diff options
Diffstat (limited to 'arch/powerpc/kernel/rtas.c')
| -rw-r--r-- | arch/powerpc/kernel/rtas.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c index c5fa251b8950..a09eba03f180 100644 --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -41,6 +41,7 @@ #include <asm/time.h> #include <asm/mmu.h> #include <asm/topology.h> +#include <asm/paca.h> /* This is here deliberately so it's only used in this file */ void enter_rtas(unsigned long); @@ -1014,6 +1015,57 @@ out: free_cpumask_var(offline_mask); return atomic_read(&data.error); } + +/** + * rtas_call_reentrant() - Used for reentrant rtas calls + * @token: Token for desired reentrant RTAS call + * @nargs: Number of Input Parameters + * @nret: Number of Output Parameters + * @outputs: Array of outputs + * @...: Inputs for desired RTAS call + * + * According to LoPAR documentation, only "ibm,int-on", "ibm,int-off", + * "ibm,get-xive" and "ibm,set-xive" are currently reentrant. + * Reentrant calls need their own rtas_args buffer, so not using rtas.args, but + * PACA one instead. + * + * Return: -1 on error, + * First output value of RTAS call if (nret > 0), + * 0 otherwise, + */ +int rtas_call_reentrant(int token, int nargs, int nret, int *outputs, ...) +{ + va_list list; + struct rtas_args *args; + unsigned long flags; + int i, ret = 0; + + if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE) + return -1; + + local_irq_save(flags); + preempt_disable(); + + /* We use the per-cpu (PACA) rtas args buffer */ + args = local_paca->rtas_args_reentrant; + + va_start(list, outputs); + va_rtas_call_unlocked(args, token, nargs, nret, list); + va_end(list); + + if (nret > 1 && outputs) + for (i = 0; i < nret - 1; ++i) + outputs[i] = be32_to_cpu(args->rets[i + 1]); + + if (nret > 0) + ret = be32_to_cpu(args->rets[0]); + + local_irq_restore(flags); + preempt_enable(); + + return ret; +} + #else /* CONFIG_PPC_PSERIES */ int rtas_ibm_suspend_me(u64 handle) { |