[PATCH v5 01/16] x86/cpu: create Dhyana init file and register new cpu_dev to system

Pu Wen
2018-08-29T12:43:21Z

Add x86 architecture support for new processor Hygon Dhyana Family 18h.
Rework to create a separated file(arch/x86/kernel/cpu/hygon.c) from the
AMD init one(arch/x86/kernel/cpu/amd.c) to initialize Dhyana CPU. In
this way we can remove old AMD architecture support codes from Hygon
code path and generate a clear initialization flow for Hygon processors.
It also reduce long-term maintenance effort.
Also add Maintainer information for hygon.c in accordance.

To identify Hygon processors, add a new vendor type X86_VENDOR_HYGON(9)
for system recognition.

To enable Hygon processor config, add a separated Kconfig entry
(CPU_SUP_HYGON) for Dhyana CPU in kernel config setup.

Signed-off-by: Pu Wen <puwen@hygon.cn>
---
MAINTAINERS | 6 +
arch/x86/Kconfig.cpu | 13 ++
arch/x86/include/asm/processor.h | 3 +-
arch/x86/kernel/cpu/Makefile | 1 +
arch/x86/kernel/cpu/hygon.c | 408 +++++++++++++++++++++++++++++++++++++++
5 files changed, 430 insertions(+), 1 deletion(-)
create mode 100644 arch/x86/kernel/cpu/hygon.c

diff --git a/MAINTAINERS b/MAINTAINERS
index a5b256b..9c1d920 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6759,6 +6759,12 @@ S: Maintained
F: mm/memory-failure.c
F: mm/hwpoison-inject.c

+HYGON PROCESSOR SUPPORT
+M: Pu Wen <puwen@hygon.cn>
+L: linux-arch@vger.kernel.org
+S: Supported
+F: arch/x86/kernel/cpu/hygon.c
+
Hyper-V CORE AND DRIVERS
M: "K. Y. Srinivasan" <kys@microsoft.com>
M: Haiyang Zhang <haiyangz@microsoft.com>
diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index 638411f..2e92267 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -426,6 +426,19 @@ config CPU_SUP_AMD

If unsure, say N.

+config CPU_SUP_HYGON
+ default y
+ bool "Support Hygon processors" if PROCESSOR_SELECT
+ help
+ This enables detection, tunings and quirks for Hygon processors
+
+ You need this enabled if you want your kernel to run on an
+ Hygon CPU. Disabling this option on other types of CPUs
+ makes the kernel a tiny bit smaller. Disabling it on an Hygon
+ CPU might render the kernel unbootable.
+
+ If unsure, say N.
+
config CPU_SUP_CENTAUR
default y
bool "Support Centaur processors" if PROCESSOR_SELECT
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index c242972..9f18cdb 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -153,7 +153,8 @@ enum cpuid_regs_idx {
#define X86_VENDOR_CENTAUR 5
#define X86_VENDOR_TRANSMETA 7
#define X86_VENDOR_NSC 8
-#define X86_VENDOR_NUM 9
+#define X86_VENDOR_HYGON 9
+#define X86_VENDOR_NUM 10

#define X86_VENDOR_UNKNOWN 0xff

diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 347137e..1f5d229 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_X86_FEATURE_NAMES) += capflags.o powerflags.o

obj-$(CONFIG_CPU_SUP_INTEL) += intel.o intel_pconfig.o
obj-$(CONFIG_CPU_SUP_AMD) += amd.o
+obj-$(CONFIG_CPU_SUP_HYGON) += hygon.o
obj-$(CONFIG_CPU_SUP_CYRIX_32) += cyrix.o
obj-$(CONFIG_CPU_SUP_CENTAUR) += centaur.o
obj-$(CONFIG_CPU_SUP_TRANSMETA_32) += transmeta.o
diff --git a/arch/x86/kernel/cpu/hygon.c b/arch/x86/kernel/cpu/hygon.c
new file mode 100644
index 0000000..ae90d1f
--- /dev/null
+++ b/arch/x86/kernel/cpu/hygon.c
@@ -0,0 +1,408 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Hygon Processor Support for Linux
+ *
+ * Copyright (c) Chengdu Haiguang IC Design Co., Ltd.
+ *
+ * Author: 2018 Pu Wen <puwen@hygon.cn>
+ *
+ * This file is licensed under the terms of the GNU General
+ * License v2.0 or later. See file COPYING for details.
+ */
+#include <linux/io.h>
+
+#include <asm/cpu.h>
+#include <asm/smp.h>
+#include <asm/cacheinfo.h>
+#include <asm/spec-ctrl.h>
+#include <asm/delay.h>
+#ifdef CONFIG_X86_64
+# include <asm/set_memory.h>
+#endif
+
+#include "cpu.h"
+
+/*
+ * nodes_per_socket: Stores the number of nodes per socket.
+ * Refer to CPUID Fn8000_001E_ECX Node Identifiers[10:8]
+ */
+static u32 nodes_per_socket = 1;
+
+#ifdef CONFIG_NUMA
+/*
+ * To workaround broken NUMA config. Read the comment in
+ * srat_detect_node().
+ */
+static int nearby_node(int apicid)
+{
+ int i, node;
+
+ for (i = apicid - 1; i >= 0; i--) {
+ node = __apicid_to_node[i];
+ if (node != NUMA_NO_NODE && node_online(node))
+ return node;
+ }
+ for (i = apicid + 1; i < MAX_LOCAL_APIC; i++) {
+ node = __apicid_to_node[i];
+ if (node != NUMA_NO_NODE && node_online(node))
+ return node;
+ }
+ return first_node(node_online_map); /* Shouldn't happen */
+}
+#endif
+
+static void hygon_get_topology_early(struct cpuinfo_x86 *c)
+{
+ if (cpu_has(c, X86_FEATURE_TOPOEXT))
+ smp_num_siblings = ((cpuid_ebx(0x8000001e) >> 8) & 0xff) + 1;
+}
+
+/*
+ * Fixup core topology information for
+ * (1) Hygon multi-node processors
+ * Assumption: Number of cores in each internal node is the same.
+ * (2) Hygon processors supporting compute units
+ */
+static void hygon_get_topology(struct cpuinfo_x86 *c)
+{
+ u8 node_id;
+ int cpu = smp_processor_id();
+
+ /* get information required for multi-node processors */
+ if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
+ int err;
+ u32 eax, ebx, ecx, edx;
+
+ cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
+
+ node_id = ecx & 0xff;
+
+ c->cpu_core_id = ebx & 0xff;
+
+ if (smp_num_siblings > 1)
+ c->x86_max_cores /= smp_num_siblings;
+
+ /*
+ * In case leaf B is available, use it to derive
+ * topology information.
+ */
+ err = detect_extended_topology(c);
+ if (!err)
+ c->x86_coreid_bits = get_count_order(c->x86_max_cores);
+
+ } else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) {
+ u64 value;
+
+ rdmsrl(MSR_FAM10H_NODE_ID, value);
+ node_id = value & 7;
+
+ per_cpu(cpu_llc_id, cpu) = node_id;
+ } else
+ return;
+
+ if (nodes_per_socket > 1)
+ set_cpu_cap(c, X86_FEATURE_AMD_DCM);
+}
+
+/*
+ * On Hygon setup the lower bits of the APIC id distinguish the cores.
+ * Assumes number of cores is a power of two.
+ */
+static void hygon_detect_cmp(struct cpuinfo_x86 *c)
+{
+ unsigned int bits;
+ int cpu = smp_processor_id();
+
+ bits = c->x86_coreid_bits;
+ /* Low order bits define the core id (index of core in socket) */
+ c->cpu_core_id = c->initial_apicid & ((1 << bits)-1);
+ /* Convert the initial APIC ID into the socket ID */
+ c->phys_proc_id = c->initial_apicid >> bits;
+ /* use socket ID also for last level cache */
+ per_cpu(cpu_llc_id, cpu) = c->phys_proc_id;
+}
+
+static void srat_detect_node(struct cpuinfo_x86 *c)
+{
+#ifdef CONFIG_NUMA
+ int cpu = smp_processor_id();
+ int node;
