--- zzzz-none-000/linux-3.10.107/arch/mips/mm/sc-mips.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/mips/mm/sc-mips.c	2021-02-04 17:41:59.000000000 +0000
@@ -6,6 +6,7 @@
 #include <linux/sched.h>
 #include <linux/mm.h>
 
+#include <asm/cpu-type.h>
 #include <asm/mipsregs.h>
 #include <asm/bcache.h>
 #include <asm/cacheops.h>
@@ -13,6 +14,7 @@
 #include <asm/pgtable.h>
 #include <asm/mmu_context.h>
 #include <asm/r4kcache.h>
+#include <asm/mips-cm.h>
 
 /*
  * MIPS32/MIPS64 L2 cache handling
@@ -49,11 +51,69 @@
 	/* L2 cache is permanently enabled */
 }
 
+static void mips_sc_prefetch_enable(void)
+{
+	unsigned long pftctl;
+
+	if (mips_cm_revision() < CM_REV_CM2_5)
+		return;
+
+	/*
+	 * If there is one or more L2 prefetch unit present then enable
+	 * prefetching for both code & data, for all ports.
+	 */
+	pftctl = read_gcr_l2_pft_control();
+	if (pftctl & CM_GCR_L2_PFT_CONTROL_NPFT_MSK) {
+		pftctl &= ~CM_GCR_L2_PFT_CONTROL_PAGEMASK_MSK;
+		pftctl |= PAGE_MASK & CM_GCR_L2_PFT_CONTROL_PAGEMASK_MSK;
+		pftctl |= CM_GCR_L2_PFT_CONTROL_PFTEN_MSK;
+		write_gcr_l2_pft_control(pftctl);
+
+		pftctl = read_gcr_l2_pft_control_b();
+		pftctl |= CM_GCR_L2_PFT_CONTROL_B_PORTID_MSK;
+		pftctl |= CM_GCR_L2_PFT_CONTROL_B_CEN_MSK;
+		write_gcr_l2_pft_control_b(pftctl);
+	}
+}
+
+static void mips_sc_prefetch_disable(void)
+{
+	unsigned long pftctl;
+
+	if (mips_cm_revision() < CM_REV_CM2_5)
+		return;
+
+	pftctl = read_gcr_l2_pft_control();
+	pftctl &= ~CM_GCR_L2_PFT_CONTROL_PFTEN_MSK;
+	write_gcr_l2_pft_control(pftctl);
+
+	pftctl = read_gcr_l2_pft_control_b();
+	pftctl &= ~CM_GCR_L2_PFT_CONTROL_B_PORTID_MSK;
+	pftctl &= ~CM_GCR_L2_PFT_CONTROL_B_CEN_MSK;
+	write_gcr_l2_pft_control_b(pftctl);
+}
+
+static bool mips_sc_prefetch_is_enabled(void)
+{
+	unsigned long pftctl;
+
+	if (mips_cm_revision() < CM_REV_CM2_5)
+		return false;
+
+	pftctl = read_gcr_l2_pft_control();
+	if (!(pftctl & CM_GCR_L2_PFT_CONTROL_NPFT_MSK))
+		return false;
+	return !!(pftctl & CM_GCR_L2_PFT_CONTROL_PFTEN_MSK);
+}
+
 static struct bcache_ops mips_sc_ops = {
 	.bc_enable = mips_sc_enable,
 	.bc_disable = mips_sc_disable,
 	.bc_wback_inv = mips_sc_wback_inv,
-	.bc_inv = mips_sc_inv
+	.bc_inv = mips_sc_inv,
+	.bc_prefetch_enable = mips_sc_prefetch_enable,
+	.bc_prefetch_disable = mips_sc_prefetch_disable,
+	.bc_prefetch_is_enabled = mips_sc_prefetch_is_enabled,
 };
 
 /*
@@ -71,11 +131,16 @@
 	unsigned int tmp;
 
 	/* Check the bypass bit (L2B) */
-	switch (c->cputype) {
+	switch (current_cpu_type()) {
 	case CPU_34K:
 	case CPU_74K:
 	case CPU_1004K:
+	case CPU_1074K:
+	case CPU_INTERAPTIV:
+	case CPU_PROAPTIV:
+	case CPU_P5600:
 	case CPU_BMIPS5000:
+	case CPU_QEMU_GENERIC:
 		if (config2 & (1 << 12))
 			return 0;
 	}
@@ -88,6 +153,43 @@
 	return 1;
 }
 
+static int __init mips_sc_probe_cm3(void)
+{
+	struct cpuinfo_mips *c = &current_cpu_data;
+	unsigned long cfg = read_gcr_l2_config();
+	unsigned long sets, line_sz, assoc;
+
+	if (cfg & CM_GCR_L2_CONFIG_BYPASS_MSK)
+		return 0;
+
+	sets = cfg & CM_GCR_L2_CONFIG_SET_SIZE_MSK;
+	sets >>= CM_GCR_L2_CONFIG_SET_SIZE_SHF;
+	if (sets)
+		c->scache.sets = 64 << sets;
+
+	line_sz = cfg & CM_GCR_L2_CONFIG_LINE_SIZE_MSK;
+	line_sz >>= CM_GCR_L2_CONFIG_LINE_SIZE_SHF;
+	if (line_sz)
+		c->scache.linesz = 2 << line_sz;
+
+	assoc = cfg & CM_GCR_L2_CONFIG_ASSOC_MSK;
+	assoc >>= CM_GCR_L2_CONFIG_ASSOC_SHF;
+	c->scache.ways = assoc + 1;
+	c->scache.waysize = c->scache.sets * c->scache.linesz;
+	c->scache.waybit = __ffs(c->scache.waysize);
+
+	if (c->scache.linesz) {
+		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
+		return 1;
+	}
+
+	return 0;
+}
+
+void __weak platform_early_l2_init(void)
+{
+}
+
 static inline int __init mips_sc_probe(void)
 {
 	struct cpuinfo_mips *c = &current_cpu_data;
@@ -97,9 +199,19 @@
 	/* 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();
+
 	/* Ignore anything but MIPSxx processors */
 	if (!(c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M32R2 |
-			      MIPS_CPU_ISA_M64R1 | MIPS_CPU_ISA_M64R2)))
+			      MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R1 |
+			      MIPS_CPU_ISA_M64R2 | MIPS_CPU_ISA_M64R6)))
 		return 0;
 
 	/* Does this MIPS32/MIPS64 CPU have a config2 register? */
@@ -113,13 +225,13 @@
 		return 0;
 
 	tmp = (config2 >> 8) & 0x0f;
-	if (0 <= tmp && tmp <= 7)
+	if (tmp <= 7)
 		c->scache.sets = 64 << tmp;
 	else
 		return 0;
 
 	tmp = (config2 >> 0) & 0x0f;
-	if (0 <= tmp && tmp <= 7)
+	if (tmp <= 7)
 		c->scache.ways = tmp + 1;
 	else
 		return 0;
@@ -132,11 +244,12 @@
 	return 1;
 }
 
-int __cpuinit mips_sc_init(void)
+int mips_sc_init(void)
 {
 	int found = mips_sc_probe();
 	if (found) {
 		mips_sc_enable();
+		mips_sc_prefetch_enable();
 		bcops = &mips_sc_ops;
 	}
 	return found;