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OpenCloudOS-Kernel/arch/powerpc/kernel/fpu.S

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-27 14:55:01 +08:00
/* SPDX-License-Identifier: GPL-2.0-or-later */
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
/*
* FPU support code, moved here from head.S so that it can be used
* by chips which use other head-whatever.S files.
*
[POWERPC] Restore copyright notice in arch/powerpc/kernel/fpu.S This code got moved from head.S but the copyright notice on head.S didn't get transferred with it. Noticed by Cort Dougan <cort@fsmlabs.com>. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-08-30 12:45:35 +08:00
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
* Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
* Copyright (C) 1996 Paul Mackerras.
* Copyright (C) 1997 Dan Malek (dmalek@jlc.net).
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
*/
powerpc: Use reg.h instead of processor.h when we just want reg names Now that the register names and bit definitions are all in reg.h, use that instead of processor.h in assembly code in a few places. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-10 20:20:10 +08:00
#include <asm/reg.h>
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/cputable.h>
#include <asm/cache.h>
#include <asm/thread_info.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
powerpc: Remove second definition of STACK_FRAME_OVERHEAD Since STACK_FRAME_OVERHEAD is defined in asm/ptrace.h and that is ASSEMBER safe, we can just include that instead of going via asm-offsets.h. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-11-18 23:06:17 +08:00
#include <asm/ptrace.h>
ppc: move exports to definitions Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-14 12:33:46 +08:00
#include <asm/export.h>
powerpc: move ASM_CONST and stringify_in_c() into asm-const.h This patch moves ASM_CONST() and stringify_in_c() into dedicated asm-const.h, then cleans all related inclusions. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: asm-compat.h should include asm-const.h] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-06 00:24:57 +08:00
#include <asm/asm-compat.h>
powerpc: clean inclusions of asm/feature-fixups.h files not using feature fixup don't need asm/feature-fixups.h files using feature fixup need asm/feature-fixups.h Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-06 00:25:01 +08:00
#include <asm/feature-fixups.h>
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
powerpc: Add VSX assembler code macros This adds the macros for the VSX load/store instruction as most binutils are not going to support this for a while. Also add VSX register save/restore macros and vsr[0-63] register definitions. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-25 12:07:18 +08:00
#ifdef CONFIG_VSX
powerpc: Enforce usage of R0-R31 where possible Enforce the use of R0-R31 in macros where possible now we have all the fixes in. R0-R31 macros are removed here so that can't be used anymore. They should not be defined anywhere. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-06-25 21:33:23 +08:00
#define __REST_32FPVSRS(n,c,base) \
powerpc: Add VSX assembler code macros This adds the macros for the VSX load/store instruction as most binutils are not going to support this for a while. Also add VSX register save/restore macros and vsr[0-63] register definitions. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-25 12:07:18 +08:00
BEGIN_FTR_SECTION \
b 2f; \
END_FTR_SECTION_IFSET(CPU_FTR_VSX); \
REST_32FPRS(n,base); \
b 3f; \
2: REST_32VSRS(n,c,base); \
3:
powerpc: Enforce usage of R0-R31 where possible Enforce the use of R0-R31 in macros where possible now we have all the fixes in. R0-R31 macros are removed here so that can't be used anymore. They should not be defined anywhere. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-06-25 21:33:23 +08:00
#define __SAVE_32FPVSRS(n,c,base) \
powerpc: Add VSX assembler code macros This adds the macros for the VSX load/store instruction as most binutils are not going to support this for a while. Also add VSX register save/restore macros and vsr[0-63] register definitions. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-25 12:07:18 +08:00
BEGIN_FTR_SECTION \
b 2f; \
END_FTR_SECTION_IFSET(CPU_FTR_VSX); \
SAVE_32FPRS(n,base); \
b 3f; \
2: SAVE_32VSRS(n,c,base); \
3:
#else
powerpc: Enforce usage of R0-R31 where possible Enforce the use of R0-R31 in macros where possible now we have all the fixes in. R0-R31 macros are removed here so that can't be used anymore. They should not be defined anywhere. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-06-25 21:33:23 +08:00
#define __REST_32FPVSRS(n,b,base) REST_32FPRS(n, base)
#define __SAVE_32FPVSRS(n,b,base) SAVE_32FPRS(n, base)
