OpenE2K/qemu-e2k
13
4
Fork 0
Code Issues 4 Pull Requests Projects 2 Releases Activity

i386: Simplify CPUID_8000_001E for AMD

Browse Source 
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>
This commit is contained in:
Babu Moger 2020-09-01 10:57:32 -05:00 committed by Eduardo Habkost
parent 2f084d1e1d
commit 31ada106d8
1 changed files with 45 additions and 150 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

191
target/i386/cpu.c
View File

@ -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,
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: