From: Peter Hoyes Peter.Hoyes@arm.com
On Armv8-R, the EL1&0 memory system architecture is configurable as a VMSA or PMSA, and resets to an "architecturally unknown" value.
Add code to armv8_switch_to_el1_m which detects whether the MSA at EL1&0 is configurable using the id_aa64mmfr0_el1 register MSA fields. If it is we must ensure the VMSA is enabled so that a rich OS can boot.
The MSA and MSA_FRAC fields are described in the Armv8-R architecture profile supplement (section G1.3.7): https://developer.arm.com/documentation/ddi0600/latest/
Signed-off-by: Peter Hoyes Peter.Hoyes@arm.com --- arch/arm/include/asm/macro.h | 17 +++++++++++++++++ arch/arm/include/asm/system.h | 24 ++++++++++++++++++++++++ 2 files changed, 41 insertions(+)
diff --git a/arch/arm/include/asm/macro.h b/arch/arm/include/asm/macro.h index e1eefc283f..ecd8221c0d 100644 --- a/arch/arm/include/asm/macro.h +++ b/arch/arm/include/asm/macro.h @@ -316,6 +316,23 @@ lr .req x30 csel \tmp, \tmp2, \tmp, eq msr hcr_el2, \tmp
+ /* + * Detect whether the system has a configurable memory system + * architecture at EL1&0 + */ + mrs \tmp, id_aa64mmfr0_el1 + lsr \tmp, \tmp, #48 + and \tmp, \tmp, #((ID_AA64MMFR0_EL1_MSA_MASK | \ + ID_AA64MMFR0_EL1_MSA_FRAC_MASK) >> 48) + cmp \tmp, #((ID_AA64MMFR0_EL1_MSA_USE_FRAC | \ + ID_AA64MMFR0_EL1_MSA_FRAC_VMSA) >> 48) + bne 2f + + /* Ensure the EL1&0 VMSA is enabled */ + mov \tmp, #(VTCR_EL2_MSA) + msr vtcr_el2, \tmp +2: + /* Return to the EL1_SP1 mode from EL2 */ ldr \tmp, =(SPSR_EL_DEBUG_MASK | SPSR_EL_SERR_MASK |\ SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\ diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h index 77aa18909e..e4c11e830a 100644 --- a/arch/arm/include/asm/system.h +++ b/arch/arm/include/asm/system.h @@ -83,6 +83,30 @@ #define HCR_EL2_RW_AARCH32 (0 << 31) /* Lower levels are AArch32 */ #define HCR_EL2_HCD_DIS (1 << 29) /* Hypervisor Call disabled */
+/* + * VTCR_EL2 bits definitions + */ +#define VTCR_EL2_MSA (1 << 31) /* EL1&0 memory architecture */ + +/* + * ID_AA64MMFR0_EL1 bits definitions + */ +#define ID_AA64MMFR0_EL1_MSA_FRAC_MASK (0xFUL << 52) /* Memory system + architecture + frac */ +#define ID_AA64MMFR0_EL1_MSA_FRAC_VMSA (0x2UL << 52) /* EL1&0 supports + VMSA */ +#define ID_AA64MMFR0_EL1_MSA_FRAC_PMSA (0x1UL << 52) /* EL1&0 only + supports PMSA*/ +#define ID_AA64MMFR0_EL1_MSA_FRAC_NO_PMSA (0x0UL << 52) /* No PMSA + support */ +#define ID_AA64MMFR0_EL1_MSA_MASK (0xFUL << 48) /* Memory system + architecture */ +#define ID_AA64MMFR0_EL1_MSA_USE_FRAC (0xFUL << 48) /* Use MSA_FRAC */ +#define ID_AA64MMFR0_EL1_MSA_VMSA (0x0UL << 48) /* Memory system + architecture + is VMSA */ + /* * ID_AA64ISAR1_EL1 bits definitions */