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author | Jason Gunthorpe <jgg@mellanox.com> | 2019-08-21 14:10:36 -0300 |
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committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-08-21 14:10:36 -0300 |
commit | 868df536f5e84672c3e002b949e0e44f97cb0f09 (patch) | |
tree | f76da5f6d06125b6d91c75ebfe4079ec9e2f958a /arch/x86/kernel/cpu/umwait.c | |
parent | RDMA: Delete DEBUG code (diff) | |
parent | RDMA/mlx5: Use odp instead of mr->umem in pagefault_mr (diff) | |
download | linux-dev-868df536f5e84672c3e002b949e0e44f97cb0f09.tar.xz linux-dev-868df536f5e84672c3e002b949e0e44f97cb0f09.zip |
Merge branch 'odp_fixes' into rdma.git for-next
Jason Gunthorpe says:
====================
This is a collection of general cleanups for ODP to clarify some of the
flows around umem creation and use of the interval tree.
====================
The branch is based on v5.3-rc5 due to dependencies
* odp_fixes:
RDMA/mlx5: Use odp instead of mr->umem in pagefault_mr
RDMA/mlx5: Use ib_umem_start instead of umem.address
RDMA/core: Make invalidate_range a device operation
RDMA/odp: Use kvcalloc for the dma_list and page_list
RDMA/odp: Check for overflow when computing the umem_odp end
RDMA/odp: Provide ib_umem_odp_release() to undo the allocs
RDMA/odp: Split creating a umem_odp from ib_umem_get
RDMA/odp: Make the three ways to create a umem_odp clear
RMDA/odp: Consolidate umem_odp initialization
RDMA/odp: Make it clearer when a umem is an implicit ODP umem
RDMA/odp: Iterate over the whole rbtree directly
RDMA/odp: Use the common interval tree library instead of generic
RDMA/mlx5: Fix MR npages calculation for IB_ACCESS_HUGETLB
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'arch/x86/kernel/cpu/umwait.c')
-rw-r--r-- | arch/x86/kernel/cpu/umwait.c | 39 |
1 files changed, 38 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/umwait.c b/arch/x86/kernel/cpu/umwait.c index 6a204e7336c1..32b4dc9030aa 100644 --- a/arch/x86/kernel/cpu/umwait.c +++ b/arch/x86/kernel/cpu/umwait.c @@ -18,6 +18,12 @@ static u32 umwait_control_cached = UMWAIT_CTRL_VAL(100000, UMWAIT_C02_ENABLE); /* + * Cache the original IA32_UMWAIT_CONTROL MSR value which is configured by + * hardware or BIOS before kernel boot. + */ +static u32 orig_umwait_control_cached __ro_after_init; + +/* * Serialize access to umwait_control_cached and IA32_UMWAIT_CONTROL MSR in * the sysfs write functions. */ @@ -53,6 +59,23 @@ static int umwait_cpu_online(unsigned int cpu) } /* + * The CPU hotplug callback sets the control MSR to the original control + * value. + */ +static int umwait_cpu_offline(unsigned int cpu) +{ + /* + * This code is protected by the CPU hotplug already and + * orig_umwait_control_cached is never changed after it caches + * the original control MSR value in umwait_init(). So there + * is no race condition here. + */ + wrmsr(MSR_IA32_UMWAIT_CONTROL, orig_umwait_control_cached, 0); + + return 0; +} + +/* * On resume, restore IA32_UMWAIT_CONTROL MSR on the boot processor which * is the only active CPU at this time. The MSR is set up on the APs via the * CPU hotplug callback. @@ -185,8 +208,22 @@ static int __init umwait_init(void) if (!boot_cpu_has(X86_FEATURE_WAITPKG)) return -ENODEV; + /* + * Cache the original control MSR value before the control MSR is + * changed. This is the only place where orig_umwait_control_cached + * is modified. + */ + rdmsrl(MSR_IA32_UMWAIT_CONTROL, orig_umwait_control_cached); + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "umwait:online", - umwait_cpu_online, NULL); + umwait_cpu_online, umwait_cpu_offline); + if (ret < 0) { + /* + * On failure, the control MSR on all CPUs has the + * original control value. + */ + return ret; + } register_syscore_ops(&umwait_syscore_ops); |