]> git.kernelconcepts.de Git - karo-tx-linux.git/blobdiff - arch/arm64/kernel/cpufeature.c
Merge remote-tracking branch 'arm64/for-next/core'
[karo-tx-linux.git] / arch / arm64 / kernel / cpufeature.c
index 305f30dc9e633fe86947621e54d802744e59df52..369975c3a9956efc14ee2f2f393eea9b2f225bbe 100644 (file)
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#define pr_fmt(fmt) "alternatives: " fmt
+#define pr_fmt(fmt) "CPU features: " fmt
 
+#include <linux/bsearch.h>
+#include <linux/sort.h>
 #include <linux/types.h>
 #include <asm/cpu.h>
 #include <asm/cpufeature.h>
+#include <asm/cpu_ops.h>
 #include <asm/processor.h>
+#include <asm/sysreg.h>
+
+unsigned long elf_hwcap __read_mostly;
+EXPORT_SYMBOL_GPL(elf_hwcap);
+
+#ifdef CONFIG_COMPAT
+#define COMPAT_ELF_HWCAP_DEFAULT       \
+                               (COMPAT_HWCAP_HALF|COMPAT_HWCAP_THUMB|\
+                                COMPAT_HWCAP_FAST_MULT|COMPAT_HWCAP_EDSP|\
+                                COMPAT_HWCAP_TLS|COMPAT_HWCAP_VFP|\
+                                COMPAT_HWCAP_VFPv3|COMPAT_HWCAP_VFPv4|\
+                                COMPAT_HWCAP_NEON|COMPAT_HWCAP_IDIV|\
+                                COMPAT_HWCAP_LPAE)
+unsigned int compat_elf_hwcap __read_mostly = COMPAT_ELF_HWCAP_DEFAULT;
+unsigned int compat_elf_hwcap2 __read_mostly;
+#endif
+
+DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
+
+#define ARM64_FTR_BITS(STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
+       {                                               \
+               .strict = STRICT,                       \
+               .type = TYPE,                           \
+               .shift = SHIFT,                         \
+               .width = WIDTH,                         \
+               .safe_val = SAFE_VAL,                   \
+       }
+
+#define ARM64_FTR_END                                  \
+       {                                               \
+               .width = 0,                             \
+       }
+
+static struct arm64_ftr_bits ftr_id_aa64isar0[] = {
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64ISAR0_RDM_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 24, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_ATOMICS_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_CRC32_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA2_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA1_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_AES_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0), /* RAZ */
+       ARM64_FTR_END,
+};
+
+static struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 28, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64PFR0_GIC_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI),
+       /* Linux doesn't care about the EL3 */
+       ARM64_FTR_BITS(FTR_NONSTRICT, FTR_EXACT, ID_AA64PFR0_EL3_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64PFR0_EL2_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64PFR0_EL1_SHIFT, 4, ID_AA64PFR0_EL1_64BIT_ONLY),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64PFR0_EL0_SHIFT, 4, ID_AA64PFR0_EL0_64BIT_ONLY),
+       ARM64_FTR_END,
+};
+
+static struct arm64_ftr_bits ftr_id_aa64mmfr0[] = {
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN16_SHIFT, 4, ID_AA64MMFR0_TGRAN16_NI),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_BIGENDEL0_SHIFT, 4, 0),
+       /* Linux shouldn't care about secure memory */
+       ARM64_FTR_BITS(FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_SNSMEM_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_BIGENDEL_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_ASID_SHIFT, 4, 0),
+       /*
+        * Differing PARange is fine as long as all peripherals and memory are mapped
+        * within the minimum PARange of all CPUs
+        */
+       ARM64_FTR_BITS(FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_PARANGE_SHIFT, 4, 0),
+       ARM64_FTR_END,
+};
+
+static struct arm64_ftr_bits ftr_id_aa64mmfr1[] = {
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_PAN_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_LOR_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_HPD_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_VHE_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_VMIDBITS_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_HADBS_SHIFT, 4, 0),
+       ARM64_FTR_END,
+};
+
+static struct arm64_ftr_bits ftr_ctr[] = {
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 31, 1, 1),        /* RAO */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 28, 3, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_HIGHER_SAFE, 24, 4, 0),  /* CWG */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),   /* ERG */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 1),   /* DminLine */
+       /*
+        * Linux can handle differing I-cache policies. Userspace JITs will
+        * make use of *minLine
+        */
+       ARM64_FTR_BITS(FTR_NONSTRICT, FTR_EXACT, 14, 2, 0),     /* L1Ip */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 10, 0),        /* RAZ */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),    /* IminLine */
+       ARM64_FTR_END,
+};
+
+static struct arm64_ftr_bits ftr_id_mmfr0[] = {
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 28, 4, 0),        /* InnerShr */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 24, 4, 0),        /* FCSE */
+       ARM64_FTR_BITS(FTR_NONSTRICT, FTR_LOWER_SAFE, 20, 4, 0),        /* AuxReg */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 16, 4, 0),        /* TCM */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 12, 4, 0),        /* ShareLvl */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 8, 4, 0), /* OuterShr */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0), /* PMSA */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0), /* VMSA */
+       ARM64_FTR_END,
+};
+
+static struct arm64_ftr_bits ftr_id_aa64dfr0[] = {
