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Diffstat (limited to 'arch/s390/kernel/fpu.c')
-rw-r--r--arch/s390/kernel/fpu.c317
1 files changed, 122 insertions, 195 deletions
diff --git a/arch/s390/kernel/fpu.c b/arch/s390/kernel/fpu.c
index 81d1d1887507..1235b9438df4 100644
--- a/arch/s390/kernel/fpu.c
+++ b/arch/s390/kernel/fpu.c
@@ -10,240 +10,167 @@
#include <asm/fpu/types.h>
#include <asm/fpu/api.h>
-/*
- * Per-CPU variable to maintain FPU register ranges that are in use
- * by the kernel.
- */
-static DEFINE_PER_CPU(u32, kernel_fpu_state);
-
-#define KERNEL_FPU_STATE_MASK (KERNEL_FPU_MASK|KERNEL_FPC)
-
+asm(".include \"asm/vx-insn.h\"\n");
void __kernel_fpu_begin(struct kernel_fpu *state, u32 flags)
{
- if (!__this_cpu_read(kernel_fpu_state)) {
- /*
- * Save user space FPU state and register contents. Multiple
- * calls because of interruptions do not matter and return
- * immediately. This also sets CIF_FPU to lazy restore FP/VX
- * register contents when returning to user space.
- */
- save_fpu_regs();
- }
-
- /* Update flags to use the vector facility for KERNEL_FPR */
- if (MACHINE_HAS_VX && (state->mask & KERNEL_FPR)) {
- flags |= KERNEL_VXR_LOW | KERNEL_FPC;
- flags &= ~KERNEL_FPR;
- }
-
- /* Save and update current kernel VX state */
- state->mask = __this_cpu_read(kernel_fpu_state);
- __this_cpu_or(kernel_fpu_state, flags & KERNEL_FPU_STATE_MASK);
-
/*
- * If this is the first call to __kernel_fpu_begin(), no additional
- * work is required.
+ * Limit the save to the FPU/vector registers already
+ * in use by the previous context
*/
- if (!(state->mask & KERNEL_FPU_STATE_MASK))
- return;
+ flags &= state->mask;
- /*
- * If KERNEL_FPR is still set, the vector facility is not available
- * and, thus, save floating-point control and registers only.
- */
- if (state->mask & KERNEL_FPR) {
- asm volatile("stfpc %0" : "=Q" (state->fpc));
- asm volatile("std 0,%0" : "=Q" (state->fprs[0]));
- asm volatile("std 1,%0" : "=Q" (state->fprs[1]));
- asm volatile("std 2,%0" : "=Q" (state->fprs[2]));
- asm volatile("std 3,%0" : "=Q" (state->fprs[3]));
- asm volatile("std 4,%0" : "=Q" (state->fprs[4]));
- asm volatile("std 5,%0" : "=Q" (state->fprs[5]));
- asm volatile("std 6,%0" : "=Q" (state->fprs[6]));
- asm volatile("std 7,%0" : "=Q" (state->fprs[7]));
- asm volatile("std 8,%0" : "=Q" (state->fprs[8]));
- asm volatile("std 9,%0" : "=Q" (state->fprs[9]));
- asm volatile("std 10,%0" : "=Q" (state->fprs[10]));
- asm volatile("std 11,%0" : "=Q" (state->fprs[11]));
- asm volatile("std 12,%0" : "=Q" (state->fprs[12]));
- asm volatile("std 13,%0" : "=Q" (state->fprs[13]));
- asm volatile("std 14,%0" : "=Q" (state->fprs[14]));
- asm volatile("std 15,%0" : "=Q" (state->fprs[15]));
+ if (flags & KERNEL_FPC)
+ /* Save floating point control */
+ asm volatile("stfpc %0" : "=m" (state->fpc));
+
+ if (!MACHINE_HAS_VX) {
+ if (flags & KERNEL_VXR_V0V7) {
+ /* Save floating-point registers */
+ asm volatile("std 0,%0" : "=Q" (state->fprs[0]));
