The current value of HSCTLR_BASE for Arm64 is pretty wrong. It would
actually turn on SCTLR_EL2.nAA (bit 6) on hardware implementing
ARMv8.4-LSE.
Furthermore, the documentation of what is cleared/set in SCTLR_EL2 is
also not correct and looks like to be a verbatim copy from Arm32.
HSCTLR_BASE is replaced with a bunch of per-architecture new defines
helping to understand better what is the initialie value for
SCTLR_EL2/HSCTLR.
Note the defines *_CLEAR are only used to check the state of each bits
are known.
Lastly, the documentation is dropped from arm{32,64}/head.S as it would
be pretty easy to get out-of-sync with the definitions.
Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
---
xen/arch/arm/arm32/head.S | 12 +---------
xen/arch/arm/arm64/head.S | 10 +-------
xen/include/asm-arm/processor.h | 52 ++++++++++++++++++++++++++++++++++++++++-
3 files changed, 53 insertions(+), 21 deletions(-)
diff --git a/xen/arch/arm/arm32/head.S b/xen/arch/arm/arm32/head.S
index 5ef7e5a2f3..8a98607459 100644
--- a/xen/arch/arm/arm32/head.S
+++ b/xen/arch/arm/arm32/head.S
@@ -234,17 +234,7 @@ cpu_init_done:
ldr r0,
=(TCR_RES1|TCR_SH0_IS|TCR_ORGN0_WBWA|TCR_IRGN0_WBWA|TCR_T0SZ(0))
mcr CP32(r0, HTCR)
- /*
- * Set up the HSCTLR:
- * Exceptions in LE ARM,
- * Low-latency IRQs disabled,
- * Write-implies-XN disabled (for now),
- * D-cache disabled (for now),
- * I-cache enabled,
- * Alignment checking enabled,
- * MMU translation disabled (for now).
- */
- ldr r0, =(HSCTLR_BASE|SCTLR_AXX_A)
+ ldr r0, =HSCTLR_SET
mcr CP32(r0, HSCTLR)
/*
diff --git a/xen/arch/arm/arm64/head.S b/xen/arch/arm/arm64/head.S
index 8a6be3352e..4fe904c51d 100644
--- a/xen/arch/arm/arm64/head.S
+++ b/xen/arch/arm/arm64/head.S
@@ -363,15 +363,7 @@ skip_bss:
msr tcr_el2, x0
- /* Set up the SCTLR_EL2:
- * Exceptions in LE ARM,
- * Low-latency IRQs disabled,
- * Write-implies-XN disabled (for now),
- * D-cache disabled (for now),
- * I-cache enabled,
- * Alignment checking disabled,
- * MMU translation disabled (for now). */
- ldr x0, =(HSCTLR_BASE)
+ ldr x0, =SCTLR_EL2_SET
msr SCTLR_EL2, x0
/* Ensure that any exceptions encountered at EL2
diff --git a/xen/include/asm-arm/processor.h b/xen/include/asm-arm/processor.h
index 1a143fb6a3..6dac500e40 100644
--- a/xen/include/asm-arm/processor.h
+++ b/xen/include/asm-arm/processor.h
@@ -122,6 +122,9 @@
#define SCTLR_A32_ELx_TE _BITUL(30)
#define SCTLR_A32_ELx_FI _BITUL(21)
+/* Common bits for SCTLR_ELx for Arm64 */
+#define SCTLR_A64_ELx_SA _BITUL(3)
+
/* Common bits for SCTLR_ELx on all architectures */
#define SCTLR_Axx_ELx_EE _BITUL(25)
#define SCTLR_Axx_ELx_WXN _BITUL(19)
@@ -130,7 +133,54 @@
#define SCTLR_Axx_ELx_A _BITUL(1)
#define SCTLR_Axx_ELx_M _BITUL(0)
-#define HSCTLR_BASE _AC(0x30c51878,U)
+#ifdef CONFIG_ARM_32
+
+#define HSCTLR_RES1 (_BITUL(3) | _BITUL(4) | _BITUL(5) | _BITUL(6) |\
+ _BITUL(11) | _BITUL(16) | _BITUL(18) | _BITUL(22) |\
+ _BITUL(23) | _BITUL(28) | _BITUL(29))
+
+#define HSCTLR_RES0 (_BITUL(7) | _BITUL(8) | _BITUL(9) | _BITUL(10) |\
+ _BITUL(13) | _BITUL(14) | _BITUL(15) | _BITUL(17) |\
+ _BITUL(20) | _BITUL(24) | _BITUL(26) | _BITUL(27) |\
+ _BITUL(31))
+
+/* Initial value for HSCTLR */
+#define HSCTLR_SET (HSCTLR_RES1 | SCTLR_Axx_ELx_A | SCTLR_Axx_ELx_I)
+
+#define HSCTLR_CLEAR (HSCTLR_RES0 | SCTLR_Axx_ELx_M |\
+ SCTLR_Axx_ELx_C | SCTLR_Axx_ELx_WXN |\
+ SCTLR_A32_ELx_FI | SCTLR_Axx_ELx_EE |\
+ SCTLR_A32_ELx_TE)
+
+#if (HSCTLR_SET ^ HSCTLR_CLEAR) != 0xffffffffU
+#error "Inconsistent HSCTLR set/clear bits"
+#endif
+
+#else
+
+#define SCTLR_EL2_RES1 (_BITUL(4) | _BITUL(5) | _BITUL(11) | _BITUL(16) |\
+ _BITUL(18) | _BITUL(22) | _BITUL(23) | _BITUL(28) |\
+ _BITUL(29))
+
+#define SCTLR_EL2_RES0 (_BITUL(6) | _BITUL(7) | _BITUL(8) | _BITUL(9) |\
+ _BITUL(10) | _BITUL(13) | _BITUL(14) | _BITUL(15) |\
+ _BITUL(17) | _BITUL(20) | _BITUL(21) | _BITUL(24) |\
+ _BITUL(26) | _BITUL(27) | _BITUL(30) | _BITUL(31) |\
+ (0xffffffffULL << 32))
+
+/* Initial value for SCTLR_EL2 */
+#define SCTLR_EL2_SET (SCTLR_EL2_RES1 | SCTLR_A64_ELx_SA |\
+ SCTLR_Axx_ELx_I)
+
+#define SCTLR_EL2_CLEAR (SCTLR_EL2_RES0 | SCTLR_Axx_ELx_M |\
+ SCTLR_Axx_ELx_A | SCTLR_Axx_ELx_C |\
+ SCTLR_Axx_ELx_WXN | SCTLR_Axx_ELx_EE)
+
+#if (SCTLR_EL2_SET ^ SCTLR_EL2_CLEAR) != 0xffffffffffffffffUL
+#error "Inconsistent SCTLR_EL2 set/clear bits"
+#endif
+
+#endif
/* HCR Hyp Configuration Register */
#define HCR_RW (_AC(1,UL)<<31) /* Register Width, ARM64 only */
