From 31ada106d891f56f54d4234ce58c552bc2e734af Mon Sep 17 00:00:00 2001 From: Babu Moger Date: Tue, 1 Sep 2020 10:57:32 -0500 Subject: [PATCH] i386: Simplify CPUID_8000_001E for AMD apic_id contains all the information required to build CPUID_8000_001E. core_id and node_id is already part of apic_id generated by x86_topo_ids_from_apicid. Also remove the restriction on number bits on core_id and node_id. Remove all the hardcoded values and replace with generalized fields. Refer the Processor Programming Reference (PPR) documentation available from the bugzilla Link below. Signed-off-by: Babu Moger Reviewed-by: Igor Mammedov Reviewed-by: Pankaj Gupta Acked-by: Michael S. Tsirkin Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 Message-Id: <159897585257.30750.5815593918927986935.stgit@naples-babu.amd.com> Signed-off-by: Eduardo Habkost --- target/i386/cpu.c | 195 +++++++++++++----------------------------------------- 1 file changed, 45 insertions(+), 150 deletions(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 52694a4198..1c58f764dc 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -338,62 +338,6 @@ static void encode_cache_cpuid80000006(CPUCacheInfo *l2, } } -/* - * Definitions used for building CPUID Leaf 0x8000001D and 0x8000001E - * Please refer to the AMD64 Architecture Programmer’s Manual Volume 3. - * Define the constants to build the cpu topology. Right now, TOPOEXT - * feature is enabled only on EPYC. So, these constants are based on - * EPYC supported configurations. We may need to handle the cases if - * these values change in future. - */ -/* Maximum core complexes in a node */ -#define MAX_CCX 2 -/* Maximum cores in a core complex */ -#define MAX_CORES_IN_CCX 4 -/* Maximum cores in a node */ -#define MAX_CORES_IN_NODE 8 -/* Maximum nodes in a socket */ -#define MAX_NODES_PER_SOCKET 4 - -/* - * Figure out the number of nodes required to build this config. - * Max cores in a node is 8 - */ -static int nodes_in_socket(int nr_cores) -{ - int nodes; - - nodes = DIV_ROUND_UP(nr_cores, MAX_CORES_IN_NODE); - - /* Hardware does not support config with 3 nodes, return 4 in that case */ - return (nodes == 3) ? 4 : nodes; -} - -/* - * Decide the number of cores in a core complex with the given nr_cores using - * following set constants MAX_CCX, MAX_CORES_IN_CCX, MAX_CORES_IN_NODE and - * MAX_NODES_PER_SOCKET. Maintain symmetry as much as possible - * L3 cache is shared across all cores in a core complex. So, this will also - * tell us how many cores are sharing the L3 cache. - */ -static int cores_in_core_complex(int nr_cores) -{ - int nodes; - - /* Check if we can fit all the cores in one core complex */ - if (nr_cores <= MAX_CORES_IN_CCX) { - return nr_cores; - } - /* Get the number of nodes required to build this config */ - nodes = nodes_in_socket(nr_cores); - - /* - * Divide the cores accros all the core complexes - * Return rounded up value - */ - return DIV_ROUND_UP(nr_cores, nodes * MAX_CCX); -} - /* Encode cache info for CPUID[8000001D] */ static void encode_cache_cpuid8000001d(CPUCacheInfo *cache, X86CPUTopoInfo *topo_info, @@ -432,107 +376,58 @@ static void encode_cache_cpuid8000001d(CPUCacheInfo *cache, (cache->complex_indexing ? CACHE_COMPLEX_IDX : 0); } -/* Data structure to hold the configuration info for a given core index */ -struct core_topology { - /* core complex id of the current core index */ - int ccx_id; - /* - * Adjusted core index for this core in the topology - * This can be 0,1,2,3 with max 4 cores in a core complex - */ - int core_id; - /* Node id for this core index */ - int node_id; - /* Number of nodes in this config */ - int num_nodes; -}; - -/* - * Build the configuration closely match the EPYC hardware. Using the EPYC - * hardware configuration values (MAX_CCX, MAX_CORES_IN_CCX, MAX_CORES_IN_NODE) - * right now. This could change in future. - * nr_cores : Total number of cores in the config - * core_id : Core index of the current CPU - * topo : Data structure to hold all the config info for this core index - */ -static void build_core_topology(int nr_cores, int core_id, - struct core_topology *topo) -{ - int nodes, cores_in_ccx; - - /* First get the number of nodes required */ - nodes = nodes_in_socket(nr_cores); - - cores_in_ccx = cores_in_core_complex(nr_cores); - - topo->node_id = core_id / (cores_in_ccx * MAX_CCX); - topo->ccx_id = (core_id % (cores_in_ccx * MAX_CCX)) / cores_in_ccx; - topo->core_id = core_id % cores_in_ccx; - topo->num_nodes = nodes; -} - /* Encode cache info for CPUID[8000001E] */ -static void encode_topo_cpuid8000001e(CPUState *cs, X86CPU *cpu, - uint32_t *eax, uint32_t *ebx, - uint32_t *ecx, uint32_t *edx) +static void encode_topo_cpuid8000001e(X86CPU *cpu, X86CPUTopoInfo *topo_info, + uint32_t *eax, uint32_t *ebx, + uint32_t *ecx, uint32_t *edx) { - struct core_topology topo = {0}; - unsigned long nodes; - int shift; + X86CPUTopoIDs topo_ids; + + x86_topo_ids_from_apicid(cpu->apic_id, topo_info, &topo_ids); - build_core_topology(cs->nr_cores, cpu->core_id, &topo); *eax = cpu->apic_id; + /* - * CPUID_Fn8000001E_EBX - * 31:16 Reserved - * 15:8 Threads per core (The number of threads per core is - * Threads per core + 1) - * 7:0 Core id (see bit decoding below) - * SMT: - * 4:3 node id - * 2 Core complex id - * 1:0 Core id - * Non SMT: - * 5:4 node id - * 3 Core complex id - * 1:0 Core id + * CPUID_Fn8000001E_EBX [Core Identifiers] (CoreId) + * Read-only. Reset: 0000_XXXXh. + * See Core::X86::Cpuid::ExtApicId. + * Core::X86::Cpuid::CoreId_lthree[1:0]_core[3:0]_thread[1:0]; + * Bits Description + * 31:16 Reserved. + * 15:8 ThreadsPerCore: threads per core. Read-only. Reset: XXh. + * The number of threads per core is ThreadsPerCore+1. + * 7:0 CoreId: core ID. Read-only. Reset: XXh. + * + * NOTE: CoreId is already part of apic_id. Just use it. We can + * use all the 8 bits to represent the core_id here. */ - if (cs->nr_threads - 1) { - *ebx = ((cs->nr_threads - 1) << 8) | (topo.node_id << 3) | - (topo.ccx_id << 2) | topo.core_id; - } else { - *ebx = (topo.node_id << 4) | (topo.ccx_id << 3) | topo.core_id; - } + *ebx = ((topo_info->threads_per_core - 1) << 8) | (topo_ids.core_id & 0xFF); + /* - * CPUID_Fn8000001E_ECX - * 31:11 Reserved - * 10:8 Nodes per processor (Nodes per processor is number of nodes + 1) - * 7:0 Node id (see bit decoding below) - * 2 Socket id - * 1:0 Node id + * CPUID_Fn8000001E_ECX [Node Identifiers] (NodeId) + * Read-only. Reset: 0000_0XXXh. + * Core::X86::Cpuid::NodeId_lthree[1:0]_core[3:0]_thread[1:0]; + * Bits Description + * 31:11 Reserved. + * 10:8 NodesPerProcessor: Node per processor. Read-only. Reset: XXXb. + * ValidValues: + * Value Description + * 000b 1 node per processor. + * 001b 2 nodes per processor. + * 010b Reserved. + * 011b 4 nodes per processor. + * 111b-100b Reserved. + * 7:0 NodeId: Node ID. Read-only. Reset: XXh. + * + * NOTE: Hardware reserves 3 bits for number of nodes per processor. + * But users can create more nodes than the actual hardware can + * support. To genaralize we can use all the upper 8 bits for nodes. + * NodeId is combination of node and socket_id which is already decoded + * in apic_id. Just use it by shifting. */ - if (topo.num_nodes <= 4) { - *ecx = ((topo.num_nodes - 1) << 8) | (cpu->socket_id << 2) | - topo.node_id; - } else { - /* - * Node id fix up. Actual hardware supports up to 4 nodes. But with - * more than 32 cores, we may end up with more than 4 nodes. - * Node id is a combination of socket id and node id. Only requirement - * here is that this number should be unique accross the system. - * Shift the socket id to accommodate more nodes. We dont expect both - * socket id and node id to be big number at the same time. This is not - * an ideal config but we need to to support it. Max nodes we can have - * is 32 (255/8) with 8 cores per node and 255 max cores. We only need - * 5 bits for nodes. Find the left most set bit to represent the total - * number of nodes. find_last_bit returns last set bit(0 based). Left - * shift(+1) the socket id to represent all the nodes. - */ - nodes = topo.num_nodes - 1; - shift = find_last_bit(&nodes, 8); - *ecx = ((topo.num_nodes - 1) << 8) | (cpu->socket_id << (shift + 1)) | - topo.node_id; - } + *ecx = ((topo_info->dies_per_pkg - 1) << 8) | + ((cpu->apic_id >> apicid_die_offset(topo_info)) & 0xFF); + *edx = 0; } @@ -6018,7 +5913,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, break; case 0x8000001E: assert(cpu->core_id <= 255); - encode_topo_cpuid8000001e(cs, cpu, + encode_topo_cpuid8000001e(cpu, &topo_info, eax, ebx, ecx, edx); break; case 0xC0000000: -- 2.11.0