+ asm volatile("std 1,%0" : "=Q" (state->fprs[1]));
+ asm volatile("std 2,%0" : "=Q" (state->fprs[2]));
+ asm volatile("std 3,%0" : "=Q" (state->fprs[3]));
+ asm volatile("std 4,%0" : "=Q" (state->fprs[4]));
+ asm volatile("std 5,%0" : "=Q" (state->fprs[5]));
+ asm volatile("std 6,%0" : "=Q" (state->fprs[6]));
+ asm volatile("std 7,%0" : "=Q" (state->fprs[7]));
+ asm volatile("std 8,%0" : "=Q" (state->fprs[8]));
+ asm volatile("std 9,%0" : "=Q" (state->fprs[9]));
+ asm volatile("std 10,%0" : "=Q" (state->fprs[10]));
+ asm volatile("std 11,%0" : "=Q" (state->fprs[11]));
+ asm volatile("std 12,%0" : "=Q" (state->fprs[12]));
+ asm volatile("std 13,%0" : "=Q" (state->fprs[13]));
+ asm volatile("std 14,%0" : "=Q" (state->fprs[14]));
+ asm volatile("std 15,%0" : "=Q" (state->fprs[15]));
+ }
return;
}
- /*
- * If this is a nested call to __kernel_fpu_begin(), check the saved
- * state mask to save and later restore the vector registers that
- * are already in use. Let's start with checking floating-point
- * controls.
- */
- if (state->mask & KERNEL_FPC)
- asm volatile("stfpc %0" : "=m" (state->fpc));
-
/* Test and save vector registers */
asm volatile (
/*
* Test if any vector register must be saved and, if so,
* test if all register can be saved.
*/
- " tmll %[m],15\n" /* KERNEL_VXR_MASK */
- " jz 20f\n" /* no work -> done */
" la 1,%[vxrs]\n" /* load save area */
- " jo 18f\n" /* -> save V0..V31 */
-
+ " tmll %[m],30\n" /* KERNEL_VXR */
+ " jz 7f\n" /* no work -> done */
+ " jo 5f\n" /* -> save V0..V31 */
/*
- * Test if V8..V23 can be saved at once... this speeds up
- * for KERNEL_fpu_MID only. Otherwise continue to split the
- * range of vector registers into two halves and test them
- * separately.
+ * Test for special case KERNEL_FPU_MID only. In this
+ * case a vstm V8..V23 is the best instruction
*/
- " tmll %[m],6\n" /* KERNEL_VXR_MID */
- " jo 17f\n" /* -> save V8..V23 */
-
+ " chi %[m],12\n" /* KERNEL_VXR_MID */
+ " jne 0f\n" /* -> save V8..V23 */
+ " VSTM 8,23,128,1\n" /* vstm %v8,%v23,128(%r1) */
+ " j 7f\n"
/* Test and save the first half of 16 vector registers */
- "1: tmll %[m],3\n" /* KERNEL_VXR_LOW */
- " jz 10f\n" /* -> KERNEL_VXR_HIGH */
+ "0: tmll %[m],6\n" /* KERNEL_VXR_LOW */
+ " jz 3f\n" /* -> KERNEL_VXR_HIGH */
" jo 2f\n" /* 11 -> save V0..V15 */
- " brc 4,3f\n" /* 01 -> save V0..V7 */
- " brc 2,4f\n" /* 10 -> save V8..V15 */
-
+ " brc 2,1f\n" /* 10 -> save V8..V15 */
+ " VSTM 0,7,0,1\n" /* vstm %v0,%v7,0(%r1) */
+ " j 3f\n"
+ "1: VSTM 8,15,128,1\n" /* vstm %v8,%v15,128(%r1) */
+ " j 3f\n"
+ "2: VSTM 0,15,0,1\n" /* vstm %v0,%v15,0(%r1) */
/* Test and save the second half of 16 vector registers */
- "10: tmll %[m],12\n" /* KERNEL_VXR_HIGH */
- " jo 19f\n" /* 11 -> save V16..V31 */
- " brc 4,11f\n" /* 01 -> save V16..V23 */
- " brc 2,12f\n" /* 10 -> save V24..V31 */
- " j 20f\n" /* 00 -> done */
-
- /*
- * Below are the vstm combinations to save multiple vector
- * registers at once.
