From: Paul Burton <paul.burton@xxxxxxxxxx> [ Upstream commit 35e6de38858f59b6b65dcfeaf700b5d06fc2b93d ] On systems with CM3, we must ensure that the L1 & L2 ECC enables are set to the same value. This is presumed by the hardware & cache corruption can occur when it is not the case. Support enabling & disabling the L2 ECC checking on CM3 systems where this is controlled via a GCR, and ensure that it matches the state of L1 ECC checking. Remove I6400 from the switch statement it will no longer hit, and which was incorrect since the L2 ECC enable bit isn't in the CP0 ErrCtl register. Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx> Cc: linux-mips@xxxxxxxxxxxxxx Patchwork: https://patchwork.linux-mips.org/patch/14413/ Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> --- arch/mips/include/asm/mips-cm.h | 7 +++++ arch/mips/kernel/traps.c | 63 +++++++++++++++++++++++++++++++++++++++-- 2 files changed, 67 insertions(+), 3 deletions(-) diff --git a/arch/mips/include/asm/mips-cm.h b/arch/mips/include/asm/mips-cm.h index 2e4180797b21..cfdbab015769 100644 --- a/arch/mips/include/asm/mips-cm.h +++ b/arch/mips/include/asm/mips-cm.h @@ -187,6 +187,7 @@ BUILD_CM_R_(config, MIPS_CM_GCB_OFS + 0x00) BUILD_CM_RW(base, MIPS_CM_GCB_OFS + 0x08) BUILD_CM_RW(access, MIPS_CM_GCB_OFS + 0x20) BUILD_CM_R_(rev, MIPS_CM_GCB_OFS + 0x30) +BUILD_CM_RW(err_control, MIPS_CM_GCB_OFS + 0x38) BUILD_CM_RW(error_mask, MIPS_CM_GCB_OFS + 0x40) BUILD_CM_RW(error_cause, MIPS_CM_GCB_OFS + 0x48) BUILD_CM_RW(error_addr, MIPS_CM_GCB_OFS + 0x50) @@ -266,6 +267,12 @@ BUILD_CM_Cx_R_(tcid_8_priority, 0x80) #define CM_REV_CM2_5 CM_ENCODE_REV(7, 0) #define CM_REV_CM3 CM_ENCODE_REV(8, 0) +/* GCR_ERR_CONTROL register fields */ +#define CM_GCR_ERR_CONTROL_L2_ECC_EN_SHF 1 +#define CM_GCR_ERR_CONTROL_L2_ECC_EN_MSK (_ULCAST_(0x1) << 1) +#define CM_GCR_ERR_CONTROL_L2_ECC_SUPPORT_SHF 0 +#define CM_GCR_ERR_CONTROL_L2_ECC_SUPPORT_MSK (_ULCAST_(0x1) << 0) + /* GCR_ERROR_CAUSE register fields */ #define CM_GCR_ERROR_CAUSE_ERRTYPE_SHF 27 #define CM_GCR_ERROR_CAUSE_ERRTYPE_MSK (_ULCAST_(0x1f) << 27) diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index b0b29cb6f3d8..bb1d9ff1be5c 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -51,6 +51,7 @@ #include <asm/idle.h> #include <asm/mips-cm.h> #include <asm/mips-r2-to-r6-emul.h> +#include <asm/mips-cm.h> #include <asm/mipsregs.h> #include <asm/mipsmtregs.h> #include <asm/module.h> @@ -1646,6 +1647,65 @@ __setup("nol2par", nol2parity); */ static inline void parity_protection_init(void) { +#define ERRCTL_PE 0x80000000 +#define ERRCTL_L2P 0x00800000 + + if (mips_cm_revision() >= CM_REV_CM3) { + ulong gcr_ectl, cp0_ectl; + + /* + * With CM3 systems we need to ensure that the L1 & L2 + * parity enables are set to the same value, since this + * is presumed by the hardware engineers. + * + * If the user disabled either of L1 or L2 ECC checking, + * disable both. + */ + l1parity &= l2parity; + l2parity &= l1parity; + + /* Probe L1 ECC support */ + cp0_ectl = read_c0_ecc(); + write_c0_ecc(cp0_ectl | ERRCTL_PE); + back_to_back_c0_hazard(); + cp0_ectl = read_c0_ecc(); + + /* Probe L2 ECC support */ + gcr_ectl = read_gcr_err_control(); + + if (!(gcr_ectl & CM_GCR_ERR_CONTROL_L2_ECC_SUPPORT_MSK) || + !(cp0_ectl & ERRCTL_PE)) { + /* + * One of L1 or L2 ECC checking isn't supported, + * so we cannot enable either. + */ + l1parity = l2parity = 0; + } + + /* Configure L1 ECC checking */ + if (l1parity) + cp0_ectl |= ERRCTL_PE; + else + cp0_ectl &= ~ERRCTL_PE; + write_c0_ecc(cp0_ectl); + back_to_back_c0_hazard(); + WARN_ON(!!(read_c0_ecc() & ERRCTL_PE) != l1parity); + + /* Configure L2 ECC checking */ + if (l2parity) + gcr_ectl |= CM_GCR_ERR_CONTROL_L2_ECC_EN_MSK; + else + gcr_ectl &= ~CM_GCR_ERR_CONTROL_L2_ECC_EN_MSK; + write_gcr_err_control(gcr_ectl); + gcr_ectl = read_gcr_err_control(); + gcr_ectl &= CM_GCR_ERR_CONTROL_L2_ECC_EN_MSK; + WARN_ON(!!gcr_ectl != l2parity); + + pr_info("Cache parity protection %sabled\n", + l1parity ? "en" : "dis"); + return; + } + switch (current_cpu_type()) { case CPU_24K: case CPU_34K: @@ -1656,11 +1716,8 @@ static inline void parity_protection_init(void) case CPU_PROAPTIV: case CPU_P5600: case CPU_QEMU_GENERIC: - case CPU_I6400: case CPU_P6600: { -#define ERRCTL_PE 0x80000000 -#define ERRCTL_L2P 0x00800000 unsigned long errctl; unsigned int l1parity_present, l2parity_present; -- 2.11.0