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armv8: Ensure EL1&0 VMSA is enabled 

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>
This commit is contained in:
Peter Hoyes 2021-08-19 16:53:10 +01:00 committed by Tom Rini
parent 53b40e8d54
commit 37a757e227
2 changed files with 41 additions and 0 deletions
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17
arch/arm/include/asm/macro.h
View File

@ -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 |\

24
arch/arm/include/asm/system.h
View File

@ -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
*/