* [PATCH v2 2/3] powerpc: Replace RFI by rfi on book3s/32 and booke
2020-11-08 16:57 [PATCH v2 1/3] powerpc/64s: Replace RFI by RFI_TO_KERNEL and remove RFI Christophe Leroy
@ 2020-11-08 16:57 ` Christophe Leroy
2020-11-08 16:57 ` [PATCH v2 3/3] powerpc: Remove RFI macro Christophe Leroy
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Christophe Leroy @ 2020-11-08 16:57 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
Cc: linux-kernel, linuxppc-dev
For book3s/32 and for booke, RFI is just an rfi.
Only 40x has a non trivial RFI.
CONFIG_PPC_RTAS is never selected by 40x platforms.
Make it more explicit by replacing RFI by rfi wherever possible.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/entry_32.S | 6 +++---
arch/powerpc/kernel/head_book3s_32.S | 18 +++++++++---------
arch/powerpc/kernel/head_booke.h | 2 +-
arch/powerpc/kvm/book3s_rmhandlers.S | 4 ++--
4 files changed, 15 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 8cdc8bcde703..e10e1167ffb1 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -1027,7 +1027,7 @@ exc_exit_restart:
lwz r1,GPR1(r1)
.globl exc_exit_restart_end
exc_exit_restart_end:
- RFI
+ rfi
_ASM_NOKPROBE_SYMBOL(exc_exit_restart)
_ASM_NOKPROBE_SYMBOL(exc_exit_restart_end)
@@ -1356,7 +1356,7 @@ _GLOBAL(enter_rtas)
stw r7, THREAD + RTAS_SP(r2)
mtspr SPRN_SRR0,r8
mtspr SPRN_SRR1,r9
- RFI
+ rfi
1: tophys_novmstack r9, r1
#ifdef CONFIG_VMAP_STACK
li r0, MSR_KERNEL & ~MSR_IR /* can take DTLB miss */
@@ -1371,6 +1371,6 @@ _GLOBAL(enter_rtas)
stw r0, THREAD + RTAS_SP(r7)
mtspr SPRN_SRR0,r8
mtspr SPRN_SRR1,r9
- RFI /* return to caller */
+ rfi /* return to caller */
_ASM_NOKPROBE_SYMBOL(enter_rtas)
#endif /* CONFIG_PPC_RTAS */
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 5eb9eedac920..40e8c8ce4018 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -206,7 +206,7 @@ turn_on_mmu:
lis r0,start_here@h
ori r0,r0,start_here@l
mtspr SPRN_SRR0,r0
- RFI /* enables MMU */
+ rfi /* enables MMU */
/*
* We need __secondary_hold as a place to hold the other cpus on
@@ -769,13 +769,13 @@ fast_hash_page_return:
mtcr r11
lwz r11, THR11(r10)
mfspr r10, SPRN_SPRG_SCRATCH0
- RFI
+ rfi
1: /* ISI */
mtcr r11
mfspr r11, SPRN_SPRG_SCRATCH1
mfspr r10, SPRN_SPRG_SCRATCH0
- RFI
+ rfi
stack_overflow:
vmap_stack_overflow_exception
@@ -910,7 +910,7 @@ __secondary_start:
ori r3,r3,start_secondary@l
mtspr SPRN_SRR0,r3
mtspr SPRN_SRR1,r4
- RFI
+ rfi
#endif /* CONFIG_SMP */
#ifdef CONFIG_KVM_BOOK3S_HANDLER
@@ -1038,7 +1038,7 @@ start_here:
.align 4
mtspr SPRN_SRR0,r4
mtspr SPRN_SRR1,r3
- RFI
+ rfi
/* Load up the kernel context */
2: bl load_up_mmu
@@ -1062,7 +1062,7 @@ start_here:
ori r3,r3,start_kernel@l
mtspr SPRN_SRR0,r3
mtspr SPRN_SRR1,r4
- RFI
+ rfi
/*
* void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next);
@@ -1177,7 +1177,7 @@ _ENTRY(update_bats)
.align 4
mtspr SPRN_SRR0, r4
