1 files changed, 303 insertions, 0 deletions
diff --git a/arch/arm/mm/cache-tauros2.c b/arch/arm/mm/cache-tauros2.c
new file mode 100644
index 0000000000..b1e1aba602
--- /dev/null
+++ b/arch/arm/mm/cache-tauros2.c
@@ -0,0 +1,303 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * arch/arm/mm/cache-tauros2.c - Tauros2 L2 cache controller support
+ *
+ * Copyright (C) 2008 Marvell Semiconductor
+ *
+ * References:
+ * - PJ1 CPU Core Datasheet,
+ *   Document ID MV-S104837-01, Rev 0.7, January 24 2008.
+ * - PJ4 CPU Core Datasheet,
+ *   Document ID MV-S105190-00, Rev 0.7, March 14 2008.
+ */
+
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <asm/cacheflush.h>
+#include <asm/cp15.h>
+#include <asm/cputype.h>
+#include <asm/hardware/cache-tauros2.h>
+
+/* CP15 PJ4 Control configuration register */
+#define CCR_L2C_PREFETCH_DISABLE	BIT(24)
+#define CCR_L2C_ECC_ENABLE		BIT(23)
+#define CCR_L2C_WAY7_4_DISABLE		BIT(21)
+#define CCR_L2C_BURST8_ENABLE		BIT(20)
+
+/*
+ * When Tauros2 is used on a CPU that supports the v7 hierarchical
+ * cache operations, the cache handling code in proc-v7.S takes care
+ * of everything, including handling DMA coherency.
+ *
+ * So, we only need to register outer cache operations here if we're
+ * being used on a pre-v7 CPU, and we only need to build support for
+ * outer cache operations into the kernel image if the kernel has been
+ * configured to support a pre-v7 CPU.
+ */
+#ifdef CONFIG_CPU_32v5
+/*
+ * Low-level cache maintenance operations.
+ */
+static inline void tauros2_clean_pa(unsigned long addr)
+{
+	__asm__("mcr p15, 1, %0, c7, c11, 3" : : "r" (addr));
+}
+
+static inline void tauros2_clean_inv_pa(unsigned long addr)
+{
+	__asm__("mcr p15, 1, %0, c7, c15, 3" : : "r" (addr));
+}
+
+static inline void tauros2_inv_pa(unsigned long addr)
+{
+	__asm__("mcr p15, 1, %0, c7, c7, 3" : : "r" (addr));
+}
+
+
+/*
+ * Linux primitives.
+ *
+ * Note that the end addresses passed to Linux primitives are
+ * noninclusive.
+ */
+#define CACHE_LINE_SIZE		32
+
+static void tauros2_inv_range(unsigned long start, unsigned long end)
+{
+	/*
+	 * Clean and invalidate partial first cache line.
+	 */
+	if (start & (CACHE_LINE_SIZE - 1)) {
+		tauros2_clean_inv_pa(start & ~(CACHE_LINE_SIZE - 1));
+		start = (start | (CACHE_LINE_SIZE - 1)) + 1;
+	}
+
+	/*
+	 * Clean and invalidate partial last cache line.
+	 */
+	if (end & (CACHE_LINE_SIZE - 1)) {
+		tauros2_clean_inv_pa(end & ~(CACHE_LINE_SIZE - 1));
+		end &= ~(CACHE_LINE_SIZE - 1);
+	}
+
+	/*
+	 * Invalidate all full cache lines between 'start' and 'end'.
+	 */
+	while (start < end) {
+		tauros2_inv_pa(start);
+		start += CACHE_LINE_SIZE;
+	}
+
+	dsb();
+}
+
+static void tauros2_clean_range(unsigned long start, unsigned long end)
+{
+	start &= ~(CACHE_LINE_SIZE - 1);
+	while (start < end) {
+		tauros2_clean_pa(start);
+		start += CACHE_LINE_SIZE;
+	}
+
+	dsb();
+}
+
+static void tauros2_flush_range(unsigned long start, unsigned long end)
+{
+	start &= ~(CACHE_LINE_SIZE - 1);
+	while (start < end) {
+		tauros2_clean_inv_pa(start);
+		start += CACHE_LINE_SIZE;
+	}
+
+	dsb();
+}
+
+static void tauros2_disable(void)
+{
+	__asm__ __volatile__ (
+	"mcr	p15, 1, %0, c7, c11, 0 @L2 Cache Clean All\n\t"
+	"mrc	p15, 0, %0, c1, c0, 0\n\t"
+	"bic	%0, %0, #(1 << 26)\n\t"
+	"mcr	p15, 0, %0, c1, c0, 0  @Disable L2 Cache\n\t"
+	: : "r" (0x0));
+}
+
+static void tauros2_resume(void)
+{
+	__asm__ __volatile__ (
+	"mcr	p15, 1, %0, c7, c7, 0 @L2 Cache Invalidate All\n\t"
+	"mrc	p15, 0, %0, c1, c0, 0\n\t"
+	"orr	%0, %0, #(1 << 26)\n\t"
+	"mcr	p15, 0, %0, c1, c0, 0 @Enable L2 Cache\n\t"
+	: : "r" (0x0));
+}
+#endif
+
+static inline u32 __init read_extra_features(void)
+{
+	u32 u;
+
+	__asm__("mrc p15, 1, %0, c15, c1, 0" : "=r" (u));
+
+	return u;
+}
+
+static inline void __init write_extra_features(u32 u)
