39141ddfb6
After commit846a136881("ARM: vfp: fix saving d16-d31 vfp registers on v6+ kernels"), the OMAP 2430SDP board started crashing during boot with omap2plus_defconfig: [ 3.875122] mmcblk0: mmc0:e624 SD04G 3.69 GiB [ 3.915954] mmcblk0: p1 [ 4.086639] Internal error: Oops - undefined instruction: 0 [#1] SMP ARM [ 4.093719] Modules linked in: [ 4.096954] CPU: 0 Not tainted (3.6.0-02232-g759e00b #570) [ 4.103149] PC is at vfp_reload_hw+0x1c/0x44 [ 4.107666] LR is at __und_usr_fault_32+0x0/0x8 It turns out that the context save/restore fix unmasked a latent bug in commit5aaf254409("ARM: 6203/1: Make VFPv3 usable on ARMv6"). When CONFIG_VFPv3 is set, but the kernel is booted on a pre-VFPv3 core, the code attempts to save and restore the d16-d31 VFP registers. These are only present on non-D16 VFPv3+, so this results in an undefined instruction exception. The code didn't crash before commit846a136because the save and restore code was only touching d0-d15, present on all VFP. Fix by implementing a request from Russell King to add a new HWCAP flag that affirmatively indicates the presence of the d16-d31 registers: http://marc.info/?l=linux-arm-kernel&m=135013547905283&w=2 and some feedback from Måns to clarify the name of the HWCAP flag. Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Tony Lindgren <tony@atomide.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Martin <dave.martin@linaro.org> Cc: Måns Rullgård <mans.rullgard@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
31 lines
884 B
C
31 lines
884 B
C
#ifndef _UAPI__ASMARM_HWCAP_H
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#define _UAPI__ASMARM_HWCAP_H
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/*
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* HWCAP flags - for elf_hwcap (in kernel) and AT_HWCAP
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*/
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#define HWCAP_SWP (1 << 0)
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#define HWCAP_HALF (1 << 1)
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#define HWCAP_THUMB (1 << 2)
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#define HWCAP_26BIT (1 << 3) /* Play it safe */
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#define HWCAP_FAST_MULT (1 << 4)
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#define HWCAP_FPA (1 << 5)
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#define HWCAP_VFP (1 << 6)
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#define HWCAP_EDSP (1 << 7)
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#define HWCAP_JAVA (1 << 8)
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#define HWCAP_IWMMXT (1 << 9)
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#define HWCAP_CRUNCH (1 << 10)
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#define HWCAP_THUMBEE (1 << 11)
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#define HWCAP_NEON (1 << 12)
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#define HWCAP_VFPv3 (1 << 13)
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#define HWCAP_VFPv3D16 (1 << 14) /* also set for VFPv4-D16 */
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#define HWCAP_TLS (1 << 15)
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#define HWCAP_VFPv4 (1 << 16)
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#define HWCAP_IDIVA (1 << 17)
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#define HWCAP_IDIVT (1 << 18)
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#define HWCAP_VFPD32 (1 << 19) /* set if VFP has 32 regs (not 16) */
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#define HWCAP_IDIV (HWCAP_IDIVA | HWCAP_IDIVT)
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#endif /* _UAPI__ASMARM_HWCAP_H */
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