Re: [PATCH v3] ARM: vfp: fix save and restore when running on pre-VFPv3 and CONFIG_VFPv3 set
On 10/15/2012 12:53 PM, Tony Lindgren wrote: * Paul Walmsley p...@pwsan.com [121014 22:26]: After commit 846a136881b8f73c1f74250bf6acfaa309cab1f2 (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: 0Not 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 commit 5aaf254409f8d58229107b59507a8235b715a960 (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 commit 846a136 because 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-kernelm=135013547905283w=2 and some feedback from Måns to clarify the name of the HWCAP flag. Signed-off-by: Paul Walmsley p...@pwsan.com Cc: Tony Lindgren t...@atomide.com Cc: Russell King rmk+ker...@arm.linux.org.uk Cc: Catalin Marinas catalin.mari...@arm.com Cc: Dave Martin dave.mar...@linaro.org Cc: Måns Rullgård mans.rullg...@linaro.org This fixes the error above on my 2430sdp: Tested-by: Tony Lindgren t...@atomide.com Fixes same error on 2420 H4. Tested-by: Jon Hunter jon-hun...@ti.com Cheers Jon -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v3] ARM: vfp: fix save and restore when running on pre-VFPv3 and CONFIG_VFPv3 set
* Paul Walmsley p...@pwsan.com [121014 22:26]: After commit 846a136881b8f73c1f74250bf6acfaa309cab1f2 (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: 0Not 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 commit 5aaf254409f8d58229107b59507a8235b715a960 (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 commit 846a136 because 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-kernelm=135013547905283w=2 and some feedback from Måns to clarify the name of the HWCAP flag. Signed-off-by: Paul Walmsley p...@pwsan.com Cc: Tony Lindgren t...@atomide.com Cc: Russell King rmk+ker...@arm.linux.org.uk Cc: Catalin Marinas catalin.mari...@arm.com Cc: Dave Martin dave.mar...@linaro.org Cc: Måns Rullgård mans.rullg...@linaro.org This fixes the error above on my 2430sdp: Tested-by: Tony Lindgren t...@atomide.com -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH v3] ARM: vfp: fix save and restore when running on pre-VFPv3 and CONFIG_VFPv3 set
After commit 846a136881b8f73c1f74250bf6acfaa309cab1f2 (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: 0Not 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 commit 5aaf254409f8d58229107b59507a8235b715a960 (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 commit 846a136 because 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-kernelm=135013547905283w=2
and some feedback from Måns to clarify the name of the HWCAP flag.
Signed-off-by: Paul Walmsley p...@pwsan.com
Cc: Tony Lindgren t...@atomide.com
Cc: Russell King rmk+ker...@arm.linux.org.uk
Cc: Catalin Marinas catalin.mari...@arm.com
Cc: Dave Martin dave.mar...@linaro.org
Cc: Måns Rullgård mans.rullg...@linaro.org
---
Thanks for the suggestion, Måns; certainly a readability improvement.
arch/arm/include/asm/vfpmacros.h | 12 ++--
arch/arm/include/uapi/asm/hwcap.h |3 ++-
arch/arm/vfp/vfpmodule.c |9 ++---
3 files changed, 14 insertions(+), 10 deletions(-)
diff --git a/arch/arm/include/asm/vfpmacros.h b/arch/arm/include/asm/vfpmacros.h
index 6a6f1e4..301c1db 100644
--- a/arch/arm/include/asm/vfpmacros.h
+++ b/arch/arm/include/asm/vfpmacros.h
@@ -27,9 +27,9 @@
#if __LINUX_ARM_ARCH__ = 6
ldr \tmp, =elf_hwcap@ may not have MVFR regs
ldr \tmp, [\tmp, #0]
- tst \tmp, #HWCAP_VFPv3D16
- ldceql p11, cr0, [\base],#32*4 @ FLDMIAD \base!, {d16-d31}
- addne \base, \base, #32*4 @ step over unused register
space
+ 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
@@ -51,9 +51,9 @@
#if __LINUX_ARM_ARCH__ = 6
ldr \tmp, =elf_hwcap@ may not have MVFR regs
ldr \tmp, [\tmp, #0]
- tst \tmp, #HWCAP_VFPv3D16
- stceql p11, cr0, [\base],#32*4 @ FSTMIAD \base!, {d16-d31}
- addne \base, \base, #32*4 @ step over unused register
space
+ 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
diff --git a/arch/arm/include/uapi/asm/hwcap.h
b/arch/arm/include/uapi/asm/hwcap.h
index f254f65..3688fd1 100644
--- a/arch/arm/include/uapi/asm/hwcap.h
+++ b/arch/arm/include/uapi/asm/hwcap.h
@@ -18,11 +18,12 @@
#define HWCAP_THUMBEE (1 11)
#define HWCAP_NEON (1 12)
#define HWCAP_VFPv3(1 13)
-#define HWCAP_VFPv3D16 (1 14)
+#define HWCAP_VFPv3D16 (1 14) /* also set for VFPv4-D16 */
#define HWCAP_TLS (1 15)
#define HWCAP_VFPv4(1 16)
#define HWCAP_IDIVA(1 17)
#define HWCAP_IDIVT(1 18)
+#define HWCAP_VFPD32 (1 19) /* set if VFP has 32 regs (not 16) */
#define HWCAP_IDIV (HWCAP_IDIVA | HWCAP_IDIVT)
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index c834b32..3b44e0d 100644
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -701,11 +701,14 @@ static int __init vfp_init(void)
elf_hwcap |= HWCAP_VFPv3;
/*
-* Check for VFPv3 D16. CPUs in this configuration
-* only have 16 x 64bit registers.
+* Check for VFPv3 D16 and VFPv4 D16. CPUs in
+* this configuration only have 16 x 64bit
+* registers.
*/
if (((fmrx(MVFR0) MVFR0_A_SIMD_MASK)) == 1)
- elf_hwcap |= HWCAP_VFPv3D16;
+ elf_hwcap |=
