linux/arch/arm64/kernel/setup.c
Will Deacon d13027bb35 Revert "arm64: initialize per-cpu offsets earlier"
This reverts commit 353e228eb3.

Qian Cai reports that TX2 no longer boots with his .config as it appears
that task_cpu() gets instrumented and used before KASAN has been
initialised.

Although Mark has a proposed fix, let's take the safe option of reverting
this for now and sorting it out properly later.

Link: https://lore.kernel.org/r/711bc57a314d8d646b41307008db2845b7537b3d.camel@redhat.com
Reported-by: Qian Cai <cai@redhat.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-10-09 11:24:17 +01:00

442 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Based on arch/arm/kernel/setup.c
*
* Copyright (C) 1995-2001 Russell King
* Copyright (C) 2012 ARM Ltd.
*/
#include <linux/acpi.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/stddef.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/initrd.h>
#include <linux/console.h>
#include <linux/cache.h>
#include <linux/screen_info.h>
#include <linux/init.h>
#include <linux/kexec.h>
#include <linux/root_dev.h>
#include <linux/cpu.h>
#include <linux/interrupt.h>
#include <linux/smp.h>
#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/memblock.h>
#include <linux/of_fdt.h>
#include <linux/efi.h>
#include <linux/psci.h>
#include <linux/sched/task.h>
#include <linux/mm.h>
#include <asm/acpi.h>
#include <asm/fixmap.h>
#include <asm/cpu.h>
#include <asm/cputype.h>
#include <asm/daifflags.h>
#include <asm/elf.h>
#include <asm/cpufeature.h>
#include <asm/cpu_ops.h>
#include <asm/kasan.h>
#include <asm/numa.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/smp_plat.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/traps.h>
#include <asm/efi.h>
#include <asm/xen/hypervisor.h>
#include <asm/mmu_context.h>
static int num_standard_resources;
static struct resource *standard_resources;
phys_addr_t __fdt_pointer __initdata;
/*
* Standard memory resources
*/
static struct resource mem_res[] = {
{
.name = "Kernel code",
.start = 0,
.end = 0,
.flags = IORESOURCE_SYSTEM_RAM
},
{
.name = "Kernel data",
.start = 0,
.end = 0,
.flags = IORESOURCE_SYSTEM_RAM
}
};
#define kernel_code mem_res[0]
#define kernel_data mem_res[1]
/*
* The recorded values of x0 .. x3 upon kernel entry.
*/
u64 __cacheline_aligned boot_args[4];
void __init smp_setup_processor_id(void)
{
u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
set_cpu_logical_map(0, mpidr);
/*
* 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);
pr_info("Booting Linux on physical CPU 0x%010lx [0x%08x]\n",
(unsigned long)mpidr, read_cpuid_id());
}
bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
{
return phys_id == cpu_logical_map(cpu);
}
struct mpidr_hash mpidr_hash;
/**
* 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");
}
static void __init setup_machine_fdt(phys_addr_t dt_phys)
{
int size;
void *dt_virt = fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL);
const char *name;
if (dt_virt)
memblock_reserve(dt_phys, size);
if (!dt_virt || !early_init_dt_scan(dt_virt)) {
pr_crit("\n"
"Error: invalid device tree blob at physical address %pa (virtual address 0x%p)\n"
"The dtb must be 8-byte aligned and must not exceed 2 MB in size\n"
"\nPlease check your bootloader.",
&dt_phys, dt_virt);
while (true)
cpu_relax();
}
/* Early fixups are done, map the FDT as read-only now */
fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL_RO);
name = of_flat_dt_get_machine_name();
if (!name)
return;
pr_info("Machine model: %s\n", name);
dump_stack_set_arch_desc("%s (DT)", name);
}
static void __init request_standard_resources(void)
{
struct memblock_region *region;
struct resource *res;
unsigned long i = 0;
size_t res_size;
kernel_code.start = __pa_symbol(_text);
kernel_code.end = __pa_symbol(__init_begin - 1);
kernel_data.start = __pa_symbol(_sdata);
kernel_data.end = __pa_symbol(_end - 1);
num_standard_resources = memblock.memory.cnt;
res_size = num_standard_resources * sizeof(*standard_resources);
standard_resources = memblock_alloc(res_size, SMP_CACHE_BYTES);
if (!standard_resources)
panic("%s: Failed to allocate %zu bytes\n", __func__, res_size);
for_each_memblock(memory, region) {
res = &standard_resources[i++];
if (memblock_is_nomap(region)) {
res->name = "reserved";
res->flags = IORESOURCE_MEM;
} else {
res->name = "System RAM";
res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
}
res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
request_resource(&iomem_resource, res);
if (kernel_code.start >= res->start &&
kernel_code.end <= res->end)
request_resource(res, &kernel_code);
if (kernel_data.start >= res->start &&
kernel_data.end <= res->end)
request_resource(res, &kernel_data);
#ifdef CONFIG_KEXEC_CORE
/* Userspace will find "Crash kernel" region in /proc/iomem. */
if (crashk_res.end && crashk_res.start >= res->start &&
crashk_res.end <= res->end)
request_resource(res, &crashk_res);
#endif
}
}
static int __init reserve_memblock_reserved_regions(void)
{
u64 i, j;
for (i = 0; i < num_standard_resources; ++i) {
struct resource *mem = &standard_resources[i];
phys_addr_t r_start, r_end, mem_size = resource_size(mem);
if (!memblock_is_region_reserved(mem->start, mem_size))
continue;
for_each_reserved_mem_region(j, &r_start, &r_end) {
resource_size_t start, end;
start = max(PFN_PHYS(PFN_DOWN(r_start)), mem->start);
end = min(PFN_PHYS(PFN_UP(r_end)) - 1, mem->end);
if (start > mem->end || end < mem->start)
continue;
reserve_region_with_split(mem, start, end, "reserved");
}
}
return 0;
}
arch_initcall(reserve_memblock_reserved_regions);
u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
u64 cpu_logical_map(int cpu)
{
return __cpu_logical_map[cpu];
}
EXPORT_SYMBOL_GPL(cpu_logical_map);
void __init __no_sanitize_address setup_arch(char **cmdline_p)
{
init_mm.start_code = (unsigned long) _text;
init_mm.end_code = (unsigned long) _etext;
init_mm.end_data = (unsigned long) _edata;
init_mm.brk = (unsigned long) _end;
*cmdline_p = boot_command_line;
/*
* If know now we are going to need KPTI then use non-global
* mappings from the start, avoiding the cost of rewriting
* everything later.
*/
arm64_use_ng_mappings = kaslr_requires_kpti();
early_fixmap_init();
early_ioremap_init();
setup_machine_fdt(__fdt_pointer);
/*
* Initialise the static keys early as they may be enabled by the
* cpufeature code and early parameters.
*/
jump_label_init();
parse_early_param();
/*
* Unmask asynchronous aborts and fiq after bringing up possible
* earlycon. (Report possible System Errors once we can report this
* occurred).
*/
local_daif_restore(DAIF_PROCCTX_NOIRQ);
/*
* TTBR0 is only used for the identity mapping at this stage. Make it
* point to zero page to avoid speculatively fetching new entries.
*/
cpu_uninstall_idmap();
xen_early_init();
efi_init();
if (!efi_enabled(EFI_BOOT) && ((u64)_text % MIN_KIMG_ALIGN) != 0)
pr_warn(FW_BUG "Kernel image misaligned at boot, please fix your bootloader!");
arm64_memblock_init();
paging_init();
acpi_table_upgrade();
/* Parse the ACPI tables for possible boot-time configuration */
acpi_boot_table_init();
if (acpi_disabled)
unflatten_device_tree();
bootmem_init();
kasan_init();
request_standard_resources();
early_ioremap_reset();
if (acpi_disabled)
psci_dt_init();
else
psci_acpi_init();
init_bootcpu_ops();
smp_init_cpus();
smp_build_mpidr_hash();
/* Init percpu seeds for random tags after cpus are set up. */
kasan_init_tags();
#ifdef CONFIG_ARM64_SW_TTBR0_PAN
/*
* Make sure init_thread_info.ttbr0 always generates translation
* faults in case uaccess_enable() is inadvertently called by the init
* thread.
*/
init_task.thread_info.ttbr0 = __pa_symbol(empty_zero_page);
#endif
if (boot_args[1] || boot_args[2] || boot_args[3]) {
pr_err("WARNING: x1-x3 nonzero in violation of boot protocol:\n"
"\tx1: %016llx\n\tx2: %016llx\n\tx3: %016llx\n"
"This indicates a broken bootloader or old kernel\n",
boot_args[1], boot_args[2], boot_args[3]);
}
}
static inline bool cpu_can_disable(unsigned int cpu)
{
#ifdef CONFIG_HOTPLUG_CPU
const struct cpu_operations *ops = get_cpu_ops(cpu);
if (ops && ops->cpu_can_disable)
return ops->cpu_can_disable(cpu);
#endif
return false;
}
static int __init topology_init(void)
{
int i;
for_each_online_node(i)
register_one_node(i);
for_each_possible_cpu(i) {
struct cpu *cpu = &per_cpu(cpu_data.cpu, i);
cpu->hotpluggable = cpu_can_disable(i);
register_cpu(cpu, i);
}
return 0;
}
subsys_initcall(topology_init);
static void dump_kernel_offset(void)
{
const unsigned long offset = kaslr_offset();
if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && offset > 0) {
pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n",
offset, KIMAGE_VADDR);
pr_emerg("PHYS_OFFSET: 0x%llx\n", PHYS_OFFSET);
} else {
pr_emerg("Kernel Offset: disabled\n");
}
}
static int arm64_panic_block_dump(struct notifier_block *self,
unsigned long v, void *p)
{
dump_kernel_offset();
dump_cpu_features();
dump_mem_limit();
return 0;
}
static struct notifier_block arm64_panic_block = {
.notifier_call = arm64_panic_block_dump
};
static int __init register_arm64_panic_block(void)
{
atomic_notifier_chain_register(&panic_notifier_list,
&arm64_panic_block);
return 0;
}
device_initcall(register_arm64_panic_block);