blob: afe436179d42da50c1de8760b42e27db2f30499c [file] [log] [blame]
/*
* Secondary cpu support
*
* Copyright 2016 Suraj Jitindar Singh, IBM.
*
* This work is licensed under the terms of the GNU LGPL, version 2.
*/
#include <devicetree.h>
#include <asm/setup.h>
#include <asm/rtas.h>
#include <asm/smp.h>
int nr_threads;
struct secondary_entry_data {
secondary_entry_fn entry;
uint64_t r3;
int nr_started;
};
/*
* Start stopped thread cpu_id at entry
* Returns: <0 on failure to start stopped cpu
* 0 on success
* >0 on cpu not in stopped state
*/
int start_thread(int cpu_id, secondary_entry_fn entry, uint32_t r3)
{
uint32_t query_token, start_token;
int outputs[1], ret;
ret = rtas_token("query-cpu-stopped-state", &query_token);
assert(ret == 0);
ret = rtas_token("start-cpu", &start_token);
assert(ret == 0);
ret = rtas_call(query_token, 1, 2, outputs, cpu_id);
if (ret) {
printf("query-cpu-stopped-state failed for cpu %d\n", cpu_id);
} else if (!outputs[0]) { /* cpu in stopped state */
ret = rtas_call(start_token, 3, 1, NULL, cpu_id, entry, r3);
if (ret)
printf("failed to start cpu %d\n", cpu_id);
} else { /* cpu not in stopped state */
ret = outputs[0];
}
return ret;
}
/*
* Start all stopped threads (vcpus) on cpu_node
* Returns: Number of stopped cpus which were successfully started
*/
struct start_threads start_cpu(int cpu_node, secondary_entry_fn entry,
uint32_t r3)
{
int len, i, nr_threads, nr_started = 0;
const struct fdt_property *prop;
u32 *threads;
/* Get the id array of threads on this cpu_node */
prop = fdt_get_property(dt_fdt(), cpu_node,
"ibm,ppc-interrupt-server#s", &len);
assert(prop);
nr_threads = len >> 2; /* Divide by 4 since 4 bytes per thread */
threads = (u32 *)prop->data; /* Array of valid ids */
for (i = 0; i < nr_threads; i++) {
if (!start_thread(fdt32_to_cpu(threads[i]), entry, r3))
nr_started++;
}
return (struct start_threads) { nr_threads, nr_started };
}
static void start_each_secondary(int fdtnode, u64 regval __unused, void *info)
{
struct secondary_entry_data *datap = info;
struct start_threads ret = start_cpu(fdtnode, datap->entry, datap->r3);
nr_threads += ret.nr_threads;
datap->nr_started += ret.nr_started;
}
/*
* Start all stopped cpus on the guest at entry with register 3 set to r3
* We expect that we come in with only one thread currently started
* Returns: TRUE on success
* FALSE on failure
*/
bool start_all_cpus(secondary_entry_fn entry, uint32_t r3)
{
struct secondary_entry_data data = { entry, r3, 0 };
int ret;
ret = dt_for_each_cpu_node(start_each_secondary, &data);
assert(ret == 0);
/* We expect that we come in with one thread already started */
return data.nr_started == nr_threads - 1;
}