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-rw-r--r--arch/arm64/kernel/setup.c122
1 files changed, 117 insertions, 5 deletions
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index bd9bbd0e44e..c8e9effe52e 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -108,20 +108,95 @@ void __init early_print(const char *str, ...)
printk("%s", buf);
}
+void __init smp_setup_processor_id(void)
+{
+ /*
+ * clear __my_cpu_offset on boot CPU to avoid hang caused by
+ * using percpu variable early, for example, lockdep will
+ * access percpu variable inside lock_release
+ */
+ set_my_cpu_offset(0);
+}
+
bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
{
return phys_id == cpu_logical_map(cpu);
}
+struct mpidr_hash mpidr_hash;
+#ifdef CONFIG_SMP
+/**
+ * smp_build_mpidr_hash - Pre-compute shifts required at each affinity
+ * level in order to build a linear index from an
+ * MPIDR value. Resulting algorithm is a collision
+ * free hash carried out through shifting and ORing
+ */
+static void __init smp_build_mpidr_hash(void)
+{
+ u32 i, affinity, fs[4], bits[4], ls;
+ u64 mask = 0;
+ /*
+ * Pre-scan the list of MPIDRS and filter out bits that do
+ * not contribute to affinity levels, ie they never toggle.
+ */
+ for_each_possible_cpu(i)
+ mask |= (cpu_logical_map(i) ^ cpu_logical_map(0));
+ pr_debug("mask of set bits %#llx\n", mask);
+ /*
+ * Find and stash the last and first bit set at all affinity levels to
+ * check how many bits are required to represent them.
+ */
+ for (i = 0; i < 4; i++) {
+ affinity = MPIDR_AFFINITY_LEVEL(mask, i);
+ /*
+ * Find the MSB bit and LSB bits position
+ * to determine how many bits are required
+ * to express the affinity level.
+ */
+ ls = fls(affinity);
+ fs[i] = affinity ? ffs(affinity) - 1 : 0;
+ bits[i] = ls - fs[i];
+ }
+ /*
+ * An index can be created from the MPIDR_EL1 by isolating the
+ * significant bits at each affinity level and by shifting
+ * them in order to compress the 32 bits values space to a
+ * compressed set of values. This is equivalent to hashing
+ * the MPIDR_EL1 through shifting and ORing. It is a collision free
+ * hash though not minimal since some levels might contain a number
+ * of CPUs that is not an exact power of 2 and their bit
+ * representation might contain holes, eg MPIDR_EL1[7:0] = {0x2, 0x80}.
+ */
+ mpidr_hash.shift_aff[0] = MPIDR_LEVEL_SHIFT(0) + fs[0];
+ mpidr_hash.shift_aff[1] = MPIDR_LEVEL_SHIFT(1) + fs[1] - bits[0];
+ mpidr_hash.shift_aff[2] = MPIDR_LEVEL_SHIFT(2) + fs[2] -
+ (bits[1] + bits[0]);
+ mpidr_hash.shift_aff[3] = MPIDR_LEVEL_SHIFT(3) +
+ fs[3] - (bits[2] + bits[1] + bits[0]);
+ mpidr_hash.mask = mask;
+ mpidr_hash.bits = bits[3] + bits[2] + bits[1] + bits[0];
+ pr_debug("MPIDR hash: aff0[%u] aff1[%u] aff2[%u] aff3[%u] mask[%#llx] bits[%u]\n",
+ mpidr_hash.shift_aff[0],
+ mpidr_hash.shift_aff[1],
+ mpidr_hash.shift_aff[2],
+ mpidr_hash.shift_aff[3],
+ mpidr_hash.mask,
+ mpidr_hash.bits);
+ /*
+ * 4x is an arbitrary value used to warn on a hash table much bigger
+ * than expected on most systems.
+ */
+ if (mpidr_hash_size() > 4 * num_possible_cpus())
+ pr_warn("Large number of MPIDR hash buckets detected\n");
+ __flush_dcache_area(&mpidr_hash, sizeof(struct mpidr_hash));
+}
+#endif
+
static void __init setup_processor(void)
{
struct cpu_info *cpu_info;
+ u64 features, block;
- /*
- * locate processor in the list of supported processor
- * types. The linker builds this table for us from the
- * entries in arch/arm/mm/proc.S
- */
cpu_info = lookup_processor_type(read_cpuid_id());
if (!cpu_info) {
printk("CPU configuration botched (ID %08x), unable to continue.\n",
@@ -136,6 +211,37 @@ static void __init setup_processor(void)
sprintf(init_utsname()->machine, ELF_PLATFORM);
elf_hwcap = 0;
+
+ /*
+ * ID_AA64ISAR0_EL1 contains 4-bit wide signed feature blocks.
+ * The blocks we test below represent incremental functionality
+ * for non-negative values. Negative values are reserved.
+ */
+ features = read_cpuid(ID_AA64ISAR0_EL1);
+ block = (features >> 4) & 0xf;
+ if (!(block & 0x8)) {
+ switch (block) {
+ default:
+ case 2:
+ elf_hwcap |= HWCAP_PMULL;
+ case 1:
+ elf_hwcap |= HWCAP_AES;
+ case 0:
+ break;
+ }
+ }
+
+ block = (features >> 8) & 0xf;
+ if (block && !(block & 0x8))
+ elf_hwcap |= HWCAP_SHA1;
+
+ block = (features >> 12) & 0xf;
+ if (block && !(block & 0x8))
+ elf_hwcap |= HWCAP_SHA2;
+
+ block = (features >> 16) & 0xf;
+ if (block && !(block & 0x8))
+ elf_hwcap |= HWCAP_CRC32;
}
static void __init setup_machine_fdt(phys_addr_t dt_phys)
@@ -236,6 +342,7 @@ void __init setup_arch(char **cmdline_p)
cpu_read_bootcpu_ops();
#ifdef CONFIG_SMP
smp_init_cpus();
+ smp_build_mpidr_hash();
#endif
#ifdef CONFIG_VT
@@ -275,6 +382,11 @@ static const char *hwcap_str[] = {
"fp",
"asimd",
"evtstrm",
+ "aes",
+ "pmull",
+ "sha1",
+ "sha2",
+ "crc32",
NULL
};