/*
*
* Common boot and setup code.
*
* Copyright (C) 2001 PPC64 Team, IBM Corp
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#define DEBUG
#include <linux/export.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/reboot.h>
#include <linux/delay.h>
#include <linux/initrd.h>
#include <linux/seq_file.h>
#include <linux/ioport.h>
#include <linux/console.h>
#include <linux/utsname.h>
#include <linux/tty.h>
#include <linux/root_dev.h>
#include <linux/notifier.h>
#include <linux/cpu.h>
#include <linux/unistd.h>
#include <linux/serial.h>
#include <linux/serial_8250.h>
#include <linux/bootmem.h>
#include <linux/pci.h>
#include <linux/lockdep.h>
#include <linux/memblock.h>
#include <linux/memory.h>
#include <linux/nmi.h>
#include <asm/io.h>
#include <asm/kdump.h>
#include <asm/prom.h>
#include <asm/processor.h>
#include <asm/pgtable.h>
#include <asm/smp.h>
#include <asm/elf.h>
#include <asm/machdep.h>
#include <asm/paca.h>
#include <asm/time.h>
#include <asm/cputable.h>
#include <asm/dt_cpu_ftrs.h>
#include <asm/sections.h>
#include <asm/btext.h>
#include <asm/nvram.h>
#include <asm/setup.h>
#include <asm/rtas.h>
#include <asm/iommu.h>
#include <asm/serial.h>
#include <asm/cache.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/firmware.h>
#include <asm/xmon.h>
#include <asm/udbg.h>
#include <asm/kexec.h>
#include <asm/code-patching.h>
#include <asm/livepatch.h>
#include <asm/opal.h>
#include <asm/cputhreads.h>
#ifdef DEBUG
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif
int spinning_secondaries;
u64 ppc64_pft_size;
struct ppc64_caches ppc64_caches = {
.l1d = {
.block_size = 0x40,
.log_block_size = 6,
},
.l1i = {
.block_size = 0x40,
.log_block_size = 6
},
};
EXPORT_SYMBOL_GPL(ppc64_caches);
#if defined(CONFIG_PPC_BOOK3E) && defined(CONFIG_SMP)
void __init setup_tlb_core_data(void)
{
int cpu;
BUILD_BUG_ON(offsetof(struct tlb_core_data, lock) != 0);
for_each_possible_cpu(cpu) {
int first = cpu_first_thread_sibling(cpu);
/*
* If we boot via kdump on a non-primary thread,
* make sure we point at the thread that actually
* set up this TLB.
*/
if (cpu_first_thread_sibling(boot_cpuid) == first)
first = boot_cpuid;
paca[cpu].tcd_ptr = &paca[first].tcd;
/*
* If we have threads, we need either tlbsrx.
* or e6500 tablewalk mode, or else TLB handlers
* will be racy and could produce duplicate entries.
* Should we panic instead?
*/
WARN_ONCE(smt_enabled_at_boot >= 2 &&
!mmu_has_feature(MMU_FTR_USE_TLBRSRV) &&
book3e_htw_mode != PPC_HTW_E6500,
"%s: unsupported MMU configuration\n", __func__);
}
}
#endif
#ifdef CONFIG_SMP
static char *smt_enabled_cmdline;
/* Look for ibm,smt-enabled OF option */
void __init check_smt_enabled(void)
{
struct device_node *dn;
const char *smt_option;
/* Default to enabling all threads */
smt_enabled_at_boot = threads_per_core;
/* Allow the command line to overrule the OF option */
if (smt_enabled_cmdline) {
if (!strcmp(smt_enabled_cmdline, "on"))
smt_enabled_at_boot = threads_per_core;
else if (!strcmp(smt_enabled_cmdline, "off"))
smt_enabled_at_boot = 0;
else {
int smt;
int rc;
rc = kstrtoint(smt_enabled_cmdline, 10, &smt);
if (!rc)
smt_enabled_at_boot =
min(threads_per_core, smt);
}
} else {
dn = of_find_node_by_path("/options");
if (dn) {
smt_option = of_get_property(dn, "ibm,smt-enabled",
NULL);
if (smt_option) {
if (!strcmp(smt_option, "on"))
smt_enabled_at_boot = threads_per_core;
else if (!strcmp(smt_option, "off"))
smt_enabled_at_boot = 0;
}
of_node_put(dn);
}
}
}
/* Look for smt-enabled= cmdline option */
static int __init early_smt_enabled(char *p)
{
smt_enabled_cmdline = p;
return 0;
}
early_param("smt-enabled", early_smt_enabled);
#endif /* CONFIG_SMP */
/** Fix up paca fields required for the boot cpu */
static void __init fixup_boot_paca(void)
{
/* The boot cpu is started */
get_paca()->cpu_start = 1;
/* Allow percpu accesses to work until we setup percpu data */
get_paca()->data_offset = 0;
}
static void __init configure_exceptions(void)
{
/*
* Setup the trampolines from the lowmem exception vectors
* to the kdump kernel when not using a relocatable kernel.