powerpc: Add VSX assembler code macros This adds the macros for the VSX load/store instruction as most binutils are not going to support this for a while. Also add VSX register save/restore macros and vsr[0-63] register definitions. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-25 12:07:18 +08:00
#endif
powerpc: Enforce usage of R0-R31 where possible Enforce the use of R0-R31 in macros where possible now we have all the fixes in. R0-R31 macros are removed here so that can't be used anymore. They should not be defined anywhere. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-06-25 21:33:23 +08:00
#define REST_32FPVSRS(n,c,base) __REST_32FPVSRS(n,__REG_##c,__REG_##base)
#define SAVE_32FPVSRS(n,c,base) __SAVE_32FPVSRS(n,__REG_##c,__REG_##base)
powerpc: Add VSX assembler code macros This adds the macros for the VSX load/store instruction as most binutils are not going to support this for a while. Also add VSX register save/restore macros and vsr[0-63] register definitions. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-25 12:07:18 +08:00
powerpc: Provide for giveup_fpu/altivec to save state in alternate location This provides a facility which is intended for use by KVM, where the contents of the FP/VSX and VMX (Altivec) registers can be saved away to somewhere other than the thread_struct when kernel code wants to use floating point or VMX instructions. This is done by providing a pointer in the thread_struct to indicate where the state should be saved to. The giveup_fpu() and giveup_altivec() functions test these pointers and save state to the indicated location if they are non-NULL. Note that the MSR_FP/VEC bits in task->thread.regs->msr are still used to indicate whether the CPU register state is live, even when an alternate save location is being used. This also provides load_fp_state() and load_vr_state() functions, which load up FP/VSX and VMX state from memory into the CPU registers, and corresponding store_fp_state() and store_vr_state() functions, which store FP/VSX and VMX state into memory from the CPU registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-10 18:21:10 +08:00
/*
* Load state from memory into FP registers including FPSCR.
* Assumes the caller has enabled FP in the MSR.
*/
_GLOBAL(load_fp_state)
lfd fr0,FPSTATE_FPSCR(r3)
MTFSF_L(fr0)
REST_32FPVSRS(0, R4, R3)
blr
ppc: move exports to definitions Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-14 12:33:46 +08:00
EXPORT_SYMBOL(load_fp_state)
powerpc/64: Don't trace code that runs with the soft irq mask unreconciled "Reconciling" in terms of interrupt handling, is to bring the soft irq mask state in to synch with the hardware, after an interrupt causes MSR[EE] to be cleared (while the soft mask may be enabled, and hard irqs not marked disabled). General kernel code should not be called while unreconciled, because local_irq_disable, etc. manipulations can cause surprising irq traces, and it's fragile because the soft irq code does not really expect to be called in this situation. When exiting from an interrupt, MSR[EE] is cleared to prevent races, but soft irq state is enabled for the returned-to context, so this is now an unreconciled state. restore_math is called in this state, and that can be ftraced, and the ftrace subsystem disables local irqs. Mark restore_math and its callees as notrace. Restore a sanity check in the soft irq code that had to be disabled for this case, by commit 4da1f79227ad4 ("powerpc/64: Disable irq restore warning for now"). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-02 13:21:07 +08:00
_ASM_NOKPROBE_SYMBOL(load_fp_state); /* used by restore_math */
powerpc: Provide for giveup_fpu/altivec to save state in alternate location This provides a facility which is intended for use by KVM, where the contents of the FP/VSX and VMX (Altivec) registers can be saved away to somewhere other than the thread_struct when kernel code wants to use floating point or VMX instructions. This is done by providing a pointer in the thread_struct to indicate where the state should be saved to. The giveup_fpu() and giveup_altivec() functions test these pointers and save state to the indicated location if they are non-NULL. Note that the MSR_FP/VEC bits in task->thread.regs->msr are still used to indicate whether the CPU register state is live, even when an alternate save location is being used. This also provides load_fp_state() and load_vr_state() functions, which load up FP/VSX and VMX state from memory into the CPU registers, and corresponding store_fp_state() and store_vr_state() functions, which store FP/VSX and VMX state into memory from the CPU registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-10 18:21:10 +08:00
/*
* Store FP state into memory, including FPSCR
* Assumes the caller has enabled FP in the MSR.
