mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-27 06:55:07 +07:00
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>
66 lines
2.1 KiB
C
66 lines
2.1 KiB
C
/*
|
|
* arch/arm/include/asm/vfpmacros.h
|
|
*
|
|
* Assembler-only file containing VFP macros and register definitions.
|
|
*/
|
|
#include <asm/hwcap.h>
|
|
|
|
#include <asm/vfp.h>
|
|
|
|
@ Macros to allow building with old toolkits (with no VFP support)
|
|
.macro VFPFMRX, rd, sysreg, cond
|
|
MRC\cond p10, 7, \rd, \sysreg, cr0, 0 @ FMRX \rd, \sysreg
|
|
.endm
|
|
|
|
.macro VFPFMXR, sysreg, rd, cond
|
|
MCR\cond p10, 7, \rd, \sysreg, cr0, 0 @ FMXR \sysreg, \rd
|
|
.endm
|
|
|
|
@ read all the working registers back into the VFP
|
|
.macro VFPFLDMIA, base, tmp
|
|
#if __LINUX_ARM_ARCH__ < 6
|
|
LDC p11, cr0, [\base],#33*4 @ FLDMIAX \base!, {d0-d15}
|
|
#else
|
|
LDC p11, cr0, [\base],#32*4 @ FLDMIAD \base!, {d0-d15}
|
|
#endif
|
|
#ifdef CONFIG_VFPv3
|
|
#if __LINUX_ARM_ARCH__ <= 6
|
|
ldr \tmp, =elf_hwcap @ may not have MVFR regs
|
|
ldr \tmp, [\tmp, #0]
|
|
tst \tmp, #HWCAP_VFPD32
|
|
ldcnel p11, cr0, [\base],#32*4 @ FLDMIAD \base!, {d16-d31}
|
|
addeq \base, \base, #32*4 @ step over unused register space
|
|
#else
|
|
VFPFMRX \tmp, MVFR0 @ Media and VFP Feature Register 0
|
|
and \tmp, \tmp, #MVFR0_A_SIMD_MASK @ A_SIMD field
|
|
cmp \tmp, #2 @ 32 x 64bit registers?
|
|
ldceql p11, cr0, [\base],#32*4 @ FLDMIAD \base!, {d16-d31}
|
|
addne \base, \base, #32*4 @ step over unused register space
|
|
#endif
|
|
#endif
|
|
.endm
|
|
|
|
@ write all the working registers out of the VFP
|
|
.macro VFPFSTMIA, base, tmp
|
|
#if __LINUX_ARM_ARCH__ < 6
|
|
STC p11, cr0, [\base],#33*4 @ FSTMIAX \base!, {d0-d15}
|
|
#else
|
|
STC p11, cr0, [\base],#32*4 @ FSTMIAD \base!, {d0-d15}
|
|
#endif
|
|
#ifdef CONFIG_VFPv3
|
|
#if __LINUX_ARM_ARCH__ <= 6
|
|
ldr \tmp, =elf_hwcap @ may not have MVFR regs
|
|
ldr \tmp, [\tmp, #0]
|
|
tst \tmp, #HWCAP_VFPD32
|
|
stcnel p11, cr0, [\base],#32*4 @ FSTMIAD \base!, {d16-d31}
|
|
addeq \base, \base, #32*4 @ step over unused register space
|
|
#else
|
|
VFPFMRX \tmp, MVFR0 @ Media and VFP Feature Register 0
|
|
and \tmp, \tmp, #MVFR0_A_SIMD_MASK @ A_SIMD field
|
|
cmp \tmp, #2 @ 32 x 64bit registers?
|
|
stceql p11, cr0, [\base],#32*4 @ FSTMIAD \base!, {d16-d31}
|
|
addne \base, \base, #32*4 @ step over unused register space
|
|
#endif
|
|
#endif
|
|
.endm
|