[MIPS] Add basic SMARTMIPS ASE support
This patch adds trivial support for SMARTMIPS extension. This extension
is currently implemented by 4KS[CD] CPUs.
Basically it saves/restores ACX register, which is part of the SMARTMIPS
ASE, when needed. This patch does *not* add any support for Smartmips MMU
features.
Futhermore this patch does not add explicit support for 4KS[CD] CPUs since
they are respectively mips32 and mips32r2 compliant. So with the current
processor configuration, a platform that has such CPUs needs to select
both configs:
CPU_HAS_SMARTMIPS
SYS_HAS_CPU_MIPS32_R[12]
This is due to the processor configuration which is mixing up all the
architecture variants and the processor types.
The drawback of this, is that we currently pass '-march=mips32' option to
gcc when building a kernel instead of '-march=4ksc' for 4KSC case. This
can lead to a kernel image a little bit bigger than required.
Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index adbfb95..f091786 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -89,6 +89,9 @@
for (i = 1; i < 32; i++)
err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
+#ifdef CONFIG_CPU_HAS_SMARTMIPS
+ err |= __put_user(regs->acx, &sc->sc_acx);
+#endif
err |= __put_user(regs->hi, &sc->sc_mdhi);
err |= __put_user(regs->lo, &sc->sc_mdlo);
if (cpu_has_dsp) {
@@ -132,6 +135,10 @@
current_thread_info()->restart_block.fn = do_no_restart_syscall;
err |= __get_user(regs->cp0_epc, &sc->sc_pc);
+
+#ifdef CONFIG_CPU_HAS_SMARTMIPS
+ err |= __get_user(regs->acx, &sc->sc_acx);
+#endif
err |= __get_user(regs->hi, &sc->sc_mdhi);
err |= __get_user(regs->lo, &sc->sc_mdlo);
if (cpu_has_dsp) {