ARCv2: Support dynamic peripheral address space in HS38 rel 3.0 cores

HS release 3.0 provides for even more flexibility in specifying the
volatile address space for mapping peripherals.

With HS 2.1 @start was made flexible / programmable - with HS 3.0 even
@end can be setup (vs. fixed to 0xFFFF_FFFF before).

So add code to reflect that and while at it remove an unused struct
defintion
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/include/asm/arcregs.h

@@ -95,7 +95,7 @@
 /* Auxiliary registers */
 #define AUX_IDENTITY		4
 #define AUX_INTR_VEC_BASE	0x25
-#define AUX_NON_VOL		0x5e
+#define AUX_VOL			0x5e
 
 /*
  * Floating Pt Registers
@@ -240,14 +240,6 @@ struct bcr_extn_xymem {
 #endif
 };
 
-struct bcr_perip {
-#ifdef CONFIG_CPU_BIG_ENDIAN
-	unsigned int start:8, pad2:8, sz:8, ver:8;
-#else
-	unsigned int ver:8, sz:8, pad2:8, start:8;
-#endif
-};
-
 struct bcr_iccm_arcompact {
 #ifdef CONFIG_CPU_BIG_ENDIAN
 	unsigned int base:16, pad:5, sz:3, ver:8;

arch/arc/include/asm/cache.h

@@ -54,7 +54,7 @@ extern char *arc_cache_mumbojumbo(int cpu_id, char *buf, int len);
 extern void read_decode_cache_bcr(void);
 
 extern int ioc_exists;
-extern unsigned long perip_base;
+extern unsigned long perip_base, perip_end;
 
 #endif	/* !__ASSEMBLY__ */
 

arch/arc/kernel/setup.c

@@ -273,8 +273,8 @@ static char *arc_extn_mumbojumbo(int cpu_id, char *buf, int len)
 	FIX_PTR(cpu);
 
 	n += scnprintf(buf + n, len - n,
-		       "Vector Table\t: %#x\nUncached Base\t: %#lx\n",
-		       cpu->vec_base, perip_base);
+		       "Vector Table\t: %#x\nPeripherals\t: %#lx:%#lx\n",
+		       cpu->vec_base, perip_base, perip_end);
 
 	if (cpu->extn.fpu_sp || cpu->extn.fpu_dp)
 		n += scnprintf(buf + n, len - n, "FPU\t\t: %s%s\n",

arch/arc/mm/cache.c

@@ -25,6 +25,7 @@ static int l2_line_sz;
 int ioc_exists;
 volatile int slc_enable = 1, ioc_enable = 1;
 unsigned long perip_base = ARC_UNCACHED_ADDR_SPACE; /* legacy value for boot */
+unsigned long perip_end = 0xFFFFFFFF; /* legacy value */
 
 void (*_cache_line_loop_ic_fn)(phys_addr_t paddr, unsigned long vaddr,
 			       unsigned long sz, const int cacheop);
@@ -76,7 +77,6 @@ char *arc_cache_mumbojumbo(int c, char *buf, int len)
 static void read_decode_cache_bcr_arcv2(int cpu)
 {
 	struct cpuinfo_arc_cache *p_slc = &cpuinfo_arc700[cpu].slc;
-	struct bcr_generic uncached_space;
 	struct bcr_generic sbcr;
 
 	struct bcr_slc_cfg {
@@ -95,6 +95,15 @@ static void read_decode_cache_bcr_arcv2(int cpu)
 #endif
 	} cbcr;
 
+	struct bcr_volatile {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+		unsigned int start:4, limit:4, pad:22, order:1, disable:1;
+#else
+		unsigned int disable:1, order:1, pad:22, limit:4, start:4;
+#endif
+	} vol;
+
+
 	READ_BCR(ARC_REG_SLC_BCR, sbcr);
 	if (sbcr.ver) {
 		READ_BCR(ARC_REG_SLC_CFG, slc_cfg);
@@ -107,10 +116,14 @@ static void read_decode_cache_bcr_arcv2(int cpu)
 	if (cbcr.c && ioc_enable)
 		ioc_exists = 1;
 
-	/* Legacy Data Uncached BCR is deprecated from v3 onwards */
-	READ_BCR(ARC_REG_D_UNCACH_BCR, uncached_space);
-	if (uncached_space.ver > 2)
-		perip_base = read_aux_reg(AUX_NON_VOL) & 0xF0000000;
+	/* HS 2.0 didn't have AUX_VOL */
+	if (cpuinfo_arc700[cpu].core.family > 0x51) {
+		READ_BCR(AUX_VOL, vol);
+		perip_base = vol.start << 28;
+		/* HS 3.0 has limit and strict-ordering fields */
+		if (cpuinfo_arc700[cpu].core.family > 0x52)
+			perip_end = (vol.limit << 28) - 1;
+	}
 }
 
 void read_decode_cache_bcr(void)

arch/arc/mm/ioremap.c

@@ -19,7 +19,7 @@ static inline bool arc_uncached_addr_space(phys_addr_t paddr)
 	if (is_isa_arcompact()) {
 		if (paddr >= ARC_UNCACHED_ADDR_SPACE)
 			return true;
-	} else if (paddr >= perip_base && paddr <= 0xFFFFFFFF) {
+	} else if (paddr >= perip_base && paddr <= perip_end) {
 		return true;
 	}