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linux/arch/arm/vfp/entry.S

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Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 00:20:36 +02:00
/*
* linux/arch/arm/vfp/entry.S
*
* Copyright (C) 2004 ARM Limited.
* Written by Deep Blue Solutions Limited.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
[ARM] 5440/1: Fix VFP state corruption due to preemption during VFP exceptions We've observed that ARM VFP state can be corrupted during VFP exception handling when PREEMPT is enabled. The exact conditions are difficult to reproduce but appear to occur during VFP exception handling when a task causes a VFP exception which is handled via VFP_bounce and is then preempted by yet another task which in turn causes yet another VFP exception. Since the VFP_bounce code is not preempt safe, VFP state then becomes corrupt. In order to prevent preemption from occuring while handling a VFP exception, this patch disables preemption while handling VFP exceptions. Signed-off-by: George G. Davis <gdavis@mvista.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-04-01 21:27:18 +02:00
#include <asm/thread_info.h>
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 00:20:36 +02:00
#include <asm/vfpmacros.h>
[ARM] 5440/1: Fix VFP state corruption due to preemption during VFP exceptions We've observed that ARM VFP state can be corrupted during VFP exception handling when PREEMPT is enabled. The exact conditions are difficult to reproduce but appear to occur during VFP exception handling when a task causes a VFP exception which is handled via VFP_bounce and is then preempted by yet another task which in turn causes yet another VFP exception. Since the VFP_bounce code is not preempt safe, VFP state then becomes corrupt. In order to prevent preemption from occuring while handling a VFP exception, this patch disables preemption while handling VFP exceptions. Signed-off-by: George G. Davis <gdavis@mvista.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-04-01 21:27:18 +02:00
#include "../kernel/entry-header.S"
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 00:20:36 +02:00
ARM: Fix undefined instruction exception handling While trying to get a v3.5 kernel booted on the cubox, I noticed that VFP does not work correctly with VFP bounce handling. This is because of the confusion over 16-bit vs 32-bit instructions, and where PC is supposed to point to. The rule is that FP handlers are entered with regs->ARM_pc pointing at the _next_ instruction to be executed. However, if the exception is not handled, regs->ARM_pc points at the faulting instruction. This is easy for ARM mode, because we know that the next instruction and previous instructions are separated by four bytes. This is not true of Thumb2 though. Since all FP instructions are 32-bit in Thumb2, it makes things easy. We just need to select the appropriate adjustment. Do this by moving the adjustment out of do_undefinstr() into the assembly code, as only the assembly code knows whether it's dealing with a 32-bit or 16-bit instruction. Cc: <stable@vger.kernel.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-30 20:42:10 +02:00
@ VFP entry point.
@
@ r0 = instruction opcode (32-bit ARM or two 16-bit Thumb)
@ r2 = PC value to resume execution after successful emulation
@ r9 = normal "successful" return address
@ r10 = this threads thread_info structure
@ lr = unrecognised instruction return address
@ IRQs disabled.
@
[ARM] 5227/1: Add the ENDPROC declarations to the .S files This declaration specifies the "function" type and size for various assembly functions, mainly needed for generating the correct branch instructions in Thumb-2. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-08-28 12:22:32 +02:00
ENTRY(do_vfp)
ARM: 7627/1: Predicate preempt logic on PREEMP_COUNT not PREEMPT alone Patrik Kluba reports that the preempt count becomes invalid due to the preempt_enable() call being unbalanced with a preempt_disable() call in the vfp assembly routines. This happens because preempt_enable() and preempt_disable() update preempt counts under PREEMPT_COUNT=y but the vfp assembly routines do so under PREEMPT=y. In a configuration where PREEMPT=n and DEBUG_ATOMIC_SLEEP=y, PREEMPT_COUNT=y and so the preempt_enable() call in VFP_bounce() keeps subtracting from the preempt count until it goes negative. Fix this by always using PREEMPT_COUNT to decided when to update preempt counts in the ARM assembly code. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Reported-by: Patrik Kluba <pkluba@dension.com> Tested-by: Patrik Kluba <pkluba@dension.com> Cc: <stable@vger.kernel.org> # 2.6.30 Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-01-14 19:50:42 +01:00
#ifdef CONFIG_PREEMPT_COUNT
[ARM] 5440/1: Fix VFP state corruption due to preemption during VFP exceptions We've observed that ARM VFP state can be corrupted during VFP exception handling when PREEMPT is enabled. The exact conditions are difficult to reproduce but appear to occur during VFP exception handling when a task causes a VFP exception which is handled via VFP_bounce and is then preempted by yet another task which in turn causes yet another VFP exception. Since the VFP_bounce code is not preempt safe, VFP state then becomes corrupt. In order to prevent preemption from occuring while handling a VFP exception, this patch disables preemption while handling VFP exceptions. Signed-off-by: George G. Davis <gdavis@mvista.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-04-01 21:27:18 +02:00
