From 46f4976f22a4549322307b34272e053d38653243 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 19 Nov 2020 21:56:14 +0000 Subject: [PATCH] target/arm: Implement M-profile "minimal RAS implementation" For v8.1M the architecture mandates that CPUs must provide at least the "minimal RAS implementation" from the Reliability, Availability and Serviceability extension. This consists of: * an ESB instruction which is a NOP -- since it is in the HINT space we need only add a comment * an RFSR register which will RAZ/WI * a RAZ/WI AIRCR.IESB bit -- the code which handles writes to AIRCR does not allow setting of RES0 bits, so we already treat this as RAZ/WI; add a comment noting that this is deliberate * minimal implementation of the RAS register block at 0xe0005000 -- this will be in a subsequent commit * setting the ID_PFR0.RAS field to 0b0010 -- we will do this when we add the Cortex-M55 CPU model Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20201119215617.29887-26-peter.maydell@linaro.org --- hw/intc/armv7m_nvic.c | 13 +++++++++++++ target/arm/cpu.h | 14 ++++++++++++++ target/arm/t32.decode | 4 ++++ 3 files changed, 31 insertions(+) diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index cf233c0561..01e331ab1e 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -1483,6 +1483,12 @@ static uint32_t nvic_readl(NVICState *s, uint32_t offset, MemTxAttrs attrs) return 0; } return cpu->env.v7m.sfar; + case 0xf04: /* RFSR */ + if (!cpu_isar_feature(aa32_ras, cpu)) { + goto bad_offset; + } + /* We provide minimal-RAS only: RFSR is RAZ/WI */ + return 0; case 0xf34: /* FPCCR */ if (!cpu_isar_feature(aa32_vfp_simd, cpu)) { return 0; @@ -1611,6 +1617,7 @@ static void nvic_writel(NVICState *s, uint32_t offset, uint32_t value, R_V7M_AIRCR_PRIGROUP_SHIFT, R_V7M_AIRCR_PRIGROUP_LENGTH); } + /* AIRCR.IESB is RAZ/WI because we implement only minimal RAS */ if (attrs.secure) { /* These bits are only writable by secure */ cpu->env.v7m.aircr = value & @@ -2026,6 +2033,12 @@ static void nvic_writel(NVICState *s, uint32_t offset, uint32_t value, } break; } + case 0xf04: /* RFSR */ + if (!cpu_isar_feature(aa32_ras, cpu)) { + goto bad_offset; + } + /* We provide minimal-RAS only: RFSR is RAZ/WI */ + break; case 0xf34: /* FPCCR */ if (cpu_isar_feature(aa32_vfp_simd, cpu)) { /* Not all bits here are banked. */ diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 22c55c8193..7e6c881a7e 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -1827,6 +1827,15 @@ FIELD(ID_MMFR4, LSM, 20, 4) FIELD(ID_MMFR4, CCIDX, 24, 4) FIELD(ID_MMFR4, EVT, 28, 4) +FIELD(ID_PFR0, STATE0, 0, 4) +FIELD(ID_PFR0, STATE1, 4, 4) +FIELD(ID_PFR0, STATE2, 8, 4) +FIELD(ID_PFR0, STATE3, 12, 4) +FIELD(ID_PFR0, CSV2, 16, 4) +FIELD(ID_PFR0, AMU, 20, 4) +FIELD(ID_PFR0, DIT, 24, 4) +FIELD(ID_PFR0, RAS, 28, 4) + FIELD(ID_PFR1, PROGMOD, 0, 4) FIELD(ID_PFR1, SECURITY, 4, 4) FIELD(ID_PFR1, MPROGMOD, 8, 4) @@ -3573,6 +3582,11 @@ static inline bool isar_feature_aa32_predinv(const ARMISARegisters *id) return FIELD_EX32(id->id_isar6, ID_ISAR6, SPECRES) != 0; } +static inline bool isar_feature_aa32_ras(const ARMISARegisters *id) +{ + return FIELD_EX32(id->id_pfr0, ID_PFR0, RAS) != 0; +} + static inline bool isar_feature_aa32_mprofile(const ARMISARegisters *id) { return FIELD_EX32(id->id_pfr1, ID_PFR1, MPROGMOD) != 0; diff --git a/target/arm/t32.decode b/target/arm/t32.decode index f045eb62c8..8b2c487fa7 100644 --- a/target/arm/t32.decode +++ b/target/arm/t32.decode @@ -307,6 +307,10 @@ CLZ 1111 1010 1011 ---- 1111 .... 1000 .... @rdm # SEV 1111 0011 1010 1111 1000 0000 0000 0100 # SEVL 1111 0011 1010 1111 1000 0000 0000 0101 + # For M-profile minimal-RAS ESB can be a NOP, which is the + # default behaviour since it is in the hint space. + # ESB 1111 0011 1010 1111 1000 0000 0001 0000 + # The canonical nop ends in 0000 0000, but the whole rest # of the space is "reserved hint, behaves as nop". NOP 1111 0011 1010 1111 1000 0000 ---- ---- -- 2.11.4.GIT