Add basic P9 fused core support

P9 cores can be configured into fused core mode where two core chiplets
function as an 8-threaded, single core.  So, bump four to eight in boot_entry
when in fused core mode and cpu_thread_count in init_boot_cpu.

The HID, AMOR, TSCR, RPR require the first active thread on that core chiplet
to load the copy for that core chiplet.  So, send thread 1 of a fused core to
init_shared_sprs in boot_entry.

The code checks for fused core mode in the core thead state register and puts a
field in struct cpu_thread.  This flag is checked when updating the HID and in
XIVE code when setting the special bar.

For XSCOM, the core ID is the non-fused EX.  So, create macros to arrange the
bits.  It's fairly verbose but somewhat readable.

This was tested on a P9 ZZ with 16 fused cores and ran HTX for over 24 hours.

Signed-off-by: Ryan Grimm <grimm@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/hw/xive.c b/hw/xive.c
index f8837ae..cf2cede 100644
--- a/hw/xive.c
+++ b/hw/xive.c
@@ -3089,7 +3089,7 @@ static void xive_init_cpu(struct cpu_thread *c)
 	 * of a pair is present we just do the setup for each of them, which
 	 * is harmless.
 	 */
-	if (cpu_is_thread0(c))
+	if (cpu_is_thread0(c) || cpu_is_core_chiplet_primary(c))
 		xive_configure_ex_special_bar(x, c);
 
 	/* Initialize the state structure */