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| author | Anup Patel <Anup.Patel@wdc.com> | 2019-04-25 08:38:41 +0000 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@sifive.com> | 2019-05-16 20:42:11 -0700 |
| commit | a3182c91ef4e7dda90ff080a4132efd3ecb8786a (patch) | |
| tree | 5309b2480f3c6bb9e6df4d7921c7a71ce18dcc4d /arch/riscv/kernel/entry.S | |
| parent | 6dcaf00487ca10d87e53fc8decb2e30f113c955d (diff) | |
| download | linux-a3182c91ef4e7dda90ff080a4132efd3ecb8786a.tar.bz2 | |
RISC-V: Access CSRs using CSR numbers
We should prefer accessing CSRs using their CSR numbers because:
1. It compiles fine with older toolchains.
2. We can use latest CSR names in #define macro names of CSR numbers
as-per RISC-V spec.
3. We can access newly added CSRs even if toolchain does not recognize
newly addes CSRs by name.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Diffstat (limited to 'arch/riscv/kernel/entry.S')
| -rw-r--r-- | arch/riscv/kernel/entry.S | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index fd9b57c8b4ce..1c1ecc238cfa 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -37,11 +37,11 @@ * the kernel thread pointer. If we came from the kernel, sscratch * will contain 0, and we should continue on the current TP. */ - csrrw tp, sscratch, tp + csrrw tp, CSR_SSCRATCH, tp bnez tp, _save_context _restore_kernel_tpsp: - csrr tp, sscratch + csrr tp, CSR_SSCRATCH REG_S sp, TASK_TI_KERNEL_SP(tp) _save_context: REG_S sp, TASK_TI_USER_SP(tp) @@ -87,11 +87,11 @@ _save_context: li t0, SR_SUM | SR_FS REG_L s0, TASK_TI_USER_SP(tp) - csrrc s1, sstatus, t0 - csrr s2, sepc - csrr s3, sbadaddr - csrr s4, scause - csrr s5, sscratch + csrrc s1, CSR_SSTATUS, t0 + csrr s2, CSR_SEPC + csrr s3, CSR_STVAL + csrr s4, CSR_SCAUSE + csrr s5, CSR_SSCRATCH REG_S s0, PT_SP(sp) REG_S s1, PT_SSTATUS(sp) REG_S s2, PT_SEPC(sp) @@ -107,8 +107,8 @@ _save_context: .macro RESTORE_ALL REG_L a0, PT_SSTATUS(sp) REG_L a2, PT_SEPC(sp) - csrw sstatus, a0 - csrw sepc, a2 + csrw CSR_SSTATUS, a0 + csrw CSR_SEPC, a2 REG_L x1, PT_RA(sp) REG_L x3, PT_GP(sp) @@ -155,7 +155,7 @@ ENTRY(handle_exception) * Set sscratch register to 0, so that if a recursive exception * occurs, the exception vector knows it came from the kernel */ - csrw sscratch, x0 + csrw CSR_SSCRATCH, x0 /* Load the global pointer */ .option push @@ -248,7 +248,7 @@ resume_userspace: * Save TP into sscratch, so we can find the kernel data structures * again. */ - csrw sscratch, tp + csrw CSR_SSCRATCH, tp restore_all: RESTORE_ALL |