Hi Simon,
-----"Simon Glass" sjg@chromium.org schrieb: -----
Betreff: [PATCH v2 10/25] x86: mp: Support APs waiting for instructions
At present the APs (non-boot CPUs) are inited once and then parked ready for the OS to use them. However in some cases we want to send new requests through, such as to change MTRRs and keep them consistent across CPUs.
Change the last state of the flight plan to go into a wait loop, accepting instructions from the main CPU.
Signed-off-by: Simon Glass sjg@chromium.org
Changes in v2:
- Add more comments
arch/x86/cpu/mp_init.c | 126 +++++++++++++++++++++++++++++++++++--- arch/x86/include/asm/mp.h | 11 ++++ 2 files changed, 128 insertions(+), 9 deletions(-)
[snip]
@@ -455,6 +478,86 @@ static int get_bsp(struct udevice **devp, int *cpu_countp) return dev->req_seq; }
+/**
- read_callback() - Read the pointer in a callback slot
- This is called by APs to read their callback slow to see if there is a
Typo: callback slot
- pointer to new instructions
- @slot: Pointer to the AP's callback slot
- @return value of that pointer
- */
+static struct mp_callback *read_callback(struct mp_callback **slot) +{
- struct mp_callback *ret;
- asm volatile ("mov %1, %0\n"
: "=r" (ret): "m" (*slot): "memory"- );
- return ret;
+}
[snip]
Reviewed-by: Wolfgang Wallner wolfgang.wallner@br-automation.com