*/
_GLOBAL(store_fp_state)
SAVE_32FPVSRS(0, R4, R3)
mffs fr0
stfd fr0,FPSTATE_FPSCR(r3)
blr
ppc: move exports to definitions Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-14 12:33:46 +08:00
EXPORT_SYMBOL(store_fp_state)
powerpc: Provide for giveup_fpu/altivec to save state in alternate location This provides a facility which is intended for use by KVM, where the contents of the FP/VSX and VMX (Altivec) registers can be saved away to somewhere other than the thread_struct when kernel code wants to use floating point or VMX instructions. This is done by providing a pointer in the thread_struct to indicate where the state should be saved to. The giveup_fpu() and giveup_altivec() functions test these pointers and save state to the indicated location if they are non-NULL. Note that the MSR_FP/VEC bits in task->thread.regs->msr are still used to indicate whether the CPU register state is live, even when an alternate save location is being used. This also provides load_fp_state() and load_vr_state() functions, which load up FP/VSX and VMX state from memory into the CPU registers, and corresponding store_fp_state() and store_vr_state() functions, which store FP/VSX and VMX state into memory from the CPU registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-10 18:21:10 +08:00
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
/*
* This task wants to use the FPU now.
* On UP, disable FP for the task which had the FPU previously,
* and save its floating-point registers in its thread_struct.
* Load up this task's FP registers from its thread_struct,
* enable the FPU for the current task and return to the task.
powerpc: Don't corrupt user registers on 32-bit Commit de79f7b9f6 ("powerpc: Put FP/VSX and VR state into structures") modified load_up_fpu() and load_up_altivec() in such a way that they now use r7 and r8. Unfortunately, the callers of these functions on 32-bit machines then return to userspace via fast_exception_return, which doesn't restore all of the volatile GPRs, but only r1, r3 -- r6 and r9 -- r12. This was causing userspace segfaults and other userspace misbehaviour on 32-bit machines. This fixes the problem by changing the register usage of load_up_fpu() and load_up_altivec() to avoid using r7 and r8 and instead use r6 and r10. This also adds comments to those functions saying which registers may be used. Signed-off-by: Paul Mackerras <paulus@samba.org> Tested-by: Scott Wood <scottwood@freescale.com> (on e500mc, so no altivec) Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-23 16:40:02 +08:00
* Note that on 32-bit this can only use registers that will be
* restored by fast_exception_return, i.e. r3 - r6, r10 and r11.
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
*/
powerpc: Define 32/64 bit asm macros and use them in fpu.S These macros help in writing assembly code that works for both ppc32 and ppc64. With this we now have a common fpu.S. This takes out load_up_fpu from head_64.S. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-06 08:59:19 +08:00
_GLOBAL(load_up_fpu)
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
mfmsr r5
powerpc/64s/interrupt: handle MSR EE and RI in interrupt entry wrapper The mtmsrd to enable MSR[RI] can be combined with the mtmsrd to enable MSR[EE] in interrupt entry code, for those interrupts which enable EE. This helps performance of important synchronous interrupts (e.g., page faults). This is similar to what commit dd152f70bdc1 ("powerpc/64s: system call avoid setting MSR[RI] until we set MSR[EE]") does for system calls. Do this by enabling EE and RI together at the beginning of the entry wrapper if PACA_IRQ_HARD_DIS is clear, and only enabling RI if it is set. Asynchronous interrupts set PACA_IRQ_HARD_DIS, but synchronous ones leave it unchanged, so by default they always get EE=1 unless they have interrupted a caller that is hard disabled. When the sync interrupt later calls interrupt_cond_local_irq_enable(), it will not require another mtmsrd because MSR[EE] was already enabled here. This avoids one mtmsrd L=1 for synchronous interrupts on 64s, which saves about 20 cycles on POWER9. And for kernel-mode interrupts, both synchronous and asynchronous, this saves an additional 40 cycles due to the mtmsrd being moved ahead of mfspr SPRN_AMR, which prevents a SPR scoreboard stall. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210922145452.352571-3-npiggin@gmail.com
2021-09-22 22:54:48 +08:00
#ifdef CONFIG_PPC_BOOK3S_64
/* interrupt doesn't set MSR[RI] and HPT can fault on current access */
ori r5,r5,MSR_FP|MSR_RI
#else
