mips: Extract HWREna configuration and call from APs

The intent of mips_get_identity is to perform any feature detection and
corresponding global system configuration, but currently it is also
abused to set HWREna.UL on the BSP when available, with APs being left
unconfigured. Extract that part out into its own function that gets
called after mips_get_identity on the BSP, and call it on the APs from
smp_init_secondary.

This is a direct commit to stable/13 as mips no longer exists in main.

Reviewed by:	jhibbits
Differential Revision:	https://reviews.freebsd.org/D48064

sys/mips/include/md_var.h

@@ -71,6 +71,7 @@ void	mips_wait(void);
 
 void	mips_vector_init(void);
 void	mips_cpu_init(void);
+void	mips_hwrena_init(void);
 void	mips_pcpu0_init(void);
 void	mips_proc0_init(void);
 void	mips_postboot_fixup(void);

sys/mips/mips/cpu.c

@@ -141,10 +141,11 @@ mips_get_identity(struct mips_cpuinfo *cpuinfo)
 
 	/* Check to see if UserLocal register is implemented. */
 	if (cfg3 & MIPS_CONFIG3_ULR) {
-		/* UserLocal register is implemented, enable it. */
+		/*
+		 * UserLocal register is implemented, enable it later in
+		 * mips_hwrena_init.
+		 */
 		cpuinfo->userlocal_reg = true;
-		tmp = mips_rd_hwrena();
-		mips_wr_hwrena(tmp | MIPS_HWRENA_UL);
 	} else {
 		/*
 		 * UserLocal register is not implemented. Patch
@@ -275,11 +276,25 @@ mips_get_identity(struct mips_cpuinfo *cpuinfo)
 #endif
 }
 
+void
+mips_hwrena_init(void)
+{
+	uint32_t reg;
+
+	reg = mips_rd_hwrena();
+
+	if (cpuinfo.userlocal_reg)
+		reg |= MIPS_HWRENA_UL;
+
+	mips_wr_hwrena(reg);
+}
+
 void
 mips_cpu_init(void)
 {
 	platform_cpu_init();
 	mips_get_identity(&cpuinfo);
+	mips_hwrena_init();
 	num_tlbentries = cpuinfo.tlb_nentries;
 	mips_wr_wired(0);
 	tlb_invalidate_all();

sys/mips/mips/mp_machdep.c

@@ -52,6 +52,7 @@
 #include <machine/intr_machdep.h>
 #include <machine/cache.h>
 #include <machine/tlb.h>
+#include <machine/md_var.h>
 
 struct pcb stoppcbs[MAXCPU];
 
@@ -276,6 +277,8 @@ void
 smp_init_secondary(u_int32_t cpuid)
 {
 
+	mips_hwrena_init();
+
 	/* TLB */
 	mips_wr_wired(0);
 	tlb_invalidate_all();