powerpc/64e/interrupt: always save nvgprs on interrupt

In order to use the C interrupt return, nvgprs must always be saved.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210316104206.407354-3-npiggin@gmail.com

diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 95600f3..c93511b 100644 (file)
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -186,18 +186,11 @@ static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
        ((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1)
 
 #ifdef __powerpc64__
-#ifdef CONFIG_PPC_BOOK3S
 #define TRAP_FLAGS_MASK                0x10
 #define TRAP(regs)             ((regs)->trap & ~TRAP_FLAGS_MASK)
 #define FULL_REGS(regs)                true
 #define SET_FULL_REGS(regs)    do { } while (0)
-#else
-#define TRAP_FLAGS_MASK                0x11
-#define TRAP(regs)             ((regs)->trap & ~TRAP_FLAGS_MASK)
-#define FULL_REGS(regs)                (((regs)->trap & 1) == 0)
-#define SET_FULL_REGS(regs)    ((regs)->trap &= ~1)
-#endif
-#define CHECK_FULL_REGS(regs)  BUG_ON(!FULL_REGS(regs))
+#define CHECK_FULL_REGS(regs)  do { } while (0)
 #define NV_REG_POISON          0xdeadbeefdeadbeefUL
 #else
 /*

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 6c4d9e2..853534b 100644 (file)
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -417,19 +417,6 @@ _GLOBAL(ret_from_kernel_thread)
        li      r3,0
        b       .Lsyscall_exit
 
-#ifdef CONFIG_PPC_BOOK3E
-/* Save non-volatile GPRs, if not already saved. */
-_GLOBAL(save_nvgprs)
-       ld      r11,_TRAP(r1)
-       andi.   r0,r11,1
-       beqlr-
-       SAVE_NVGPRS(r1)
-       clrrdi  r0,r11,1
-       std     r0,_TRAP(r1)
-       blr
-_ASM_NOKPROBE_SYMBOL(save_nvgprs);
-#endif
-
 #ifdef CONFIG_PPC_BOOK3S_64
 
 #define FLUSH_COUNT_CACHE      \

diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index e8eb999..a7d9ce9 100644 (file)
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -417,14 +417,15 @@ exc_##n##_common:                                                     \
        std     r6,_LINK(r1);                                               \
        std     r7,_CTR(r1);                                                \
        std     r8,_XER(r1);                                                \
-       li      r3,(n)+1;               /* indicate partial regs in trap */ \
+       li      r3,(n);                 /* regs.trap vector */              \
        std     r9,0(r1);               /* store stack frame back link */   \
        std     r10,_CCR(r1);           /* store orig CR in stackframe */   \
        std     r9,GPR1(r1);            /* store stack frame back link */   \
        std     r11,SOFTE(r1);          /* and save it to stackframe */     \
        std     r12,STACK_FRAME_OVERHEAD-16(r1); /* mark the frame */       \
        std     r3,_TRAP(r1);           /* set trap number              */  \
-       std     r0,RESULT(r1);          /* clear regs->result */
+       std     r0,RESULT(r1);          /* clear regs->result */            \
+       SAVE_NVGPRS(r1);
 
 #define EXCEPTION_COMMON(n) \
        EXCEPTION_COMMON_LVL(n, SPRN_SPRG_GEN_SCRATCH, PACA_EXGEN)
@@ -561,7 +562,6 @@ __end_interrupts:
        CRIT_EXCEPTION_PROLOG(0x100, BOOKE_INTERRUPT_CRITICAL,
                              PROLOG_ADDITION_NONE)
        EXCEPTION_COMMON_CRIT(0x100)
-       bl      save_nvgprs
        bl      special_reg_save
        CHECK_NAPPING();
        addi    r3,r1,STACK_FRAME_OVERHEAD
@@ -573,7 +573,6 @@ __end_interrupts:
        MC_EXCEPTION_PROLOG(0x000, BOOKE_INTERRUPT_MACHINE_CHECK,
                            PROLOG_ADDITION_NONE)
        EXCEPTION_COMMON_MC(0x000)
-       bl      save_nvgprs
        bl      special_reg_save
        CHECK_NAPPING();
        addi    r3,r1,STACK_FRAME_OVERHEAD
@@ -623,7 +622,6 @@ __end_interrupts:
        std     r14,_DSISR(r1)
        addi    r3,r1,STACK_FRAME_OVERHEAD
        ld      r14,PACA_EXGEN+EX_R14(r13)
-       bl      save_nvgprs
        bl      program_check_exception
        b       ret_from_except
 