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
ori r5,r5,MSR_FP
powerpc/64s/interrupt: handle MSR EE and RI in interrupt entry wrapper The mtmsrd to enable MSR[RI] can be combined with the mtmsrd to enable MSR[EE] in interrupt entry code, for those interrupts which enable EE. This helps performance of important synchronous interrupts (e.g., page faults). This is similar to what commit dd152f70bdc1 ("powerpc/64s: system call avoid setting MSR[RI] until we set MSR[EE]") does for system calls. Do this by enabling EE and RI together at the beginning of the entry wrapper if PACA_IRQ_HARD_DIS is clear, and only enabling RI if it is set. Asynchronous interrupts set PACA_IRQ_HARD_DIS, but synchronous ones leave it unchanged, so by default they always get EE=1 unless they have interrupted a caller that is hard disabled. When the sync interrupt later calls interrupt_cond_local_irq_enable(), it will not require another mtmsrd because MSR[EE] was already enabled here. This avoids one mtmsrd L=1 for synchronous interrupts on 64s, which saves about 20 cycles on POWER9. And for kernel-mode interrupts, both synchronous and asynchronous, this saves an additional 40 cycles due to the mtmsrd being moved ahead of mfspr SPRN_AMR, which prevents a SPR scoreboard stall. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210922145452.352571-3-npiggin@gmail.com
2021-09-22 22:54:48 +08:00
#endif
powerpc: Add VSX context save/restore, ptrace and signal support This patch extends the floating point save and restore code to use the VSX load/stores when VSX is available. This will make FP context save/restore marginally slower on FP only code, when VSX is available, as it has to load/store 128bits rather than just 64bits. Mixing FP, VMX and VSX code will get constant architected state. The signals interface is extended to enable access to VSR 0-31 doubleword 1 after discussions with tool chain maintainers. Backward compatibility is maintained. The ptrace interface is also extended to allow access to VSR 0-31 full registers. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-25 12:07:18 +08:00
#ifdef CONFIG_VSX
BEGIN_FTR_SECTION
oris r5,r5,MSR_VSX@h
END_FTR_SECTION_IFSET(CPU_FTR_VSX)
#endif
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
MTMSRD(r5) /* enable use of fpu now */
isync
/* enable use of FP after return */
powerpc: Define 32/64 bit asm macros and use them in fpu.S These macros help in writing assembly code that works for both ppc32 and ppc64. With this we now have a common fpu.S. This takes out load_up_fpu from head_64.S. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-06 08:59:19 +08:00
#ifdef CONFIG_PPC32
powerpc/32: Remove unneccessary calculations in load_up_{fpu/altivec} No need to re-read SPRN_THREAD, we can calculate thread address from current (r2). And remove a reload of value 1 into r4 as r4 is already 1. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c04cce578b97a76a9e69a096698b1d89f721768a.1629276437.git.christophe.leroy@csgroup.eu
2021-08-18 16:47:28 +08:00
addi r5,r2,THREAD
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
lwz r4,THREAD_FPEXC_MODE(r5)
ori r9,r9,MSR_FP /* enable FP for current */
or r9,r9,r4
powerpc: Define 32/64 bit asm macros and use them in fpu.S These macros help in writing assembly code that works for both ppc32 and ppc64. With this we now have a common fpu.S. This takes out load_up_fpu from head_64.S. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-06 08:59:19 +08:00
#else
ld r4,PACACURRENT(r13)
addi r5,r4,THREAD /* Get THREAD */
powerpc/64: Fix bug in setting floating-point exception mode When loading up the FPU, we were using a 'ld' (load doubleword) instruction to get the FP exception mode from the thread_struct, but it's only an int field. This changes the ld to lwz (load word and zero-extend). Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-07 10:55:30 +08:00
lwz r4,THREAD_FPEXC_MODE(r5)
powerpc: Define 32/64 bit asm macros and use them in fpu.S These macros help in writing assembly code that works for both ppc32 and ppc64. With this we now have a common fpu.S. This takes out load_up_fpu from head_64.S. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-06 08:59:19 +08:00
ori r12,r12,MSR_FP
or r12,r12,r4
std r12,_MSR(r1)
