From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
npiggin@gmail.com
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [RFC PATCH v1 06/41] powerpc/40x: Prepare for enabling MMU in critical exception prolog
Date: Tue, 9 Feb 2021 09:56:30 +0000 (UTC) [thread overview]
Message-ID: <2391e6e333c7f2a170244e1d298e1639d6e3159d.1612864003.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <cover.1612864003.git.christophe.leroy@csgroup.eu>
In order the enable MMU early in exception prolog, implement
CONFIG_VMAP_STACK principles in critical exception prolog.
There is no intention to use CONFIG_VMAP_STACK on 40x,
but related code will be used to enable MMU early in exception
in a later patch.
Also address (critirq_ctx-PAGE_OFFSET) directly instead of
using tophys() in order to win one instruction.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_40x.S | 40 +++++++++++++++++++++++++++++++---
1 file changed, 37 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 5b337bf49bcb..1468f38c3860 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -89,6 +89,12 @@ _ENTRY(crit_srr0)
.space 4
_ENTRY(crit_srr1)
.space 4
+_ENTRY(crit_r1)
+ .space 4
+_ENTRY(crit_dear)
+ .space 4
+_ENTRY(crit_esr)
+ .space 4
_ENTRY(saved_ksp_limit)
.space 4
@@ -107,32 +113,60 @@ _ENTRY(saved_ksp_limit)
mfspr r11,SPRN_SRR1
stw r10,crit_srr0@l(0)
stw r11,crit_srr1@l(0)
+#ifdef CONFIG_VMAP_STACK
+ mfspr r10,SPRN_DEAR
+ mfspr r11,SPRN_ESR
+ stw r10,crit_dear@l(0)
+ stw r11,crit_esr@l(0)
+#endif
mfcr r10 /* save CR in r10 for now */
mfspr r11,SPRN_SRR3 /* check whether user or kernel */
andi. r11,r11,MSR_PR
- lis r11,critirq_ctx@ha
- tophys(r11,r11)
- lwz r11,critirq_ctx@l(r11)
+ lis r11,(critirq_ctx-PAGE_OFFSET)@ha
+ lwz r11,(critirq_ctx-PAGE_OFFSET)@l(r11)
beq 1f
/* COMING FROM USER MODE */
mfspr r11,SPRN_SPRG_THREAD /* if from user, start at top of */
lwz r11,TASK_STACK-THREAD(r11) /* this thread's kernel stack */
+#ifdef CONFIG_VMAP_STACK
+1: stw r1,crit_r1@l(0)
+ addi r1,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm */
+ LOAD_REG_IMMEDIATE(r11,MSR_KERNEL & ~(MSR_IR | MSR_RI))
+ mtmsr r11
+ isync
+ lwz r11,crit_r1@l(0)
+ stw r11,GPR1(r1)
+ stw r11,0(r1)
+ mr r11,r1
+#else
1: addi r11,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm */
tophys(r11,r11)
stw r1,GPR1(r11)
stw r1,0(r11)
tovirt(r1,r11)
+#endif
stw r10,_CCR(r11) /* save various registers */
stw r12,GPR12(r11)
stw r9,GPR9(r11)
mflr r10
stw r10,_LINK(r11)
+#ifdef CONFIG_VMAP_STACK
+ lis r9,PAGE_OFFSET@ha
+ lwz r10,crit_r10@l(r9)
+ lwz r12,crit_r11@l(r9)
+#else
lwz r10,crit_r10@l(0)
lwz r12,crit_r11@l(0)
+#endif
stw r10,GPR10(r11)
stw r12,GPR11(r11)
+#ifdef CONFIG_VMAP_STACK
+ lwz r12,crit_dear@l(r9)
+ lwz r9,crit_esr@l(r9)
+#else
mfspr r12,SPRN_DEAR /* save DEAR and ESR in the frame */
mfspr r9,SPRN_ESR /* in them at the point where the */
+#endif
stw r12,_DEAR(r11) /* since they may have had stuff */
stw r9,_ESR(r11) /* exception was taken */
mfspr r12,SPRN_SRR2
--
2.25.0
next prev parent reply other threads:[~2021-02-09 10:03 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-09 9:56 [RFC PATCH v1 00/41] powerpc/32: Switch to interrupt entry/exit in C Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 01/41] powerpc/32: Preserve cr1 in exception prolog stack check to fix build error Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 02/41] powerpc/40x: Don't use SPRN_SPRG_SCRATCH0/1 in TLB miss handlers Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 03/41] powerpc/40x: Change CRITICAL_EXCEPTION_PROLOG macro to a gas macro Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 04/41] powerpc/40x: Save SRR0/SRR1 and r10/r11 earlier in critical exception Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 05/41] powerpc/40x: Reorder a few instructions in critical exception prolog Christophe Leroy
2021-02-09 9:56 ` Christophe Leroy [this message]
