MIPS: Fix early CM probing

Commit c014d164f21d ("MIPS: Add platform callback before initializing
the L2 cache") added a platform_early_l2_init function in order to allow
platforms to probe for the CM before L2 initialisation is performed, so
that CM GCRs are available to mips_sc_probe.

That commit actually fails to do anything useful, since it checks
mips_cm_revision to determine whether it should call mips_cm_probe but
the result of mips_cm_revision will always be 0 until mips_cm_probe has
been called. Thus the "early" mips_cm_probe call never occurs.

Fix this & drop the useless weak platform_early_l2_init function by
simply calling mips_cm_probe from setup_arch. For platforms that don't
select CONFIG_MIPS_CM this will be a no-op, and for those that do it
removes the requirement for them to call mips_cm_probe manually
(although doing so isn't harmful for now).

Signed-off-by: Paul Burton <[e-mail]>
Reviewed-by: Alexander Sverdlin <[e-mail]>
Cc: Andrzej Hajda <[e-mail]>
Cc: Aaro Koskinen <[e-mail]>
Cc: Masahiro Yamada <[e-mail]>
Cc: Rob Herring <[e-mail]>
Cc: Peter Hurley <[e-mail]>
Cc: Leonid Yegoshin <[e-mail]>
Cc: Jaedon Shin <[e-mail]>
Cc: James Hogan <[e-mail]>
Cc: Jonas Gorski <[e-mail]>
Cc: Markos Chandras <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Patchwork: https://patchwork.linux-mips.org/patch/12475/
Signed-off-by: Ralf Baechle <[e-mail]>

arch/mips/kernel/setup.c

···
 void __init setup_arch(char **cmdline_p)
 {
 	cpu_probe();
+	mips_cm_probe();
 	prom_init();
 
 	setup_early_fdc_console();

arch/mips/mm/sc-mips.c

···
 	return 1;
 }
 
-void __weak platform_early_l2_init(void)
-{
-}
-
 static inline int __init mips_sc_probe(void)
 {
 	struct cpuinfo_mips *c = &current_cpu_data;
···
 
 	/* Mark as not present until probe completed */
 	c->scache.flags |= MIPS_CACHE_NOT_PRESENT;
-
-	/*
-	 * Do we need some platform specific probing before
-	 * we configure L2?
-	 */
-	platform_early_l2_init();
 
 	if (mips_cm_revision() >= CM_REV_CM3)
 		return mips_sc_probe_cm3();

arch/mips/mti-malta/malta-init.c

···
 	console_config();
 #endif
 	/* Early detection of CMP support */
-	mips_cm_probe();
 	mips_cpc_probe();
 
 	if (!register_cps_smp_ops())
···
 	if (!register_vsmp_smp_ops())
 		return;
 	register_up_smp_ops();
-}
-
-void platform_early_l2_init(void)
-{
-	/* L2 configuration lives in the CM3 */
-	if (mips_cm_revision() >= CM_REV_CM3)
-		mips_cm_probe();
 }