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_CTX_CMPS_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_WRPS_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_BRPS_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64DFR0_PMUVER_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64DFR0_TRACEVER_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64DFR0_DEBUGVER_SHIFT, 4, 0x6),
+       ARM64_FTR_END,
+};
+
+static struct arm64_ftr_bits ftr_mvfr2[] = {
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 8, 24, 0),        /* RAZ */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0),         /* FPMisc */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0),         /* SIMDMisc */
+       ARM64_FTR_END,
+};
+
+static struct arm64_ftr_bits ftr_dczid[] = {
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 5, 27, 0),        /* RAZ */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 1, 1),         /* DZP */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),    /* BS */
+       ARM64_FTR_END,
+};
+
+
+static struct arm64_ftr_bits ftr_id_isar5[] = {
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_RDM_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 20, 4, 0),        /* RAZ */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_CRC32_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_SHA2_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_SHA1_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_AES_SHIFT, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_SEVL_SHIFT, 4, 0),
+       ARM64_FTR_END,
+};
+
+static struct arm64_ftr_bits ftr_id_mmfr4[] = {
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 8, 24, 0),        /* RAZ */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0),         /* ac2 */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0),         /* RAZ */
+       ARM64_FTR_END,
+};
+
+static struct arm64_ftr_bits ftr_id_pfr0[] = {
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 16, 16, 0),       /* RAZ */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 12, 4, 0),        /* State3 */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 8, 4, 0),         /* State2 */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0),         /* State1 */
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0),         /* State0 */
+       ARM64_FTR_END,
+};
+
+/*
+ * Common ftr bits for a 32bit register with all hidden, strict
+ * attributes, with 4bit feature fields and a default safe value of
+ * 0. Covers the following 32bit registers:
+ * id_isar[0-4], id_mmfr[1-3], id_pfr1, mvfr[0-1]
+ */
+static struct arm64_ftr_bits ftr_generic_32bits[] = {
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
+       ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
+       ARM64_FTR_END,
+};
+
+static struct arm64_ftr_bits ftr_generic[] = {
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 64, 0),
+       ARM64_FTR_END,
+};
+
+static struct arm64_ftr_bits ftr_generic32[] = {
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 32, 0),
+       ARM64_FTR_END,
+};
+
+static struct arm64_ftr_bits ftr_aa64raz[] = {
+       ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 64, 0),
+       ARM64_FTR_END,
+};
+
+#define ARM64_FTR_REG(id, table)               \
+       {                                       \
+               .sys_id = id,                   \
+               .name = #id,                    \
+               .ftr_bits = &((table)[0]),      \
+       }
+
+static struct arm64_ftr_reg arm64_ftr_regs[] = {
+
+       /* Op1 = 0, CRn = 0, CRm = 1 */
+       ARM64_FTR_REG(SYS_ID_PFR0_EL1, ftr_id_pfr0),
+       ARM64_FTR_REG(SYS_ID_PFR1_EL1, ftr_generic_32bits),
+       ARM64_FTR_REG(SYS_ID_DFR0_EL1, ftr_generic_32bits),
+       ARM64_FTR_REG(SYS_ID_MMFR0_EL1, ftr_id_mmfr0),
+       ARM64_FTR_REG(SYS_ID_MMFR1_EL1, ftr_generic_32bits),
+       ARM64_FTR_REG(SYS_ID_MMFR2_EL1, ftr_generic_32bits),
+       ARM64_FTR_REG(SYS_ID_MMFR3_EL1, ftr_generic_32bits),
+
+       /* Op1 = 0, CRn = 0, CRm = 2 */
+       ARM64_FTR_REG(SYS_ID_ISAR0_EL1, ftr_generic_32bits),
+       ARM64_FTR_REG(SYS_ID_ISAR1_EL1, ftr_generic_32bits),
+       ARM64_FTR_REG(SYS_ID_ISAR2_EL1, ftr_generic_32bits),
+       ARM64_FTR_REG(SYS_ID_ISAR3_EL1, ftr_generic_32bits),
+       ARM64_FTR_REG(SYS_ID_ISAR4_EL1, ftr_generic_32bits),
+       ARM64_FTR_REG(SYS_ID_ISAR5_EL1, ftr_id_isar5),
+       ARM64_FTR_REG(SYS_ID_MMFR4_EL1, ftr_id_mmfr4),
+
+       /* Op1 = 0, CRn = 0, CRm = 3 */
+       ARM64_FTR_REG(SYS_MVFR0_EL1, ftr_generic_32bits),
+       ARM64_FTR_REG(SYS_MVFR1_EL1, ftr_generic_32bits),
+       ARM64_FTR_REG(SYS_MVFR2_EL1, ftr_mvfr2),
+
+       /* Op1 = 0, CRn = 0, CRm = 4 */
+       ARM64_FTR_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0),
+       ARM64_FTR_REG(SYS_ID_AA64PFR1_EL1, ftr_aa64raz),
+
+       /* Op1 = 0, CRn = 0, CRm = 5 */
+       ARM64_FTR_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0),
+       ARM64_FTR_REG(SYS_ID_AA64DFR1_EL1, ftr_generic),
+
+       /* Op1 = 0, CRn = 0, CRm = 6 */
+       ARM64_FTR_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0),
+       ARM64_FTR_REG(SYS_ID_AA64ISAR1_EL1, ftr_aa64raz),
+
+       /* Op1 = 0, CRn = 0, CRm = 7 */
+       ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0),
+       ARM64_FTR_REG(SYS_ID_AA64MMFR1_EL1, ftr_id_aa64mmfr1),
+
+       /* Op1 = 3, CRn = 0, CRm = 0 */
+       ARM64_FTR_REG(SYS_CTR_EL0, ftr_ctr),
+       ARM64_FTR_REG(SYS_DCZID_EL0, ftr_dczid),
+
+       /* Op1 = 3, CRn = 14, CRm = 0 */
+       ARM64_FTR_REG(SYS_CNTFRQ_EL0, ftr_generic32),
+};
+
+static int search_cmp_ftr_reg(const void *id, const void *regp)
+{
+       return (int)(unsigned long)id - (int)((const struct arm64_ftr_reg *)regp)->sys_id;
+}
+
+/*
+ * get_arm64_ftr_reg - Lookup a feature register entry using its
+ * sys_reg() encoding. With the array arm64_ftr_regs sorted in the
+ * ascending order of sys_id , we use binary search to find a matching
+ * entry.
