[PATCH v3 02/10] lib: sbi: Remove sbi_trap_exit() and related code

[Anup Patel <apatel@ventanamicro.com>]

Over the years, no uses of sbi_trap_exit() have been found so remove
it and also remove related code from fw_base.S and sbi_scratch.h.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
---
 firmware/fw_base.S        | 11 -----------
 include/sbi/sbi_scratch.h | 15 +++------------
 include/sbi/sbi_trap.h    |  2 --
 lib/sbi/sbi_trap.c        | 19 -------------------
 4 files changed, 3 insertions(+), 44 deletions(-)

diff --git a/firmware/fw_base.S b/firmware/fw_base.S
index 126b067..c404d8b 100644
--- a/firmware/fw_base.S
+++ b/firmware/fw_base.S
@@ -298,9 +298,6 @@ _scratch_init:
 	/* Store hartid-to-scratch function address in scratch space */
 	lla	a4, _hartid_to_scratch
 	REG_S	a4, SBI_SCRATCH_HARTID_TO_SCRATCH_OFFSET(tp)
-	/* Store trap-exit function address in scratch space */
-	lla	a4, _trap_exit
-	REG_S	a4, SBI_SCRATCH_TRAP_EXIT_OFFSET(tp)
 	/* Clear tmp0 in scratch space */
 	REG_S	zero, SBI_SCRATCH_TMP0_OFFSET(tp)
 	/* Store firmware options in scratch space */
@@ -453,10 +450,6 @@ _start_warm:
 	srli	a5, a5, ('H' - 'A')
 	andi	a5, a5, 0x1
 	beq	a5, zero, _skip_trap_handler_rv32_hyp
-	/* Override trap exit for H-extension */
-	csrr	a5, CSR_MSCRATCH
-	lla	a4, _trap_exit_rv32_hyp
-	REG_S	a4, SBI_SCRATCH_TRAP_EXIT_OFFSET(a5)
 	lla	a4, _trap_handler_rv32_hyp
 _skip_trap_handler_rv32_hyp:
 #endif
@@ -695,7 +688,6 @@ memcmp:
 	.section .entry, "ax", %progbits
 	.align 3
 	.globl _trap_handler
-	.globl _trap_exit
 _trap_handler:
 	TRAP_SAVE_AND_SETUP_SP_T0
 
@@ -705,7 +697,6 @@ _trap_handler:
 
 	TRAP_CALL_C_ROUTINE
 
-_trap_exit:
 	TRAP_RESTORE_GENERAL_REGS_EXCEPT_A0_T0
 
 	TRAP_RESTORE_MEPC_MSTATUS 0
@@ -718,7 +709,6 @@ _trap_exit:
 	.section .entry, "ax", %progbits
 	.align 3
 	.globl _trap_handler_rv32_hyp
-	.globl _trap_exit_rv32_hyp
 _trap_handler_rv32_hyp:
 	TRAP_SAVE_AND_SETUP_SP_T0
 
@@ -728,7 +718,6 @@ _trap_handler_rv32_hyp:
 
 	TRAP_CALL_C_ROUTINE
 
-_trap_exit_rv32_hyp:
 	TRAP_RESTORE_GENERAL_REGS_EXCEPT_A0_T0
 
 	TRAP_RESTORE_MEPC_MSTATUS 1
diff --git a/include/sbi/sbi_scratch.h b/include/sbi/sbi_scratch.h
index e6a33ba..55b937f 100644
--- a/include/sbi/sbi_scratch.h
+++ b/include/sbi/sbi_scratch.h
@@ -36,14 +36,12 @@
 #define SBI_SCRATCH_PLATFORM_ADDR_OFFSET	(9 * __SIZEOF_POINTER__)
 /** Offset of hartid_to_scratch member in sbi_scratch */
 #define SBI_SCRATCH_HARTID_TO_SCRATCH_OFFSET	(10 * __SIZEOF_POINTER__)
-/** Offset of trap_exit member in sbi_scratch */
-#define SBI_SCRATCH_TRAP_EXIT_OFFSET		(11 * __SIZEOF_POINTER__)
 /** Offset of tmp0 member in sbi_scratch */
-#define SBI_SCRATCH_TMP0_OFFSET			(12 * __SIZEOF_POINTER__)
+#define SBI_SCRATCH_TMP0_OFFSET			(11 * __SIZEOF_POINTER__)
 /** Offset of options member in sbi_scratch */
-#define SBI_SCRATCH_OPTIONS_OFFSET		(13 * __SIZEOF_POINTER__)
+#define SBI_SCRATCH_OPTIONS_OFFSET		(12 * __SIZEOF_POINTER__)
 /** Offset of extra space in sbi_scratch */
-#define SBI_SCRATCH_EXTRA_SPACE_OFFSET		(14 * __SIZEOF_POINTER__)
+#define SBI_SCRATCH_EXTRA_SPACE_OFFSET		(13 * __SIZEOF_POINTER__)
 /** Maximum size of sbi_scratch (4KB) */
 #define SBI_SCRATCH_SIZE			(0x1000)
 
@@ -77,8 +75,6 @@ struct sbi_scratch {
 	unsigned long platform_addr;
 	/** Address of HART ID to sbi_scratch conversion function */
 	unsigned long hartid_to_scratch;
-	/** Address of trap exit function */
-	unsigned long trap_exit;
 	/** Temporary storage */
 	unsigned long tmp0;
 	/** Options for OpenSBI library */
@@ -129,11 +125,6 @@ _Static_assert(
 		== SBI_SCRATCH_HARTID_TO_SCRATCH_OFFSET,
 	"struct sbi_scratch definition has changed, please redefine "
 	"SBI_SCRATCH_HARTID_TO_SCRATCH_OFFSET");
-_Static_assert(
-	offsetof(struct sbi_scratch, trap_exit)
-		== SBI_SCRATCH_TRAP_EXIT_OFFSET,
-	"struct sbi_scratch definition has changed, please redefine "
-	"SBI_SCRATCH_TRAP_EXIT_OFFSET");
 _Static_assert(
 	offsetof(struct sbi_scratch, tmp0)
 		== SBI_SCRATCH_TMP0_OFFSET,
diff --git a/include/sbi/sbi_trap.h b/include/sbi/sbi_trap.h
index 3757694..a6032ab 100644
--- a/include/sbi/sbi_trap.h
+++ b/include/sbi/sbi_trap.h
@@ -225,8 +225,6 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs,
 
 struct sbi_trap_regs *sbi_trap_handler(struct sbi_trap_regs *regs);
 
-void __noreturn sbi_trap_exit(const struct sbi_trap_regs *regs);
-
 #endif
 
 #endif
diff --git a/lib/sbi/sbi_trap.c b/lib/sbi/sbi_trap.c
index c9db73f..b059c4b 100644
--- a/lib/sbi/sbi_trap.c
+++ b/lib/sbi/sbi_trap.c
@@ -334,22 +334,3 @@ trap_error:
 		sbi_trap_error(msg, rc, mcause, mtval, mtval2, mtinst, regs);
 	return regs;
 }
-
-typedef void (*trap_exit_t)(const struct sbi_trap_regs *regs);
-
-/**
- * Exit trap/interrupt handling
- *
- * This function is called by non-firmware code to abruptly exit
- * trap/interrupt handling and resume execution at context pointed
- * by given register state.
- *
- * @param regs pointer to register state
- */
-void __noreturn sbi_trap_exit(const struct sbi_trap_regs *regs)
-{
-	struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
-
-	((trap_exit_t)scratch->trap_exit)(regs);
-	__builtin_unreachable();
-}
-- 
2.34.1