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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: [PATCH v3 06/41] powerpc/40x: Prepare for enabling MMU in critical exception prolog
Date: Fri, 12 Mar 2021 12:50:15 +0000 (UTC)	[thread overview]
Message-ID: <3fd75ee54c48307119acdbf66cfea966c1463bbd.1615552866.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <cover.1615552866.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


  parent reply	other threads:[~2021-03-12 12:51 UTC|newest]

Thread overview: 53+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-12 12:50 [PATCH v3 00/41] powerpc/32: Switch to interrupt entry/exit in C Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 01/41] powerpc/traps: Declare unrecoverable_exception() as __noreturn Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 02/41] powerpc/40x: Don't use SPRN_SPRG_SCRATCH0/1 in TLB miss handlers Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 03/41] powerpc/40x: Change CRITICAL_EXCEPTION_PROLOG macro to a gas macro Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 04/41] powerpc/40x: Save SRR0/SRR1 and r10/r11 earlier in critical exception Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 05/41] powerpc/40x: Reorder a few instructions in critical exception prolog Christophe Leroy
2021-03-12 12:50 ` Christophe Leroy [this message]
2021-03-12 12:50 ` [PATCH v3 07/41] powerpc/40x: Prepare normal exception handler for enabling MMU early Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 08/41] powerpc/32: Reconcile interrupts in C Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 09/41] powerpc/32: Entry cpu time accounting " Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 10/41] powerpc/32: Handle bookE debugging in C in exception entry Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 11/41] powerpc/32: Use fast instruction to set MSR RI in exception prolog on 8xx Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 12/41] powerpc/32: Remove ksp_limit Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 13/41] powerpc/32: Always enable data translation in exception prolog Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 14/41] powerpc/32: Tag DAR in EXCEPTION_PROLOG_2 for the 8xx Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 15/41] powerpc/32: Enable instruction translation at the same time as data translation Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 16/41] powerpc/32: Statically initialise first emergency context Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 17/41] powerpc/32: Add vmap_stack_overflow label inside the macro Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 18/41] powerpc/32: Use START_EXCEPTION() as much as possible Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 19/41] powerpc/32: Move exception prolog code into .text once MMU is back on Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 20/41] powerpc/32: Provide a name to exception prolog continuation in virtual mode Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 21/41] powerpc/32: Refactor booke critical registers saving Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 22/41] powerpc/32: Perform normal function call in exception entry Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 23/41] powerpc/32: Always save non volatile registers on " Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 24/41] powerpc/32: Replace ASM exception exit by C exception exit from ppc64 Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 25/41] powerpc/32: Don't save thread.regs on interrupt entry Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 26/41] powerpc/32: Set regs parameter in r3 in transfer_to_handler Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 27/41] powerpc/32: Call bad_page_fault() from do_page_fault() Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 28/41] powerpc/32: Save trap number on stack in exception prolog Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 29/41] powerpc/32: Add a prepare_transfer_to_handler macro for exception prologs Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 30/41] powerpc/32: Only restore non volatile registers when required Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 31/41] powerpc/32: Dismantle EXC_XFER_STD/LITE/TEMPLATE Christophe Leroy
2021-07-31 10:12   ` Finn Thain
2021-07-31 15:39     ` Christophe Leroy
2021-08-01  1:21       ` Finn Thain
     [not found]         ` <34e52975-4ab9-4eb4-3501-02376e38a27c@yahoo.com>
2021-08-01 23:48           ` Finn Thain
2021-08-02 15:19         ` LEROY Christophe
2021-08-03  0:43           ` Finn Thain
     [not found]           ` <62d36dbb-4b39-f5bd-7962-4dcfbea729b3@linux-m68k.org>
     [not found]             ` <683c8156-97b0-5ba7-ce31-2e8613089836@yahoo.com>
2021-08-04  4:57               ` Finn Thain
2021-07-31 16:40     ` Christophe Leroy
2021-08-01  1:39       ` Finn Thain
2021-03-12 12:50 ` [PATCH v3 32/41] powerpc/32: Remove the xfer parameter in EXCEPTION() macro Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 33/41] powerpc/32: Refactor saving of volatile registers in exception prologs Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 34/41] powerpc/32: Save remaining registers in exception prolog Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 35/41] powerpc/32: Return directly from power_save_ppc32_restore() Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 36/41] powerpc/32: Only use prepare_transfer_to_handler function on book3s/32 and e500 Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 37/41] powerpc/32s: Move KUEP locking/unlocking in C Christophe Leroy
2021-03-27 17:24   ` Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 38/41] powerpc/64s: Make kuap_check_amr() and kuap_get_and_check_amr() generic Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 39/41] powerpc/32s: Create C version of kuap save/restore/check helpers Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 40/41] powerpc/8xx: " Christophe Leroy
2021-03-12 12:50 ` [PATCH v3 41/41] powerpc/32: Manage KUAP in C Christophe Leroy
2021-03-31  1:09 ` [PATCH v3 00/41] powerpc/32: Switch to interrupt entry/exit " Michael Ellerman

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