[PATCH 3/9] lib: sbi_emulate_csr: Utilize platform hooks for unknown CSRs

[Christoph Müllner]

In case we trap during CSR accesses, we have a few defined CSRs
that are gracefully emulated. In case we don't know what to do
with an unknown CSR, let's give the platform a chance to handle
the CSR access.

Signed-off-by: Christoph Müllner <christoph.muellner at vrull.eu>
---
 lib/sbi/sbi_emulate_csr.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/lib/sbi/sbi_emulate_csr.c b/lib/sbi/sbi_emulate_csr.c
index 5f3b111..a6cb855 100644
--- a/lib/sbi/sbi_emulate_csr.c
+++ b/lib/sbi/sbi_emulate_csr.c
@@ -14,6 +14,7 @@
 #include <sbi/sbi_emulate_csr.h>
 #include <sbi/sbi_error.h>
 #include <sbi/sbi_hart.h>
+#include <sbi/sbi_platform.h>
 #include <sbi/sbi_scratch.h>
 #include <sbi/sbi_timer.h>
 #include <sbi/sbi_trap.h>
@@ -147,7 +148,8 @@ int sbi_emulate_csr_read(int csr_num, struct sbi_trap_regs *regs,
 #undef switchcase_hpm
 
 	default:
-		ret = SBI_ENOTSUPP;
+		ret = sbi_platform_read_csr(sbi_platform_ptr(scratch),
+					    csr_num, regs, csr_val);
 		break;
 	}
 
@@ -162,6 +164,7 @@ int sbi_emulate_csr_write(int csr_num, struct sbi_trap_regs *regs,
 			  ulong csr_val)
 {
 	int ret = 0;
+	struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
 	ulong prev_mode = (regs->mstatus & MSTATUS_MPP) >> MSTATUS_MPP_SHIFT;
 #if __riscv_xlen == 32
 	bool virt = (regs->mstatusH & MSTATUSH_MPV) ? true : false;
@@ -185,7 +188,8 @@ int sbi_emulate_csr_write(int csr_num, struct sbi_trap_regs *regs,
 		break;
 #endif
 	default:
-		ret = SBI_ENOTSUPP;
+		ret = sbi_platform_write_csr(sbi_platform_ptr(scratch),
+					     csr_num, regs, csr_val);
 		break;
 	}
 
-- 
2.44.0