diff options
Diffstat (limited to 'arch/arm64/include/asm/arch_gicv3.h')
| -rw-r--r-- | arch/arm64/include/asm/arch_gicv3.h | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/arch_gicv3.h b/arch/arm64/include/asm/arch_gicv3.h index 4ad22c3135db..8bd5afc7b692 100644 --- a/arch/arm64/include/asm/arch_gicv3.h +++ b/arch/arm64/include/asm/arch_gicv3.h @@ -53,17 +53,36 @@ static inline u64 gic_read_iar_common(void) * The gicv3 of ThunderX requires a modified version for reading the * IAR status to ensure data synchronization (access to icc_iar1_el1 * is not sync'ed before and after). + * + * Erratum 38545 + * + * When a IAR register read races with a GIC interrupt RELEASE event, + * GIC-CPU interface could wrongly return a valid INTID to the CPU + * for an interrupt that is already released(non activated) instead of 0x3ff. + * + * To workaround this, return a valid interrupt ID only if there is a change + * in the active priority list after the IAR read. + * + * Common function used for both the workarounds since, + * 1. On Thunderx 88xx 1.x both erratas are applicable. + * 2. Having extra nops doesn't add any side effects for Silicons where + * erratum 23154 is not applicable. */ static inline u64 gic_read_iar_cavium_thunderx(void) { - u64 irqstat; + u64 irqstat, apr; + apr = read_sysreg_s(SYS_ICC_AP1R0_EL1); nops(8); irqstat = read_sysreg_s(SYS_ICC_IAR1_EL1); nops(4); mb(); - return irqstat; + /* Max priority groups implemented is only 32 */ + if (likely(apr != read_sysreg_s(SYS_ICC_AP1R0_EL1))) + return irqstat; + + return 0x3ff; } static inline void gic_write_ctlr(u32 val) |