+{
+	__asm__("mcr p15, 1, %0, c15, c1, 0" : : "r" (u));
+}
+
+static inline int __init cpuid_scheme(void)
+{
+	return !!((processor_id & 0x000f0000) == 0x000f0000);
+}
+
+static inline u32 __init read_mmfr3(void)
+{
+	u32 mmfr3;
+
+	__asm__("mrc p15, 0, %0, c0, c1, 7\n" : "=r" (mmfr3));
+
+	return mmfr3;
+}
+
+static inline u32 __init read_actlr(void)
+{
+	u32 actlr;
+
+	__asm__("mrc p15, 0, %0, c1, c0, 1\n" : "=r" (actlr));
+
+	return actlr;
+}
+
+static inline void __init write_actlr(u32 actlr)
+{
+	__asm__("mcr p15, 0, %0, c1, c0, 1\n" : : "r" (actlr));
+}
+
+static void enable_extra_feature(unsigned int features)
+{
+	u32 u;
+
+	u = read_extra_features();
+
+	if (features & CACHE_TAUROS2_PREFETCH_ON)
+		u &= ~CCR_L2C_PREFETCH_DISABLE;
+	else
+		u |= CCR_L2C_PREFETCH_DISABLE;
+	pr_info("Tauros2: %s L2 prefetch.\n",
+			(features & CACHE_TAUROS2_PREFETCH_ON)
+			? "Enabling" : "Disabling");
+
+	if (features & CACHE_TAUROS2_LINEFILL_BURST8)
+		u |= CCR_L2C_BURST8_ENABLE;
+	else
+		u &= ~CCR_L2C_BURST8_ENABLE;
+	pr_info("Tauros2: %s burst8 line fill.\n",
+			(features & CACHE_TAUROS2_LINEFILL_BURST8)
+			? "Enabling" : "Disabling");
+
+	write_extra_features(u);
+}
+
+static void __init tauros2_internal_init(unsigned int features)
+{
+	char *mode = NULL;
+
+	enable_extra_feature(features);
+
+#ifdef CONFIG_CPU_32v5
+	if ((processor_id & 0xff0f0000) == 0x56050000) {
+		u32 feat;
+
+		/*
+		 * v5 CPUs with Tauros2 have the L2 cache enable bit
+		 * located in the CPU Extra Features register.
+		 */
+		feat = read_extra_features();
+		if (!(feat & 0x00400000)) {
+			pr_info("Tauros2: Enabling L2 cache.\n");
+			write_extra_features(feat | 0x00400000);
+		}
+
+		mode = "ARMv5";
+		outer_cache.inv_range = tauros2_inv_range;
+		outer_cache.clean_range = tauros2_clean_range;
+		outer_cache.flush_range = tauros2_flush_range;
+		outer_cache.disable = tauros2_disable;
+		outer_cache.resume = tauros2_resume;
+	}
+#endif
+
+#ifdef CONFIG_CPU_32v7
+	/*
+	 * Check whether this CPU has support for the v7 hierarchical
+	 * cache ops.  (PJ4 is in its v7 personality mode if the MMFR3
+	 * register indicates support for the v7 hierarchical cache
+	 * ops.)
+	 *
+	 * (Although strictly speaking there may exist CPUs that
+	 * implement the v7 cache ops but are only ARMv6 CPUs (due to
+	 * not complying with all of the other ARMv7 requirements),
+	 * there are no real-life examples of Tauros2 being used on
+	 * such CPUs as of yet.)
+	 */
+	if (cpuid_scheme() && (read_mmfr3() & 0xf) == 1) {
+		u32 actlr;
+
+		/*
+		 * When Tauros2 is used in an ARMv7 system, the L2
+		 * enable bit is located in the Auxiliary System Control
+		 * Register (which is the only register allowed by the
+		 * ARMv7 spec to contain fine-grained cache control bits).
+		 */
+		actlr = read_actlr();
+		if (!(actlr & 0x00000002)) {
+			pr_info("Tauros2: Enabling L2 cache.\n");
+			write_actlr(actlr | 0x00000002);
+		}
+
+		mode = "ARMv7";
+	}
+#endif
+
+	if (mode == NULL) {
+		pr_crit("Tauros2: Unable to detect CPU mode.\n");
+		return;
+	}
+
+	pr_info("Tauros2: L2 cache support initialised "
+			 "in %s mode.\n", mode);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id tauros2_ids[] __initconst = {
+	{ .compatible = "marvell,tauros2-cache"},
+	{}
+};
+#endif
+
+void __init tauros2_init(unsigned int features)
+{
+#ifdef CONFIG_OF
+	struct device_node *node;
+	int ret;
+	unsigned int f;
+
+	node = of_find_matching_node(NULL, tauros2_ids);
+	if (!node) {
+		pr_info("Not found marvell,tauros2-cache, disable it\n");
+	} else {
+		ret = of_property_read_u32(node, "marvell,tauros2-cache-features", &f);
+		if (ret) {
+			pr_info("Not found marvell,tauros-cache-features property, "
+				"disable extra features\n");
+			features = 0;
+		} else
+			features = f;
+	}
+#endif
+	tauros2_internal_init(features);
+}