[PATCH v2] riscv: Using CSR numbers to access CSRs

From: Bin Meng
Date: Wed Aug 07 2019 - 09:33:30 EST

Since commit a3182c91ef4e ("RISC-V: Access CSRs using CSR numbers"),
we should prefer accessing CSRs using their CSR numbers, but there
are several leftovers like sstatus / sptbr we missed.

Signed-off-by: Bin Meng <bmeng.cn@xxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andreas Schwab <schwab@xxxxxxx>
Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>

---

Changes in v2:
- add SoB tag of Christoph Hellwig and Andreas Schwab
- change CSR_SATP in mm/init.c that was recently changed after v1 patch

arch/riscv/kernel/entry.S | 6 +++---
arch/riscv/kernel/fpu.S | 8 ++++----
arch/riscv/kernel/head.S | 2 +-
arch/riscv/lib/uaccess.S | 12 ++++++------
arch/riscv/mm/context.c | 7 +------
arch/riscv/mm/init.c | 2 +-
6 files changed, 16 insertions(+), 21 deletions(-)

diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index bc7a56e..74ccfd4 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -167,7 +167,7 @@ ENTRY(handle_exception)
tail do_IRQ
1:
/* Exceptions run with interrupts enabled */
- csrs sstatus, SR_SIE
+ csrs CSR_SSTATUS, SR_SIE

/* Handle syscalls */
li t0, EXC_SYSCALL
@@ -222,7 +222,7 @@ ret_from_syscall:

ret_from_exception:
REG_L s0, PT_SSTATUS(sp)
- csrc sstatus, SR_SIE
+ csrc CSR_SSTATUS, SR_SIE
andi s0, s0, SR_SPP
bnez s0, resume_kernel

@@ -265,7 +265,7 @@ work_pending:
bnez s1, work_resched
work_notifysig:
/* Handle pending signals and notify-resume requests */
- csrs sstatus, SR_SIE /* Enable interrupts for do_notify_resume() */
+ csrs CSR_SSTATUS, SR_SIE /* Enable interrupts for do_notify_resume() */
move a0, sp /* pt_regs */
move a1, s0 /* current_thread_info->flags */
tail do_notify_resume
diff --git a/arch/riscv/kernel/fpu.S b/arch/riscv/kernel/fpu.S
index 1defb06..631d315 100644
--- a/arch/riscv/kernel/fpu.S
+++ b/arch/riscv/kernel/fpu.S
@@ -23,7 +23,7 @@ ENTRY(__fstate_save)
li a2, TASK_THREAD_F0
add a0, a0, a2
li t1, SR_FS
- csrs sstatus, t1
+ csrs CSR_SSTATUS, t1
frcsr t0
fsd f0, TASK_THREAD_F0_F0(a0)
fsd f1, TASK_THREAD_F1_F0(a0)
@@ -58,7 +58,7 @@ ENTRY(__fstate_save)
fsd f30, TASK_THREAD_F30_F0(a0)
fsd f31, TASK_THREAD_F31_F0(a0)
sw t0, TASK_THREAD_FCSR_F0(a0)
- csrc sstatus, t1
+ csrc CSR_SSTATUS, t1
ret
ENDPROC(__fstate_save)

@@ -67,7 +67,7 @@ ENTRY(__fstate_restore)
add a0, a0, a2
li t1, SR_FS
lw t0, TASK_THREAD_FCSR_F0(a0)
- csrs sstatus, t1
+ csrs CSR_SSTATUS, t1
fld f0, TASK_THREAD_F0_F0(a0)
fld f1, TASK_THREAD_F1_F0(a0)
fld f2, TASK_THREAD_F2_F0(a0)
@@ -101,6 +101,6 @@ ENTRY(__fstate_restore)
fld f30, TASK_THREAD_F30_F0(a0)
fld f31, TASK_THREAD_F31_F0(a0)
fscsr t0
- csrc sstatus, t1
+ csrc CSR_SSTATUS, t1
ret
ENDPROC(__fstate_restore)
diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index 0f1ba17..86049ae 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -61,7 +61,7 @@ _start_kernel:
* floating point in kernel space
*/
li t0, SR_FS
- csrc sstatus, t0
+ csrc CSR_SSTATUS, t0

/* Pick one hart to run the main boot sequence */
la a3, hart_lottery
diff --git a/arch/riscv/lib/uaccess.S b/arch/riscv/lib/uaccess.S
index 399e6f0..ed2696c 100644
--- a/arch/riscv/lib/uaccess.S
+++ b/arch/riscv/lib/uaccess.S
@@ -18,7 +18,7 @@ ENTRY(__asm_copy_from_user)

/* Enable access to user memory */
li t6, SR_SUM
- csrs sstatus, t6
+ csrs CSR_SSTATUS, t6

add a3, a1, a2
/* Use word-oriented copy only if low-order bits match */
@@ -47,7 +47,7 @@ ENTRY(__asm_copy_from_user)

3:
/* Disable access to user memory */
- csrc sstatus, t6
+ csrc CSR_SSTATUS, t6
li a0, 0
ret
4: /* Edge case: unalignment */
@@ -72,7 +72,7 @@ ENTRY(__clear_user)

/* Enable access to user memory */
li t6, SR_SUM
- csrs sstatus, t6
+ csrs CSR_SSTATUS, t6

add a3, a0, a1
addi t0, a0, SZREG-1
@@ -94,7 +94,7 @@ ENTRY(__clear_user)

3:
/* Disable access to user memory */
- csrc sstatus, t6
+ csrc CSR_SSTATUS, t6
li a0, 0
ret
4: /* Edge case: unalignment */
@@ -114,11 +114,11 @@ ENDPROC(__clear_user)
/* Fixup code for __copy_user(10) and __clear_user(11) */
10:
/* Disable access to user memory */
- csrs sstatus, t6
+ csrs CSR_SSTATUS, t6
mv a0, a2
ret
11:
- csrs sstatus, t6
+ csrs CSR_SSTATUS, t6
mv a0, a1
ret
.previous
diff --git a/arch/riscv/mm/context.c b/arch/riscv/mm/context.c
index 89ceb3c..beeb5d7 100644
--- a/arch/riscv/mm/context.c
+++ b/arch/riscv/mm/context.c
@@ -57,12 +57,7 @@ void switch_mm(struct mm_struct *prev, struct mm_struct *next,
cpumask_clear_cpu(cpu, mm_cpumask(prev));
cpumask_set_cpu(cpu, mm_cpumask(next));

- /*
- * Use the old spbtr name instead of using the current satp
- * name to support binutils 2.29 which doesn't know about the
- * privileged ISA 1.10 yet.
- */
- csr_write(sptbr, virt_to_pfn(next->pgd) | SATP_MODE);
+ csr_write(CSR_SATP, virt_to_pfn(next->pgd) | SATP_MODE);
local_flush_tlb_all();

flush_icache_deferred(next);
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 42bf939..238fc41 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -435,7 +435,7 @@ static void __init setup_vm_final(void)
clear_fixmap(FIX_PMD);

/* Move to swapper page table */
- csr_write(sptbr, PFN_DOWN(__pa(swapper_pg_dir)) | SATP_MODE);
+ csr_write(CSR_SATP, PFN_DOWN(__pa(swapper_pg_dir)) | SATP_MODE);
local_flush_tlb_all();
}

--
2.7.4