powerpc/64s: avoid reloading (H)SRR registers if they are still valid When an interrupt is taken, the SRR registers are set to return to where it left off. Unless they are modified in the meantime, or the return address or MSR are modified, there is no need to reload these registers when returning from interrupt. Introduce per-CPU flags that track the validity of SRR and HSRR registers. These are cleared when returning from interrupt, when using the registers for something else (e.g., OPAL calls), when adjusting the return address or MSR of a context, and when context switching (which changes the return address and MSR). This improves the performance of interrupt returns. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fold in fixup patch from Nick] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210617155116.2167984-5-npiggin@gmail.com
2021-06-17 23:51:03 +08:00
#ifdef CONFIG_PPC_BOOK3S_64
li r4,0
stb r4,PACASRR_VALID(r13)
#endif
powerpc: Define 32/64 bit asm macros and use them in fpu.S These macros help in writing assembly code that works for both ppc32 and ppc64. With this we now have a common fpu.S. This takes out load_up_fpu from head_64.S. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-06 08:59:19 +08:00
#endif
powerpc: re-initialise lazy FPU/VEC counters on every fault When a FP/VEC/VSX unavailable fault loads registers and enables the facility in the MSR, re-set the lazy restore counters to 1 rather than incrementing them so every fault gets the same number of restores before the next fault. This probably shouldn't be a practical change because if a lazy counter was non-zero then it should have been restored and would not cause a fault when userspace tries to access it. However the code and comment implies otherwise so that's misleading and unnecessary. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200623234139.2262227-3-npiggin@gmail.com
2020-06-24 07:41:39 +08:00
li r4,1
powerpc: Restore FPU/VEC/VSX if previously used Currently the FPU, VEC and VSX facilities are lazily loaded. This is not a problem unless a process is using these facilities. Modern versions of GCC are very good at automatically vectorising code, new and modernised workloads make use of floating point and vector facilities, even the kernel makes use of vectorised memcpy. All this combined greatly increases the cost of a syscall since the kernel uses the facilities sometimes even in syscall fast-path making it increasingly common for a thread to take an *_unavailable exception soon after a syscall, not to mention potentially taking all three. The obvious overcompensation to this problem is to simply always load all the facilities on every exit to userspace. Loading up all FPU, VEC and VSX registers every time can be expensive and if a workload does avoid using them, it should not be forced to incur this penalty. An 8bit counter is used to detect if the registers have been used in the past and the registers are always loaded until the value wraps to back to zero. Several versions of the assembly in entry_64.S were tested: 1. Always calling C. 2. Performing a common case check and then calling C. 3. A complex check in asm. After some benchmarking it was determined that avoiding C in the common case is a performance benefit (option 2). The full check in asm (option 3) greatly complicated that codepath for a negligible performance gain and the trade-off was deemed not worth it. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> [mpe: Move load_vec in the struct to fill an existing hole, reword change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> fixup
2016-02-29 14:53:47 +08:00
stb r4,THREAD_LOAD_FP(r5)
powerpc: Don't corrupt user registers on 32-bit Commit de79f7b9f6 ("powerpc: Put FP/VSX and VR state into structures") modified load_up_fpu() and load_up_altivec() in such a way that they now use r7 and r8. Unfortunately, the callers of these functions on 32-bit machines then return to userspace via fast_exception_return, which doesn't restore all of the volatile GPRs, but only r1, r3 -- r6 and r9 -- r12. This was causing userspace segfaults and other userspace misbehaviour on 32-bit machines. This fixes the problem by changing the register usage of load_up_fpu() and load_up_altivec() to avoid using r7 and r8 and instead use r6 and r10. This also adds comments to those functions saying which registers may be used. Signed-off-by: Paul Mackerras <paulus@samba.org> Tested-by: Scott Wood <scottwood@freescale.com> (on e500mc, so no altivec) Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-23 16:40:02 +08:00
addi r10,r5,THREAD_FPSTATE
lfd fr0,FPSTATE_FPSCR(r10)
[POWERPC] 64bit FPSCR support Forthcoming machines will extend the FPSCR to 64 bits. We already had a 64-bit save area for the FPSCR, but we need to use a new form of the mtfsf instruction. Fortunately this new form is decoded as an ordinary mtfsf by existing 64-bit processors. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-10 18:18:39 +08:00
