[PATCH 1/2] powerpc: Add module autoloading based on CPU features

[alastair]

From: Alastair D'Silva <alastair@xxxxxxxxxxx>

This patch provides the necessary infrastructure to allow drivers
to be automatically loaded via UDEV. It implements the minimum
required to be able to use module_cpu_feature_match to trigger
the GENERIC_CPU_AUTOPROBE mechanisms.

The features exposed are a mirror of the cpu_user_features
(converted to an offset from a mask). This decision was made to
ensure that the behavior between features for module loading and
userspace are consistent.

Signed-off-by: Alastair D'Silva <alastair@xxxxxxxxxxx>
---
 arch/powerpc/Kconfig                  |  1 +
 arch/powerpc/include/asm/cpufeature.h | 70 +++++++++++++++++++++++++++++++++++
 2 files changed, 71 insertions(+)
 create mode 100644 arch/powerpc/include/asm/cpufeature.h

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 0a9d439..a6e49db 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -164,6 +164,7 @@ config PPC
 	select ARCH_HAS_UBSAN_SANITIZE_ALL
 	select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
 	select HAVE_LIVEPATCH if HAVE_DYNAMIC_FTRACE_WITH_REGS
+	select GENERIC_CPU_AUTOPROBE
 
 config GENERIC_CSUM
 	def_bool CPU_LITTLE_ENDIAN
diff --git a/arch/powerpc/include/asm/cpufeature.h b/arch/powerpc/include/asm/cpufeature.h
new file mode 100644
index 0000000..df31627
--- /dev/null
+++ b/arch/powerpc/include/asm/cpufeature.h
@@ -0,0 +1,70 @@
+/* CPU feature definitions for module loading, used by
+ * module_cpu_feature_match(), see asm/cputable.h for powerpc CPU features
+ *
+ * Copyright 2016 Alastair D'Silva, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef __ASM_CPUFEATURE_H
+#define __ASM_POWERPC_CPUFEATURE_H
+
+#include <asm/cputable.h>
+
+/* Keep these in step with powerpc/include/asm/cputable.h */
+#define MAX_CPU_FEATURES (2 * 32)
+
+#define PPC_MODULE_FEATURE_32				(ilog2(PPC_FEATURE_32))
+#define PPC_MODULE_FEATURE_64				(ilog2(PPC_FEATURE_64))
+#define PPC_MODULE_FEATURE_601_INSTR			(ilog2(PPC_FEATURE_601_INSTR))
+#define PPC_MODULE_FEATURE_HAS_ALTIVEC			(ilog2(PPC_FEATURE_HAS_ALTIVEC))
+#define PPC_MODULE_FEATURE_HAS_FPU			(ilog2(PPC_FEATURE_HAS_FPU))
+#define PPC_MODULE_FEATURE_HAS_MMU			(ilog2(PPC_FEATURE_HAS_MMU))
+#define PPC_MODULE_FEATURE_HAS_4xxMAC			(ilog2(PPC_FEATURE_HAS_4xxMAC))
+#define PPC_MODULE_FEATURE_UNIFIED_CACHE		ilog2(PPC_FEATURE_UNIFIED_CACHE))
+#define PPC_MODULE_FEATURE_HAS_SPE			(ilog2(PPC_FEATURE_HAS_SPE))
+#define PPC_MODULE_FEATURE_HAS_EFP_SINGLE		(ilog2(PPC_FEATURE_HAS_EFP_SINGLE))
+#define PPC_MODULE_FEATURE_HAS_EFP_DOUBLE		(ilog2(PPC_FEATURE_HAS_EFP_DOUBLE))
+#define PPC_MODULE_FEATURE_NO_TB			(ilog2(PPC_FEATURE_NO_TB))
+#define PPC_MODULE_FEATURE_POWER4			(ilog2(PPC_FEATURE_POWER4))
+#define PPC_MODULE_FEATURE_POWER5			(ilog2(PPC_FEATURE_POWER5))
+#define PPC_MODULE_FEATURE_POWER5_PLUS			(ilog2(PPC_FEATURE_POWER5_PLUS))
+#define PPC_MODULE_FEATURE_CELL				(ilog2(PPC_FEATURE_CELL))
+#define PPC_MODULE_FEATURE_BOOKE			(ilog2(PPC_FEATURE_BOOKE))
+#define PPC_MODULE_FEATURE_SMT				(ilog2(PPC_FEATURE_SMT))
+#define PPC_MODULE_FEATURE_ICACHE_SNOOP			(ilog2(PPC_FEATURE_ICACHE_SNOOP))
+#define PPC_MODULE_FEATURE_ARCH_2_05			(ilog2(PPC_FEATURE_ARCH_2_05))
+#define PPC_MODULE_FEATURE_PA6T				(ilog2(PPC_FEATURE_PA6T))
+#define PPC_MODULE_FEATURE_HAS_DFP			(ilog2(PPC_FEATURE_HAS_DFP))
+#define PPC_MODULE_FEATURE_POWER6_EXT			(ilog2(PPC_FEATURE_POWER6_EXT))
+#define PPC_MODULE_FEATURE_ARCH_2_06			(ilog2(PPC_FEATURE_ARCH_2_06))
+#define PPC_MODULE_FEATURE_HAS_VSX			(ilog2(PPC_FEATURE_HAS_VSX))
+#define PPC_MODULE_FEATURE_PSERIES_PERFMON_COMPAT	(ilog2(PPC_FEATURE_PSERIES_PERFMON_COMPAT))
+#define PPC_MODULE_FEATURE_TRUE_LE			(ilog2(PPC_FEATURE_TRUE_LE))
+#define PPC_MODULE_FEATURE_PPC_LE			(ilog2(PPC_FEATURE_PPC_LE))
+
+#define PPC_MODULE_FEATURE_ARCH_2_07			(32 + ilog2(PPC_FEATURE2_ARCH_2_07))
+#define PPC_MODULE_FEATURE_HTM				(32 + ilog2(PPC_FEATURE2_HTM))
+#define PPC_MODULE_FEATURE_DSCR				(32 + ilog2(PPC_FEATURE2_DSCR))
+#define PPC_MODULE_FEATURE_EBB				(32 + ilog2(PPC_FEATURE2_EBB))
+#define PPC_MODULE_FEATURE_ISEL				(32 + ilog2(PPC_FEATURE2_ISEL))
+#define PPC_MODULE_FEATURE_TAR				(32 + ilog2(PPC_FEATURE2_TAR))
+#define PPC_MODULE_FEATURE_VEC_CRYPTO			(32 + ilog2(PPC_FEATURE2_VEC_CRYPTO))
+#define PPC_MODULE_FEATURE_HTM_NOSC			(32 + ilog2(PPC_FEATURE2_HTM_NOSC))
+#define PPC_MODULE_FEATURE_ARCH_3_00			(32 + ilog2(PPC_FEATURE2_ARCH_3_00))
+#define PPC_MODULE_FEATURE_HAS_IEEE128			(32 + ilog2(PPC_FEATURE2_HAS_IEEE128))
+
+#define cpu_feature(x)		(x)
+
+static inline bool cpu_have_feature(unsigned int num)
+{
+	if (num < 32)
+		return !!(cur_cpu_spec->cpu_user_features & 1UL << num);
+	else
+		return !!(cur_cpu_spec->cpu_user_features2 & 1UL << (num - 32));
+}
+
+#endif /* __ASM_POWERPC_CPUFEATURE_H */
-- 
2.7.4