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-rw-r--r--src/arch/x86/cpu.c13
-rw-r--r--src/cpu/x86/Kconfig6
-rw-r--r--src/cpu/x86/mp_init.c107
-rw-r--r--src/include/cpu/x86/mp.h18
4 files changed, 137 insertions, 7 deletions
diff --git a/src/arch/x86/cpu.c b/src/arch/x86/cpu.c
index fbd48b0c2b..1e74d0cd59 100644
--- a/src/arch/x86/cpu.c
+++ b/src/arch/x86/cpu.c
@@ -11,11 +11,13 @@
* GNU General Public License for more details.
*/
+#include <bootstate.h>
#include <boot/coreboot_tables.h>
#include <console/console.h>
#include <cpu/cpu.h>
#include <arch/io.h>
#include <string.h>
+#include <cpu/x86/mp.h>
#include <cpu/x86/mtrr.h>
#include <cpu/x86/msr.h>
#include <cpu/x86/lapic.h>
@@ -310,3 +312,14 @@ void lb_arch_add_records(struct lb_header *header)
tsc_info->size = sizeof(*tsc_info);
tsc_info->freq_khz = freq_khz;
}
+
+void arch_bootstate_coreboot_exit(void)
+{
+ /* APs are already parked by existing infrastructure. */
+ if (!IS_ENABLED(CONFIG_PARALLEL_MP_AP_WORK))
+ return;
+
+ /* APs are waiting for work. Last thing to do is park them. */
+ if (mp_park_aps())
+ printk(BIOS_ERR, "Parking APs failed.\n");
+}
diff --git a/src/cpu/x86/Kconfig b/src/cpu/x86/Kconfig
index 3e56d721f5..2e233cc778 100644
--- a/src/cpu/x86/Kconfig
+++ b/src/cpu/x86/Kconfig
@@ -10,6 +10,12 @@ config PARALLEL_MP
in parallel. It additionally provides a more flexible mechanism
for sequencing the steps of bringing up the APs.
+config PARALLEL_MP_AP_WORK
+ def_bool n
+ depends on PARALLEL_MP
+ help
+ Allow APs to do other work after initialization instead of going
+ to sleep.
config UDELAY_IO
bool
diff --git a/src/cpu/x86/mp_init.c b/src/cpu/x86/mp_init.c
index baa3599a94..c989963442 100644
--- a/src/cpu/x86/mp_init.c
+++ b/src/cpu/x86/mp_init.c
@@ -127,6 +127,7 @@ struct mp_flight_plan {
struct mp_flight_record *records;
};
+static int global_num_aps;
static struct mp_flight_plan mp_info;
struct cpu_map {
@@ -185,6 +186,11 @@ static void ap_do_flight_plan(void)
}
}
+static void park_this_cpu(void)
+{
+ stop_this_cpu();
+}
+
/* By the time APs call ap_init() caching has been setup, and microcode has
* been loaded. */
static void asmlinkage ap_init(unsigned int cpu)
@@ -210,7 +216,7 @@ static void asmlinkage ap_init(unsigned int cpu)
ap_do_flight_plan();
/* Park the AP. */
- stop_this_cpu();
+ park_this_cpu();
}
static void setup_default_sipi_vector_params(struct sipi_params *sp)
@@ -587,7 +593,6 @@ static void init_bsp(struct bus *cpu_bus)
static int mp_init(struct bus *cpu_bus, struct mp_params *p)
{
int num_cpus;
- int num_aps;
atomic_t *ap_count;
init_bsp(cpu_bus);
@@ -621,11 +626,11 @@ static int mp_init(struct bus *cpu_bus, struct mp_params *p)
wbinvd();
/* Start the APs providing number of APs and the cpus_entered field. */
- num_aps = p->num_cpus - 1;
- if (start_aps(cpu_bus, num_aps, ap_count) < 0) {
+ global_num_aps = p->num_cpus - 1;
+ if (start_aps(cpu_bus, global_num_aps, ap_count) < 0) {
mdelay(1000);
printk(BIOS_DEBUG, "%d/%d eventually checked in?\n",
- atomic_read(ap_count), num_aps);
+ atomic_read(ap_count), global_num_aps);
return -1;
}
@@ -838,6 +843,94 @@ static void trigger_smm_relocation(void)
mp_state.ops.per_cpu_smm_trigger();
}
+static mp_callback_t ap_callbacks[CONFIG_MAX_CPUS];
+
+static mp_callback_t read_callback(mp_callback_t *slot)
+{
+ return *(volatile mp_callback_t *)slot;
+}
+
+static void store_callback(mp_callback_t *slot, mp_callback_t value)
+{
