MIPS: Probe for small (1KiB) page support

Probe Config3 for small page support. This will be useful to give clues
as to whether the PageGrain register exists.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10722/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/cpu-features.h

@@ -411,4 +411,8 @@
 # define cpu_has_cdmm		(cpu_data[0].options & MIPS_CPU_CDMM)
 #endif
 
+#ifndef cpu_has_small_pages
+# define cpu_has_small_pages	(cpu_data[0].options & MIPS_CPU_SP)
+#endif
+
 #endif /* __ASM_CPU_FEATURES_H */

arch/mips/include/asm/cpu.h

@@ -384,6 +384,7 @@ enum cpu_type_enum {
 #define MIPS_CPU_XPA		0x2000000000ull /* CPU supports Extended Physical Addressing */
 #define MIPS_CPU_CDMM		0x4000000000ull	/* CPU has Common Device Memory Map */
 #define MIPS_CPU_BP_GHIST	0x8000000000ull /* R12K+ Branch Prediction Global History */
+#define MIPS_CPU_SP		0x10000000000ull /* Small (1KB) page support */
 
 /*
  * CPU ASE encodings

arch/mips/kernel/cpu-probe.c

@@ -538,6 +538,8 @@ static inline unsigned int decode_config3(struct cpuinfo_mips *c)
 	}
 	if (config3 & MIPS_CONF3_CDMM)
 		c->options |= MIPS_CPU_CDMM;
+	if (config3 & MIPS_CONF3_SP)
+		c->options |= MIPS_CPU_SP;
 
 	return config3 & MIPS_CONF_M;
 }