ARC: cache boot reporting updates

* print aliasing or not, VIPT/PIPT etc
* compress param storage using bitfields
* more use of IS_ENABLED to de-uglify code

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/include/asm/arcregs.h

@@ -296,7 +296,7 @@ struct cpuinfo_arc_mmu {
 };
 
 struct cpuinfo_arc_cache {
-	unsigned int sz, line_len, assoc, ver;
+	unsigned int sz_k:8, line_len:8, assoc:4, ver:4, alias:1, vipt:1, pad:6;
 };
 
 struct cpuinfo_arc_ccm {

arch/arc/mm/cache_arc700.c

@@ -77,21 +77,19 @@ char *arc_cache_mumbojumbo(int c, char *buf, int len)
 {
 	int n = 0;
 
-#define PR_CACHE(p, enb, str)						\
-{									\
+#define PR_CACHE(p, cfg, str)						\
 	if (!(p)->ver)							\
 		n += scnprintf(buf + n, len - n, str"\t\t: N/A\n");	\
 	else								\
 		n += scnprintf(buf + n, len - n,			\
-			str"\t\t: (%uK) VIPT, %dway set-asc, %ub Line %s\n", \
-			TO_KB((p)->sz), (p)->assoc, (p)->line_len,	\
-			enb ?  "" : "DISABLED (kernel-build)");		\
-}
+			str"\t\t: %uK, %dway/set, %uB Line, %s%s%s\n",	\
+			(p)->sz_k, (p)->assoc, (p)->line_len,		\
+			(p)->vipt ? "VIPT" : "PIPT",			\
+			(p)->alias ? " aliasing" : "",			\
+			IS_ENABLED(cfg) ? "" : " (not used)");
 
-	PR_CACHE(&cpuinfo_arc700[c].icache, IS_ENABLED(CONFIG_ARC_HAS_ICACHE),
-			"I-Cache");
-	PR_CACHE(&cpuinfo_arc700[c].dcache, IS_ENABLED(CONFIG_ARC_HAS_DCACHE),
-			"D-Cache");
+	PR_CACHE(&cpuinfo_arc700[c].icache, CONFIG_ARC_HAS_ICACHE, "I-Cache");
+	PR_CACHE(&cpuinfo_arc700[c].dcache, CONFIG_ARC_HAS_DCACHE, "D-Cache");
 
 	return buf;
 }
@@ -116,20 +114,31 @@ void read_decode_cache_bcr(void)
 	p_ic = &cpuinfo_arc700[cpu].icache;
 	READ_BCR(ARC_REG_IC_BCR, ibcr);
 
+	if (!ibcr.ver)
+		goto dc_chk;
+
 	BUG_ON(ibcr.config != 3);
 	p_ic->assoc = 2;		/* Fixed to 2w set assoc */
 	p_ic->line_len = 8 << ibcr.line_len;
-	p_ic->sz = 0x200 << ibcr.sz;
+	p_ic->sz_k = 1 << (ibcr.sz - 1);
 	p_ic->ver = ibcr.ver;
+	p_ic->vipt = 1;
+	p_ic->alias = p_ic->sz_k/p_ic->assoc/TO_KB(PAGE_SIZE) > 1;
 
+dc_chk:
 	p_dc = &cpuinfo_arc700[cpu].dcache;
 	READ_BCR(ARC_REG_DC_BCR, dbcr);
 
+	if (!dbcr.ver)
+		return;
+
 	BUG_ON(dbcr.config != 2);
 	p_dc->assoc = 4;		/* Fixed to 4w set assoc */
 	p_dc->line_len = 16 << dbcr.line_len;
-	p_dc->sz = 0x200 << dbcr.sz;
+	p_dc->sz_k = 1 << (dbcr.sz - 1);
 	p_dc->ver = dbcr.ver;
+	p_dc->vipt = 1;
+	p_dc->alias = p_dc->sz_k/p_dc->assoc/TO_KB(PAGE_SIZE) > 1;
 }
 
 /*
@@ -142,14 +151,16 @@ void read_decode_cache_bcr(void)
 void arc_cache_init(void)
 {
 	unsigned int __maybe_unused cpu = smp_processor_id();
-	struct cpuinfo_arc_cache __maybe_unused *ic, __maybe_unused *dc;
 	char str[256];
 
 	printk(arc_cache_mumbojumbo(0, str, sizeof(str)));
 
-#ifdef CONFIG_ARC_HAS_ICACHE
-	ic = &cpuinfo_arc700[cpu].icache;
-	if (ic->ver) {
+	if (IS_ENABLED(CONFIG_ARC_HAS_ICACHE)) {
+		struct cpuinfo_arc_cache *ic = &cpuinfo_arc700[cpu].icache;
+
+		if (!ic->ver)
+			panic("cache support enabled but non-existent cache\n");
+
 		if (ic->line_len != L1_CACHE_BYTES)
 			panic("ICache line [%d] != kernel Config [%d]",
 			      ic->line_len, L1_CACHE_BYTES);
@@ -158,26 +169,26 @@ void arc_cache_init(void)
 			panic("Cache ver [%d] doesn't match MMU ver [%d]\n",
 			      ic->ver, CONFIG_ARC_MMU_VER);
 	}
-#endif
 
-#ifdef CONFIG_ARC_HAS_DCACHE
-	dc = &cpuinfo_arc700[cpu].dcache;
-	if (dc->ver) {
-		unsigned int dcache_does_alias;
+	if (IS_ENABLED(CONFIG_ARC_HAS_DCACHE)) {
+		struct cpuinfo_arc_cache *dc = &cpuinfo_arc700[cpu].dcache;
+		int handled;
+
+		if (!dc->ver)
+			panic("cache support enabled but non-existent cache\n");
 
 		if (dc->line_len != L1_CACHE_BYTES)
 			panic("DCache line [%d] != kernel Config [%d]",
 			      dc->line_len, L1_CACHE_BYTES);
 
 		/* check for D-Cache aliasing */
-		dcache_does_alias = (dc->sz / dc->assoc) > PAGE_SIZE;
+		handled = IS_ENABLED(CONFIG_ARC_CACHE_VIPT_ALIASING);
 
-		if (dcache_does_alias && !cache_is_vipt_aliasing())
+		if (dc->alias && !handled)
 			panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
-		else if (!dcache_does_alias && cache_is_vipt_aliasing())
+		else if (!dc->alias && handled)
 			panic("Don't need CONFIG_ARC_CACHE_VIPT_ALIASING\n");
 	}
-#endif
 }
 
 #define OP_INV		0x1