Re: [PATCH v2 2/2] powerpc: Use ibm, chip-id property to compute cpu_core_mask if available
flat view
From: Vasant Hegde <hidden>
Date: 2013-08-12 07:54:41
On 08/12/2013 11:59 AM, Paul Mackerras wrote:
Some systems have an ibm,chip-id property in the cpu nodes in the device tree. On these systems, we now use that to compute the cpu_core_mask (i.e. the set of core siblings) rather than looking at cache properties.
Looks fine. Tested-by: Vasant Hegde <redacted> -Vasant
quoted hunk ↗ jump to hunk
Signed-off-by: Paul Mackerras <redacted> --- v2: add is bool, use of_read_number arch/powerpc/kernel/smp.c | 48 ++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 45 insertions(+), 3 deletions(-)diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 1568525..a4137de 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c@@ -587,6 +587,33 @@ int cpu_first_thread_of_core(int core) } EXPORT_SYMBOL_GPL(cpu_first_thread_of_core); +static void traverse_siblings_chip_id(int cpu, bool add, int chipid) +{ + const struct cpumask *mask; + struct device_node *np; + int i, plen; + const __be32 *prop; + + mask = add ? cpu_online_mask : cpu_present_mask; + for_each_cpu(i, mask) { + np = of_get_cpu_node(i, NULL); + if (!np) + continue; + prop = of_get_property(np, "ibm,chip-id", &plen); + if (prop && plen == sizeof(int) && + of_read_number(prop, 1) == chipid) { + if (add) { + cpumask_set_cpu(cpu, cpu_core_mask(i)); + cpumask_set_cpu(i, cpu_core_mask(cpu)); + } else { + cpumask_clear_cpu(cpu, cpu_core_mask(i)); + cpumask_clear_cpu(i, cpu_core_mask(cpu)); + } + } + of_node_put(np); + } +} + /* Must be called when no change can occur to cpu_present_mask, * i.e. during cpu online or offline. */@@ -611,14 +638,29 @@ static struct device_node *cpu_to_l2cache(int cpu) static void traverse_core_siblings(int cpu, bool add) { - struct device_node *l2_cache; + struct device_node *l2_cache, *np; const struct cpumask *mask; - int i; + int i, chip, plen; + const __be32 *prop; + + /* First see if we have ibm,chip-id properties in cpu nodes */ + np = of_get_cpu_node(cpu, NULL); + if (np) { + chip = -1; + prop = of_get_property(np, "ibm,chip-id", &plen); + if (prop && plen == sizeof(int)) + chip = of_read_number(prop, 1); + of_node_put(np); + if (chip >= 0) { + traverse_siblings_chip_id(cpu, add, chip); + return; + } + } l2_cache = cpu_to_l2cache(cpu); mask = add ? cpu_online_mask : cpu_present_mask; for_each_cpu(i, mask) { - struct device_node *np = cpu_to_l2cache(i); + np = cpu_to_l2cache(i); if (!np) continue; if (np == l2_cache) {