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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, msuchanek@suse.de
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v5 22/22] powerpc/32: Handle bookE debugging in C in syscall entry/exit
Date: Mon,  8 Feb 2021 15:10:42 +0000 (UTC)	[thread overview]
Message-ID: <f942059e5b0dc6366f23b7aca70dfcb29efeaf2a.1612796617.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <cover.1612796617.git.christophe.leroy@csgroup.eu>

The handling of SPRN_DBCR0 and other registers can easily
be done in C instead of ASM.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
v5: New
---
 arch/powerpc/include/asm/reg_booke.h |  3 +++
 arch/powerpc/kernel/entry_32.S       |  7 -------
 arch/powerpc/kernel/head_32.h        | 15 --------------
 arch/powerpc/kernel/head_booke.h     | 19 ------------------
 arch/powerpc/kernel/interrupt.c      | 29 +++++++++++++++++++++++++++-
 5 files changed, 31 insertions(+), 42 deletions(-)

diff --git a/arch/powerpc/include/asm/reg_booke.h b/arch/powerpc/include/asm/reg_booke.h
index 262782f08fd4..17b8dcd9a40d 100644
--- a/arch/powerpc/include/asm/reg_booke.h
+++ b/arch/powerpc/include/asm/reg_booke.h
@@ -691,6 +691,9 @@
 #define mttmr(rn, v)	asm volatile(MTTMR(rn, %0) : \
 				     : "r" ((unsigned long)(v)) \
 				     : "memory")
+
+extern unsigned long global_dbcr0[];
+
 #endif /* !__ASSEMBLY__ */
 
 #endif /* __ASM_POWERPC_REG_BOOKE_H__ */
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index a574201b0eb6..8dea4d3b1d06 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -342,13 +342,6 @@ transfer_to_syscall:
 ret_from_syscall:
 	addi    r4,r1,STACK_FRAME_OVERHEAD
 	bl	syscall_exit_prepare
-#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
-	/* If the process has its own DBCR0 value, load it up.  The internal
-	   debug mode bit tells us that dbcr0 should be loaded. */
-	lwz	r0,THREAD+THREAD_DBCR0(r2)
-	andis.	r10,r0,DBCR0_IDM@h
-	bnel-	load_dbcr0
-#endif
 #ifdef CONFIG_PPC_47x
 	lis	r4,icache_44x_need_flush@ha
 	lwz	r5,icache_44x_need_flush@l(r4)
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 5001c6ecc3ec..961b1ce3b6bf 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -153,21 +153,6 @@
 	SAVE_4GPRS(3, r11)
 	SAVE_2GPRS(7, r11)
 	addi	r2,r12,-THREAD
-#if defined(CONFIG_40x)
-	/* Check to see if the dbcr0 register is set up to debug.  Use the
-	   internal debug mode bit to do this. */
-	lwz	r12,THREAD_DBCR0(r12)
-	andis.	r12,r12,DBCR0_IDM@h
-	beq+	3f
-	/* From user and task is ptraced - load up global dbcr0 */
-	li	r12,-1			/* clear all pending debug events */
-	mtspr	SPRN_DBSR,r12
-	lis	r11,global_dbcr0@ha
-	addi	r11,r11,global_dbcr0@l
-	lwz	r12,0(r11)
-	mtspr	SPRN_DBCR0,r12
-3:
-#endif
 	b	transfer_to_syscall		/* jump to handler */
 .endm
 
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 5f565232b99d..47857795f50a 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -130,25 +130,6 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
 	SAVE_2GPRS(7, r11)
 
 	addi	r2,r10,-THREAD
-	/* Check to see if the dbcr0 register is set up to debug.  Use the
-	   internal debug mode bit to do this. */
-	lwz	r12,THREAD_DBCR0(r10)
-	andis.	r12,r12,DBCR0_IDM@h
-	beq+	3f
-	/* From user and task is ptraced - load up global dbcr0 */
-	li	r12,-1			/* clear all pending debug events */
-	mtspr	SPRN_DBSR,r12
-	lis	r11,global_dbcr0@ha
-	addi	r11,r11,global_dbcr0@l
-#ifdef CONFIG_SMP
-	lwz	r10, TASK_CPU(r2)
-	slwi	r10, r10, 2
-	add	r11, r11, r10
-#endif
-	lwz	r12,0(r11)
-	mtspr	SPRN_DBCR0,r12
-
-3:
 	b	transfer_to_syscall	/* jump to handler */
 .endm
 
diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index c89a8eac3e24..6111acf61373 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c
@@ -76,6 +76,13 @@ notrace long system_call_exception(long r3, long r4, long r5,
 		kuap_check_amr();
 #endif
 
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+	if (IS_ENABLED(CONFIG_PPC32) && unlikely(current->thread.debug.dbcr0 & DBCR0_IDM)) {
+		mtspr(SPRN_DBSR, -1);
+		mtspr(SPRN_DBCR0, global_dbcr0[smp_processor_id()]);
+	}
+#endif
+
 	account_cpu_user_entry();
 
 	account_stolen_time();
@@ -324,6 +331,22 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
 	local_paca->tm_scratch = regs->msr;
 #endif
 