+ unsigned int apicid = c->apicid;
+
+ node = numa_cpu_node(cpu);
+ if (node == NUMA_NO_NODE)
+ node = per_cpu(cpu_llc_id, cpu);
+
+ /*
+ * On multi-fabric platform (e.g. Numascale NumaChip) a
+ * platform-specific handler needs to be called to fixup some
+ * IDs of the CPU.
+ */
+ if (x86_cpuinit.fixup_cpu_id)
+ x86_cpuinit.fixup_cpu_id(c, node);
+
+ if (!node_online(node)) {
+ /*
+ * Two possibilities here:
+ *
+ * - The CPU is missing memory and no node was created. In
+ * that case try picking one from a nearby CPU.
+ *
+ * - The APIC IDs differ from the HyperTransport node IDs.
+ * Assume they are all increased by a constant offset, but
+ * in the same order as the HT nodeids. If that doesn't
+ * result in a usable node fall back to the path for the
+ * previous case.
+ *
+ * This workaround operates directly on the mapping between
+ * APIC ID and NUMA node, assuming certain relationship
+ * between APIC ID, HT node ID and NUMA topology. As going
+ * through CPU mapping may alter the outcome, directly
+ * access __apicid_to_node[].
+ */
+ int ht_nodeid = c->initial_apicid;
+
+ if (__apicid_to_node[ht_nodeid] != NUMA_NO_NODE)
+ node = __apicid_to_node[ht_nodeid];
+ /* Pick a nearby node */
+ if (!node_online(node))
+ node = nearby_node(apicid);
+ }
+ numa_set_node(cpu, node);
+#endif
+}
+
+static void early_init_hygon_mc(struct cpuinfo_x86 *c)
+{
+#ifdef CONFIG_SMP
+ unsigned int bits, ecx;
+
+ /* Multi core CPU? */
+ if (c->extended_cpuid_level < 0x80000008)
+ return;
+
+ ecx = cpuid_ecx(0x80000008);
+
+ c->x86_max_cores = (ecx & 0xff) + 1;
+
+ /* CPU telling us the core id bits shift? */
+ bits = (ecx >> 12) & 0xF;
+
+ /* Otherwise recompute */
+ if (bits == 0) {
+ while ((1 << bits) < c->x86_max_cores)
+ bits++;
+ }
+
+ c->x86_coreid_bits = bits;
+#endif
+}
+
+static void bsp_init_hygon(struct cpuinfo_x86 *c)
+{
+#ifdef CONFIG_X86_64
+ unsigned long long tseg;
+
+ /*
+ * Split up direct mapping around the TSEG SMM area.
+ * Don't do it for gbpages because there seems very little
+ * benefit in doing so.
+ */
+ if (!rdmsrl_safe(MSR_K8_TSEG_ADDR, &tseg)) {
+ unsigned long pfn = tseg >> PAGE_SHIFT;
+
+ pr_debug("tseg: %010llx\n", tseg);
+ if (pfn_range_is_mapped(pfn, pfn + 1))
+ set_memory_4k((unsigned long)__va(tseg), 1);
+ }
+#endif
+
+ if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
+ u64 val;
+
+ rdmsrl(MSR_K7_HWCR, val);
+ if (!(val & BIT(24)))
+ pr_warn(FW_BUG "TSC doesn't count with P0 frequency!\n");
+ }
+
+ if (cpu_has(c, X86_FEATURE_MWAITX))
+ use_mwaitx_delay();
+
+ if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
+ u32 ecx;
+
+ ecx = cpuid_ecx(0x8000001e);
+ nodes_per_socket = ((ecx >> 8) & 7) + 1;
+ } else if (boot_cpu_has(X86_FEATURE_NODEID_MSR)) {
+ u64 value;
+
+ rdmsrl(MSR_FAM10H_NODE_ID, value);
+ nodes_per_socket = ((value >> 3) & 7) + 1;
+ }
+
+ if (!boot_cpu_has(X86_FEATURE_AMD_SSBD) &&
+ !boot_cpu_has(X86_FEATURE_VIRT_SSBD)) {
+ /*
+ * Try to cache the base value so further operations can
+ * avoid RMW. If that faults, do not enable SSBD.
+ */
+ if (!rdmsrl_safe(MSR_AMD64_LS_CFG, &x86_amd_ls_cfg_base)) {
+ setup_force_cpu_cap(X86_FEATURE_LS_CFG_SSBD);
+ setup_force_cpu_cap(X86_FEATURE_SSBD);
+ x86_amd_ls_cfg_ssbd_mask = 1ULL << 10;
+ }
+ }
+}
+
+static void early_init_hygon(struct cpuinfo_x86 *c)
+{
+ u32 dummy;
+
+ early_init_hygon_mc(c);
+
+ set_cpu_cap(c, X86_FEATURE_K8);
+
+ rdmsr_safe(MSR_AMD64_PATCH_LEVEL, &c->microcode, &dummy);
+
+ /*
+ * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
+ * with P/T states and does not stop in deep C-states
+ */
+ if (c->x86_power & (1 << 8)) {
+ set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
+ set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
