powerpc/64s: Support new device tree binding for discovering CPU features

The ibm,powerpc-cpu-features device tree binding describes CPU features with
ASCII names and extensible compatibility, privilege, and enablement metadata
that allows improved flexibility and compatibility with new hardware.

The interface is described in detail in ibm,powerpc-cpu-features.txt in this
patch.

Currently this code is not enabled by default, and there are no released
firmwares that provide the binding.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

5 files changed, 39 insertions, 3 deletions

diff --git a/arch/powerpc/include/asm/cpu_has_feature.h b/arch/powerpc/include/asm/cpu_has_feature.h
index 6e834caa3720..0d1df02bf99d 100644
--- a/arch/powerpc/include/asm/cpu_has_feature.h
+++ b/arch/powerpc/include/asm/cpu_has_feature.h
@@ -1,5 +1,5 @@
-#ifndef __ASM_POWERPC_CPUFEATURES_H
-#define __ASM_POWERPC_CPUFEATURES_H
+#ifndef __ASM_POWERPC_CPU_HAS_FEATURE_H
+#define __ASM_POWERPC_CPU_HAS_FEATURE_H
 
 #ifndef __ASSEMBLY__
 
@@ -52,4 +52,4 @@ static inline bool cpu_has_feature(unsigned long feature)
 #endif
 
 #endif /* __ASSEMBLY__ */
-#endif /* __ASM_POWERPC_CPUFEATURE_H */
+#endif /* __ASM_POWERPC_CPU_HAS_FEATURE_H */
diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
index 1f6847b107e4..c2d509584a98 100644
--- a/arch/powerpc/include/asm/cputable.h
+++ b/arch/powerpc/include/asm/cputable.h
@@ -118,7 +118,9 @@ extern struct cpu_spec		*cur_cpu_spec;
 
 extern unsigned int __start___ftr_fixup, __stop___ftr_fixup;
 
+extern void set_cur_cpu_spec(struct cpu_spec *s);
 extern struct cpu_spec *identify_cpu(unsigned long offset, unsigned int pvr);
+extern void identify_cpu_name(unsigned int pvr);
 extern void do_feature_fixups(unsigned long value, void *fixup_start,
 			      void *fixup_end);
 
diff --git a/arch/powerpc/include/asm/dt_cpu_ftrs.h b/arch/powerpc/include/asm/dt_cpu_ftrs.h
new file mode 100644
index 000000000000..7a34fc11bf63
--- /dev/null
+++ b/arch/powerpc/include/asm/dt_cpu_ftrs.h
@@ -0,0 +1,26 @@
+#ifndef __ASM_POWERPC_DT_CPU_FTRS_H
+#define __ASM_POWERPC_DT_CPU_FTRS_H
+
+/*
+ *  Copyright 2017, IBM Corporation
+ *  cpufeatures is the new way to discover CPU features with /cpus/features
+ *  devicetree. This supersedes PVR based discovery ("cputable"), and older
+ *  device tree feature advertisement.
+ */
+
+#include <linux/types.h>
+#include <asm/asm-compat.h>
+#include <asm/feature-fixups.h>
+#include <uapi/asm/cputable.h>
+
+#ifdef CONFIG_PPC_DT_CPU_FTRS
+bool dt_cpu_ftrs_init(void *fdt);
+void dt_cpu_ftrs_scan(void);
+bool dt_cpu_ftrs_in_use(void);
+#else
+static inline bool dt_cpu_ftrs_init(void *fdt) { return false; }
+static inline void dt_cpu_ftrs_scan(void) { }
+static inline bool dt_cpu_ftrs_in_use(void) { return false; }
+#endif
+
+#endif /* __ASM_POWERPC_DT_CPU_FTRS_H */
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index d4f653c9259a..7e50e47375d6 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -1229,6 +1229,7 @@
 #define PVR_POWER8E	0x004B
 #define PVR_POWER8NVL	0x004C
 #define PVR_POWER8	0x004D
+#define PVR_POWER9	0x004E
 #define PVR_BE		0x0070
 #define PVR_PA6T	0x0090
 
diff --git a/arch/powerpc/include/uapi/asm/cputable.h b/arch/powerpc/include/uapi/asm/cputable.h
index f63c96cd3608..3e7ce86d5c13 100644
--- a/arch/powerpc/include/uapi/asm/cputable.h
+++ b/arch/powerpc/include/uapi/asm/cputable.h
@@ -47,4 +47,11 @@
 #define PPC_FEATURE2_ARCH_3_00		0x00800000 /* ISA 3.00 */
 #define PPC_FEATURE2_HAS_IEEE128	0x00400000 /* VSX IEEE Binary Float 128-bit */
 
+/*
+ * IMPORTANT!
+ * All future PPC_FEATURE definitions should be allocated in cooperation with
+ * OPAL / skiboot firmware, in accordance with the ibm,powerpc-cpu-features
+ * device tree binding.
+ */
+
 #endif /* _UAPI__ASM_POWERPC_CPUTABLE_H */