1 files changed, 144 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/dcr-native.h b/arch/powerpc/include/asm/dcr-native.h
new file mode 100644
index 000000000..a92059964
--- /dev/null
+++ b/arch/powerpc/include/asm/dcr-native.h
@@ -0,0 +1,144 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
+ *                    <benh@kernel.crashing.org>
+ */
+
+#ifndef _ASM_POWERPC_DCR_NATIVE_H
+#define _ASM_POWERPC_DCR_NATIVE_H
+#ifdef __KERNEL__
+#ifndef __ASSEMBLY__
+
+#include <linux/spinlock.h>
+#include <asm/cputable.h>
+#include <asm/cpu_has_feature.h>
+#include <linux/stringify.h>
+
+typedef struct {
+	unsigned int base;
+} dcr_host_native_t;
+
+static inline bool dcr_map_ok_native(dcr_host_native_t host)
+{
+	return true;
+}
+
+#define dcr_map_native(dev, dcr_n, dcr_c) \
+	((dcr_host_native_t){ .base = (dcr_n) })
+#define dcr_unmap_native(host, dcr_c)		do {} while (0)
+#define dcr_read_native(host, dcr_n)		mfdcr(dcr_n + host.base)
+#define dcr_write_native(host, dcr_n, value)	mtdcr(dcr_n + host.base, value)
+
+/* Table based DCR accessors */
+extern void __mtdcr(unsigned int reg, unsigned int val);
+extern unsigned int __mfdcr(unsigned int reg);
+
+/* mfdcrx/mtdcrx instruction based accessors. We hand code
+ * the opcodes in order not to depend on newer binutils
+ */
+static inline unsigned int mfdcrx(unsigned int reg)
+{
+	unsigned int ret;
+	asm volatile(".long 0x7c000206 | (%0 << 21) | (%1 << 16)"
+		     : "=r" (ret) : "r" (reg));
+	return ret;
+}
+
+static inline void mtdcrx(unsigned int reg, unsigned int val)
+{
+	asm volatile(".long 0x7c000306 | (%0 << 21) | (%1 << 16)"
+		     : : "r" (val), "r" (reg));
+}
+
+#define mfdcr(rn)						\
+	({unsigned int rval;					\
+	if (__builtin_constant_p(rn) && rn < 1024)		\
+		asm volatile("mfdcr %0, %1" : "=r" (rval)	\
+			      : "n" (rn));			\
+	else if (likely(cpu_has_feature(CPU_FTR_INDEXED_DCR)))	\
+		rval = mfdcrx(rn);				\
+	else							\
+		rval = __mfdcr(rn);				\
+	rval;})
+
+#define mtdcr(rn, v)						\
+do {								\
+	if (__builtin_constant_p(rn) && rn < 1024)		\
+		asm volatile("mtdcr %0, %1"			\
+			      : : "n" (rn), "r" (v));		\
+	else if (likely(cpu_has_feature(CPU_FTR_INDEXED_DCR)))	\
+		mtdcrx(rn, v);					\
+	else							\
+		__mtdcr(rn, v);					\
+} while (0)
+
+/* R/W of indirect DCRs make use of standard naming conventions for DCRs */
+extern spinlock_t dcr_ind_lock;
+
+static inline unsigned __mfdcri(int base_addr, int base_data, int reg)
+{
+	unsigned long flags;
+	unsigned int val;
+
+	spin_lock_irqsave(&dcr_ind_lock, flags);
+	if (cpu_has_feature(CPU_FTR_INDEXED_DCR)) {
+		mtdcrx(base_addr, reg);
+		val = mfdcrx(base_data);
+	} else {
+		__mtdcr(base_addr, reg);
+		val = __mfdcr(base_data);
+	}
+	spin_unlock_irqrestore(&dcr_ind_lock, flags);
+	return val;
+}
+
+static inline void __mtdcri(int base_addr, int base_data, int reg,
+			    unsigned val)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&dcr_ind_lock, flags);
+	if (cpu_has_feature(CPU_FTR_INDEXED_DCR)) {
+		mtdcrx(base_addr, reg);
+		mtdcrx(base_data, val);
+	} else {
+		__mtdcr(base_addr, reg);
+		__mtdcr(base_data, val);
+	}
+	spin_unlock_irqrestore(&dcr_ind_lock, flags);
+}
+
+static inline void __dcri_clrset(int base_addr, int base_data, int reg,
+				 unsigned clr, unsigned set)
+{
+	unsigned long flags;
+	unsigned int val;
+
+	spin_lock_irqsave(&dcr_ind_lock, flags);
+	if (cpu_has_feature(CPU_FTR_INDEXED_DCR)) {
+		mtdcrx(base_addr, reg);
+		val = (mfdcrx(base_data) & ~clr) | set;
+		mtdcrx(base_data, val);
+	} else {
+		__mtdcr(base_addr, reg);
+		val = (__mfdcr(base_data) & ~clr) | set;
+		__mtdcr(base_data, val);
+	}
+	spin_unlock_irqrestore(&dcr_ind_lock, flags);
+}
+
+#define mfdcri(base, reg)	__mfdcri(DCRN_ ## base ## _CONFIG_ADDR,	\
+					 DCRN_ ## base ## _CONFIG_DATA,	\
+					 reg)
+
+#define mtdcri(base, reg, data)	__mtdcri(DCRN_ ## base ## _CONFIG_ADDR,	\
+					 DCRN_ ## base ## _CONFIG_DATA,	\
+					 reg, data)
+
+#define dcri_clrset(base, reg, clr, set)	__dcri_clrset(DCRN_ ## base ## _CONFIG_ADDR,	\
+							      DCRN_ ## base ## _CONFIG_DATA,	\
+							      reg, clr, set)
+
+#endif /* __ASSEMBLY__ */
+#endif /* __KERNEL__ */
+#endif /* _ASM_POWERPC_DCR_NATIVE_H */