mirror of
https://github.com/Fishwaldo/opensbi.git
synced 2025-03-15 19:31:32 +00:00
lib: sbi: Introduce sbi_trap_exit() API
We introduce sbi_trap_exit() API which can help non-firmware (i.e. generic or platform) code to force exit trap/interrupt handling and resume execution at context pointed by parameter "const struct sbi_trap_regs *regs". This new sbi_trap_exit() API will help Keystone Enclave project to resume execution of enclave from custom SBI call handler. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
This commit is contained in:
parent
80bc5065bb
commit
b7df5e4392
4 changed files with 72 additions and 3 deletions
|
@ -261,6 +261,9 @@ _scratch_init:
|
|||
/* Store hartid-to-scratch function address in scratch space */
|
||||
la a4, _hartid_to_scratch
|
||||
REG_S a4, SBI_SCRATCH_HARTID_TO_SCRATCH_OFFSET(tp)
|
||||
/* Store trap-exit function address in scratch space */
|
||||
la 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 */
|
||||
|
@ -423,6 +426,18 @@ _skip_trap_handler_rv32_hyp:
|
|||
#endif
|
||||
csrw CSR_MTVEC, a4
|
||||
|
||||
#if __riscv_xlen == 32
|
||||
/* Override trap exit for H-extension */
|
||||
csrr a5, CSR_MISA
|
||||
srli a5, a5, ('H' - 'A')
|
||||
andi a5, a5, 0x1
|
||||
beq a5, zero, _skip_trap_exit_rv32_hyp
|
||||
la a4, _trap_exit_rv32_hyp
|
||||
csrr a5, CSR_MSCRATCH
|
||||
REG_S a4, SBI_SCRATCH_TRAP_EXIT_OFFSET(a5)
|
||||
_skip_trap_exit_rv32_hyp:
|
||||
#endif
|
||||
|
||||
/* Initialize SBI runtime */
|
||||
csrr a0, CSR_MSCRATCH
|
||||
call sbi_init
|
||||
|
@ -653,6 +668,20 @@ _trap_handler:
|
|||
|
||||
mret
|
||||
|
||||
.section .entry, "ax", %progbits
|
||||
.align 3
|
||||
.globl _trap_exit
|
||||
_trap_exit:
|
||||
add sp, a0, zero
|
||||
|
||||
TRAP_RESTORE_GENERAL_REGS_EXCEPT_SP_T0
|
||||
|
||||
TRAP_RESTORE_MEPC_MSTATUS 0
|
||||
|
||||
TRAP_RESTORE_SP_T0
|
||||
|
||||
mret
|
||||
|
||||
#if __riscv_xlen == 32
|
||||
.section .entry, "ax", %progbits
|
||||
.align 3
|
||||
|
@ -673,6 +702,20 @@ _trap_handler_rv32_hyp:
|
|||
TRAP_RESTORE_SP_T0
|
||||
|
||||
mret
|
||||
|
||||
.section .entry, "ax", %progbits
|
||||
.align 3
|
||||
.globl _trap_exit_rv32_hyp
|
||||
_trap_exit_rv32_hyp:
|
||||
add sp, a0, zero
|
||||
|
||||
TRAP_RESTORE_GENERAL_REGS_EXCEPT_SP_T0
|
||||
|
||||
TRAP_RESTORE_MEPC_MSTATUS 1
|
||||
|
||||
TRAP_RESTORE_SP_T0
|
||||
|
||||
mret
|
||||
#endif
|
||||
|
||||
.section .entry, "ax", %progbits
|
||||
|
|
|
@ -30,12 +30,14 @@
|
|||
#define SBI_SCRATCH_PLATFORM_ADDR_OFFSET (6 * __SIZEOF_POINTER__)
|
||||
/** Offset of hartid_to_scratch member in sbi_scratch */
|
||||
#define SBI_SCRATCH_HARTID_TO_SCRATCH_OFFSET (7 * __SIZEOF_POINTER__)
|
||||
/** Offset of trap_exit member in sbi_scratch */
|
||||
#define SBI_SCRATCH_TRAP_EXIT_OFFSET (8 * __SIZEOF_POINTER__)
|
||||
/** Offset of tmp0 member in sbi_scratch */
|
||||
#define SBI_SCRATCH_TMP0_OFFSET (8 * __SIZEOF_POINTER__)
|
||||
#define SBI_SCRATCH_TMP0_OFFSET (9 * __SIZEOF_POINTER__)
|
||||
/** Offset of options member in sbi_scratch */
|
||||
#define SBI_SCRATCH_OPTIONS_OFFSET (9 * __SIZEOF_POINTER__)
|
||||
#define SBI_SCRATCH_OPTIONS_OFFSET (10 * __SIZEOF_POINTER__)
|
||||
/** Offset of extra space in sbi_scratch */
|
||||
#define SBI_SCRATCH_EXTRA_SPACE_OFFSET (10 * __SIZEOF_POINTER__)
|
||||
#define SBI_SCRATCH_EXTRA_SPACE_OFFSET (11 * __SIZEOF_POINTER__)
|
||||
/** Maximum size of sbi_scratch (4KB) */
|
||||
#define SBI_SCRATCH_SIZE (0x1000)
|
||||
|
||||
|
@ -63,6 +65,8 @@ 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 */
|
||||
|
|
|
@ -207,6 +207,8 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs,
|
|||
|
||||
void sbi_trap_handler(struct sbi_trap_regs *regs);
|
||||
|
||||
void __noreturn sbi_trap_exit(const struct sbi_trap_regs *regs);
|
||||
|
||||
#endif
|
||||
|
||||
#endif
|
||||
|
|
|
@ -16,6 +16,7 @@
|
|||
#include <sbi/sbi_illegal_insn.h>
|
||||
#include <sbi/sbi_ipi.h>
|
||||
#include <sbi/sbi_misaligned_ldst.h>
|
||||
#include <sbi/sbi_scratch.h>
|
||||
#include <sbi/sbi_timer.h>
|
||||
#include <sbi/sbi_trap.h>
|
||||
|
||||
|
@ -271,3 +272,22 @@ trap_error:
|
|||
if (rc)
|
||||
sbi_trap_error(msg, rc, mcause, mtval, mtval2, mtinst, 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();
|
||||
}
|
||||
|
|
Loading…
Add table
Reference in a new issue