+ *(volatile mp_callback_t *)slot = value;
+}
+
+static int run_ap_work(mp_callback_t func, long expire_us)
+{
+ int i;
+ int cpus_accepted;
+ struct stopwatch sw;
+ int cur_cpu = cpu_index();
+
+ if (!IS_ENABLED(CONFIG_PARALLEL_MP_AP_WORK)) {
+ printk(BIOS_ERR, "APs already parked. PARALLEL_MP_AP_WORK not selected.\n");
+ return -1;
+ }
+
+ /* Signal to all the APs to run the func. */
+ for (i = 0; i < ARRAY_SIZE(ap_callbacks); i++) {
+ if (cur_cpu == i)
+ continue;
+ store_callback(&ap_callbacks[i], func);
+ }
+ mfence();
+
+ /* Wait for all the APs to signal back that call has been accepted. */
+ stopwatch_init_usecs_expire(&sw, expire_us);
+ for (cpus_accepted = 0; !stopwatch_expired(&sw); cpus_accepted = 0) {
+ for (i = 0; i < ARRAY_SIZE(ap_callbacks); i++) {
+ if (cur_cpu == i)
+ continue;
+ if (read_callback(&ap_callbacks[i]) == NULL)
+ cpus_accepted++;
+ }
+ if (cpus_accepted == global_num_aps)
+ return 0;
+ }
+
+ printk(BIOS_ERR, "AP call expired. %d/%d CPUs accepted.\n",
+ cpus_accepted, global_num_aps);
+ return -1;
+}
+
+static void ap_wait_for_instruction(void)
+{
+ int cur_cpu = cpu_index();
+
+ if (!IS_ENABLED(CONFIG_PARALLEL_MP_AP_WORK))
+ return;
+
+ while (1) {
+ mp_callback_t func = read_callback(&ap_callbacks[cur_cpu]);
+
+ if (func == NULL) {
+ asm ("pause");
+ continue;
+ }
+
+ store_callback(&ap_callbacks[cur_cpu], NULL);
+ mfence();
+ func();
+ }
+}
+
+int mp_run_on_aps(void (*func)(void), long expire_us)
+{
+ return run_ap_work(func, expire_us);
+}
+
+int mp_run_on_all_cpus(void (*func)(void), long expire_us)
+{
+ /* Run on BSP first. */
+ func();
+ return mp_run_on_aps(func, expire_us);
+}
+
+int mp_park_aps(void)
+{
+ return mp_run_on_aps(park_this_cpu, 10 * USECS_PER_MSEC);
+}
+
static struct mp_flight_record mp_steps[] = {
/* Once the APs are up load the SMM handlers. */
MP_FR_BLOCK_APS(NULL, load_smm_handlers),
@@ -845,8 +938,8 @@ static struct mp_flight_record mp_steps[] = {
MP_FR_NOBLOCK_APS(trigger_smm_relocation, trigger_smm_relocation),
/* Initialize each CPU through the driver framework. */
MP_FR_BLOCK_APS(mp_initialize_cpu, mp_initialize_cpu),
- /* Wait for APs to finish everything else then let them park. */
- MP_FR_BLOCK_APS(NULL, NULL),
+ /* Wait for APs to finish then optionally start looking for work. */
+ MP_FR_BLOCK_APS(ap_wait_for_instruction, NULL),
};
static void fill_mp_state(struct mp_state *state, const struct mp_ops *ops)
diff --git a/src/include/cpu/x86/mp.h b/src/include/cpu/x86/mp.h
index 6d51d7b005..b9b4d5772c 100644
--- a/src/include/cpu/x86/mp.h
+++ b/src/include/cpu/x86/mp.h
@@ -124,6 +124,24 @@ struct mp_ops {
*/
int mp_init_with_smm(struct bus *cpu_bus, const struct mp_ops *mp_ops);
+
+/*
+ * After APs are up and PARALLEL_MP_AP_WORK is enabled one can issue work
+ * to all the APs to perform. Currently the BSP is the only CPU that is allowed
+ * to issue work. i.e. the APs should not call any of these functions.
+ * All functions return < 0 on error, 0 on success.
+ */
+int mp_run_on_aps(void (*func)(void), long expire_us);
+
+/* Like mp_run_on_aps() but also runs func on BSP. */
+int mp_run_on_all_cpus(void (*func)(void), long expire_us);
+
+/*
+ * Park all APs to prepare for OS boot. This is handled automatically
+ * by the coreboot infrastructure.
+ */
+int mp_park_aps(void);
+
/*
* SMM helpers to use with initializing CPUs.
*/
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-31 01:44:08 +0000