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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 21/22] powerpc/32: Remove the counter in global_dbcr0
Date: Mon,  8 Feb 2021 15:10:41 +0000 (UTC)	[thread overview]
Message-ID: <7e381dc58b3f583556cfab37ba5d813bfd5cce1e.1612796617.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <cover.1612796617.git.christophe.leroy@csgroup.eu>

global_dbcr0 has two parts, 4 bytes to save/restore the
value of SPRN_DBCR0, and 4 bytes that are incremented/decremented
everytime something is saving/loading the above value.

This counter is only incremented/decremented, its value is never
used and never read.

Remove the counter and devide the size of global_dbcr0 by 2.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
v5: New
---
 arch/powerpc/kernel/entry_32.S   | 12 +++---------
 arch/powerpc/kernel/head_32.h    |  3 ---
 arch/powerpc/kernel/head_booke.h |  5 +----
 3 files changed, 4 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 7c824e8928d0..a574201b0eb6 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -175,14 +175,11 @@ transfer_to_handler:
 	addi	r11,r11,global_dbcr0@l
 #ifdef CONFIG_SMP
 	lwz	r9,TASK_CPU(r2)
-	slwi	r9,r9,3
+	slwi	r9,r9,2
 	add	r11,r11,r9
 #endif
 	lwz	r12,0(r11)
 	mtspr	SPRN_DBCR0,r12
-	lwz	r12,4(r11)
-	addi	r12,r12,-1
-	stw	r12,4(r11)
 #endif
 
 	b	3f
@@ -980,14 +977,11 @@ load_dbcr0:
 	addi	r11,r11,global_dbcr0@l
 #ifdef CONFIG_SMP
 	lwz	r9,TASK_CPU(r2)
-	slwi	r9,r9,3
+	slwi	r9,r9,2
 	add	r11,r11,r9
 #endif
 	stw	r10,0(r11)
 	mtspr	SPRN_DBCR0,r0
-	lwz	r10,4(r11)
-	addi	r10,r10,1
-	stw	r10,4(r11)
 	li	r11,-1
 	mtspr	SPRN_DBSR,r11	/* clear all pending debug events */
 	blr
@@ -996,7 +990,7 @@ load_dbcr0:
 	.align	4
 	.global global_dbcr0
 global_dbcr0:
-	.space	8*NR_CPUS
+	.space	4*NR_CPUS
 	.previous
 #endif /* !(CONFIG_4xx || CONFIG_BOOKE) */
 
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 282d8fd443a9..5001c6ecc3ec 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -166,9 +166,6 @@
 	addi	r11,r11,global_dbcr0@l
 	lwz	r12,0(r11)
 	mtspr	SPRN_DBCR0,r12
-	lwz	r12,4(r11)
-	addi	r12,r12,-1
-	stw	r12,4(r11)
 3:
 #endif
 	b	transfer_to_syscall		/* jump to handler */
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index bfbd240cc8a2..5f565232b99d 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -142,14 +142,11 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
 	addi	r11,r11,global_dbcr0@l
 #ifdef CONFIG_SMP
 	lwz	r10, TASK_CPU(r2)
-	slwi	r10, r10, 3
+	slwi	r10, r10, 2
 	add	r11, r11, r10
 #endif
 	lwz	r12,0(r11)
 	mtspr	SPRN_DBCR0,r12
-	lwz	r12,4(r11)
-	addi	r12,r12,-1
-	stw	r12,4(r11)
 
 3:
 	b	transfer_to_syscall	/* jump to handler */
-- 
2.25.0


  parent reply	other threads:[~2021-02-08 16:35 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 ` Christophe Leroy [this message]
2021-02-08 15:10 ` [PATCH v5 22/22] powerpc/32: Handle bookE debugging in C in syscall entry/exit Christophe Leroy
2021-02-09  1:03 ` [PATCH v5 00/22] powerpc/32: Implement C " Nicholas Piggin
2021-02-12  0:19 ` Michael Ellerman

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