
 arch/riscv/include/asm/sbi.h | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index 6e68f8dff76b..e79ff1a2f387 100644
--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -34,6 +34,9 @@ enum sbi_ext_id {
 	SBI_EXT_DBCN = 0x4442434E,
 	SBI_EXT_STA = 0x535441,
 
+	/* SBI Debug Trigger Extension */
+	SBI_EXT_DBTR = 0x44425452,
+
 	/* Experimentals extensions must lie within this range */
 	SBI_EXT_EXPERIMENTAL_START = 0x08000000,
 	SBI_EXT_EXPERIMENTAL_END = 0x08FFFFFF,
@@ -124,6 +127,34 @@ enum sbi_ext_susp_sleep_type {
 	SBI_SUSP_SLEEP_TYPE_SUSPEND_TO_RAM = 0,
 };
 
+/* SBI debug triggers function IDs */
+enum sbi_ext_dbtr_fid {
+	SBI_EXT_DBTR_NUM_TRIGGERS = 0,
+	SBI_EXT_DBTR_SETUP_SHMEM,
+	SBI_EXT_DBTR_TRIG_READ,
+	SBI_EXT_DBTR_TRIG_INSTALL,
+	SBI_EXT_DBTR_TRIG_UPDATE,
+	SBI_EXT_DBTR_TRIG_UNINSTALL,
+	SBI_EXT_DBTR_TRIG_ENABLE,
+	SBI_EXT_DBTR_TRIG_DISABLE,
+};
+
+struct sbi_dbtr_data_msg {
+	unsigned long tstate;
+	unsigned long tdata1;
+	unsigned long tdata2;
+	unsigned long tdata3;
+};
+
+struct sbi_dbtr_id_msg {
+	unsigned long idx;
+};
+
+struct sbi_dbtr_shmem_entry {
+        struct sbi_dbtr_data_msg data;
+        struct sbi_dbtr_id_msg id;
+};
+
 enum sbi_ext_pmu_fid {
 	SBI_EXT_PMU_NUM_COUNTERS = 0,
 	SBI_EXT_PMU_COUNTER_GET_INFO,
-- 
2.34.1