From b015f6bc9547dbc056edde7177c7868ca8629c4c Mon Sep 17 00:00:00 2001 From: Tyrel Datwyler Date: Sun, 10 Nov 2019 23:21:30 -0600 Subject: [PATCH] powerpc/pseries: Add cpu DLPAR support for drc-info property Older firmwares provided information about Dynamic Reconfig Connectors (DRC) through several device tree properties, namely ibm,drc-types, ibm,drc-indexes, ibm,drc-names, and ibm,drc-power-domains. New firmwares have the ability to present this same information in a much condensed format through a device tree property called ibm,drc-info. The existing cpu DLPAR hotplug code only understands the older DRC property format when validating the drc-index of a cpu during a hotplug add. This updates those code paths to use the ibm,drc-info property, when present, instead for validation. Signed-off-by: Tyrel Datwyler Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/1573449697-5448-4-git-send-email-tyreld@linux.ibm.com --- arch/powerpc/platforms/pseries/hotplug-cpu.c | 127 ++++++++++++++++--- 1 file changed, 112 insertions(+), 15 deletions(-) diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c index 8ab24bd7f89c..3e8cbfe7a80f 100644 --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c @@ -465,17 +465,67 @@ static bool dlpar_cpu_exists(struct device_node *parent, u32 drc_index) return found; } +static bool drc_info_valid_index(struct device_node *parent, u32 drc_index) +{ + struct property *info; + struct of_drc_info drc; + const __be32 *value; + u32 index; + int count, i, j; + + info = of_find_property(parent, "ibm,drc-info", NULL); + if (!info) + return false; + + value = of_prop_next_u32(info, NULL, &count); + + /* First value of ibm,drc-info is number of drc-info records */ + if (value) + value++; + else + return false; + + for (i = 0; i < count; i++) { + if (of_read_drc_info_cell(&info, &value, &drc)) + return false; + + if (strncmp(drc.drc_type, "CPU", 3)) + break; + + if (drc_index > drc.last_drc_index) + continue; + + index = drc.drc_index_start; + for (j = 0; j < drc.num_sequential_elems; j++) { + if (drc_index == index) + return true; + + index += drc.sequential_inc; + } + } + + return false; +} + static bool valid_cpu_drc_index(struct device_node *parent, u32 drc_index) { bool found = false; int rc, index; - index = 0; + if (of_find_property(parent, "ibm,drc-info", NULL)) + return drc_info_valid_index(parent, drc_index); + + /* Note that the format of the ibm,drc-indexes array is + * the number of entries in the array followed by the array + * of drc values so we start looking at index = 1. + */ + index = 1; while (!found) { u32 drc; rc = of_property_read_u32_index(parent, "ibm,drc-indexes", index++, &drc); + if (rc) break; @@ -718,19 +768,52 @@ static int dlpar_cpu_remove_by_count(u32 cpus_to_remove) return rc; } -static int find_dlpar_cpus_to_add(u32 *cpu_drcs, u32 cpus_to_add) +static int find_drc_info_cpus_to_add(struct device_node *cpus, + struct property *info, + u32 *cpu_drcs, u32 cpus_to_add) { - struct device_node *parent; + struct of_drc_info drc; + const __be32 *value; + u32 count, drc_index; int cpus_found = 0; - int index, rc; + int i, j; - parent = of_find_node_by_path("/cpus"); - if (!parent) { - pr_warn("Could not find CPU root node in device tree\n"); - kfree(cpu_drcs); + if (!info) return -1; + + value = of_prop_next_u32(info, NULL, &count); + if (value) + value++; + + for (i = 0; i < count; i++) { + of_read_drc_info_cell(&info, &value, &drc); + if (strncmp(drc.drc_type, "CPU", 3)) + break; + + drc_index = drc.drc_index_start; + for (j = 0; j < drc.num_sequential_elems; j++) { + if (dlpar_cpu_exists(cpus, drc_index)) + continue; + + cpu_drcs[cpus_found++] = drc_index; + + if (cpus_found == cpus_to_add) + return cpus_found; + + drc_index += drc.sequential_inc; + } } + return cpus_found; +} + +static int find_drc_index_cpus_to_add(struct device_node *cpus, + u32 *cpu_drcs, u32 cpus_to_add) +{ + int cpus_found = 0; + int index, rc; + u32 drc_index; + /* Search the ibm,drc-indexes array for possible CPU drcs to * add. Note that the format of the ibm,drc-indexes array is * the number of entries in the array followed by the array @@ -738,25 +821,25 @@ static int find_dlpar_cpus_to_add(u32 *cpu_drcs, u32 cpus_to_add) */ index = 1; while (cpus_found < cpus_to_add) { - u32 drc; + rc = of_property_read_u32_index(cpus, "ibm,drc-indexes", + index++, &drc_index); - rc = of_property_read_u32_index(parent, "ibm,drc-indexes", - index++, &drc); if (rc) break; - if (dlpar_cpu_exists(parent, drc)) + if (dlpar_cpu_exists(cpus, drc_index)) continue; - cpu_drcs[cpus_found++] = drc; + cpu_drcs[cpus_found++] = drc_index; } - of_node_put(parent); return cpus_found; } static int dlpar_cpu_add_by_count(u32 cpus_to_add) { + struct device_node *parent; + struct property *info; u32 *cpu_drcs; int cpus_added = 0; int cpus_found; @@ -768,7 +851,21 @@ static int dlpar_cpu_add_by_count(u32 cpus_to_add) if (!cpu_drcs) return -EINVAL; - cpus_found = find_dlpar_cpus_to_add(cpu_drcs, cpus_to_add); + parent = of_find_node_by_path("/cpus"); + if (!parent) { + pr_warn("Could not find CPU root node in device tree\n"); + kfree(cpu_drcs); + return -1; + } + + info = of_find_property(parent, "ibm,drc-info", NULL); + if (info) + cpus_found = find_drc_info_cpus_to_add(parent, info, cpu_drcs, cpus_to_add); + else + cpus_found = find_drc_index_cpus_to_add(parent, cpu_drcs, cpus_to_add); + + of_node_put(parent); + if (cpus_found < cpus_to_add) { pr_warn("Failed to find enough CPUs (%d of %d) to add\n", cpus_found, cpus_to_add); -- 2.20.1