2021-02-09 9:56 ` [RFC PATCH v1 07/41] powerpc/40x: Prepare normal exception handler for enabling MMU early Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 08/41] powerpc/32: Reconcile interrupts in C Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 09/41] powerpc/32: Entry cpu time accounting " Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 10/41] powerpc/32: Handle bookE debugging in C in exception entry Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 11/41] powerpc/32: Use fast instruction to set MSR RI in exception prolog on 8xx Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 12/41] powerpc/32: Remove ksp_limit Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 13/41] powerpc/32: Always enable data translation in exception prolog Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 14/41] powerpc/32: Tag DAR in EXCEPTION_PROLOG_2 for the 8xx Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 15/41] powerpc/32: Enable instruction translation at the same time as data translation Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 16/41] powerpc/32: Statically initialise first emergency context Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 17/41] powerpc/32: Add vmap_stack_overflow label inside the macro Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 18/41] powerpc/32: Use START_EXCEPTION() as much as possible Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 19/41] powerpc/32: Move exception prolog code into .text once MMU is back on Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 20/41] powerpc/32: Provide a name to exception prolog continuation in virtual mode Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 21/41] powerpc/32: Refactor booke critical registers saving Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 22/41] powerpc/32: Perform normal function call in exception entry Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 23/41] powerpc/32: Always save non volatile registers on " Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 24/41] powerpc/32: Replace ASM exception exit by C exception exit from ppc64 Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 25/41] powerpc/32: Set regs parameter in r3 in transfer_to_handler Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 26/41] powerpc/32: Remove handle_page_fault() Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 27/41] powerpc/32: Save trap number on stack in exception prolog Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 28/41] powerpc/32: Add a prepare_transfer_to_handler macro for exception prologs Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 29/41] powerpc/32: Only restore non volatile registers when required Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 30/41] powerpc/32: Dismantle EXC_XFER_STD/LITE/TEMPLATE Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 31/41] powerpc/32: Remove the xfer parameter in EXCEPTION() macro Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 32/41] powerpc/32: Refactor saving of volatile registers in exception prologs Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 33/41] powerpc/32: Save remaining registers in exception prolog Christophe Leroy
2021-02-09 9:56 ` [RFC PATCH v1 34/41] powerpc/32: Set current->thread.regs in C interrupt entry Christophe Leroy
2021-02-09 9:57 ` [RFC PATCH v1 35/41] powerpc/32: Return directly from power_save_ppc32_restore() Christophe Leroy
2021-02-09 9:57 ` [RFC PATCH v1 36/41] powerpc/32: Only use prepare_transfer_to_handler function on book3s/32 and e500 Christophe Leroy
2021-02-09 9:57 ` [RFC PATCH v1 37/41] powerpc/32s: Move KUEP locking/unlocking in C Christophe Leroy
2021-02-09 9:57 ` [RFC PATCH v1 38/41] powerpc/64s: Make kuap_check_amr() and kuap_get_and_check_amr() generic Christophe Leroy
2021-02-09 9:57 ` [RFC PATCH v1 39/41] powerpc/32s: Create C version of kuap save/restore/check helpers Christophe Leroy
2021-02-09 9:57 ` [RFC PATCH v1 40/41] powerpc/8xx: " Christophe Leroy
2021-02-09 9:57 ` [RFC PATCH v1 41/41] powerpc/32: Manage KUAP in C Christophe Leroy
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