- */
- "2: .word 0xe70f,0x1000,0x003e\n" /* vstm 0,15,0(1) */
- " j 10b\n" /* -> VXR_HIGH */
- "3: .word 0xe707,0x1000,0x003e\n" /* vstm 0,7,0(1) */
- " j 10b\n" /* -> VXR_HIGH */
- "4: .word 0xe78f,0x1080,0x003e\n" /* vstm 8,15,128(1) */
- " j 10b\n" /* -> VXR_HIGH */
- "\n"
- "11: .word 0xe707,0x1100,0x0c3e\n" /* vstm 16,23,256(1) */
- " j 20f\n" /* -> done */
- "12: .word 0xe78f,0x1180,0x0c3e\n" /* vstm 24,31,384(1) */
- " j 20f\n" /* -> done */
- "\n"
- "17: .word 0xe787,0x1080,0x043e\n" /* vstm 8,23,128(1) */
- " nill %[m],249\n" /* m &= ~VXR_MID */
- " j 1b\n" /* -> VXR_LOW */
- "\n"
- "18: .word 0xe70f,0x1000,0x003e\n" /* vstm 0,15,0(1) */
- "19: .word 0xe70f,0x1100,0x0c3e\n" /* vstm 16,31,256(1) */
- "20:"
+ "3: tmll %[m],24\n" /* KERNEL_VXR_HIGH */
+ " jz 7f\n"
+ " jo 6f\n" /* 11 -> save V16..V31 */
+ " brc 2,4f\n" /* 10 -> save V24..V31 */
+ " VSTM 16,23,256,1\n" /* vstm %v16,%v23,256(%r1) */
+ " j 7f\n"
+ "4: VSTM 24,31,384,1\n" /* vstm %v24,%v31,384(%r1) */
+ " j 7f\n"
+ "5: VSTM 0,15,0,1\n" /* vstm %v0,%v15,0(%r1) */
+ "6: VSTM 16,31,256,1\n" /* vstm %v16,%v31,256(%r1) */
+ "7:"
: [vxrs] "=Q" (*(struct vx_array *) &state->vxrs)
- : [m] "d" (state->mask)
+ : [m] "d" (flags)
: "1", "cc");
}
EXPORT_SYMBOL(__kernel_fpu_begin);
-void __kernel_fpu_end(struct kernel_fpu *state)
+void __kernel_fpu_end(struct kernel_fpu *state, u32 flags)
{
- /* Just update the per-CPU state if there is nothing to restore */
- if (!(state->mask & KERNEL_FPU_STATE_MASK))
- goto update_fpu_state;
-
/*
- * If KERNEL_FPR is specified, the vector facility is not available
- * and, thus, restore floating-point control and registers only.
