On Fri, Jun 14, 2013 at 12:31 PM, Ralf Baechle <ralf@xxxxxxxxxxxxxx> wrote: > On Mon, Jun 03, 2013 at 05:39:33PM +0200, Jonas Gorski wrote: > >> >> This involves two changes to the BSP code: >> >> 1) register_smp_ops() for BMIPS SMP >> >> 2) The CPU1 boot vector on some of the BCM63xx platforms conflicts with >> the special interrupt vector (IV). Move it to 0x8000_0380 at boot time, >> to resolve the conflict. >> >> Signed-off-by: Kevin Cernekee <cernekee@xxxxxxxxx> >> [jogo@xxxxxxxxxxx: moved SMP ops registration into ifdef guard] >> Signed-off-by: Jonas Gorski <jogo@xxxxxxxxxxx> >> --- >> arch/mips/bcm63xx/prom.c | 33 +++++++++++++++++++++++++++++++++ >> 1 file changed, 33 insertions(+) >> >> diff --git a/arch/mips/bcm63xx/prom.c b/arch/mips/bcm63xx/prom.c >> index fd69808..1209373 100644 >> --- a/arch/mips/bcm63xx/prom.c >> +++ b/arch/mips/bcm63xx/prom.c >> @@ -8,7 +8,11 @@ >> >> #include <linux/init.h> >> #include <linux/bootmem.h> >> +#include <linux/smp.h> >> #include <asm/bootinfo.h> >> +#include <asm/bmips.h> >> +#include <asm/smp-ops.h> >> +#include <asm/mipsregs.h> >> #include <bcm63xx_board.h> >> #include <bcm63xx_cpu.h> >> #include <bcm63xx_io.h> >> @@ -52,6 +56,35 @@ void __init prom_init(void) >> >> /* do low level board init */ >> board_prom_init(); >> + >> +#if defined(CONFIG_CPU_BMIPS4350) && defined(CONFIG_SMP) >> + /* set up SMP */ >> + register_smp_ops(&bmips_smp_ops); > > The call to register_smp_ops() can remain outside the #ifdef. It's defined > as: > > static inline void register_smp_ops(struct plat_smp_ops *ops) > { > } > > so the compiler will completly discard it and the referenced SMP ops. As long as it doesn't cause linking errors with -O0 or something, I'm fine with either way. >> + >> + /* >> + * BCM6328 does not have its second CPU enabled, while BCM6358 >> + * needs special handling for its shared TLB, so disable SMP for now. >> + */ >> + if (BCMCPU_IS_6328() || BCMCPU_IS_6358()) { >> + bmips_smp_enabled = 0; >> + return; >> + } >> + >> + /* >> + * The bootloader has set up the CPU1 reset vector at 0xa000_0200. >> + * This conflicts with the special interrupt vector (IV). >> + * The bootloader has also set up CPU1 to respond to the wrong >> + * IPI interrupt. >> + * Here we will start up CPU1 in the background and ask it to >> + * reconfigure itself then go back to sleep. >> + */ >> + memcpy((void *)0xa0000200, &bmips_smp_movevec, 0x20); >> + __sync(); >> + set_c0_cause(C_SW0); >> + cpumask_set_cpu(1, &bmips_booted_mask); >> + >> + /* FIXME: we really should have some sort of hazard barrier here */ > > Any reason why the remainder of this code can't go into the smp_setup > method? That then would entirely eleminate the <censored> ifdef. Yes, it would introduce an ifdef there, as this is (as far as I understood Kevin) bcm63xx specific, and other platforms with BMIPS CPUs aren't affected by it. If you want I can replace the #ifdef with if (IS_ENABLED()) if that suits you better. Jonas