MTFSF_L(fr0)
powerpc: Don't corrupt user registers on 32-bit Commit de79f7b9f6 ("powerpc: Put FP/VSX and VR state into structures") modified load_up_fpu() and load_up_altivec() in such a way that they now use r7 and r8. Unfortunately, the callers of these functions on 32-bit machines then return to userspace via fast_exception_return, which doesn't restore all of the volatile GPRs, but only r1, r3 -- r6 and r9 -- r12. This was causing userspace segfaults and other userspace misbehaviour on 32-bit machines. This fixes the problem by changing the register usage of load_up_fpu() and load_up_altivec() to avoid using r7 and r8 and instead use r6 and r10. This also adds comments to those functions saying which registers may be used. Signed-off-by: Paul Mackerras <paulus@samba.org> Tested-by: Scott Wood <scottwood@freescale.com> (on e500mc, so no altivec) Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-23 16:40:02 +08:00
REST_32FPVSRS(0, R4, R10)
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
/* restore registers and return */
/* we haven't used ctr or xer or lr */
powerpc: Make load_up_fpu and load_up_altivec callable Make load_up_fpu and load_up_altivec callable so they can be reused by the VSX code. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-25 12:07:18 +08:00
blr
powerpc/32: Blacklist functions running with MMU disabled for kprobe kprobe does not handle events happening in real mode, all functions running with MMU disabled have to be blacklisted. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/3bf57066d05518644dee0840af69d36ab5086729.1585670437.git.christophe.leroy@c-s.fr
2020-04-01 00:03:44 +08:00
_ASM_NOKPROBE_SYMBOL(load_up_fpu)
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
/*
powerpc: Add the ability to save FPU without giving it up This patch adds the ability to be able to save the FPU registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch optimises the thread copy path (as a result of a fork() or clone()) so that the parent thread can return to userspace with hot registers avoiding a possibly pointless reload of FPU register state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:49 +08:00
* save_fpu(tsk)
* Save the floating-point registers in its thread_struct.
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
* Enables the FPU for use in the kernel on return.
*/
powerpc: Add the ability to save FPU without giving it up This patch adds the ability to be able to save the FPU registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch optimises the thread copy path (as a result of a fork() or clone()) so that the parent thread can return to userspace with hot registers avoiding a possibly pointless reload of FPU register state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:49 +08:00
_GLOBAL(save_fpu)
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
addi r3,r3,THREAD /* want THREAD of task */
powerpc: Provide for giveup_fpu/altivec to save state in alternate location This provides a facility which is intended for use by KVM, where the contents of the FP/VSX and VMX (Altivec) registers can be saved away to somewhere other than the thread_struct when kernel code wants to use floating point or VMX instructions. This is done by providing a pointer in the thread_struct to indicate where the state should be saved to. The giveup_fpu() and giveup_altivec() functions test these pointers and save state to the indicated location if they are non-NULL. Note that the MSR_FP/VEC bits in task->thread.regs->msr are still used to indicate whether the CPU register state is live, even when an alternate save location is being used. This also provides load_fp_state() and load_vr_state() functions, which load up FP/VSX and VMX state from memory into the CPU registers, and corresponding store_fp_state() and store_vr_state() functions, which store FP/VSX and VMX state into memory from the CPU registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-10 18:21:10 +08:00
PPC_LL r6,THREAD_FPSAVEAREA(r3)
[PATCH] powerpc: Consolidate asm compatibility macros This patch consolidates macros used to generate assembly for compatibility across different CPUs or configs. A new header, asm-powerpc/asm-compat.h contains the main compatibility macros. It uses some preprocessor magic to make the macros suitable both for use in .S files, and in inline asm in .c files. Headers (bitops.h, uaccess.h, atomic.h, bug.h) which had their own such compatibility macros are changed to use asm-compat.h. ppc_asm.h is now for use in .S files *only*, and a #error enforces that. As such, we're a lot more careless about namespace pollution here than in asm-compat.h. While we're at it, this patch adds a call to the PPC405_ERR77 macro in futex.h which should have had it already, but didn't. Built and booted on pSeries, Maple and iSeries (ARCH=powerpc). Built for 32-bit powermac (ARCH=powerpc) and Walnut (ARCH=ppc). Signed-off-by: David Gibson <dwg@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-10 09:56:55 +08:00