+ *
+ * returns - Upon success,  matching ftr_reg entry for id.
+ *         - NULL on failure. It is upto the caller to decide
+ *          the impact of a failure.
+ */
+static struct arm64_ftr_reg *get_arm64_ftr_reg(u32 sys_id)
+{
+       return bsearch((const void *)(unsigned long)sys_id,
+                       arm64_ftr_regs,
+                       ARRAY_SIZE(arm64_ftr_regs),
+                       sizeof(arm64_ftr_regs[0]),
+                       search_cmp_ftr_reg);
+}
+
+static u64 arm64_ftr_set_value(struct arm64_ftr_bits *ftrp, s64 reg, s64 ftr_val)
+{
+       u64 mask = arm64_ftr_mask(ftrp);
+
+       reg &= ~mask;
+       reg |= (ftr_val << ftrp->shift) & mask;
+       return reg;
+}
+
+static s64 arm64_ftr_safe_value(struct arm64_ftr_bits *ftrp, s64 new, s64 cur)
+{
+       s64 ret = 0;
+
+       switch (ftrp->type) {
+       case FTR_EXACT:
+               ret = ftrp->safe_val;
+               break;
+       case FTR_LOWER_SAFE:
+               ret = new < cur ? new : cur;
+               break;
+       case FTR_HIGHER_SAFE:
+               ret = new > cur ? new : cur;
+               break;
+       default:
+               BUG();
+       }
+
+       return ret;
+}
+
+static int __init sort_cmp_ftr_regs(const void *a, const void *b)
+{
+       return ((const struct arm64_ftr_reg *)a)->sys_id -
+                ((const struct arm64_ftr_reg *)b)->sys_id;
+}
+
+static void __init swap_ftr_regs(void *a, void *b, int size)
+{
+       struct arm64_ftr_reg tmp = *(struct arm64_ftr_reg *)a;
+       *(struct arm64_ftr_reg *)a = *(struct arm64_ftr_reg *)b;
+       *(struct arm64_ftr_reg *)b = tmp;
+}
+
+static void __init sort_ftr_regs(void)
+{
+       /* Keep the array sorted so that we can do the binary search */
+       sort(arm64_ftr_regs,
+               ARRAY_SIZE(arm64_ftr_regs),
+               sizeof(arm64_ftr_regs[0]),
+               sort_cmp_ftr_regs,
+               swap_ftr_regs);
+}
+
+/*
+ * Initialise the CPU feature register from Boot CPU values.
+ * Also initiliases the strict_mask for the register.
+ */
+static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new)
+{
+       u64 val = 0;
+       u64 strict_mask = ~0x0ULL;
+       struct arm64_ftr_bits *ftrp;
+       struct arm64_ftr_reg *reg = get_arm64_ftr_reg(sys_reg);
+
+       BUG_ON(!reg);
+
+       for (ftrp  = reg->ftr_bits; ftrp->width; ftrp++) {
+               s64 ftr_new = arm64_ftr_value(ftrp, new);
+
+               val = arm64_ftr_set_value(ftrp, val, ftr_new);
+               if (!ftrp->strict)
+                       strict_mask &= ~arm64_ftr_mask(ftrp);
+       }
+       reg->sys_val = val;
+       reg->strict_mask = strict_mask;
+}
+
+void __init init_cpu_features(struct cpuinfo_arm64 *info)
+{
+       /* Before we start using the tables, make sure it is sorted */
+       sort_ftr_regs();
+
+       init_cpu_ftr_reg(SYS_CTR_EL0, info->reg_ctr);
+       init_cpu_ftr_reg(SYS_DCZID_EL0, info->reg_dczid);
+       init_cpu_ftr_reg(SYS_CNTFRQ_EL0, info->reg_cntfrq);
+       init_cpu_ftr_reg(SYS_ID_AA64DFR0_EL1, info->reg_id_aa64dfr0);
+       init_cpu_ftr_reg(SYS_ID_AA64DFR1_EL1, info->reg_id_aa64dfr1);
+       init_cpu_ftr_reg(SYS_ID_AA64ISAR0_EL1, info->reg_id_aa64isar0);
+       init_cpu_ftr_reg(SYS_ID_AA64ISAR1_EL1, info->reg_id_aa64isar1);
+       init_cpu_ftr_reg(SYS_ID_AA64MMFR0_EL1, info->reg_id_aa64mmfr0);
+       init_cpu_ftr_reg(SYS_ID_AA64MMFR1_EL1, info->reg_id_aa64mmfr1);
+       init_cpu_ftr_reg(SYS_ID_AA64PFR0_EL1, info->reg_id_aa64pfr0);
+       init_cpu_ftr_reg(SYS_ID_AA64PFR1_EL1, info->reg_id_aa64pfr1);
+       init_cpu_ftr_reg(SYS_ID_DFR0_EL1, info->reg_id_dfr0);
+       init_cpu_ftr_reg(SYS_ID_ISAR0_EL1, info->reg_id_isar0);
+       init_cpu_ftr_reg(SYS_ID_ISAR1_EL1, info->reg_id_isar1);
+       init_cpu_ftr_reg(SYS_ID_ISAR2_EL1, info->reg_id_isar2);
+       init_cpu_ftr_reg(SYS_ID_ISAR3_EL1, info->reg_id_isar3);
+       init_cpu_ftr_reg(SYS_ID_ISAR4_EL1, info->reg_id_isar4);
+       init_cpu_ftr_reg(SYS_ID_ISAR5_EL1, info->reg_id_isar5);
+       init_cpu_ftr_reg(SYS_ID_MMFR0_EL1, info->reg_id_mmfr0);
+       init_cpu_ftr_reg(SYS_ID_MMFR1_EL1, info->reg_id_mmfr1);
+       init_cpu_ftr_reg(SYS_ID_MMFR2_EL1, info->reg_id_mmfr2);
+       init_cpu_ftr_reg(SYS_ID_MMFR3_EL1, info->reg_id_mmfr3);
+       init_cpu_ftr_reg(SYS_ID_PFR0_EL1, info->reg_id_pfr0);
+       init_cpu_ftr_reg(SYS_ID_PFR1_EL1, info->reg_id_pfr1);
+       init_cpu_ftr_reg(SYS_MVFR0_EL1, info->reg_mvfr0);
+       init_cpu_ftr_reg(SYS_MVFR1_EL1, info->reg_mvfr1);
+       init_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2);
+}
+
+static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
+{
+       struct arm64_ftr_bits *ftrp;
+
+       for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
+               s64 ftr_cur = arm64_ftr_value(ftrp, reg->sys_val);
+               s64 ftr_new = arm64_ftr_value(ftrp, new);
+
+               if (ftr_cur == ftr_new)
+                       continue;
+               /* Find a safe value */
+               ftr_new = arm64_ftr_safe_value(ftrp, ftr_new, ftr_cur);
+               reg->sys_val = arm64_ftr_set_value(ftrp, reg->sys_val, ftr_new);
+       }
+
+}
+
+static int check_update_ftr_reg(u32 sys_id, int cpu, u64 val, u64 boot)
+{
+       struct arm64_ftr_reg *regp = get_arm64_ftr_reg(sys_id);
+
+       BUG_ON(!regp);
+       update_cpu_ftr_reg(regp, val);
+       if ((boot & regp->strict_mask) == (val & regp->strict_mask))
+               return 0;
+       pr_warn("SANITY CHECK: Unexpected variation in %s. Boot CPU: %#016llx, CPU%d: %#016llx\n",
+                       regp->name, boot, cpu, val);
+       return 1;
+}
+
+/*
+ * Update system wide CPU feature registers with the values from a
+ * non-boot CPU. Also performs SANITY checks to make sure that there
+ * aren't any insane variations from that of the boot CPU.
+ */
+void update_cpu_features(int cpu,
+                        struct cpuinfo_arm64 *info,
+                        struct cpuinfo_arm64 *boot)
+{
+       int taint = 0;
+
+       /*
+        * The kernel can handle differing I-cache policies, but otherwise
+        * caches should look identical. Userspace JITs will make use of
+        * *minLine.
+        */
+       taint |= check_update_ftr_reg(SYS_CTR_EL0, cpu,
+                                     info->reg_ctr, boot->reg_ctr);
+
+       /*
+        * 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.
+        */
+       taint |= check_update_ftr_reg(SYS_DCZID_EL0, cpu,
+                                     info->reg_dczid, boot->reg_dczid);
+
+       /* If different, timekeeping will be broken (especially with KVM) */
+       taint |= check_update_ftr_reg(SYS_CNTFRQ_EL0, cpu,
+                                     info->reg_cntfrq, boot->reg_cntfrq);
+
+       /*
+        * 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.
+        */
+       taint |= check_update_ftr_reg(SYS_ID_AA64DFR0_EL1, cpu,
+                                     info->reg_id_aa64dfr0, boot->reg_id_aa64dfr0);
+       taint |= check_update_ftr_reg(SYS_ID_AA64DFR1_EL1, cpu,
+                                     info->reg_id_aa64dfr1, boot->reg_id_aa64dfr1);
+       /*
+        * Even in big.LITTLE, processors should be identical instruction-set
+        * wise.
+        */
+       taint |= check_update_ftr_reg(SYS_ID_AA64ISAR0_EL1, cpu,
+                                     info->reg_id_aa64isar0, boot->reg_id_aa64isar0);
+       taint |= check_update_ftr_reg(SYS_ID_AA64ISAR1_EL1, cpu,
+                                     info->reg_id_aa64isar1, boot->reg_id_aa64isar1);
+
+       /*
+        * 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.
+        */
+       taint |= check_update_ftr_reg(SYS_ID_AA64MMFR0_EL1, cpu,
+                                     info->reg_id_aa64mmfr0, boot->reg_id_aa64mmfr0);
+       taint |= check_update_ftr_reg(SYS_ID_AA64MMFR1_EL1, cpu,
+                                     info->reg_id_aa64mmfr1, boot->reg_id_aa64mmfr1);
+
+       /*
+        * EL3 is not our concern.
+        * ID_AA64PFR1 is currently RES0.
+        */
+       taint |= check_update_ftr_reg(SYS_ID_AA64PFR0_EL1, cpu,
+                                     info->reg_id_aa64pfr0, boot->reg_id_aa64pfr0);
+       taint |= check_update_ftr_reg(SYS_ID_AA64PFR1_EL1, cpu,
+                                     info->reg_id_aa64pfr1, boot->reg_id_aa64pfr1);
+
+       /*
+        * If we have AArch32, we care about 32-bit features for compat. These
+        * registers should be RES0 otherwise.
+        */
+       taint |= check_update_ftr_reg(SYS_ID_DFR0_EL1, cpu,
+                                       info->reg_id_dfr0, boot->reg_id_dfr0);
+       taint |= check_update_ftr_reg(SYS_ID_ISAR0_EL1, cpu,
+                                       info->reg_id_isar0, boot->reg_id_isar0);
+       taint |= check_update_ftr_reg(SYS_ID_ISAR1_EL1, cpu,
+                                       info->reg_id_isar1, boot->reg_id_isar1);
+       taint |= check_update_ftr_reg(SYS_ID_ISAR2_EL1, cpu,
+                                       info->reg_id_isar2, boot->reg_id_isar2);
+       taint |= check_update_ftr_reg(SYS_ID_ISAR3_EL1, cpu,
+                                       info->reg_id_isar3, boot->reg_id_isar3);
+       taint |= check_update_ftr_reg(SYS_ID_ISAR4_EL1, cpu,
+                                       info->reg_id_isar4, boot->reg_id_isar4);
+       taint |= check_update_ftr_reg(SYS_ID_ISAR5_EL1, cpu,
+                                       info->reg_id_isar5, boot->reg_id_isar5);
+
+       /*
+        * 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.
+        */
+       taint |= check_update_ftr_reg(SYS_ID_MMFR0_EL1, cpu,
+                                       info->reg_id_mmfr0, boot->reg_id_mmfr0);
+       taint |= check_update_ftr_reg(SYS_ID_MMFR1_EL1, cpu,
+                                       info->reg_id_mmfr1, boot->reg_id_mmfr1);
+       taint |= check_update_ftr_reg(SYS_ID_MMFR2_EL1, cpu,
+                                       info->reg_id_mmfr2, boot->reg_id_mmfr2);
+       taint |= check_update_ftr_reg(SYS_ID_MMFR3_EL1, cpu,
+                                       info->reg_id_mmfr3, boot->reg_id_mmfr3);
+       taint |= check_update_ftr_reg(SYS_ID_PFR0_EL1, cpu,
+                                       info->reg_id_pfr0, boot->reg_id_pfr0);
+       taint |= check_update_ftr_reg(SYS_ID_PFR1_EL1, cpu,
+                                       info->reg_id_pfr1, boot->reg_id_pfr1);
+       taint |= check_update_ftr_reg(SYS_MVFR0_EL1, cpu,
+                                       info->reg_mvfr0, boot->reg_mvfr0);
+       taint |= check_update_ftr_reg(SYS_MVFR1_EL1, cpu,
+                                       info->reg_mvfr1, boot->reg_mvfr1);
+       taint |= check_update_ftr_reg(SYS_MVFR2_EL1, cpu,
+                                       info->reg_mvfr2, boot->reg_mvfr2);
+
+       /*
+        * Mismatched CPU features are a recipe for disaster. Don't even
+        * pretend to support them.
+        */
+       WARN_TAINT_ONCE(taint, TAINT_CPU_OUT_OF_SPEC,
+                       "Unsupported CPU feature variation.\n");
+}
+
+u64 read_system_reg(u32 id)
+{
+       struct arm64_ftr_reg *regp = get_arm64_ftr_reg(id);
+
+       /* We shouldn't get a request for an unsupported register */
+       BUG_ON(!regp);
+       return regp->sys_val;
+}
 
 #include <linux/irqchip/arm-gic-v3.h>
 
@@ -33,31 +588,25 @@ feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
        return val >= entry->min_field_value;
 }
 
-#define __ID_FEAT_CHK(reg)                                             \
-static bool __maybe_unused                                             \
-has_##reg##_feature(const struct arm64_cpu_capabilities *entry)                \
-{                                                                      \
-       u64 val;                                                        \
-                                                                       \
-       val = read_cpuid(reg##_el1);                                    \
-       return feature_matches(val, entry);                             \
-}
+static bool
+has_cpuid_feature(const struct arm64_cpu_capabilities *entry)
+{
+       u64 val;
 
-__ID_FEAT_CHK(id_aa64pfr0);
-__ID_FEAT_CHK(id_aa64mmfr1);
-__ID_FEAT_CHK(id_aa64isar0);
+       val = read_system_reg(entry->sys_reg);
+       return feature_matches(val, entry);
+}
 
 static bool has_useable_gicv3_cpuif(const struct arm64_cpu_capabilities *entry)
 {
        bool has_sre;
 
-       if (!has_id_aa64pfr0_feature(entry))
+       if (!has_cpuid_feature(entry))
                return false;
-
        has_sre = gic_enable_sre();
        if (!has_sre)
                pr_warn_once("%s present but disabled by higher exception level\n",
-                            entry->desc);
+                               entry->desc);
 
        return has_sre;
 }
@@ -67,15 +616,17 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
                .desc = "GIC system register CPU interface",
                .capability = ARM64_HAS_SYSREG_GIC_CPUIF,
                .matches = has_useable_gicv3_cpuif,
-               .field_pos = 24,
+               .sys_reg = SYS_ID_AA64PFR0_EL1,
+               .field_pos = ID_AA64PFR0_GIC_SHIFT,
                .min_field_value = 1,
        },
 #ifdef CONFIG_ARM64_PAN
        {
                .desc = "Privileged Access Never",
                .capability = ARM64_HAS_PAN,
-               .matches = has_id_aa64mmfr1_feature,
-               .field_pos = 20,
+               .matches = has_cpuid_feature,
+               .sys_reg = SYS_ID_AA64MMFR1_EL1,
+               .field_pos = ID_AA64MMFR1_PAN_SHIFT,
                .min_field_value = 1,
                .enable = cpu_enable_pan,
        },
@@ -84,15 +635,101 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
        {
                .desc = "LSE atomic instructions",
                .capability = ARM64_HAS_LSE_ATOMICS,
-               .matches = has_id_aa64isar0_feature,
-               .field_pos = 20,
+               .matches = has_cpuid_feature,
+               .sys_reg = SYS_ID_AA64ISAR0_EL1,
+               .field_pos = ID_AA64ISAR0_ATOMICS_SHIFT,
                .min_field_value = 2,
        },
 #endif /* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
        {},
 };
 
-void check_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
+#define HWCAP_CAP(reg, field, min_value, type, cap)            \
+       {                                                       \
+               .desc = #cap,                                   \
+               .matches = has_cpuid_feature,                   \
+               .sys_reg = reg,                                 \
+               .field_pos = field,                             \
+               .min_field_value = min_value,                   \
+               .hwcap_type = type,                             \
+               .hwcap = cap,                                   \
+       }
+
+static const struct arm64_cpu_capabilities arm64_hwcaps[] = {
+       HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, 2, CAP_HWCAP, HWCAP_PMULL),
+       HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_AES_SHIFT, 1, CAP_HWCAP, HWCAP_AES),
+       HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA1_SHIFT, 1, CAP_HWCAP, HWCAP_SHA1),
+       HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_SHA2_SHIFT, 1, CAP_HWCAP, HWCAP_SHA2),
+       HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_CRC32_SHIFT, 1, CAP_HWCAP, HWCAP_CRC32),
+       HWCAP_CAP(SYS_ID_AA64ISAR0_EL1, ID_AA64ISAR0_ATOMICS_SHIFT, 2, CAP_HWCAP, HWCAP_ATOMICS),
+       HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_FP_SHIFT, 0, CAP_HWCAP, HWCAP_FP),
+       HWCAP_CAP(SYS_ID_AA64PFR0_EL1, ID_AA64PFR0_ASIMD_SHIFT, 0, CAP_HWCAP, HWCAP_ASIMD),
+#ifdef CONFIG_COMPAT
+       HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, 2, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_PMULL),
+       HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_AES_SHIFT, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_AES),
+       HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA1_SHIFT, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA1),
+       HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_SHA2_SHIFT, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_SHA2),
+       HWCAP_CAP(SYS_ID_ISAR5_EL1, ID_ISAR5_CRC32_SHIFT, 1, CAP_COMPAT_HWCAP2, COMPAT_HWCAP2_CRC32),
+#endif
+       {},
+};
+
+static void cap_set_hwcap(const struct arm64_cpu_capabilities *cap)
+{
+       switch (cap->hwcap_type) {
+       case CAP_HWCAP:
+               elf_hwcap |= cap->hwcap;
+               break;
+#ifdef CONFIG_COMPAT
+       case CAP_COMPAT_HWCAP:
+               compat_elf_hwcap |= (u32)cap->hwcap;
+               break;
+       case CAP_COMPAT_HWCAP2:
+               compat_elf_hwcap2 |= (u32)cap->hwcap;
+               break;
+#endif
+       default:
+               WARN_ON(1);
+               break;
+       }
+}
+
+/* Check if we have a particular HWCAP enabled */
+static bool cpus_have_hwcap(const struct arm64_cpu_capabilities *cap)
+{
+       bool rc;
+
+       switch (cap->hwcap_type) {
+       case CAP_HWCAP:
+               rc = (elf_hwcap & cap->hwcap) != 0;
+               break;
+#ifdef CONFIG_COMPAT
+       case CAP_COMPAT_HWCAP:
+               rc = (compat_elf_hwcap & (u32)cap->hwcap) != 0;
+               break;
+       case CAP_COMPAT_HWCAP2:
+               rc = (compat_elf_hwcap2 & (u32)cap->hwcap) != 0;
+               break;
+#endif
+       default:
+               WARN_ON(1);
+               rc = false;
+       }
+
+       return rc;
+}
+
+static void setup_cpu_hwcaps(void)
+{
+       int i;
+       const struct arm64_cpu_capabilities *hwcaps = arm64_hwcaps;
+
+       for (i = 0; hwcaps[i].desc; i++)
+               if (hwcaps[i].matches(&hwcaps[i]))
+                       cap_set_hwcap(&hwcaps[i]);
+}
+
+void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
                            const char *info)
 {
        int i;
@@ -105,15 +742,178 @@ void check_cpu_capabilities(const struct arm64_cpu_capabilities *caps,
                        pr_info("%s %s\n", info, caps[i].desc);
                cpus_set_cap(caps[i].capability);
        }
+}
 
-       /* second pass allows enable() to consider interacting capabilities */
+/*
+ * Run through the enabled capabilities and enable() it on all active
+ * CPUs
+ */
+static void enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps)
+{
+       int i;
+
+       for (i = 0; caps[i].desc; i++)
+               if (caps[i].enable && cpus_have_cap(caps[i].capability))
+                       on_each_cpu(caps[i].enable, NULL, true);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+/*
+ * Flag to indicate if we have computed the system wide
+ * capabilities based on the boot time active CPUs. This
+ * will be used to determine if a new booting CPU should
+ * go through the verification process to make sure that it
+ * supports the system capabilities, without using a hotplug
+ * notifier.
+ */
+static bool sys_caps_initialised;
+
+static inline void set_sys_caps_initialised(void)
+{
+       sys_caps_initialised = true;
+}
+
+/*
+ * __raw_read_system_reg() - Used by a STARTING cpu before cpuinfo is populated.
+ */
+static u64 __raw_read_system_reg(u32 sys_id)
+{
+       switch (sys_id) {
+       case SYS_ID_PFR0_EL1:           return (u64)read_cpuid(ID_PFR0_EL1);
+       case SYS_ID_PFR1_EL1:           return (u64)read_cpuid(ID_PFR1_EL1);
+       case SYS_ID_DFR0_EL1:           return (u64)read_cpuid(ID_DFR0_EL1);
+       case SYS_ID_MMFR0_EL1:          return (u64)read_cpuid(ID_MMFR0_EL1);
+       case SYS_ID_MMFR1_EL1:          return (u64)read_cpuid(ID_MMFR1_EL1);
+       case SYS_ID_MMFR2_EL1:          return (u64)read_cpuid(ID_MMFR2_EL1);
+       case SYS_ID_MMFR3_EL1:          return (u64)read_cpuid(ID_MMFR3_EL1);
+       case SYS_ID_ISAR0_EL1:          return (u64)read_cpuid(ID_ISAR0_EL1);
+       case SYS_ID_ISAR1_EL1:          return (u64)read_cpuid(ID_ISAR1_EL1);
+       case SYS_ID_ISAR2_EL1:          return (u64)read_cpuid(ID_ISAR2_EL1);
+       case SYS_ID_ISAR3_EL1:          return (u64)read_cpuid(ID_ISAR3_EL1);
+       case SYS_ID_ISAR4_EL1:          return (u64)read_cpuid(ID_ISAR4_EL1);
+       case SYS_ID_ISAR5_EL1:          return (u64)read_cpuid(ID_ISAR4_EL1);
+       case SYS_MVFR0_EL1:             return (u64)read_cpuid(MVFR0_EL1);
+       case SYS_MVFR1_EL1:             return (u64)read_cpuid(MVFR1_EL1);
+       case SYS_MVFR2_EL1:             return (u64)read_cpuid(MVFR2_EL1);
+
+       case SYS_ID_AA64PFR0_EL1:       return (u64)read_cpuid(ID_AA64PFR0_EL1);
+       case SYS_ID_AA64PFR1_EL1:       return (u64)read_cpuid(ID_AA64PFR0_EL1);
+       case SYS_ID_AA64DFR0_EL1:       return (u64)read_cpuid(ID_AA64DFR0_EL1);
+       case SYS_ID_AA64DFR1_EL1:       return (u64)read_cpuid(ID_AA64DFR0_EL1);
+       case SYS_ID_AA64MMFR0_EL1:      return (u64)read_cpuid(ID_AA64MMFR0_EL1);
+       case SYS_ID_AA64MMFR1_EL1:      return (u64)read_cpuid(ID_AA64MMFR1_EL1);
+       case SYS_ID_AA64ISAR0_EL1:      return (u64)read_cpuid(ID_AA64ISAR0_EL1);
+       case SYS_ID_AA64ISAR1_EL1:      return (u64)read_cpuid(ID_AA64ISAR1_EL1);
+
+       case SYS_CNTFRQ_EL0:            return (u64)read_cpuid(CNTFRQ_EL0);
+       case SYS_CTR_EL0:               return (u64)read_cpuid(CTR_EL0);
+       case SYS_DCZID_EL0:             return (u64)read_cpuid(DCZID_EL0);
+       default:
+               BUG();
+               return 0;
+       }
+}
+
+/*
+ * Park the CPU which doesn't have the capability as advertised
+ * by the system.