ldr r4, [r10, #TI_PREEMPT] @ get preempt count
add r11, r4, #1 @ increment it
str r11, [r10, #TI_PREEMPT]
#endif
[ARM] Move IRQ enable after coprocessor number decode Allow the individual coprocessor handlers to decide when to enable interrupts, rather than unconditionally enabling them. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-03-15 13:33:43 +01:00
enable_irq
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 00:20:36 +02:00
ldr r4, .LCvfp
[ARM] 4111/1: Allow VFP to work with thread migration on SMP The current lazy saving of the VFP registers is no longer possible with thread migration on SMP. This patch implements a per-CPU vfp-state pointer and the saving of the VFP registers at every context switch. The registers restoring is still performed in a lazy way. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-01-24 18:47:08 +01:00
ldr r11, [r10, #TI_CPU] @ CPU number
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 00:20:36 +02:00
add r10, r10, #TI_VFPSTATE @ r10 = workspace
ldr pc, [r4] @ call VFP entry point
[ARM] 5227/1: Add the ENDPROC declarations to the .S files This declaration specifies the "function" type and size for various assembly functions, mainly needed for generating the correct branch instructions in Thumb-2. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-08-28 12:22:32 +02:00
ENDPROC(do_vfp)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 00:20:36 +02:00
[ARM] VFP: fix section mismatch error Fix a real section mismatch issue; the test code is thrown away after initialisation, but if we do not detect the VFP hardware, it is left hooked into the exception handler. Any VFP instructions which are subsequently executed risk calling the discarded exception handler. Introduce a new "null" handler which returns to the "unrecognised fault" return address. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-06-10 13:22:20 +02:00
ENTRY(vfp_null_entry)
ARM: 7627/1: Predicate preempt logic on PREEMP_COUNT not PREEMPT alone Patrik Kluba reports that the preempt count becomes invalid due to the preempt_enable() call being unbalanced with a preempt_disable() call in the vfp assembly routines. This happens because preempt_enable() and preempt_disable() update preempt counts under PREEMPT_COUNT=y but the vfp assembly routines do so under PREEMPT=y. In a configuration where PREEMPT=n and DEBUG_ATOMIC_SLEEP=y, PREEMPT_COUNT=y and so the preempt_enable() call in VFP_bounce() keeps subtracting from the preempt count until it goes negative. Fix this by always using PREEMPT_COUNT to decided when to update preempt counts in the ARM assembly code. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Reported-by: Patrik Kluba <pkluba@dension.com> Tested-by: Patrik Kluba <pkluba@dension.com> Cc: <stable@vger.kernel.org> # 2.6.30 Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-01-14 19:50:42 +01:00
#ifdef CONFIG_PREEMPT_COUNT
[ARM] 5440/1: Fix VFP state corruption due to preemption during VFP exceptions We've observed that ARM VFP state can be corrupted during VFP exception handling when PREEMPT is enabled. The exact conditions are difficult to reproduce but appear to occur during VFP exception handling when a task causes a VFP exception which is handled via VFP_bounce and is then preempted by yet another task which in turn causes yet another VFP exception. Since the VFP_bounce code is not preempt safe, VFP state then becomes corrupt. In order to prevent preemption from occuring while handling a VFP exception, this patch disables preemption while handling VFP exceptions. Signed-off-by: George G. Davis <gdavis@mvista.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-04-01 21:27:18 +02:00
get_thread_info r10
ldr r4, [r10, #TI_PREEMPT] @ get preempt count
sub r11, r4, #1 @ decrement it
str r11, [r10, #TI_PREEMPT]
#endif
[ARM] VFP: fix section mismatch error Fix a real section mismatch issue; the test code is thrown away after initialisation, but if we do not detect the VFP hardware, it is left hooked into the exception handler. Any VFP instructions which are subsequently executed risk calling the discarded exception handler. Introduce a new "null" handler which returns to the "unrecognised fault" return address. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-06-10 13:22:20 +02:00
mov pc, lr
ENDPROC(vfp_null_entry)
Thumb-2: Add some .align statements to the .S files Since the Thumb-2 instructions can be 16-bit wide, data in the .text sections may not be aligned to a 32-bit word and this leads to unaligned exceptions. This patch does not affect the ARM code generation. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-07-24 13:32:52 +02:00
.align 2
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 00:20:36 +02:00
.LCvfp:
.word vfp_vector
@ This code is called if the VFP does not exist. It needs to flag the
@ failure to the VFP initialisation code.
