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: Will Deacon <will.deacon@arm.com>
Signed-off-by: Matthew Leach <matthew.leach@arm.com>
[catalin.marinas@arm.com: fix SCTLR_EL1.E0E bit setting in head.S]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 775ecb3..7009387 100644 (file)
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -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. */

diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
index b1b31bb..421b99f 100644 (file)
--- a/arch/arm64/mm/proc.S
+++ b/arch/arm64/mm/proc.S
@@ -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