PPC_LL r5,PT_REGS(r3)
powerpc: Provide for giveup_fpu/altivec to save state in alternate location This provides a facility which is intended for use by KVM, where the contents of the FP/VSX and VMX (Altivec) registers can be saved away to somewhere other than the thread_struct when kernel code wants to use floating point or VMX instructions. This is done by providing a pointer in the thread_struct to indicate where the state should be saved to. The giveup_fpu() and giveup_altivec() functions test these pointers and save state to the indicated location if they are non-NULL. Note that the MSR_FP/VEC bits in task->thread.regs->msr are still used to indicate whether the CPU register state is live, even when an alternate save location is being used. This also provides load_fp_state() and load_vr_state() functions, which load up FP/VSX and VMX state from memory into the CPU registers, and corresponding store_fp_state() and store_vr_state() functions, which store FP/VSX and VMX state into memory from the CPU registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-10 18:21:10 +08:00
PPC_LCMPI 0,r6,0
bne 2f
powerpc: Put FP/VSX and VR state into structures This creates new 'thread_fp_state' and 'thread_vr_state' structures to store FP/VSX state (including FPSCR) and Altivec/VSX state (including VSCR), and uses them in the thread_struct. In the thread_fp_state, the FPRs and VSRs are represented as u64 rather than double, since we rarely perform floating-point computations on the values, and this will enable the structures to be used in KVM code as well. Similarly FPSCR is now a u64 rather than a structure of two 32-bit values. This takes the offsets out of the macros such as SAVE_32FPRS, REST_32FPRS, etc. This enables the same macros to be used for normal and transactional state, enabling us to delete the transactional versions of the macros. This also removes the unused do_load_up_fpu and do_load_up_altivec, which were in fact buggy since they didn't create large enough stack frames to account for the fact that load_up_fpu and load_up_altivec are not designed to be called from C and assume that their caller's stack frame is an interrupt frame. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-10 18:20:42 +08:00
addi r6,r3,THREAD_FPSTATE
powerpc: Add the ability to save FPU without giving it up This patch adds the ability to be able to save the FPU registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch optimises the thread copy path (as a result of a fork() or clone()) so that the parent thread can return to userspace with hot registers avoiding a possibly pointless reload of FPU register state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-02-29 14:53:49 +08:00
2: SAVE_32FPVSRS(0, R4, R6)
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
mffs fr0
powerpc: Put FP/VSX and VR state into structures This creates new 'thread_fp_state' and 'thread_vr_state' structures to store FP/VSX state (including FPSCR) and Altivec/VSX state (including VSCR), and uses them in the thread_struct. In the thread_fp_state, the FPRs and VSRs are represented as u64 rather than double, since we rarely perform floating-point computations on the values, and this will enable the structures to be used in KVM code as well. Similarly FPSCR is now a u64 rather than a structure of two 32-bit values. This takes the offsets out of the macros such as SAVE_32FPRS, REST_32FPRS, etc. This enables the same macros to be used for normal and transactional state, enabling us to delete the transactional versions of the macros. This also removes the unused do_load_up_fpu and do_load_up_altivec, which were in fact buggy since they didn't create large enough stack frames to account for the fact that load_up_fpu and load_up_altivec are not designed to be called from C and assume that their caller's stack frame is an interrupt frame. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-10 18:20:42 +08:00
stfd fr0,FPSTATE_FPSCR(r6)
powerpc: Merge enough to start building in arch/powerpc. This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26 14:04:21 +08:00
blr