+ * Limit the restore to the FPU/vector registers of the
+ * previous context that have been overwritte by the
+ * current context
*/
- if (state->mask & KERNEL_FPR) {
- asm volatile("lfpc %0" : : "Q" (state->fpc));
- asm volatile("ld 0,%0" : : "Q" (state->fprs[0]));
- asm volatile("ld 1,%0" : : "Q" (state->fprs[1]));
- asm volatile("ld 2,%0" : : "Q" (state->fprs[2]));
- asm volatile("ld 3,%0" : : "Q" (state->fprs[3]));
- asm volatile("ld 4,%0" : : "Q" (state->fprs[4]));
- asm volatile("ld 5,%0" : : "Q" (state->fprs[5]));
- asm volatile("ld 6,%0" : : "Q" (state->fprs[6]));
- asm volatile("ld 7,%0" : : "Q" (state->fprs[7]));
- asm volatile("ld 8,%0" : : "Q" (state->fprs[8]));
- asm volatile("ld 9,%0" : : "Q" (state->fprs[9]));
- asm volatile("ld 10,%0" : : "Q" (state->fprs[10]));
- asm volatile("ld 11,%0" : : "Q" (state->fprs[11]));
- asm volatile("ld 12,%0" : : "Q" (state->fprs[12]));
- asm volatile("ld 13,%0" : : "Q" (state->fprs[13]));
- asm volatile("ld 14,%0" : : "Q" (state->fprs[14]));
- asm volatile("ld 15,%0" : : "Q" (state->fprs[15]));
- goto update_fpu_state;
- }
+ flags &= state->mask;
- /* Test and restore floating-point controls */
- if (state->mask & KERNEL_FPC)
+ if (flags & KERNEL_FPC)
+ /* Restore floating-point controls */
asm volatile("lfpc %0" : : "Q" (state->fpc));
+ if (!MACHINE_HAS_VX) {
+ if (flags & KERNEL_VXR_V0V7) {
+ /* Restore floating-point registers */
+ asm volatile("ld 0,%0" : : "Q" (state->fprs[0]));
+ asm volatile("ld 1,%0" : : "Q" (state->fprs[1]));
+ asm volatile("ld 2,%0" : : "Q" (state->fprs[2]));
+ asm volatile("ld 3,%0" : : "Q" (state->fprs[3]));
+ asm volatile("ld 4,%0" : : "Q" (state->fprs[4]));
+ asm volatile("ld 5,%0" : : "Q" (state->fprs[5]));
+ asm volatile("ld 6,%0" : : "Q" (state->fprs[6]));
+ asm volatile("ld 7,%0" : : "Q" (state->fprs[7]));
+ asm volatile("ld 8,%0" : : "Q" (state->fprs[8]));
+ asm volatile("ld 9,%0" : : "Q" (state->fprs[9]));
+ asm volatile("ld 10,%0" : : "Q" (state->fprs[10]));
+ asm volatile("ld 11,%0" : : "Q" (state->fprs[11]));
+ asm volatile("ld 12,%0" : : "Q" (state->fprs[12]));
+ asm volatile("ld 13,%0" : : "Q" (state->fprs[13]));
+ asm volatile("ld 14,%0" : : "Q" (state->fprs[14]));
+ asm volatile("ld 15,%0" : : "Q" (state->fprs[15]));
+ }
+ return;
+ }
+
/* Test and restore (load) vector registers */
asm volatile (
/*
- * Test if any vector registers must be loaded and, if so,
+ * Test if any vector register must be loaded and, if so,
* test if all registers can be loaded at once.
*/
- " tmll %[m],15\n" /* KERNEL_VXR_MASK */
- " jz 20f\n" /* no work -> done */
- " la 1,%[vxrs]\n" /* load load area */
- " jo 18f\n" /* -> load V0..V31 */
-
- /*
- * Test if V8..V23 can be restored at once... this speeds up
- * for KERNEL_VXR_MID only. Otherwise continue to split the
- * range of vector registers into two halves and test them
- * separately.
- */
- " tmll %[m],6\n" /* KERNEL_VXR_MID */
- " jo 17f\n" /* -> load V8..V23 */
-
- /* Test and load the first half of 16 vector registers */
- "1: tmll %[m],3\n" /* KERNEL_VXR_LOW */
- " jz 10f\n" /* -> KERNEL_VXR_HIGH */
- " jo 2f\n" /* 11 -> load V0..V15 */
- " brc 4,3f\n" /* 01 -> load V0..V7 */
- " brc 2,4f\n" /* 10 -> load V8..V15 */
-
- /* Test and load the second half of 16 vector registers */
- "10: tmll %[m],12\n" /* KERNEL_VXR_HIGH */
- " jo 19f\n" /* 11 -> load V16..V31 */
- " brc 4,11f\n" /* 01 -> load V16..V23 */
- " brc 2,12f\n" /* 10 -> load V24..V31 */
- " j 20f\n" /* 00 -> done */
-
+ " la 1,%[vxrs]\n" /* load restore area */
+ " tmll %[m],30\n" /* KERNEL_VXR */
+ " jz 7f\n" /* no work -> done */
+ " jo 5f\n" /* -> restore V0..V31 */
/*
- * Below are the vstm combinations to load multiple vector
- * registers at once.