__INIT
[ARM] 5227/1: Add the ENDPROC declarations to the .S files This declaration specifies the "function" type and size for various assembly functions, mainly needed for generating the correct branch instructions in Thumb-2. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-08-28 12:22:32 +02:00
ENTRY(vfp_testing_entry)
ARM: 7627/1: Predicate preempt logic on PREEMP_COUNT not PREEMPT alone Patrik Kluba reports that the preempt count becomes invalid due to the preempt_enable() call being unbalanced with a preempt_disable() call in the vfp assembly routines. This happens because preempt_enable() and preempt_disable() update preempt counts under PREEMPT_COUNT=y but the vfp assembly routines do so under PREEMPT=y. In a configuration where PREEMPT=n and DEBUG_ATOMIC_SLEEP=y, PREEMPT_COUNT=y and so the preempt_enable() call in VFP_bounce() keeps subtracting from the preempt count until it goes negative. Fix this by always using PREEMPT_COUNT to decided when to update preempt counts in the ARM assembly code. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Reported-by: Patrik Kluba <pkluba@dension.com> Tested-by: Patrik Kluba <pkluba@dension.com> Cc: <stable@vger.kernel.org> # 2.6.30 Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-01-14 19:50:42 +01:00
#ifdef CONFIG_PREEMPT_COUNT
[ARM] 5440/1: Fix VFP state corruption due to preemption during VFP exceptions We've observed that ARM VFP state can be corrupted during VFP exception handling when PREEMPT is enabled. The exact conditions are difficult to reproduce but appear to occur during VFP exception handling when a task causes a VFP exception which is handled via VFP_bounce and is then preempted by yet another task which in turn causes yet another VFP exception. Since the VFP_bounce code is not preempt safe, VFP state then becomes corrupt. In order to prevent preemption from occuring while handling a VFP exception, this patch disables preemption while handling VFP exceptions. Signed-off-by: George G. Davis <gdavis@mvista.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-04-01 21:27:18 +02:00
get_thread_info r10
ldr r4, [r10, #TI_PREEMPT] @ get preempt count
sub r11, r4, #1 @ decrement it
str r11, [r10, #TI_PREEMPT]
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 00:20:36 +02:00
ldr r0, VFP_arch_address
ARM: 7729/1: vfp: ensure VFP_arch is non-zero when VFP is not supported Commit d3f79584a8b5 ("ARM: cleanup undefined instruction entry code") improved the register scheduling when handling undefined instructions. A side effect of this is that r5 is now used as a temporary, whilst the VFP probing code relies on r5 containing a non-zero value when VFP is not supported. This patch fixes the VFP detection code so that we don't rely on the contents of r5. Without this patch, Linux dies loudly on CPUs without VFP support. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-05-16 20:38:51 +02:00
str r0, [r0] @ set to non-zero value
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 00:20:36 +02:00
mov pc, r9 @ we have handled the fault
[ARM] 5227/1: Add the ENDPROC declarations to the .S files This declaration specifies the "function" type and size for various assembly functions, mainly needed for generating the correct branch instructions in Thumb-2. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-08-28 12:22:32 +02:00
ENDPROC(vfp_testing_entry)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 00:20:36 +02:00
Thumb-2: Add some .align statements to the .S files Since the Thumb-2 instructions can be 16-bit wide, data in the .text sections may not be aligned to a 32-bit word and this leads to unaligned exceptions. This patch does not affect the ARM code generation. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-07-24 13:32:52 +02:00
.align 2
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 00:20:36 +02:00
VFP_arch_address:
.word VFP_arch
__FINIT