+ }
+
+ /* Bit 12 of 8000_0007 edx is accumulated power mechanism. */
+ if (c->x86_power & BIT(12))
+ set_cpu_cap(c, X86_FEATURE_ACC_POWER);
+
+#ifdef CONFIG_X86_64
+ set_cpu_cap(c, X86_FEATURE_SYSCALL32);
+#endif
+
+#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_PCI)
+ /*
+ * ApicID can always be treated as an 8-bit value for Hygon APIC So, we
+ * can safely set X86_FEATURE_EXTD_APICID unconditionally.
+ */
+ if (boot_cpu_has(X86_FEATURE_APIC))
+ set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
+#endif
+
+ /*
+ * This is only needed to tell the kernel whether to use VMCALL
+ * and VMMCALL. VMMCALL is never executed except under virt, so
+ * we can set it unconditionally.
+ */
+ set_cpu_cap(c, X86_FEATURE_VMMCALL);
+
+ hygon_get_topology_early(c);
+}
+
+static void init_hygon(struct cpuinfo_x86 *c)
+{
+ early_init_hygon(c);
+
+ /*
+ * Bit 31 in normal CPUID used for nonstandard 3DNow ID;
+ * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway
+ */
+ clear_cpu_cap(c, 0*32+31);
+
+ set_cpu_cap(c, X86_FEATURE_REP_GOOD);
+
+ /* get apicid instead of initial apic id from cpuid */
+ c->apicid = hard_smp_processor_id();
+
+ set_cpu_cap(c, X86_FEATURE_ZEN);
+ set_cpu_cap(c, X86_FEATURE_CPB);
+
+ cpu_detect_cache_sizes(c);
+
+ hygon_detect_cmp(c);
+ hygon_get_topology(c);
+ srat_detect_node(c);
+
+ if (cpu_has(c, X86_FEATURE_XMM2)) {
+ unsigned long long val;
+ int ret;
+
+ /*
+ * A serializing LFENCE has less overhead than MFENCE, so
+ * use it for execution serialization. On families which
+ * don't have that MSR, LFENCE is already serializing.
+ * msr_set_bit() uses the safe accessors, too, even if the MSR
+ * is not present.
+ */
+ msr_set_bit(MSR_F10H_DECFG,
+ MSR_F10H_DECFG_LFENCE_SERIALIZE_BIT);
+
+ /*
+ * Verify that the MSR write was successful (could be running
+ * under a hypervisor) and only then assume that LFENCE is
+ * serializing.
+ */
+ ret = rdmsrl_safe(MSR_F10H_DECFG, &val);
+ if (!ret && (val & MSR_F10H_DECFG_LFENCE_SERIALIZE)) {
+ /* A serializing LFENCE stops RDTSC speculation */
+ set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
+ } else {
+ /* MFENCE stops RDTSC speculation */
+ set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
+ }
+ }
+
+ /*
+ * Hygon processors have APIC timer running in deep C states.
+ */
+ set_cpu_cap(c, X86_FEATURE_ARAT);
+
+ /* Hygon CPUs don't reset SS attributes on SYSRET, Xen does. */
+ if (!cpu_has(c, X86_FEATURE_XENPV))
+ set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
+}
+
+static void cpu_detect_tlb_hygon(struct cpuinfo_x86 *c)
+{
+ u32 ebx, eax, ecx, edx;
+ u16 mask = 0xfff;
+
+ if (c->extended_cpuid_level < 0x80000006)
+ return;
+
+ cpuid(0x80000006, &eax, &ebx, &ecx, &edx);
+
+ tlb_lld_4k[ENTRIES] = (ebx >> 16) & mask;
+ tlb_lli_4k[ENTRIES] = ebx & mask;
+
+ /* Handle DTLB 2M and 4M sizes, fall back to L1 if L2 is disabled */
+ if (!((eax >> 16) & mask))
+ tlb_lld_2m[ENTRIES] = (cpuid_eax(0x80000005) >> 16) & 0xff;
+ else
+ tlb_lld_2m[ENTRIES] = (eax >> 16) & mask;
+
+ /* a 4M entry uses two 2M entries */
+ tlb_lld_4m[ENTRIES] = tlb_lld_2m[ENTRIES] >> 1;
+
+ /* Handle ITLB 2M and 4M sizes, fall back to L1 if L2 is disabled */
+ if (!(eax & mask)) {
+ cpuid(0x80000005, &eax, &ebx, &ecx, &edx);
+ tlb_lli_2m[ENTRIES] = eax & 0xff;
+ } else
+ tlb_lli_2m[ENTRIES] = eax & mask;
+
+ tlb_lli_4m[ENTRIES] = tlb_lli_2m[ENTRIES] >> 1;
+}
+
+static const struct cpu_dev hygon_cpu_dev = {
+ .c_vendor = "Hygon",
+ .c_ident = { "HygonGenuine" },
+ .c_early_init = early_init_hygon,
+ .c_detect_tlb = cpu_detect_tlb_hygon,
+ .c_bsp_init = bsp_init_hygon,
+ .c_init = init_hygon,
+ .c_x86_vendor = X86_VENDOR_HYGON,
+};
+
+cpu_dev_register(hygon_cpu_dev);
--
2.7.4