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| author | Kyösti Mälkki <kyosti.malkki@gmail.com> | 2012-03-09 17:02:37 +0200 |
|---|---|---|
| committer | Rudolf Marek <r.marek@assembler.cz> | 2012-03-25 20:33:28 +0200 |
| commit | 8b28d50cdd1384893ec0565453eea77031aa7ec8 (patch) | |
| tree | 1c6bcd46ea37a2d04a03369f6bc95840cdeda7c4 | |
| parent | 2172f61ede0ff7764eae39d4b75085c2dee9b610 (diff) | |
| download | coreboot-8b28d50cdd1384893ec0565453eea77031aa7ec8.tar.xz | |
Intel cpus: Fix deadlock on hyper-threading init
Only the BSP CPU was able to start its hyper-threading CPU siblings.
When an AP CPU attempts this it calls start_cpu() within start_cpu(),
deadlocking the system with start_cpu_lock.
At the time intel_sibling_init() is run, the BSP CPU is still
walking the cpu_bus linked list in lapic_cpu_init: start_other_cpus().
A sibling CPU appended at the end of this list will get started.
Also fail compile with #error if SERIAL_CPU_INIT==0, as microcode
updates on hyper-threading sibling CPUs must be serialized.
Tested with HT-enabled P4 Xeons on dual-socket604 platform.
Change-Id: I0053f58f49ed604605ce0a55e826d3e1afdc90b6
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/775
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Tested-by: build bot (Jenkins)
Reviewed-by: Rudolf Marek <r.marek@assembler.cz>
| -rw-r--r-- | src/cpu/intel/hyperthreading/intel_sibling.c | 22 |
1 files changed, 9 insertions, 13 deletions
diff --git a/src/cpu/intel/hyperthreading/intel_sibling.c b/src/cpu/intel/hyperthreading/intel_sibling.c index 823d77c3a3..e988664dda 100644 --- a/src/cpu/intel/hyperthreading/intel_sibling.c +++ b/src/cpu/intel/hyperthreading/intel_sibling.c @@ -5,6 +5,11 @@ #include <device/device.h> #include <pc80/mc146818rtc.h> #include <smp/spinlock.h> +#include <assert.h> + +#if CONFIG_SERIAL_CPU_INIT==0 +#error Intel hyper-threading requires serialized cpu init +#endif static int first_time = 1; static int disable_siblings = !CONFIG_LOGICAL_CPUS; @@ -30,11 +35,9 @@ void intel_sibling_init(device_t cpu) siblings = 1; } -#if 1 printk(BIOS_DEBUG, "CPU: %u %d siblings\n", cpu->path.apic.apic_id, siblings); -#endif /* See if I am a sibling cpu */ if (cpu->path.apic.apic_id & (siblings -1)) { @@ -53,25 +56,18 @@ void intel_sibling_init(device_t cpu) cpu_path.apic.apic_id = cpu->path.apic.apic_id + i; - /* Allocate the new cpu device structure */ - new = alloc_dev(cpu->bus, &cpu_path); + /* Allocate new cpu device structure iff sibling CPU + * was not in static device tree. + */ + new = alloc_find_dev(cpu->bus, &cpu_path); if (!new) { continue; } -#if 1 printk(BIOS_DEBUG, "CPU: %u has sibling %u\n", cpu->path.apic.apic_id, new->path.apic.apic_id); -#endif - /* Start the new cpu */ - if (!start_cpu(new)) { - /* Record the error in cpu? */ - printk(BIOS_ERR, "CPU %u would not start!\n", - new->path.apic.apic_id); - } } - } |