--- /dev/null
+/*
+ * Record and handle CPU attributes.
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <asm/arch_timer.h>
+#include <asm/cachetype.h>
+#include <asm/cpu.h>
+#include <asm/cputype.h>
+#include <asm/cpufeature.h>
+
+#include <linux/bitops.h>
+#include <linux/bug.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/preempt.h>
+#include <linux/printk.h>
+#include <linux/smp.h>
+
+/*
+ * In case the boot CPU is hotpluggable, we record its initial state and
+ * current state separately. Certain system registers may contain different
+ * values depending on configuration at or after reset.
+ */
+DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data);
+static struct cpuinfo_arm64 boot_cpu_data;
+static bool mixed_endian_el0 = true;
+
+static char *icache_policy_str[] = {
+ [ICACHE_POLICY_RESERVED] = "RESERVED/UNKNOWN",
+ [ICACHE_POLICY_AIVIVT] = "AIVIVT",
+ [ICACHE_POLICY_VIPT] = "VIPT",
+ [ICACHE_POLICY_PIPT] = "PIPT",
+};
+
+unsigned long __icache_flags;
+
+static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
+{
+ unsigned int cpu = smp_processor_id();
+ u32 l1ip = CTR_L1IP(info->reg_ctr);
+
+ if (l1ip != ICACHE_POLICY_PIPT) {
+ /*
+ * VIPT caches are non-aliasing if the VA always equals the PA
+ * in all bit positions that are covered by the index. This is
+ * the case if the size of a way (# of sets * line size) does
+ * not exceed PAGE_SIZE.
+ */
+ u32 waysize = icache_get_numsets() * icache_get_linesize();
+
+ if (l1ip != ICACHE_POLICY_VIPT || waysize > PAGE_SIZE)
+ set_bit(ICACHEF_ALIASING, &__icache_flags);
+ }
+ if (l1ip == ICACHE_POLICY_AIVIVT)
+ set_bit(ICACHEF_AIVIVT, &__icache_flags);
+
+ pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str[l1ip], cpu);
+}
+
+bool cpu_supports_mixed_endian_el0(void)
+{
+ return id_aa64mmfr0_mixed_endian_el0(read_cpuid(ID_AA64MMFR0_EL1));
+}
+
+bool system_supports_mixed_endian_el0(void)
+{
+ return mixed_endian_el0;
+}
+
+static void update_mixed_endian_el0_support(struct cpuinfo_arm64 *info)
+{
+ mixed_endian_el0 &= id_aa64mmfr0_mixed_endian_el0(info->reg_id_aa64mmfr0);
+}
+
+static void update_cpu_features(struct cpuinfo_arm64 *info)
+{
+ update_mixed_endian_el0_support(info);
+}
+
+static int check_reg_mask(char *name, u64 mask, u64 boot, u64 cur, int cpu)
+{
+ if ((boot & mask) == (cur & mask))
+ return 0;
+
+ pr_warn("SANITY CHECK: Unexpected variation in %s. Boot CPU: %#016lx, CPU%d: %#016lx\n",
+ name, (unsigned long)boot, cpu, (unsigned long)cur);
+
+ return 1;
+}
+
+#define CHECK_MASK(field, mask, boot, cur, cpu) \
+ check_reg_mask(#field, mask, (boot)->reg_ ## field, (cur)->reg_ ## field, cpu)
+
+#define CHECK(field, boot, cur, cpu) \
+ CHECK_MASK(field, ~0ULL, boot, cur, cpu)
+
+/*
+ * Verify that CPUs don't have unexpected differences that will cause problems.
+ */
+static void cpuinfo_sanity_check(struct cpuinfo_arm64 *cur)
+{
+ unsigned int cpu = smp_processor_id();
+ struct cpuinfo_arm64 *boot = &boot_cpu_data;
+ unsigned int diff = 0;
+
+ /*
+ * The kernel can handle differing I-cache policies, but otherwise
+ * caches should look identical. Userspace JITs will make use of
+ * *minLine.
+ */
+ diff |= CHECK_MASK(ctr, 0xffff3fff, boot, cur, cpu);
+
+ /*
+ * Userspace may perform DC ZVA instructions. Mismatched block sizes
+ * could result in too much or too little memory being zeroed if a
+ * process is preempted and migrated between CPUs.
+ */
+ diff |= CHECK(dczid, boot, cur, cpu);
+
+ /* If different, timekeeping will be broken (especially with KVM) */
+ diff |= CHECK(cntfrq, boot, cur, cpu);
+
+ /*
+ * The kernel uses self-hosted debug features and expects CPUs to
+ * support identical debug features. We presently need CTX_CMPs, WRPs,
+ * and BRPs to be identical.
+ * ID_AA64DFR1 is currently RES0.
+ */
+ diff |= CHECK(id_aa64dfr0, boot, cur, cpu);
+ diff |= CHECK(id_aa64dfr1, boot, cur, cpu);
+
+ /*
+ * Even in big.LITTLE, processors should be identical instruction-set
+ * wise.
+ */
+ diff |= CHECK(id_aa64isar0, boot, cur, cpu);
+ diff |= CHECK(id_aa64isar1, boot, cur, cpu);
+
+ /*
+ * Differing PARange support is fine as long as all peripherals and
+ * memory are mapped within the minimum PARange of all CPUs.
+ * Linux should not care about secure memory.
+ * ID_AA64MMFR1 is currently RES0.
