From: vladimir.murzin@arm.com (Vladimir Murzin)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/4] ARM: NOMMU: Postpone MPU activation till __after_proc_init
Date: Mon, 12 Feb 2018 11:19:31 +0000 [thread overview]
Message-ID: <1518434373-27907-3-git-send-email-vladimir.murzin@arm.com> (raw)
In-Reply-To: <1518434373-27907-1-git-send-email-vladimir.murzin@arm.com>
This patch postpone MPU activation till __after_proc_init (which is
placed in .text section) rather than doing it in __setup_mpu. It
allows us ignore used-only-once .head.text section while programming
PMSAv8 MPU (for PMSAv7 it stays covered anyway).
Tested-by: Szemz? Andr?s <sza@esh.hu>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
---
arch/arm/kernel/head-nommu.S | 45 ++++++++++++++++++++++----------------------
1 file changed, 22 insertions(+), 23 deletions(-)
diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S
index aaa25a6..482936a 100644
--- a/arch/arm/kernel/head-nommu.S
+++ b/arch/arm/kernel/head-nommu.S
@@ -125,11 +125,24 @@ __secondary_data:
*/
.text
__after_proc_init:
+#ifdef CONFIG_ARM_MPU
+M_CLASS(movw r12, #:lower16:BASEADDR_V7M_SCB)
+M_CLASS(movt r12, #:upper16:BASEADDR_V7M_SCB)
+M_CLASS(ldr r3, [r12, 0x50])
+AR_CLASS(mrc p15, 0, r3, c0, c1, 4) @ Read ID_MMFR0
+ and r3, r3, #(MMFR0_PMSA) @ PMSA field
+ teq r3, #(MMFR0_PMSAv7) @ PMSA v7
+#endif
#ifdef CONFIG_CPU_CP15
/*
* CP15 system control register value returned in r0 from
* the CPU init function.
*/
+
+#ifdef CONFIG_ARM_MPU
+ biceq r0, r0, #CR_BR @ Disable the 'default mem-map'
+ orreq r0, r0, #CR_M @ Set SCTRL.M (MPU on)
+#endif
#if defined(CONFIG_ALIGNMENT_TRAP) && __LINUX_ARM_ARCH__ < 6
orr r0, r0, #CR_A
#else
@@ -145,7 +158,15 @@ __after_proc_init:
bic r0, r0, #CR_I
#endif
mcr p15, 0, r0, c1, c0, 0 @ write control reg
+ isb
#elif defined (CONFIG_CPU_V7M)
+#ifdef CONFIG_ARM_MPU
+ ldreq r3, [r12, MPU_CTRL]
+ biceq r3, #MPU_CTRL_PRIVDEFENA
+ orreq r3, #MPU_CTRL_ENABLE
+ streq r3, [r12, MPU_CTRL]
+ isb
+#endif
/* For V7M systems we want to modify the CCR similarly to the SCTLR */
#ifdef CONFIG_CPU_DCACHE_DISABLE
bic r0, r0, #V7M_SCB_CCR_DC
@@ -156,9 +177,7 @@ __after_proc_init:
#ifdef CONFIG_CPU_ICACHE_DISABLE
bic r0, r0, #V7M_SCB_CCR_IC
#endif
- movw r3, #:lower16:(BASEADDR_V7M_SCB + V7M_SCB_CCR)
- movt r3, #:upper16:(BASEADDR_V7M_SCB + V7M_SCB_CCR)
- str r0, [r3]
+ str r0, [r12, V7M_SCB_CCR]
#endif /* CONFIG_CPU_CP15 elif CONFIG_CPU_V7M */
ret lr
ENDPROC(__after_proc_init)
@@ -282,19 +301,6 @@ M_CLASS(ldr r0, [r12, #MPU_TYPE])
setup_region r0, r5, r6, PMSAv7_INSTR_SIDE, r12 @ XIP_PHYS_ADDR, shared, enabled
3: isb
#endif
-
- /* Enable the MPU */
-AR_CLASS(mrc p15, 0, r0, c1, c0, 0) @ Read SCTLR
-AR_CLASS(bic r0, r0, #CR_BR) @ Disable the 'default mem-map'
-AR_CLASS(orr r0, r0, #CR_M) @ Set SCTRL.M (MPU on)
-AR_CLASS(mcr p15, 0, r0, c1, c0, 0) @ Enable MPU
-
-M_CLASS(ldr r0, [r12, #MPU_CTRL])
-M_CLASS(bic r0, #MPU_CTRL_PRIVDEFENA)
-M_CLASS(orr r0, #MPU_CTRL_ENABLE)
-M_CLASS(str r0, [r12, #MPU_CTRL])
- isb
-
ret lr
ENDPROC(__setup_pmsa_v7)
@@ -352,13 +358,6 @@ ENTRY(__secondary_setup_pmsa_v7)
cmp r4, #0
bgt 1b
- /* Enable the MPU */
- mrc p15, 0, r0, c1, c0, 0 @ Read SCTLR
- bic r0, r0, #CR_BR @ Disable the 'default mem-map'
- orr r0, r0, #CR_M @ Set SCTRL.M (MPU on)
- mcr p15, 0, r0, c1, c0, 0 @ Enable MPU
- isb
-
ret lr
ENDPROC(__secondary_setup_pmsa_v7)
--
2.0.0
next prev parent reply other threads:[~2018-02-12 11:19 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-12 11:19 [PATCH 0/4] Introduce PMSAv8 memory protection unit Vladimir Murzin
2018-02-12 11:19 ` [PATCH 1/4] ARM: NOMMU: Reorganise __setup_mpu Vladimir Murzin
2018-02-12 11:19 ` Vladimir Murzin [this message]
2018-02-12 11:19 ` [PATCH 3/4] ARM: NOMMU: Make _stext and _end meet PMSAv8 alignment restrictions Vladimir Murzin
2018-02-12 11:19 ` [PATCH 4/4] ARM: NOMMU: Support PMSAv8 MPU Vladimir Murzin
[not found] <a266d2d9-44dc-16aa-6b35-7bbda080c4ef@kernel.org>
2018-06-18 9:52 ` [PATCH 2/4] ARM: NOMMU: Postpone MPU activation till __after_proc_init Vladimir Murzin
2018-06-18 12:43 ` Greg Ungerer
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