mtspr SPRN_SRR1, r3
- RFI
+ rfi
1: bl clear_bats
lis r3, BATS@ha
addi r3, r3, BATS@l
@@ -1196,7 +1196,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
mtmsr r3
mtspr SPRN_SRR0, r7
mtspr SPRN_SRR1, r6
- RFI
+ rfi
flush_tlbs:
lis r10, 0x40
@@ -1217,7 +1217,7 @@ mmu_off:
mtspr SPRN_SRR0,r4
mtspr SPRN_SRR1,r3
sync
- RFI
+ rfi
/* We use one BAT to map up to 256M of RAM at _PAGE_OFFSET */
initial_bats:
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 71c359d438b5..e26d35de27e5 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -176,7 +176,7 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
#endif
mtspr SPRN_SRR1,r10
mtspr SPRN_SRR0,r11
- RFI /* jump to handler, enable MMU */
+ rfi /* jump to handler, enable MMU */
99: b ret_from_kernel_syscall
.endm
diff --git a/arch/powerpc/kvm/book3s_rmhandlers.S b/arch/powerpc/kvm/book3s_rmhandlers.S
index 3dc129a254b5..b45b750fa77a 100644
--- a/arch/powerpc/kvm/book3s_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_rmhandlers.S
@@ -36,8 +36,8 @@
#define FUNC(name) name
-#define RFI_TO_KERNEL RFI
-#define RFI_TO_GUEST RFI
+#define RFI_TO_KERNEL rfi
+#define RFI_TO_GUEST rfi
.macro INTERRUPT_TRAMPOLINE intno
--
2.25.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH v2 3/3] powerpc: Remove RFI macro
2020-11-08 16:57 [PATCH v2 1/3] powerpc/64s: Replace RFI by RFI_TO_KERNEL and remove RFI Christophe Leroy
2020-11-08 16:57 ` [PATCH v2 2/3] powerpc: Replace RFI by rfi on book3s/32 and booke Christophe Leroy
@ 2020-11-08 16:57 ` Christophe Leroy
2020-11-10 8:45 ` [PATCH v2 1/3] powerpc/64s: Replace RFI by RFI_TO_KERNEL and remove RFI Nicholas Piggin
2020-11-25 11:57 ` Michael Ellerman
3 siblings, 0 replies; 5+ messages in thread
From: Christophe Leroy @ 2020-11-08 16:57 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
Cc: linux-kernel, linuxppc-dev
RFI macro is just there to add an infinite loop past
rfi in order to avoid prefetch on 40x in half a dozen
of places in entry_32 and head_32.
Those places are already full of #ifdefs, so just add a
few more to explicitely show those loops and remove RFI.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/include/asm/ppc_asm.h | 5 -----
arch/powerpc/kernel/entry_32.S | 30 ++++++++++++++++++++++++------
arch/powerpc/kernel/head_32.h | 5 ++++-
3 files changed, 28 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index bedf3eb52ebc..101986d4a29d 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -498,11 +498,6 @@ END_FTR_SECTION_NESTED(CPU_FTR_CELL_TB_BUG, CPU_FTR_CELL_TB_BUG, 96)
#define MTMSRD(r) mtmsrd r
#define MTMSR_EERI(reg) mtmsrd reg,1
#else
-#ifndef CONFIG_40x
-#define RFI rfi
-#else
-#define RFI rfi; b . /* Prevent prefetch past rfi */
-#endif
#define MTMSRD(r) mtmsr r
#define MTMSR_EERI(reg) mtmsr reg
#endif
