From 1ec9dd80bedc208c00b18069cfd615a4cbfeab17 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Sat, 12 Aug 2017 19:49:43 -0700 Subject: [PATCH] MIPS: CPS: Detect CPUs in secondary clusters As a first step towards supporting multi-cluster systems, detect cores & VPs in secondary clusters & record their cluster information in the cpu_data array. The "VP topology" line printed during boot is extended to display multiple clusters. On a single cluster it shows output like the following: VP topology: {4,4} This would indicate a system with 2 cores which each contain 4 VPs. We extend this to cover multiple clusters in a natural way: VP topology: {4,4},{2,2} This would indicate a system with 2 clusters. The first cluster contains 2 cores which each contain 4 VPs. The second cluster contains 2 cores which each contain 2 VPs. Actually booting these cores & VPs is left to further patches once other pieces are in place. Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/17017/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/smp-cps.c | 80 ++++++++++++++++++++++++-------------- 1 file changed, 51 insertions(+), 29 deletions(-) diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c index 4b9dcca12e5f..0d9cda6a77de 100644 --- a/arch/mips/kernel/smp-cps.c +++ b/arch/mips/kernel/smp-cps.c @@ -40,44 +40,58 @@ static int __init setup_nothreads(char *s) } early_param("nothreads", setup_nothreads); -static unsigned core_vpe_count(unsigned core) +static unsigned core_vpe_count(unsigned int cluster, unsigned core) { if (threads_disabled) return 1; - return mips_cps_numvps(0, core); + return mips_cps_numvps(cluster, core); } static void __init cps_smp_setup(void) { - unsigned int ncores, nvpes, core_vpes; + unsigned int nclusters, ncores, nvpes, core_vpes; unsigned long core_entry; - int c, v; + int cl, c, v; /* Detect & record VPE topology */ - ncores = mips_cps_numcores(0); + nvpes = 0; + nclusters = mips_cps_numclusters(); pr_info("%s topology ", cpu_has_mips_r6 ? "VP" : "VPE"); - for (c = nvpes = 0; c < ncores; c++) { - core_vpes = core_vpe_count(c); - pr_cont("%c%u", c ? ',' : '{', core_vpes); - - /* Use the number of VPEs in core 0 for smp_num_siblings */ - if (!c) - smp_num_siblings = core_vpes; + for (cl = 0; cl < nclusters; cl++) { + if (cl > 0) + pr_cont(","); + pr_cont("{"); + + ncores = mips_cps_numcores(cl); + for (c = 0; c < ncores; c++) { + core_vpes = core_vpe_count(cl, c); + + if (c > 0) + pr_cont(","); + pr_cont("%u", core_vpes); + + /* Use the number of VPEs in cluster 0 core 0 for smp_num_siblings */ + if (!cl && !c) + smp_num_siblings = core_vpes; + + for (v = 0; v < min_t(int, core_vpes, NR_CPUS - nvpes); v++) { + cpu_set_cluster(&cpu_data[nvpes + v], cl); + cpu_set_core(&cpu_data[nvpes + v], c); + cpu_set_vpe_id(&cpu_data[nvpes + v], v); + } - for (v = 0; v < min_t(int, core_vpes, NR_CPUS - nvpes); v++) { - cpu_set_core(&cpu_data[nvpes + v], c); - cpu_set_vpe_id(&cpu_data[nvpes + v], v); + nvpes += core_vpes; } - nvpes += core_vpes; + pr_cont("}"); } - pr_cont("} total %u\n", nvpes); + pr_cont(" total %u\n", nvpes); /* Indicate present CPUs (CPU being synonymous with VPE) */ for (v = 0; v < min_t(unsigned, nvpes, NR_CPUS); v++) { - set_cpu_possible(v, true); - set_cpu_present(v, true); + set_cpu_possible(v, cpu_cluster(&cpu_data[v]) == 0); + set_cpu_present(v, cpu_cluster(&cpu_data[v]) == 0); __cpu_number_map[v] = v; __cpu_logical_map[v] = v; } @@ -109,7 +123,7 @@ static void __init cps_smp_setup(void) static void __init cps_prepare_cpus(unsigned int max_cpus) { unsigned ncores, core_vpes, c, cca; - bool cca_unsuitable; + bool cca_unsuitable, cores_limited; u32 *entry_code; mips_mt_set_cpuoptions(); @@ -129,19 +143,22 @@ static void __init cps_prepare_cpus(unsigned int max_cpus) } /* Warn the user if the CCA prevents multi-core */ - ncores = mips_cps_numcores(0); - if ((cca_unsuitable || cpu_has_dc_aliases) && ncores > 1) { + cores_limited = false; + if (cca_unsuitable || cpu_has_dc_aliases) { + for_each_present_cpu(c) { + if (cpus_are_siblings(smp_processor_id(), c)) + continue; + + set_cpu_present(c, false); + cores_limited = true; + } + } + if (cores_limited) pr_warn("Using only one core due to %s%s%s\n", cca_unsuitable ? "unsuitable CCA" : "", (cca_unsuitable && cpu_has_dc_aliases) ? " & " : "", cpu_has_dc_aliases ? "dcache aliasing" : ""); - for_each_present_cpu(c) { - if (!cpus_are_siblings(smp_processor_id(), c)) - set_cpu_present(c, false); - } - } - /* * Patch the start of mips_cps_core_entry to provide: * @@ -156,6 +173,7 @@ static void __init cps_prepare_cpus(unsigned int max_cpus) __sync(); /* Allocate core boot configuration structs */ + ncores = mips_cps_numcores(0); mips_cps_core_bootcfg = kcalloc(ncores, sizeof(*mips_cps_core_bootcfg), GFP_KERNEL); if (!mips_cps_core_bootcfg) { @@ -165,7 +183,7 @@ static void __init cps_prepare_cpus(unsigned int max_cpus) /* Allocate VPE boot configuration structs */ for (c = 0; c < ncores; c++) { - core_vpes = core_vpe_count(c); + core_vpes = core_vpe_count(0, c); mips_cps_core_bootcfg[c].vpe_config = kcalloc(core_vpes, sizeof(*mips_cps_core_bootcfg[c].vpe_config), GFP_KERNEL); @@ -288,6 +306,10 @@ static int cps_boot_secondary(int cpu, struct task_struct *idle) unsigned int remote; int err; + /* We don't yet support booting CPUs in other clusters */ + if (cpu_cluster(&cpu_data[cpu]) != cpu_cluster(¤t_cpu_data)) + return -ENOSYS; + vpe_cfg->pc = (unsigned long)&smp_bootstrap; vpe_cfg->sp = __KSTK_TOS(idle); vpe_cfg->gp = (unsigned long)task_thread_info(idle); -- 2.20.1