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authorJens Axboe <axboe@kernel.dk>2020-07-08 08:02:13 -0600
committerJens Axboe <axboe@kernel.dk>2020-07-08 08:02:13 -0600
commit482c6b614a4750f71ed9c928bb5b2007a05dd694 (patch)
tree60f9140b0c24fb4b2b1059afcce8ac77ecc3d3c1 /arch/x86/kernel/cpu/intel.c
parent0e6e255e7a58cdf4ee4163f83deeb5ce4946051e (diff)
parentdcb7fd82c75ee2d6e6f9d8cc71c52519ed52e258 (diff)
Merge tag 'v5.8-rc4' into for-5.9/drivers
Merge in 5.8-rc4 for-5.9/block to setup for-5.9/drivers, to provide a clean base and making the life for the NVMe changes easier. Signed-off-by: Jens Axboe <axboe@kernel.dk> * tag 'v5.8-rc4': (732 commits) Linux 5.8-rc4 x86/ldt: use "pr_info_once()" instead of open-coding it badly MIPS: Do not use smp_processor_id() in preemptible code MIPS: Add missing EHB in mtc0 -> mfc0 sequence for DSPen .gitignore: Do not track `defconfig` from `make savedefconfig` io_uring: fix regression with always ignoring signals in io_cqring_wait() x86/ldt: Disable 16-bit segments on Xen PV x86/entry/32: Fix #MC and #DB wiring on x86_32 x86/entry/xen: Route #DB correctly on Xen PV x86/entry, selftests: Further improve user entry sanity checks x86/entry/compat: Clear RAX high bits on Xen PV SYSENTER i2c: mlxcpld: check correct size of maximum RECV_LEN packet i2c: add Kconfig help text for slave mode i2c: slave-eeprom: update documentation i2c: eg20t: Load module automatically if ID matches i2c: designware: platdrv: Set class based on DMI i2c: algo-pca: Add 0x78 as SCL stuck low status for PCA9665 mm/page_alloc: fix documentation error vmalloc: fix the owner argument for the new __vmalloc_node_range callers mm/cma.c: use exact_nid true to fix possible per-numa cma leak ...
Diffstat (limited to 'arch/x86/kernel/cpu/intel.c')
-rw-r--r--arch/x86/kernel/cpu/intel.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index c25a67a34bd3..0ab48f1cdf84 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -50,6 +50,13 @@ static enum split_lock_detect_state sld_state __ro_after_init = sld_off;
static u64 msr_test_ctrl_cache __ro_after_init;
/*
+ * With a name like MSR_TEST_CTL it should go without saying, but don't touch
+ * MSR_TEST_CTL unless the CPU is one of the whitelisted models. Writing it
+ * on CPUs that do not support SLD can cause fireworks, even when writing '0'.
+ */
+static bool cpu_model_supports_sld __ro_after_init;
+
+/*
* Processors which have self-snooping capability can handle conflicting
* memory type across CPUs by snooping its own cache. However, there exists
* CPU models in which having conflicting memory types still leads to
@@ -1071,7 +1078,8 @@ static void sld_update_msr(bool on)
static void split_lock_init(void)
{
- split_lock_verify_msr(sld_state != sld_off);
+ if (cpu_model_supports_sld)
+ split_lock_verify_msr(sld_state != sld_off);
}
static void split_lock_warn(unsigned long ip)
@@ -1177,5 +1185,6 @@ void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c)
return;
}
+ cpu_model_supports_sld = true;
split_lock_setup();
}