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index e10e1167ffb1..c7c28e8acc10 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -234,7 +234,10 @@ transfer_to_handler_cont:
mtspr SPRN_SRR0,r11
mtspr SPRN_SRR1,r10
mtlr r9
- RFI /* jump to handler, enable MMU */
+ rfi /* jump to handler, enable MMU */
+#ifdef CONFIG_40x
+ b . /* Prevent prefetch past rfi */
+#endif
#if defined (CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500)
4: rlwinm r12,r12,0,~_TLF_NAPPING
@@ -263,7 +266,10 @@ _ASM_NOKPROBE_SYMBOL(transfer_to_handler_cont)
LOAD_REG_IMMEDIATE(r0, MSR_KERNEL)
mtspr SPRN_SRR0,r12
mtspr SPRN_SRR1,r0
- RFI
+ rfi
+#ifdef CONFIG_40x
+ b . /* Prevent prefetch past rfi */
+#endif
reenable_mmu:
/*
@@ -321,7 +327,10 @@ stack_ovf:
#endif
mtspr SPRN_SRR0,r9
mtspr SPRN_SRR1,r10
- RFI
+ rfi
+#ifdef CONFIG_40x
+ b . /* Prevent prefetch past rfi */
+#endif
_ASM_NOKPROBE_SYMBOL(stack_ovf)
#endif
@@ -470,7 +479,10 @@ syscall_exit_finish:
#endif
mtspr SPRN_SRR0,r7
mtspr SPRN_SRR1,r8
- RFI
+ rfi
+#ifdef CONFIG_40x
+ b . /* Prevent prefetch past rfi */
+#endif
_ASM_NOKPROBE_SYMBOL(syscall_exit_finish)
#ifdef CONFIG_44x
2: li r7,0
@@ -600,7 +612,10 @@ ret_from_kernel_syscall:
#endif
mtspr SPRN_SRR0, r9
mtspr SPRN_SRR1, r10
- RFI
+ rfi
+#ifdef CONFIG_40x
+ b . /* Prevent prefetch past rfi */
+#endif
_ASM_NOKPROBE_SYMBOL(ret_from_kernel_syscall)
/*
@@ -803,7 +818,10 @@ fast_exception_return:
REST_GPR(9, r11)
REST_GPR(12, r11)
lwz r11,GPR11(r11)
- RFI
+ rfi
+#ifdef CONFIG_40x
+ b . /* Prevent prefetch past rfi */
+#endif
_ASM_NOKPROBE_SYMBOL(fast_exception_return)
#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 7c767765071d..232000742c9a 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -222,7 +222,10 @@
#endif
mtspr SPRN_SRR1,r10
mtspr SPRN_SRR0,r11
- RFI /* jump to handler, enable MMU */
+ rfi /* jump to handler, enable MMU */
+#ifdef CONFIG_40x
+ b . /* Prevent prefetch past rfi */
+#endif
99: b ret_from_kernel_syscall
.endm
--
2.25.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v2 1/3] powerpc/64s: Replace RFI by RFI_TO_KERNEL and remove RFI
2020-11-08 16:57 [PATCH v2 1/3] powerpc/64s: Replace RFI by RFI_TO_KERNEL and remove RFI Christophe Leroy
2020-11-08 16:57 ` [PATCH v2 2/3] powerpc: Replace RFI by rfi on book3s/32 and booke Christophe Leroy
2020-11-08 16:57 ` [PATCH v2 3/3] powerpc: Remove RFI macro Christophe Leroy
@ 2020-11-10 8:45 ` Nicholas Piggin
2020-11-25 11:57 ` Michael Ellerman
3 siblings, 0 replies; 5+ messages in thread
From: Nicholas Piggin @ 2020-11-10 8:45 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Christophe Leroy, Michael Ellerman,
Paul Mackerras
Cc: linux-kernel, linuxppc-dev
Excerpts from Christophe Leroy's message of November 9, 2020 2:57 am:
> In head_64.S, we have two places using RFI to return to
> kernel. Use RFI_TO_KERNEL instead.
>
> They are the two only places using RFI on book3s/64, so
> the RFI macro can go away.
Looks good to me.