+ */
+ diff |= CHECK_MASK(id_aa64mmfr0, 0xffffffffffff0ff0, boot, cur, cpu);
+ diff |= CHECK(id_aa64mmfr1, boot, cur, cpu);
+
+ /*
+ * EL3 is not our concern.
+ * ID_AA64PFR1 is currently RES0.
+ */
+ diff |= CHECK_MASK(id_aa64pfr0, 0xffffffffffff0fff, boot, cur, cpu);
+ diff |= CHECK(id_aa64pfr1, boot, cur, cpu);
+
+ /*
+ * If we have AArch32, we care about 32-bit features for compat. These
+ * registers should be RES0 otherwise.
+ */
+ diff |= CHECK(id_dfr0, boot, cur, cpu);
+ diff |= CHECK(id_isar0, boot, cur, cpu);
+ diff |= CHECK(id_isar1, boot, cur, cpu);
+ diff |= CHECK(id_isar2, boot, cur, cpu);
+ diff |= CHECK(id_isar3, boot, cur, cpu);
+ diff |= CHECK(id_isar4, boot, cur, cpu);
+ diff |= CHECK(id_isar5, boot, cur, cpu);
+ /*
+ * Regardless of the value of the AuxReg field, the AIFSR, ADFSR, and
+ * ACTLR formats could differ across CPUs and therefore would have to
+ * be trapped for virtualization anyway.
+ */
+ diff |= CHECK_MASK(id_mmfr0, 0xff0fffff, boot, cur, cpu);
+ diff |= CHECK(id_mmfr1, boot, cur, cpu);
+ diff |= CHECK(id_mmfr2, boot, cur, cpu);
+ diff |= CHECK(id_mmfr3, boot, cur, cpu);
+ diff |= CHECK(id_pfr0, boot, cur, cpu);
+ diff |= CHECK(id_pfr1, boot, cur, cpu);
+
+ diff |= CHECK(mvfr0, boot, cur, cpu);
+ diff |= CHECK(mvfr1, boot, cur, cpu);
+ diff |= CHECK(mvfr2, boot, cur, cpu);
+
+ /*
+ * Mismatched CPU features are a recipe for disaster. Don't even
+ * pretend to support them.
+ */
+ WARN_TAINT_ONCE(diff, TAINT_CPU_OUT_OF_SPEC,
+ "Unsupported CPU feature variation.\n");
+}
+
+static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
+{
+ info->reg_cntfrq = arch_timer_get_cntfrq();
+ info->reg_ctr = read_cpuid_cachetype();
+ info->reg_dczid = read_cpuid(DCZID_EL0);
+ info->reg_midr = read_cpuid_id();
+
+ info->reg_id_aa64dfr0 = read_cpuid(ID_AA64DFR0_EL1);
+ info->reg_id_aa64dfr1 = read_cpuid(ID_AA64DFR1_EL1);
+ info->reg_id_aa64isar0 = read_cpuid(ID_AA64ISAR0_EL1);
+ info->reg_id_aa64isar1 = read_cpuid(ID_AA64ISAR1_EL1);
+ info->reg_id_aa64mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
+ info->reg_id_aa64mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
+ info->reg_id_aa64pfr0 = read_cpuid(ID_AA64PFR0_EL1);
+ info->reg_id_aa64pfr1 = read_cpuid(ID_AA64PFR1_EL1);
+
+ info->reg_id_dfr0 = read_cpuid(ID_DFR0_EL1);
+ info->reg_id_isar0 = read_cpuid(ID_ISAR0_EL1);
+ info->reg_id_isar1 = read_cpuid(ID_ISAR1_EL1);
+ info->reg_id_isar2 = read_cpuid(ID_ISAR2_EL1);
+ info->reg_id_isar3 = read_cpuid(ID_ISAR3_EL1);
+ info->reg_id_isar4 = read_cpuid(ID_ISAR4_EL1);
+ info->reg_id_isar5 = read_cpuid(ID_ISAR5_EL1);
+ info->reg_id_mmfr0 = read_cpuid(ID_MMFR0_EL1);
+ info->reg_id_mmfr1 = read_cpuid(ID_MMFR1_EL1);
+ info->reg_id_mmfr2 = read_cpuid(ID_MMFR2_EL1);
+ info->reg_id_mmfr3 = read_cpuid(ID_MMFR3_EL1);
+ info->reg_id_pfr0 = read_cpuid(ID_PFR0_EL1);
+ info->reg_id_pfr1 = read_cpuid(ID_PFR1_EL1);
+
+ info->reg_mvfr0 = read_cpuid(MVFR0_EL1);
+ info->reg_mvfr1 = read_cpuid(MVFR1_EL1);
+ info->reg_mvfr2 = read_cpuid(MVFR2_EL1);
+
+ cpuinfo_detect_icache_policy(info);
+
+ check_local_cpu_errata();
+ check_local_cpu_features();
+ update_cpu_features(info);
+}
+
+void cpuinfo_store_cpu(void)
+{
+ struct cpuinfo_arm64 *info = this_cpu_ptr(&cpu_data);
+ __cpuinfo_store_cpu(info);
+ cpuinfo_sanity_check(info);
+}
+
+void __init cpuinfo_store_boot_cpu(void)
+{
+ struct cpuinfo_arm64 *info = &per_cpu(cpu_data, 0);
+ __cpuinfo_store_cpu(info);
+
+ boot_cpu_data = *info;
+}
Code Review / kvmfornfv.git / blobdiff