@@ -639,7 +637,6 @@ __end_interrupts:
        bl      load_up_fpu
        b       fast_exception_return
 1:     INTS_DISABLE
-       bl      save_nvgprs
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      kernel_fp_unavailable_exception
        b       ret_from_except
@@ -661,7 +658,6 @@ BEGIN_FTR_SECTION
 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 #endif
        INTS_DISABLE
-       bl      save_nvgprs
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      altivec_unavailable_exception
        b       ret_from_except
@@ -673,7 +669,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
                                PROLOG_ADDITION_NONE)
        EXCEPTION_COMMON(0x220)
        INTS_DISABLE
-       bl      save_nvgprs
        addi    r3,r1,STACK_FRAME_OVERHEAD
 #ifdef CONFIG_ALTIVEC
 BEGIN_FTR_SECTION
@@ -698,7 +693,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
        CRIT_EXCEPTION_PROLOG(0x9f0, BOOKE_INTERRUPT_WATCHDOG,
                              PROLOG_ADDITION_NONE)
        EXCEPTION_COMMON_CRIT(0x9f0)
-       bl      save_nvgprs
        bl      special_reg_save
        CHECK_NAPPING();
        addi    r3,r1,STACK_FRAME_OVERHEAD
@@ -723,7 +717,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
                                PROLOG_ADDITION_NONE)
        EXCEPTION_COMMON(0xf20)
        INTS_DISABLE
-       bl      save_nvgprs
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      unknown_exception
        b       ret_from_except
@@ -792,7 +785,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
        addi    r3,r1,STACK_FRAME_OVERHEAD
        ld      r14,PACA_EXCRIT+EX_R14(r13)
        ld      r15,PACA_EXCRIT+EX_R15(r13)
-       bl      save_nvgprs
        bl      DebugException
        b       ret_from_except
 
@@ -864,7 +856,6 @@ kernel_dbg_exc:
        addi    r3,r1,STACK_FRAME_OVERHEAD
        ld      r14,PACA_EXDBG+EX_R14(r13)
        ld      r15,PACA_EXDBG+EX_R15(r13)
-       bl      save_nvgprs
        bl      DebugException
        b       ret_from_except
 
@@ -887,7 +878,6 @@ kernel_dbg_exc:
        CRIT_EXCEPTION_PROLOG(0x2a0, BOOKE_INTERRUPT_DOORBELL_CRITICAL,
                              PROLOG_ADDITION_NONE)
        EXCEPTION_COMMON_CRIT(0x2a0)
-       bl      save_nvgprs
        bl      special_reg_save
        CHECK_NAPPING();
        addi    r3,r1,STACK_FRAME_OVERHEAD
@@ -903,7 +893,6 @@ kernel_dbg_exc:
                                PROLOG_ADDITION_NONE)
        EXCEPTION_COMMON(0x2c0)
        addi    r3,r1,STACK_FRAME_OVERHEAD
-       bl      save_nvgprs
        INTS_RESTORE_HARD
        bl      unknown_exception
        b       ret_from_except
@@ -913,7 +902,6 @@ kernel_dbg_exc:
        CRIT_EXCEPTION_PROLOG(0x2e0, BOOKE_INTERRUPT_GUEST_DBELL_CRIT,
                              PROLOG_ADDITION_NONE)
        EXCEPTION_COMMON_CRIT(0x2e0)
-       bl      save_nvgprs
        bl      special_reg_save
        CHECK_NAPPING();
        addi    r3,r1,STACK_FRAME_OVERHEAD
@@ -926,7 +914,6 @@ kernel_dbg_exc:
                                PROLOG_ADDITION_NONE)
        EXCEPTION_COMMON(0x310)
        addi    r3,r1,STACK_FRAME_OVERHEAD
-       bl      save_nvgprs
        INTS_RESTORE_HARD
        bl      unknown_exception
        b       ret_from_except
@@ -937,7 +924,6 @@ kernel_dbg_exc:
                                PROLOG_ADDITION_NONE)
        EXCEPTION_COMMON(0x320)
        addi    r3,r1,STACK_FRAME_OVERHEAD
-       bl      save_nvgprs
        INTS_RESTORE_HARD
        bl      unknown_exception
        b       ret_from_except
@@ -948,7 +934,6 @@ kernel_dbg_exc:
                                PROLOG_ADDITION_NONE)
        EXCEPTION_COMMON(0x340)
        addi    r3,r1,STACK_FRAME_OVERHEAD
-       bl      save_nvgprs
        INTS_RESTORE_HARD
        bl      unknown_exception
        b       ret_from_except
@@ -1014,7 +999,6 @@ storage_fault_common:
        cmpdi   r3,0
        bne-    1f
        b       ret_from_except_lite
-1:     bl      save_nvgprs
        mr      r4,r3
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      __bad_page_fault
@@ -1030,16 +1014,12 @@ alignment_more:
        addi    r3,r1,STACK_FRAME_OVERHEAD
        ld      r14,PACA_EXGEN+EX_R14(r13)
        ld      r15,PACA_EXGEN+EX_R15(r13)
-       bl      save_nvgprs
        INTS_RESTORE_HARD
        bl      alignment_exception
        b       ret_from_except
 
        .align  7
 _GLOBAL(ret_from_except)
-       ld      r11,_TRAP(r1)
-       andi.   r0,r11,1
-       bne     ret_from_except_lite
        REST_NVGPRS(r1)
 
 _GLOBAL(ret_from_except_lite)
@@ -1080,7 +1060,6 @@ _GLOBAL(ret_from_except_lite)
        SCHEDULE_USER
        b       ret_from_except_lite
 2:
-       bl      save_nvgprs
        /*
         * Use a non volatile GPR to save and restore our thread_info flags
         * across the call to restore_interrupts.