Acked-by: Nicholas Piggin <npiggin@gmail.com>
>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
> arch/powerpc/include/asm/ppc_asm.h | 1 -
> arch/powerpc/kernel/head_64.S | 9 +++++++--
> 2 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
> index 511786f0e40d..bedf3eb52ebc 100644
> --- a/arch/powerpc/include/asm/ppc_asm.h
> +++ b/arch/powerpc/include/asm/ppc_asm.h
> @@ -495,7 +495,6 @@ END_FTR_SECTION_NESTED(CPU_FTR_CELL_TB_BUG, CPU_FTR_CELL_TB_BUG, 96)
> #endif
>
> #ifdef CONFIG_PPC_BOOK3S_64
> -#define RFI rfid
> #define MTMSRD(r) mtmsrd r
> #define MTMSR_EERI(reg) mtmsrd reg,1
> #else
> diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
> index 1510b2a56669..ecf9a88988ff 100644
> --- a/arch/powerpc/kernel/head_64.S
> +++ b/arch/powerpc/kernel/head_64.S
> @@ -41,6 +41,11 @@
> #include <asm/ppc-opcode.h>
> #include <asm/export.h>
> #include <asm/feature-fixups.h>
> +#ifdef CONFIG_PPC_BOOK3S
> +#include <asm/exception-64s.h>
> +#else
> +#include <asm/exception-64e.h>
> +#endif
>
> /* The physical memory is laid out such that the secondary processor
> * spin code sits at 0x0000...0x00ff. On server, the vectors follow
> @@ -829,7 +834,7 @@ __secondary_start:
>
> mtspr SPRN_SRR0,r3
> mtspr SPRN_SRR1,r4
> - RFI
> + RFI_TO_KERNEL
> b . /* prevent speculative execution */
>
> /*
> @@ -966,7 +971,7 @@ start_here_multiplatform:
> ld r4,PACAKMSR(r13)
> mtspr SPRN_SRR0,r3
> mtspr SPRN_SRR1,r4
> - RFI
> + RFI_TO_KERNEL
> b . /* prevent speculative execution */
>
> /* This is where all platforms converge execution */
> --
> 2.25.0
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2 1/3] powerpc/64s: Replace RFI by RFI_TO_KERNEL and remove RFI
2020-11-08 16:57 [PATCH v2 1/3] powerpc/64s: Replace RFI by RFI_TO_KERNEL and remove RFI Christophe Leroy
` (2 preceding siblings ...)
2020-11-10 8:45 ` [PATCH v2 1/3] powerpc/64s: Replace RFI by RFI_TO_KERNEL and remove RFI Nicholas Piggin
@ 2020-11-25 11:57 ` Michael Ellerman
3 siblings, 0 replies; 5+ messages in thread
From: Michael Ellerman @ 2020-11-25 11:57 UTC (permalink / raw)
To: Christophe Leroy, Michael Ellerman, Benjamin Herrenschmidt,
Paul Mackerras
Cc: linux-kernel, linuxppc-dev
On Sun, 8 Nov 2020 16:57:35 +0000 (UTC), Christophe Leroy wrote:
> In head_64.S, we have two places using RFI to return to
> kernel. Use RFI_TO_KERNEL instead.
>
> They are the two only places using RFI on book3s/64, so
> the RFI macro can go away.
Applied to powerpc/next.
[1/3] powerpc/64s: Replace RFI by RFI_TO_KERNEL and remove RFI
https://git.kernel.org/powerpc/c/879add7720172ffd2986c44587510fabb7af52f5
[2/3] powerpc: Replace RFI by rfi on book3s/32 and booke
https://git.kernel.org/powerpc/c/120c0518ec321f33cdc4670059fb76e96ceb56eb
[3/3] powerpc: Remove RFI macro
https://git.kernel.org/powerpc/c/62182e6c0faf75117f8d1719c118bb5fc8574012
cheers
^ permalink raw reply [flat|nested] 5+ messages in thread