Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 154 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/fpu.S b/arch/powerpc/kernel/fpu.S
new file mode 100644
index 0000000000..2f8f3f93cb
--- /dev/null
+++ b/arch/powerpc/kernel/fpu.S
@@ -0,0 +1,154 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *  FPU support code, moved here from head.S so that it can be used
+ *  by chips which use other head-whatever.S files.
+ *
+ *    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).
+ */
+
+#include <linux/export.h>
+#include <asm/reg.h>
+#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>
+#include <asm/ptrace.h>
+#include <asm/asm-compat.h>
+#include <asm/feature-fixups.h>
+
+#ifdef CONFIG_VSX
+#define __REST_1FPVSR(n,c,base)						\
+BEGIN_FTR_SECTION							\
+	b	2f;							\
+END_FTR_SECTION_IFSET(CPU_FTR_VSX);					\
+	REST_FPR(n,base);						\
+	b	3f;							\
+2:	REST_VSR(n,c,base);						\
+3:
+
+#define __REST_32FPVSRS(n,c,base)					\
+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:
+
+#define __SAVE_32FPVSRS(n,c,base)					\
+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
+#define __REST_1FPVSR(n,b,base)		REST_FPR(n, base)
+#define __REST_32FPVSRS(n,b,base)	REST_32FPRS(n, base)
+#define __SAVE_32FPVSRS(n,b,base)	SAVE_32FPRS(n, base)
+#endif
+#define REST_1FPVSR(n,c,base)   __REST_1FPVSR(n,__REG_##c,__REG_##base)
+#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)
+
+/*
+ * 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
+EXPORT_SYMBOL(load_fp_state)
+_ASM_NOKPROBE_SYMBOL(load_fp_state); /* used by restore_math */
+
+/*
+ * 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)
+	REST_1FPVSR(0, R4, R3)
+	blr
+EXPORT_SYMBOL(store_fp_state)
+
+/*
+ * 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.
+ * 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.
+ */
+_GLOBAL(load_up_fpu)
+	mfmsr	r5
+#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
+	ori	r5,r5,MSR_FP
+#endif
+#ifdef CONFIG_VSX
+BEGIN_FTR_SECTION
+	oris	r5,r5,MSR_VSX@h
+END_FTR_SECTION_IFSET(CPU_FTR_VSX)
+#endif
+	MTMSRD(r5)			/* enable use of fpu now */
+	isync
+	/* enable use of FP after return */
+#ifdef CONFIG_PPC32
+	addi	r5,r2,THREAD
+	lwz	r4,THREAD_FPEXC_MODE(r5)
+	ori	r9,r9,MSR_FP		/* enable FP for current */
+	or	r9,r9,r4
+#else
+	ld	r4,PACACURRENT(r13)
+	addi	r5,r4,THREAD		/* Get THREAD */
+	lwz	r4,THREAD_FPEXC_MODE(r5)
+	ori	r12,r12,MSR_FP
+	or	r12,r12,r4
+	std	r12,_MSR(r1)
+#ifdef CONFIG_PPC_BOOK3S_64
+	li	r4,0
+	stb	r4,PACASRR_VALID(r13)
+#endif
+#endif
+	li	r4,1
+	stb	r4,THREAD_LOAD_FP(r5)
+	addi	r10,r5,THREAD_FPSTATE
+	lfd	fr0,FPSTATE_FPSCR(r10)
+	MTFSF_L(fr0)
+	REST_32FPVSRS(0, R4, R10)
+	/* restore registers and return */
+	/* we haven't used ctr or xer or lr */
+	blr
+_ASM_NOKPROBE_SYMBOL(load_up_fpu)
+
+/*
+ * save_fpu(tsk)
+ * Save the floating-point registers in its thread_struct.
+ * Enables the FPU for use in the kernel on return.
+ */
+_GLOBAL(save_fpu)
+	addi	r3,r3,THREAD	        /* want THREAD of task */
+	PPC_LL	r6,THREAD_FPSAVEAREA(r3)
+	PPC_LL	r5,PT_REGS(r3)
+	PPC_LCMPI	0,r6,0
+	bne	2f
+	addi	r6,r3,THREAD_FPSTATE
+2:	SAVE_32FPVSRS(0, R4, R6)
+	mffs	fr0
+	stfd	fr0,FPSTATE_FPSCR(r6)
+	REST_1FPVSR(0, R4, R6)
+	blr