+ * Test for special case KERNEL_FPU_MID only. In this
+ * case a vlm V8..V23 is the best instruction
*/
- "2: .word 0xe70f,0x1000,0x0036\n" /* vlm 0,15,0(1) */
- " j 10b\n" /* -> VXR_HIGH */
- "3: .word 0xe707,0x1000,0x0036\n" /* vlm 0,7,0(1) */
- " j 10b\n" /* -> VXR_HIGH */
- "4: .word 0xe78f,0x1080,0x0036\n" /* vlm 8,15,128(1) */
- " j 10b\n" /* -> VXR_HIGH */
- "\n"
- "11: .word 0xe707,0x1100,0x0c36\n" /* vlm 16,23,256(1) */
- " j 20f\n" /* -> done */
- "12: .word 0xe78f,0x1180,0x0c36\n" /* vlm 24,31,384(1) */
- " j 20f\n" /* -> done */
- "\n"
- "17: .word 0xe787,0x1080,0x0436\n" /* vlm 8,23,128(1) */
- " nill %[m],249\n" /* m &= ~VXR_MID */
- " j 1b\n" /* -> VXR_LOW */
- "\n"
- "18: .word 0xe70f,0x1000,0x0036\n" /* vlm 0,15,0(1) */
- "19: .word 0xe70f,0x1100,0x0c36\n" /* vlm 16,31,256(1) */
- "20:"
- :
- : [vxrs] "Q" (*(struct vx_array *) &state->vxrs),
- [m] "d" (state->mask)
+ " chi %[m],12\n" /* KERNEL_VXR_MID */
+ " jne 0f\n" /* -> restore V8..V23 */
+ " VLM 8,23,128,1\n" /* vlm %v8,%v23,128(%r1) */
+ " j 7f\n"
+ /* Test and restore the first half of 16 vector registers */
+ "0: tmll %[m],6\n" /* KERNEL_VXR_LOW */
+ " jz 3f\n" /* -> KERNEL_VXR_HIGH */
+ " jo 2f\n" /* 11 -> restore V0..V15 */
+ " brc 2,1f\n" /* 10 -> restore V8..V15 */
+ " VLM 0,7,0,1\n" /* vlm %v0,%v7,0(%r1) */
+ " j 3f\n"
+ "1: VLM 8,15,128,1\n" /* vlm %v8,%v15,128(%r1) */
+ " j 3f\n"
+ "2: VLM 0,15,0,1\n" /* vlm %v0,%v15,0(%r1) */
+ /* Test and restore the second half of 16 vector registers */
+ "3: tmll %[m],24\n" /* KERNEL_VXR_HIGH */
+ " jz 7f\n"
+ " jo 6f\n" /* 11 -> restore V16..V31 */
+ " brc 2,4f\n" /* 10 -> restore V24..V31 */
+ " VLM 16,23,256,1\n" /* vlm %v16,%v23,256(%r1) */
+ " j 7f\n"
+ "4: VLM 24,31,384,1\n" /* vlm %v24,%v31,384(%r1) */
+ " j 7f\n"
+ "5: VLM 0,15,0,1\n" /* vlm %v0,%v15,0(%r1) */
+ "6: VLM 16,31,256,1\n" /* vlm %v16,%v31,256(%r1) */
+ "7:"
+ : [vxrs] "=Q" (*(struct vx_array *) &state->vxrs)
+ : [m] "d" (flags)
: "1", "cc");
-
-update_fpu_state:
- /* Update current kernel VX state */
- __this_cpu_write(kernel_fpu_state, state->mask);
}
EXPORT_SYMBOL(__kernel_fpu_end);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.