On Thu, Aug 12, 2021 at 06:52:23PM +0530, Aneesh Kumar K.V wrote: > PAPR interface currently supports two different ways of communicating resource > grouping details to the OS. These are referred to as Form 0 and Form 1 > associativity grouping. Form 0 is the older format and is now considered > deprecated. This patch adds another resource grouping named FORM2. > > Signed-off-by: Daniel Henrique Barboza <danielhb...@gmail.com> > Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com>
Reviewed-by: David Gibson <da...@gibson.dropbear.id.au> Though there a couple of cosmetic issues and one bad memory access issue (though only in the case of buggy firmware). [snip] > +Form 2 > +------- > +Form 2 associativity format adds separate device tree properties > representing NUMA node distance > +thereby making the node distance computation flexible. Form 2 also allows > flexible primary > +domain numbering. With numa distance computation now detached from the index > value in > +"ibm,associativity-reference-points" property, Form 2 allows a large number > of primary domain > +ids at the same domainID index representing resource groups of different > performance/latency > +characteristics. > + > +Hypervisor indicates the usage of FORM2 associativity using bit 2 of byte 5 > in the > +"ibm,architecture-vec-5" property. > + > +"ibm,numa-lookup-index-table" property contains a list of one or more > numbers representing > +the domainIDs present in the system. The offset of the domainID in this > property is > +used as an index while computing numa distance information via > "ibm,numa-distance-table". > + > +prop-encoded-array: The number N of the domainIDs encoded as with > encode-int, followed by > +N domainID encoded as with encode-int > + > +For ex: > +"ibm,numa-lookup-index-table" = {4, 0, 8, 250, 252}. The offset of domainID > 8 (2) is used when Since you're using dts syntax below, it probably makes sense to use it here as well. > +computing the distance of domain 8 from other domains present in the system. > For the rest of > +this document, this offset will be referred to as domain distance offset. > + > +"ibm,numa-distance-table" property contains a list of one or more numbers > representing the NUMA > +distance between resource groups/domains present in the system. > + > +prop-encoded-array: The number N of the distance values encoded as with > encode-int, followed by > +N distance values encoded as with encode-bytes. The max distance value we > could encode is 255. > +The number N must be equal to the square of m where m is the number of > domainIDs in the > +numa-lookup-index-table. > + > +For ex: > +ibm,numa-lookup-index-table = <3 0 8 40>; > +ibm,numa-distace-table = <9>, /bits/ 8 < 10 20 80 > + 20 10 160 > + 80 160 10>; [snip] > + > + /* FORM2 affinity */ > + nid = of_node_to_nid_single(node); > + if (nid == NUMA_NO_NODE) > + return; > + > + /* > + * With FORM2 we expect NUMA distance of all possible NUMA > + * nodes to be provided during boot. > + */ > + WARN(numa_distance_table[nid][nid] == -1, > + "NUMA distance details for node %d not provided\n", nid); > +} > + > +/* > + * ibm,numa-lookup-index-table= {N, domainid1, domainid2, ..... domainidN} > + * ibm,numa-distance-table = { N, 1, 2, 4, 5, 1, 6, .... N elements} .. and here too. > + */ > +static void initialize_form2_numa_distance_lookup_table(void) > +{ > + int i, j; > + struct device_node *root; > + const __u8 *numa_dist_table; > + const __be32 *numa_lookup_index; > + int numa_dist_table_length; > + int max_numa_index, distance_index; > + > + if (firmware_has_feature(FW_FEATURE_OPAL)) > + root = of_find_node_by_path("/ibm,opal"); > + else > + root = of_find_node_by_path("/rtas"); > + if (!root) > + root = of_find_node_by_path("/"); > + > + numa_lookup_index = of_get_property(root, > "ibm,numa-lookup-index-table", NULL); > + max_numa_index = of_read_number(&numa_lookup_index[0], 1); > + > + /* first element of the array is the size and is encode-int */ > + numa_dist_table = of_get_property(root, "ibm,numa-distance-table", > NULL); > + numa_dist_table_length = of_read_number((const __be32 > *)&numa_dist_table[0], 1); > + /* Skip the size which is encoded int */ > + numa_dist_table += sizeof(__be32); > + > + pr_debug("numa_dist_table_len = %d, numa_dist_indexes_len = %d\n", > + numa_dist_table_length, max_numa_index); You validate numa_dist_table_length below. However, AFAICT you don't anywhere check that the property actually has the length its first element claims it does. Yes, that represents a firmware bug, but it's probably best if we don't ready past the end of the array in that case, which I think is what will happen now. Same applies for the lookup-index-table. > + for (i = 0; i < max_numa_index; i++) > + /* +1 skip the max_numa_index in the property */ > + numa_id_index_table[i] = of_read_number(&numa_lookup_index[i + > 1], 1); > + > + > + if (numa_dist_table_length != max_numa_index * max_numa_index) { > + WARN(1, "Wrong NUMA distance information\n"); > + /* consider everybody else just remote. */ > + for (i = 0; i < max_numa_index; i++) { > + for (j = 0; j < max_numa_index; j++) { > + int nodeA = numa_id_index_table[i]; > + int nodeB = numa_id_index_table[j]; > + > + if (nodeA == nodeB) > + numa_distance_table[nodeA][nodeB] = > LOCAL_DISTANCE; > + else > + numa_distance_table[nodeA][nodeB] = > REMOTE_DISTANCE; > + } > + } > + } > + > + distance_index = 0; > + for (i = 0; i < max_numa_index; i++) { > + for (j = 0; j < max_numa_index; j++) { > + int nodeA = numa_id_index_table[i]; > + int nodeB = numa_id_index_table[j]; > + > + numa_distance_table[nodeA][nodeB] = > numa_dist_table[distance_index++]; > + pr_debug("dist[%d][%d]=%d ", nodeA, nodeB, > numa_distance_table[nodeA][nodeB]); > + } > + } > + of_node_put(root); > } > > static int __init find_primary_domain_index(void) > @@ -344,6 +449,9 @@ static int __init find_primary_domain_index(void) > */ > if (firmware_has_feature(FW_FEATURE_OPAL)) { > affinity_form = FORM1_AFFINITY; > + } else if (firmware_has_feature(FW_FEATURE_FORM2_AFFINITY)) { > + dbg("Using form 2 affinity\n"); > + affinity_form = FORM2_AFFINITY; > } else if (firmware_has_feature(FW_FEATURE_FORM1_AFFINITY)) { > dbg("Using form 1 affinity\n"); > affinity_form = FORM1_AFFINITY; > @@ -388,9 +496,12 @@ static int __init find_primary_domain_index(void) > > index = of_read_number(&distance_ref_points[1], 1); > } else { > + /* > + * Both FORM1 and FORM2 affinity find the primary domain details > + * at the same offset. > + */ > index = of_read_number(distance_ref_points, 1); > } > - > /* > * Warn and cap if the hardware supports more than > * MAX_DISTANCE_REF_POINTS domains. > @@ -819,6 +930,12 @@ static int __init parse_numa_properties(void) > > dbg("NUMA associativity depth for CPU/Memory: %d\n", > primary_domain_index); > > + /* > + * If it is FORM2 initialize the distance table here. > + */ > + if (affinity_form == FORM2_AFFINITY) > + initialize_form2_numa_distance_lookup_table(); > + > /* > * Even though we connect cpus to numa domains later in SMP > * init, we need to know the node ids now. This is because > diff --git a/arch/powerpc/platforms/pseries/firmware.c > b/arch/powerpc/platforms/pseries/firmware.c > index 5d4c2bc20bba..f162156b7b68 100644 > --- a/arch/powerpc/platforms/pseries/firmware.c > +++ b/arch/powerpc/platforms/pseries/firmware.c > @@ -123,6 +123,7 @@ vec5_fw_features_table[] = { > {FW_FEATURE_PRRN, OV5_PRRN}, > {FW_FEATURE_DRMEM_V2, OV5_DRMEM_V2}, > {FW_FEATURE_DRC_INFO, OV5_DRC_INFO}, > + {FW_FEATURE_FORM2_AFFINITY, OV5_FORM2_AFFINITY}, > }; > > static void __init fw_vec5_feature_init(const char *vec5, unsigned long len) -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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