Hi Ben,
> The various calls to establish exception endianness and AIL are
> now done from a single point using already established CPU and FW
> feature bits to decide what to do.
>
> Signed-off-by: Benjamin Herrenschmidt <b...@kernel.crashing.org>
...
+static void configure_exceptions(void)
+{
+ /* Setup the trampolines from the lowmem exception vectors
+ * to the kdump kernel when not using a relocatable kernel.
+ */
+ setup_kdump_trampoline();
+
+ /* Under a PAPR hypervisor, we need hypercalls */
+ if (firmware_has_feature(FW_FEATURE_SET_MODE)) {
+ long rc;
+
+ /* Enable AIL */
+ rc = pSeries_enable_reloc_on_exc();
+ if (rc == H_P2) {
+ pr_info("Relocation on exceptions not supported\n");
+ } else if (rc != H_SUCCESS) {
+ pr_warn("Unable to enable relocation on exceptions: "
+ "%ld\n", rc);
+ }
+
+ /*
+ * Tell the hypervisor that we want our exceptions to
+ * be taken in little endian mode. If this fails we don't
+ * want to use BUG() because it will trigger an exception.
+ *
+ * We don't call this for big endian as our calling convention
+ * makes us always enter in BE, and the call may fail under
+ * some circumstances with kdump.
+ */
+#ifdef __LITTLE_ENDIAN__
+ rc = pseries_little_endian_exceptions();
+ if (rc) {
+ ppc_md.progress("H_SET_MODE LE exception fail", 0);
+ panic("Could not enable little endian exceptions");
+ }
+#endif
+ } else {
+ /* Set endian mode using OPAL */
+ if (firmware_has_feature(FW_FEATURE_OPAL))
+ opal_configure_cores();
+
+ /* Enable AIL if supported, and we are in hypervisor mode */
+ if (cpu_has_feature(CPU_FTR_HVMODE) &&
+ cpu_has_feature(CPU_FTR_ARCH_207S)) {
+ unsigned long lpcr = mfspr(SPRN_LPCR);
+ mtspr(SPRN_LPCR, lpcr | LPCR_AIL_3);
+ }
+ }
+}
It looks like we only set LPCR_AIL_3 on the boot CPU after this change,
is that expected? Before that we did it in cpu_ready_for_interrupts()
which is called for the primary and all secondary CPUs.
Anton
