Commit 9cf71728 authored by Matthew Leach's avatar Matthew Leach Committed by Catalin Marinas
Browse files

arm64: big-endian: set correct endianess on kernel entry 



The endianness of memory accesses at EL2 and EL1 are configured by
SCTLR_EL2.EE and SCTLR_EL1.EE respectively. When the kernel is booted,
the state of SCTLR_EL{2,1}.EE is unknown, and thus the kernel must
ensure that they are set before performing any memory accesses.

This patch ensures that SCTLR_EL{2,1} are configured appropriately at
boot for kernels of either endianness.

Acked-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarMatthew Leach <matthew.leach@arm.com>
[catalin.marinas@arm.com: fix SCTLR_EL1.E0E bit setting in head.S]
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 828e9834

arch/arm64/kernel/head.S

+14 −3
Original line number Diff line number Diff line
@@ -159,12 +159,22 @@ ENTRY(el2_setup) 
	mrs	x0, CurrentEL

	cmp	x0, #PSR_MODE_EL2t

	ccmp	x0, #PSR_MODE_EL2h, #0x4, ne

	b.eq	1f

	b.ne	1f

	mrs	x0, sctlr_el2

CPU_BE(	orr	x0, x0, #(1 << 25)	)	// Set the EE bit for EL2

CPU_LE(	bic	x0, x0, #(1 << 25)	)	// Clear the EE bit for EL2

	msr	sctlr_el2, x0

	b	2f

1:	mrs	x0, sctlr_el1

CPU_BE(	orr	x0, x0, #(3 << 24)	)	// Set the EE and E0E bits for EL1

CPU_LE(	bic	x0, x0, #(3 << 24)	)	// Clear the EE and E0E bits for EL1

	msr	sctlr_el1, x0

	mov	w20, #BOOT_CPU_MODE_EL1		// This cpu booted in EL1

	isb

	ret



	/* Hyp configuration. */

1:	mov	x0, #(1 << 31)			// 64-bit EL1

2:	mov	x0, #(1 << 31)			// 64-bit EL1

	msr	hcr_el2, x0



	/* Generic timers. */
@@ -181,7 +191,8 @@ ENTRY(el2_setup) 


	/* sctlr_el1 */

	mov	x0, #0x0800			// Set/clear RES{1,0} bits

	movk	x0, #0x30d0, lsl #16

CPU_BE(	movk	x0, #0x33d0, lsl #16	)	// Set EE and E0E on BE systems

CPU_LE(	movk	x0, #0x30d0, lsl #16	)	// Clear EE and E0E on LE systems

	msr	sctlr_el1, x0



	/* Coprocessor traps. */

arch/arm64/mm/proc.S

+2 −2
Original line number Diff line number Diff line
@@ -162,9 +162,9 @@ ENDPROC(__cpu_setup) 
	 *       CE0      XWHW CZ     ME TEEA S

	 * .... .IEE .... NEAI TE.I ..AD DEN0 ACAM

	 * 0011 0... 1101 ..0. ..0. 10.. .... .... < hardware reserved

	 * .... .100 .... 01.1 11.1 ..01 0001 1101 < software settings

	 * .... .1.. .... 01.1 11.1 ..01 0001 1101 < software settings

	 */

	.type	crval, #object

crval:

	.word	0x030802e2			// clear

	.word	0x000802e2			// clear

	.word	0x0405d11d			// set

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