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+	if (unlikely(current->thread.debug.dbcr0 & DBCR0_IDM)) {
+		/*
+		 * Check to see if the dbcr0 register is set up to debug.
+		 * Use the internal debug mode bit to do this.
+		 */
+		mtmsr(mfmsr() & ~MSR_DE);
+		if (IS_ENABLED(CONFIG_PPC32)) {
+			isync();
+			global_dbcr0[smp_processor_id()] = mfspr(SPRN_DBCR0);
+		}
+		mtspr(SPRN_DBCR0, current->thread.debug.dbcr0);
+		mtspr(SPRN_DBSR, -1);
+	}
+#endif
+
 	account_cpu_user_exit();
 
 #ifdef CONFIG_PPC_BOOK3S_64 /* BOOK3E and ppc32 not using this */
@@ -401,13 +424,17 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned
 		goto again;
 	}
 
-#ifdef CONFIG_PPC_BOOK3E
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
 	if (unlikely(current->thread.debug.dbcr0 & DBCR0_IDM)) {
 		/*
 		 * Check to see if the dbcr0 register is set up to debug.
 		 * Use the internal debug mode bit to do this.
 		 */
 		mtmsr(mfmsr() & ~MSR_DE);
+		if (IS_ENABLED(CONFIG_PPC32)) {
+			isync();
+			global_dbcr0[smp_processor_id()] = mfspr(SPRN_DBCR0);
+		}
 		mtspr(SPRN_DBCR0, current->thread.debug.dbcr0);
 		mtspr(SPRN_DBSR, -1);
 	}
-- 
2.25.0


  parent reply	other threads:[~2021-02-08 16:37 UTC|newest]

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-08 15:10 [PATCH v5 00/22] powerpc/32: Implement C syscall entry/exit Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 01/22] powerpc/32s: Add missing call to kuep_lock on syscall entry Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 02/22] powerpc/32: Always enable data translation " Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 03/22] powerpc/32: On syscall entry, enable instruction translation at the same time as data Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 04/22] powerpc/32: Reorder instructions to avoid using CTR in syscall entry Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 05/22] powerpc/irq: Add helper to set regs->softe Christophe Leroy
2021-02-09  1:11   ` Nicholas Piggin
2021-02-09  5:57     ` Christophe Leroy
2021-02-09  7:47       ` Nicholas Piggin
2021-02-09  6:18     ` Christophe Leroy
2021-02-09  7:49       ` Nicholas Piggin
2021-03-05  8:54         ` Christophe Leroy
2021-03-08  8:47           ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 06/22] powerpc/irq: Rework helpers that manipulate MSR[EE/RI] Christophe Leroy
2021-02-09  1:14   ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 07/22] powerpc/irq: Add stub irq_soft_mask_return() for PPC32 Christophe Leroy
2021-02-09  1:19   ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 08/22] powerpc/syscall: Rename syscall_64.c into interrupt.c Christophe Leroy
2021-02-09  1:19   ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 09/22] powerpc/syscall: Make interrupt.c buildable on PPC32 Christophe Leroy
2021-02-09  1:27   ` Nicholas Piggin
2021-02-09  6:02     ` Christophe Leroy
2021-02-09  7:50       ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 10/22] powerpc/syscall: Use is_compat_task() Christophe Leroy
2021-02-09  1:29   ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 11/22] powerpc/syscall: Save r3 in regs->orig_r3 Christophe Leroy
2021-02-09  1:29   ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 12/22] powerpc/syscall: Change condition to check MSR_RI Christophe Leroy
2021-02-09  1:36   ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 13/22] powerpc/32: Always save non volatile GPRs at syscall entry Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 14/22] powerpc/syscall: implement system call entry/exit logic in C for PPC32 Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 15/22] powerpc/32: Remove verification of MSR_PR on syscall in the ASM entry Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 16/22] powerpc/syscall: Avoid stack frame in likely part of system_call_exception() Christophe Leroy
2021-02-09  1:55   ` Nicholas Piggin
2021-02-09 16:13     ` Christophe Leroy
2021-02-10  1:56       ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 17/22] powerpc/syscall: Do not check unsupported scv vector on PPC32 Christophe Leroy
2021-02-09  2:00   ` Nicholas Piggin
2021-02-09  6:13     ` Christophe Leroy
2021-02-09  7:56       ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 18/22] powerpc/syscall: Remove FULL_REGS verification in system_call_exception Christophe Leroy
2021-02-09  2:02   ` Nicholas Piggin
2021-02-09 14:31     ` Christophe Leroy
2021-02-10  1:57       ` Nicholas Piggin
2021-02-08 15:10 ` [PATCH v5 19/22] powerpc/syscall: Optimise checks in beginning of system_call_exception() Christophe Leroy
2021-02-09  2:06   ` Nicholas Piggin
2021-02-09 14:32     ` Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 20/22] powerpc/syscall: Avoid storing 'current' in another pointer Christophe Leroy
2021-02-09  2:36   ` Nicholas Piggin
2021-02-09 13:50     ` Segher Boessenkool
2021-02-09 14:31       ` David Laight
2021-02-09 17:03         ` Christophe Leroy
2021-02-09 17:16           ` David Laight
2021-02-10  2:00           ` Nicholas Piggin
2021-02-10  8:45             ` Christophe Leroy
2021-02-08 15:10 ` [PATCH v5 21/22] powerpc/32: Remove the counter in global_dbcr0 Christophe Leroy
2021-02-08 15:10 ` Christophe Leroy [this message]
2021-02-09  1:03 ` [PATCH v5 00/22] powerpc/32: Implement C syscall entry/exit Nicholas Piggin
2021-02-12  0:19 ` Michael Ellerman

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