From: jca <jca@openbsd.org>
Date: Sun, 21 Jul 2024 16:46:56 +0000 (+0000)
Subject: Export basic HWCAP bits to let applications detect Altivec on powerpc
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=dfc50e6f40a35704a776db8742330ef4df9f19e0;p=openbsd

Export basic HWCAP bits to let applications detect Altivec on powerpc

Input from miod@ and gkoehler@, tests & ok gkoehler@
---

diff --git a/sys/arch/macppc/macppc/cpu.c b/sys/arch/macppc/macppc/cpu.c
index f3dbe078fde..d5f776cadda 100644
--- a/sys/arch/macppc/macppc/cpu.c
+++ b/sys/arch/macppc/macppc/cpu.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.c,v 1.87 2023/10/24 13:20:10 claudio Exp $ */
+/*	$OpenBSD: cpu.c,v 1.88 2024/07/21 16:46:56 jca Exp $ */
 
 /*
  * Copyright (c) 1997 Per Fogelstrom
@@ -48,6 +48,7 @@
 #include <powerpc/bat.h>
 #include <machine/cpu.h>
 #include <machine/trap.h>
+#include <machine/elf.h>
 #include <powerpc/hid.h>
 
 /* SCOM addresses (24-bit) */
@@ -201,6 +202,8 @@ cpuattach(struct device *parent, struct device *dev, void *aux)
 	ci->ci_intrdepth = -1;
 	ci->ci_dev = dev;
 
+	hwcap = PPC_FEATURE_32 | PPC_FEATURE_HAS_FPU | PPC_FEATURE_HAS_MMU;
+
 	pvr = ppc_mfpvr();
 	cpu = pvr >> 16;
 	switch (cpu) {
@@ -278,6 +281,9 @@ cpuattach(struct device *parent, struct device *dev, void *aux)
 #ifndef ALTIVEC			/* altivec support absent from kernel */
 	ppc_altivec = 0;
 #endif
+	if (ppc_altivec)
+		hwcap |= PPC_FEATURE_HAS_ALTIVEC;
+
 	snprintf(cpu_model + strlen(cpu_model),
 	    sizeof(cpu_model) - strlen(cpu_model),
 	    " (Revision 0x%x)", pvr & 0xffff);
diff --git a/sys/arch/powerpc/include/elf.h b/sys/arch/powerpc/include/elf.h
index 6624f42f237..73cda20ebe0 100644
--- a/sys/arch/powerpc/include/elf.h
+++ b/sys/arch/powerpc/include/elf.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: elf.h,v 1.1 2024/07/14 09:48:48 jca Exp $	*/
+/*	$OpenBSD: elf.h,v 1.2 2024/07/21 16:46:57 jca Exp $	*/
 
 /*
  * This file is in the public domain.
@@ -8,7 +8,57 @@
 #define	_MACHINE_ELF_H_
 
 /*
- * TODO FreeBSD puts PPC_FEATURE* in cpu.h
+ * CPU Feature Attributes
+ *
+ * These are defined in the PowerPC ELF ABI for the AT_HWCAP vector,
+ * and are exported to userland via the elf_aux_info(3) function.
  */
 
+#ifdef _KERNEL
+# define __HAVE_CPU_HWCAP
+# define __HAVE_CPU_HWCAP2
+extern unsigned long hwcap;
+extern unsigned long hwcap2;
+#endif /* _KERNEL */
+
+#define	PPC_FEATURE_32		0x80000000	/* Always true */
+#define	PPC_FEATURE_64		0x40000000	/* Defined on a 64-bit CPU */
+#define	PPC_FEATURE_601_INSTR	0x20000000
+#define	PPC_FEATURE_HAS_ALTIVEC	0x10000000
+#define	PPC_FEATURE_HAS_FPU	0x08000000
+#define	PPC_FEATURE_HAS_MMU	0x04000000
+#define	PPC_FEATURE_UNIFIED_CACHE 0x01000000
+#define	PPC_FEATURE_HAS_SPE	0x00800000
+#define	PPC_FEATURE_HAS_EFP_SINGLE	0x00400000
+#define	PPC_FEATURE_HAS_EFP_DOUBLE	0x00200000
+#define	PPC_FEATURE_NO_TB	0x00100000
+#define	PPC_FEATURE_POWER4	0x00080000
+#define	PPC_FEATURE_POWER5	0x00040000
+#define	PPC_FEATURE_POWER5_PLUS	0x00020000
+#define	PPC_FEATURE_CELL	0x00010000
+#define	PPC_FEATURE_BOOKE	0x00008000
+#define	PPC_FEATURE_SMT		0x00004000
+#define	PPC_FEATURE_ICACHE_SNOOP	0x00002000
+#define	PPC_FEATURE_ARCH_2_05	0x00001000
+#define	PPC_FEATURE_HAS_DFP	0x00000400
+#define	PPC_FEATURE_POWER6_EXT	0x00000200
+#define	PPC_FEATURE_ARCH_2_06	0x00000100
+#define	PPC_FEATURE_HAS_VSX	0x00000080
+#define	PPC_FEATURE_TRUE_LE	0x00000002
+#define	PPC_FEATURE_PPC_LE	0x00000001
+
+#define	PPC_FEATURE2_ARCH_2_07	0x80000000
+#define	PPC_FEATURE2_HTM	0x40000000
+#define	PPC_FEATURE2_DSCR	0x20000000
+#define	PPC_FEATURE2_EBB	0x10000000
+#define	PPC_FEATURE2_ISEL	0x08000000
+#define	PPC_FEATURE2_TAR	0x04000000
+#define	PPC_FEATURE2_HAS_VEC_CRYPTO	0x02000000
+#define	PPC_FEATURE2_HTM_NOSC	0x01000000
+#define	PPC_FEATURE2_ARCH_3_00	0x00800000
+#define	PPC_FEATURE2_HAS_IEEE128	0x00400000
+#define	PPC_FEATURE2_DARN	0x00200000
+#define	PPC_FEATURE2_SCV	0x00100000
+#define	PPC_FEATURE2_HTM_NOSUSPEND	0x00080000
+
 #endif /* !_MACHINE_ELF_H_ */