From: ard.biesheuvel@linaro.org (Ard Biesheuvel)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v5 6/8] arm64: merge __enable_mmu and __turn_mmu_on
Date: Wed, 18 Mar 2015 15:55:25 +0100 [thread overview]
Message-ID: <1426690527-14258-7-git-send-email-ard.biesheuvel@linaro.org> (raw)
In-Reply-To: <1426690527-14258-1-git-send-email-ard.biesheuvel@linaro.org>
Enabling of the MMU is split into two functions, with an align and
a branch in the middle. On arm64, the entire kernel Image is ID mapped
so this is really not necessary, and we can just merge it into a
single function.
Also replaces an open coded adrp/add reference to __enable_mmu with
adr_l.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
arch/arm64/kernel/head.S | 33 +++++++--------------------------
1 file changed, 7 insertions(+), 26 deletions(-)
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 65c7de889c8c..9a2554558e5b 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -255,8 +255,7 @@ ENTRY(stext)
*/
ldr x27, =__mmap_switched // address to jump to after
// MMU has been enabled
- adrp lr, __enable_mmu // return (PIC) address
- add lr, lr, #:lo12:__enable_mmu
+ adr_l lr, __enable_mmu // return (PIC) address
b __cpu_setup // initialise processor
ENDPROC(stext)
@@ -615,11 +614,12 @@ ENDPROC(__secondary_switched)
#endif /* CONFIG_SMP */
/*
- * Setup common bits before finally enabling the MMU. Essentially this is just
- * loading the page table pointer and vector base registers.
+ * Enable the MMU.
*
- * On entry to this code, x0 must contain the SCTLR_EL1 value for turning on
- * the MMU.
+ * x0 = SCTLR_EL1 value for turning on the MMU.
+ * x27 = *virtual* address to jump to upon completion
+ *
+ * other registers depend on the function called upon completion
*/
__enable_mmu:
ldr x5, =vectors
@@ -627,29 +627,10 @@ __enable_mmu:
msr ttbr0_el1, x25 // load TTBR0
msr ttbr1_el1, x26 // load TTBR1
isb
- b __turn_mmu_on
-ENDPROC(__enable_mmu)
-
-/*
- * Enable the MMU. This completely changes the structure of the visible memory
- * space. You will not be able to trace execution through this.
- *
- * x0 = system control register
- * x27 = *virtual* address to jump to upon completion
- *
- * other registers depend on the function called upon completion
- *
- * We align the entire function to the smallest power of two larger than it to
- * ensure it fits within a single block map entry. Otherwise were PHYS_OFFSET
- * close to the end of a 512MB or 1GB block we might require an additional
- * table to map the entire function.
- */
- .align 4
-__turn_mmu_on:
msr sctlr_el1, x0
isb
br x27
-ENDPROC(__turn_mmu_on)
+ENDPROC(__enable_mmu)
/*
* Calculate the start of physical memory.
--
1.8.3.2
next prev parent reply other threads:[~2015-03-18 14:55 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-18 14:55 [PATCH v5 0/8] arm64: head.S cleanup Ard Biesheuvel
2015-03-18 14:55 ` [PATCH v5 1/8] arm64: Get rid of struct cpu_table Ard Biesheuvel
2015-03-18 16:11 ` Mark Rutland
2015-03-23 17:11 ` Suzuki K. Poulose
2015-03-23 17:38 ` Will Deacon
2015-03-23 17:41 ` Suzuki K. Poulose
2015-03-18 14:55 ` [PATCH v5 2/8] arm64: add macros for common adrp usages Ard Biesheuvel
2015-03-18 17:54 ` Mark Rutland
2015-03-18 17:56 ` Ard Biesheuvel
2015-03-18 18:05 ` Mark Rutland
2015-03-18 18:06 ` Ard Biesheuvel
2015-03-18 14:55 ` [PATCH v5 3/8] arm64: remove processor_id Ard Biesheuvel
2015-03-18 14:55 ` [PATCH v5 4/8] arm64: remove __switch_data object from head.S Ard Biesheuvel
2015-03-18 14:55 ` [PATCH v5 5/8] arm64: use PC-relative reference for secondary_holding_pen_release Ard Biesheuvel
2015-03-18 14:55 ` Ard Biesheuvel [this message]
2015-03-18 14:55 ` [PATCH v5 7/8] arm64: remove __calc_phys_offset Ard Biesheuvel
2015-03-18 14:55 ` [PATCH v5 8/8] arm64: enforce x1|x2|x3 == 0 upon kernel entry as per boot protocol Ard Biesheuvel
2015-03-18 18:13 ` Mark Rutland
2015-03-18 18:16 ` Ard Biesheuvel
2015-03-18 18:46 ` Ard Biesheuvel
2015-03-18 18:57 ` Mark Rutland
2015-03-18 19:55 ` Ard Biesheuvel
2015-03-18 20:24 ` Mark Rutland
2015-03-19 7:30 ` Ard Biesheuvel
2015-03-19 10:35 ` Mark Rutland
2015-03-19 10:38 ` Ard Biesheuvel
2015-03-19 10:41 ` Mark Rutland
2015-03-19 11:00 ` [PATCH v3] " Ard Biesheuvel
2015-03-19 13:36 ` Mark Rutland
2015-03-20 11:31 ` Ard Biesheuvel
2015-03-20 11:41 ` Mark Rutland
2015-03-20 11:45 ` Ard Biesheuvel
2015-03-20 12:25 ` Will Deacon
2015-03-20 12:50 ` Ard Biesheuvel
2015-03-18 22:26 ` [PATCH v5 8/8] " Peter Maydell
2015-03-18 18:23 ` [PATCH v5 0/8] arm64: head.S cleanup Mark Rutland
2015-03-18 18:28 ` Ard Biesheuvel
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