diff options
| -rw-r--r-- | arch/powerpc/kernel/prom_init.c | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c index 5fe2842e8bab..cb64a6e1dc51 100644 --- a/arch/powerpc/kernel/prom_init.c +++ b/arch/powerpc/kernel/prom_init.c @@ -858,7 +858,8 @@ static void __init prom_send_capabilities(void) { ihandle root; prom_arg_t ret; - __be32 *cores; + u32 cores; + unsigned char *ptcores; root = call_prom("open", 1, 1, ADDR("/")); if (root != 0) { @@ -868,15 +869,30 @@ static void __init prom_send_capabilities(void) * (we assume this is the same for all cores) and use it to * divide NR_CPUS. */ - cores = (__be32 *)&ibm_architecture_vec[IBM_ARCH_VEC_NRCORES_OFFSET]; - if (be32_to_cpup(cores) != NR_CPUS) { + + /* The core value may start at an odd address. If such a word + * access is made at a cache line boundary, this leads to an + * exception which may not be handled at this time. + * Forcing a per byte access to avoid exception. + */ + ptcores = &ibm_architecture_vec[IBM_ARCH_VEC_NRCORES_OFFSET]; + cores = 0; + cores |= ptcores[0] << 24; + cores |= ptcores[1] << 16; + cores |= ptcores[2] << 8; + cores |= ptcores[3]; + if (cores != NR_CPUS) { prom_printf("WARNING ! " "ibm_architecture_vec structure inconsistent: %lu!\n", - be32_to_cpup(cores)); + cores); } else { - *cores = cpu_to_be32(DIV_ROUND_UP(NR_CPUS, prom_count_smt_threads())); + cores = DIV_ROUND_UP(NR_CPUS, prom_count_smt_threads()); prom_printf("Max number of cores passed to firmware: %lu (NR_CPUS = %lu)\n", - be32_to_cpup(cores), NR_CPUS); + cores, NR_CPUS); + ptcores[0] = (cores >> 24) & 0xff; + ptcores[1] = (cores >> 16) & 0xff; + ptcores[2] = (cores >> 8) & 0xff; + ptcores[3] = cores & 0xff; } /* try calling the ibm,client-architecture-support method */ |