+ */
+static void fail_incapable_cpu(char *cap_type,
+                                const struct arm64_cpu_capabilities *cap)
+{
+       int cpu = smp_processor_id();
+
+       pr_crit("CPU%d: missing %s : %s\n", cpu, cap_type, cap->desc);
+       /* Mark this CPU absent */
+       set_cpu_present(cpu, 0);
+
+       /* Check if we can park ourselves */
+       if (cpu_ops[cpu] && cpu_ops[cpu]->cpu_die)
+               cpu_ops[cpu]->cpu_die(cpu);
+       asm(
+       "1:     wfe\n"
+       "       wfi\n"
+       "       b       1b");
+}
+
+/*
+ * Run through the enabled system capabilities and enable() it on this CPU.
+ * The capabilities were decided based on the available CPUs at the boot time.
+ * Any new CPU should match the system wide status of the capability. If the
+ * new CPU doesn't have a capability which the system now has enabled, we
+ * cannot do anything to fix it up and could cause unexpected failures. So
+ * we park the CPU.
+ */
+void verify_local_cpu_capabilities(void)
+{
+       int i;
+       const struct arm64_cpu_capabilities *caps;
+
+       /*
+        * If we haven't computed the system capabilities, there is nothing
+        * to verify.
+        */
+       if (!sys_caps_initialised)
+               return;
+
+       caps = arm64_features;
        for (i = 0; caps[i].desc; i++) {
-               if (cpus_have_cap(caps[i].capability) && caps[i].enable)
-                       caps[i].enable();
+               if (!cpus_have_cap(caps[i].capability) || !caps[i].sys_reg)
+                       continue;
+               /*
+                * If the new CPU misses an advertised feature, we cannot proceed
+                * further, park the cpu.
+                */
+               if (!feature_matches(__raw_read_system_reg(caps[i].sys_reg), &caps[i]))
+                       fail_incapable_cpu("arm64_features", &caps[i]);
+               if (caps[i].enable)
+                       caps[i].enable(NULL);
        }
+
+       for (i = 0, caps = arm64_hwcaps; caps[i].desc; i++) {
+               if (!cpus_have_hwcap(&caps[i]))
+                       continue;
+               if (!feature_matches(__raw_read_system_reg(caps[i].sys_reg), &caps[i]))
+                       fail_incapable_cpu("arm64_hwcaps", &caps[i]);
+       }
+}
+
+#else  /* !CONFIG_HOTPLUG_CPU */
+
+static inline void set_sys_caps_initialised(void)
+{
+}
+
+#endif /* CONFIG_HOTPLUG_CPU */
+
+static void setup_feature_capabilities(void)
+{
+       update_cpu_capabilities(arm64_features, "detected feature:");
+       enable_cpu_capabilities(arm64_features);
 }
 
-void check_local_cpu_features(void)
+void __init setup_cpu_features(void)
 {
-       check_cpu_capabilities(arm64_features, "detected feature:");
+       u32 cwg;
+       int cls;
+
+       /* Set the CPU feature capabilies */
+       setup_feature_capabilities();
+       setup_cpu_hwcaps();
+
+       /* Advertise that we have computed the system capabilities */
+       set_sys_caps_initialised();
+
+       /*
+        * Check for sane CTR_EL0.CWG value.
+        */
+       cwg = cache_type_cwg();
+       cls = cache_line_size();
+       if (!cwg)
+               pr_warn("No Cache Writeback Granule information, assuming cache line size %d\n",
+                       cls);
+       if (L1_CACHE_BYTES < cls)
+               pr_warn("L1_CACHE_BYTES smaller than the Cache Writeback Granule (%d < %d)\n",
+                       L1_CACHE_BYTES, cls);
 }