MIPS: Fix ISA I/II FP signal context offsets
Fix a regression introduced with commit 2db9ca0a3551 ("MIPS: Use struct
mips_abi offsets to save FP context") for MIPS I/I FP signal contexts,
by converting save/restore code to the updated internal API. Start FGR
offsets from 0 rather than SC_FPREGS from $a0 and use $a1 rather than
the offset of SC_FPC_CSR from $a0 for the Floating Point Control/Status
Register (FCSR).
Document the new internal API and adjust assembly code formatting for
consistency.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14476/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/kernel/r6000_fpu.S b/arch/mips/kernel/r6000_fpu.S
index 4707738..9cc7bfa 100644
--- a/arch/mips/kernel/r6000_fpu.S
+++ b/arch/mips/kernel/r6000_fpu.S
@@ -21,7 +21,14 @@
.set push
SET_HARDFLOAT
- /* Save floating point context */
+/**
+ * _save_fp_context() - save FP context from the FPU
+ * @a0 - pointer to fpregs field of sigcontext
+ * @a1 - pointer to fpc_csr field of sigcontext
+ *
+ * Save FP context, including the 32 FP data registers and the FP
+ * control & status register, from the FPU to signal context.
+ */
LEAF(_save_fp_context)
mfc0 t0,CP0_STATUS
sll t0,t0,2
@@ -30,59 +37,59 @@
cfc1 t1,fcr31
/* Store the 16 double precision registers */
- sdc1 $f0,(SC_FPREGS+0)(a0)
- sdc1 $f2,(SC_FPREGS+16)(a0)
- sdc1 $f4,(SC_FPREGS+32)(a0)
- sdc1 $f6,(SC_FPREGS+48)(a0)
- sdc1 $f8,(SC_FPREGS+64)(a0)
- sdc1 $f10,(SC_FPREGS+80)(a0)
- sdc1 $f12,(SC_FPREGS+96)(a0)
- sdc1 $f14,(SC_FPREGS+112)(a0)
- sdc1 $f16,(SC_FPREGS+128)(a0)
- sdc1 $f18,(SC_FPREGS+144)(a0)
- sdc1 $f20,(SC_FPREGS+160)(a0)
- sdc1 $f22,(SC_FPREGS+176)(a0)
- sdc1 $f24,(SC_FPREGS+192)(a0)
- sdc1 $f26,(SC_FPREGS+208)(a0)
- sdc1 $f28,(SC_FPREGS+224)(a0)
- sdc1 $f30,(SC_FPREGS+240)(a0)
+ sdc1 $f0,0(a0)
+ sdc1 $f2,16(a0)
+ sdc1 $f4,32(a0)
+ sdc1 $f6,48(a0)
+ sdc1 $f8,64(a0)
+ sdc1 $f10,80(a0)
+ sdc1 $f12,96(a0)
+ sdc1 $f14,112(a0)
+ sdc1 $f16,128(a0)
+ sdc1 $f18,144(a0)
+ sdc1 $f20,160(a0)
+ sdc1 $f22,176(a0)
+ sdc1 $f24,192(a0)
+ sdc1 $f26,208(a0)
+ sdc1 $f28,224(a0)
+ sdc1 $f30,240(a0)
jr ra
- sw t0,SC_FPC_CSR(a0)
+ sw t0,(a1)
1: jr ra
nop
END(_save_fp_context)
-/* Restore FPU state:
- * - fp gp registers
- * - cp1 status/control register
+/**
+ * _restore_fp_context() - restore FP context to the FPU
+ * @a0 - pointer to fpregs field of sigcontext
+ * @a1 - pointer to fpc_csr field of sigcontext
*
- * We base the decision which registers to restore from the signal stack
- * frame on the current content of c0_status, not on the content of the
- * stack frame which might have been changed by the user.
+ * Restore FP context, including the 32 FP data registers and the FP
+ * control & status register, from signal context to the FPU.
*/
LEAF(_restore_fp_context)
mfc0 t0,CP0_STATUS
sll t0,t0,2
bgez t0,1f
- lw t0,SC_FPC_CSR(a0)
+ lw t0,(a1)
/* Restore the 16 double precision registers */
- ldc1 $f0,(SC_FPREGS+0)(a0)
- ldc1 $f2,(SC_FPREGS+16)(a0)
- ldc1 $f4,(SC_FPREGS+32)(a0)
- ldc1 $f6,(SC_FPREGS+48)(a0)
- ldc1 $f8,(SC_FPREGS+64)(a0)
- ldc1 $f10,(SC_FPREGS+80)(a0)
- ldc1 $f12,(SC_FPREGS+96)(a0)
- ldc1 $f14,(SC_FPREGS+112)(a0)
- ldc1 $f16,(SC_FPREGS+128)(a0)
- ldc1 $f18,(SC_FPREGS+144)(a0)
- ldc1 $f20,(SC_FPREGS+160)(a0)
- ldc1 $f22,(SC_FPREGS+176)(a0)
- ldc1 $f24,(SC_FPREGS+192)(a0)
- ldc1 $f26,(SC_FPREGS+208)(a0)
- ldc1 $f28,(SC_FPREGS+224)(a0)
- ldc1 $f30,(SC_FPREGS+240)(a0)
+ ldc1 $f0,0(a0)
+ ldc1 $f2,16(a0)
+ ldc1 $f4,32(a0)
+ ldc1 $f6,48(a0)
+ ldc1 $f8,64(a0)
+ ldc1 $f10,80(a0)
+ ldc1 $f12,96(a0)
+ ldc1 $f14,112(a0)
+ ldc1 $f16,128(a0)
+ ldc1 $f18,144(a0)
+ ldc1 $f20,160(a0)
+ ldc1 $f22,176(a0)
+ ldc1 $f24,192(a0)
+ ldc1 $f26,208(a0)
+ ldc1 $f28,224(a0)
+ ldc1 $f30,240(a0)
jr ra
ctc1 t0,fcr31
1: jr ra