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 <babu.moger@amd.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
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 <ehabkost@redhat.com>

1 files 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: