On Mon, Dec 03, 2018 at 11:39:58PM -0800, Alison Schofield wrote:
> +struct mktme_hw_program_info {
> + struct mktme_key_program *key_program;
> + unsigned long status;
> +};
> +
> +/* Program a KeyID on a single package. */
> +static void mktme_program_package(void *hw_program_info)
> +{
> + struct mktme_hw_program_info *info = hw_program_info;
> + int ret;
> +
> + ret = mktme_key_program(info->key_program);
> + if (ret != MKTME_PROG_SUCCESS)
> + WRITE_ONCE(info->status, ret);
What's the purpose of that WRITE_ONCE()?
> +}
> +
> +/* Program a KeyID across the entire system. */
> +static int mktme_program_system(struct mktme_key_program *key_program,
> + cpumask_var_t mktme_cpumask)
> +{
> + struct mktme_hw_program_info info = {
> + .key_program = key_program,
> + .status = MKTME_PROG_SUCCESS,
> + };
> + get_online_cpus();
> + on_each_cpu_mask(mktme_cpumask, mktme_program_package, &info, 1);
> + put_online_cpus();
> +
> + return info.status;
> +}
> +
> /* Copy the payload to the HW programming structure and program this KeyID */
> static int mktme_program_keyid(int keyid, struct mktme_payload *payload)
> {
> @@ -84,7 +116,7 @@ static int mktme_program_keyid(int keyid, struct mktme_payload *payload)
> kprog->key_field_2[i] ^= kern_entropy[i];
> }
> }
> - ret = mktme_key_program(kprog);
> + ret = mktme_program_system(kprog, mktme_leadcpus);
> kmem_cache_free(mktme_prog_cache, kprog);
> return ret;
> }
> @@ -299,6 +331,28 @@ struct key_type key_type_mktme = {
> .destroy = mktme_destroy_key,
> };
>
> +static int mktme_build_leadcpus_mask(void)
> +{
> + int online_cpu, mktme_cpu;
> + int online_pkgid, mktme_pkgid = -1;
> +
> + if (!zalloc_cpumask_var(&mktme_leadcpus, GFP_KERNEL))
> + return -ENOMEM;
> +
> + for_each_online_cpu(online_cpu) {
> + online_pkgid = topology_physical_package_id(online_cpu);
> +
> + for_each_cpu(mktme_cpu, mktme_leadcpus) {
> + mktme_pkgid = topology_physical_package_id(mktme_cpu);
> + if (mktme_pkgid == online_pkgid)
> + break;
> + }
> + if (mktme_pkgid != online_pkgid)
> + cpumask_set_cpu(online_cpu, mktme_leadcpus);
Do you really need LOCK prefixed bit set here?
> + }
> + return 0;
> +}
How is that serialized and kept relevant in the face of hotplug?
Also, do you really need O(n^2) to find the first occurence of a value
in an array?