*/
setup_kdump_trampoline();
/* Under a PAPR hypervisor, we need hypercalls */
if (firmware_has_feature(FW_FEATURE_SET_MODE)) {
/* Enable AIL if possible */
pseries_enable_reloc_on_exc();
/*
* Tell the hypervisor that we want our exceptions to
* be taken in little endian mode.
*
* We don't call this for big endian as our calling convention
* makes us always enter in BE, and the call may fail under
* some circumstances with kdump.
*/
#ifdef __LITTLE_ENDIAN__
pseries_little_endian_exceptions();
#endif
} else {
/* Set endian mode using OPAL */
if (firmware_has_feature(FW_FEATURE_OPAL))
opal_configure_cores();
/* AIL on native is done in cpu_ready_for_interrupts() */
}
}
static void cpu_ready_for_interrupts(void)
{
/*
* Enable AIL if supported, and we are in hypervisor mode. This
* is called once for every processor.
*
* If we are not in hypervisor mode the job is done once for
* the whole partition in configure_exceptions().
*/
if (cpu_has_feature(CPU_FTR_HVMODE) &&
cpu_has_feature(CPU_FTR_ARCH_207S)) {
unsigned long lpcr = mfspr(SPRN_LPCR);
mtspr(SPRN_LPCR, lpcr | LPCR_AIL_3);
}
/*
* Fixup HFSCR:TM based on CPU features. The bit is set by our
* early asm init because at that point we haven't updated our
* CPU features from firmware and device-tree. Here we have,
* so let's do it.
*/
if (cpu_has_feature(CPU_FTR_HVMODE) && !cpu_has_feature(CPU_FTR_TM_COMP))
mtspr(SPRN_HFSCR, mfspr(SPRN_HFSCR) & ~HFSCR_TM);
/* Set IR and DR in PACA MSR */
get_paca()->kernel_msr = MSR_KERNEL;
}
/*
* Early initialization entry point. This is called by head.S
* with MMU translation disabled. We rely on the "feature" of
* the CPU that ignores the top 2 bits of the address in real
* mode so we can access kernel globals normally provided we
* only toy with things in the RMO region. From here, we do
* some early parsing of the device-tree to setup out MEMBLOCK
* data structures, and allocate & initialize the hash table
* and segment tables so we can start running with translation
* enabled.
*
* It is this function which will call the probe() callback of
* the various platform types and copy the matching one to the
* global ppc_md structure. Your platform can eventually do
* some very early initializations from the probe() routine, but
* this is not recommended, be very careful as, for example, the
* device-tree is not accessible via normal means at this point.
*/
void __init early_setup(unsigned long dt_ptr)
{
static __initdata struct paca_struct boot_paca;
/* -------- printk is _NOT_ safe to use here ! ------- */
/* Try new device tree based feature discovery ... */
if (!dt_cpu_ftrs_init(__va(dt_ptr)))
/* Otherwise use the old style CPU table */
identify_cpu(0, mfspr(SPRN_PVR));
/* Assume we're on cpu 0 for now. Don't write to the paca yet! */
initialise_paca(&boot_paca, 0);
setup_paca(&boot_paca);
fixup_boot_paca();
/* -------- printk is now safe to use ------- */
/* Enable early debugging if any specified (see udbg.h) */
udbg_early_init();
DBG(" -> early_setup(), dt_ptr: 0x%lx\n", dt_ptr);
/*
* Do early initialization using the flattened device
* tree, such as retrieving the physical memory map or
* calculating/retrieving the hash table size.
*/
early_init_devtree(__va(dt_ptr));
/* Now we know the logical id of our boot cpu, setup the paca. */
setup_paca(&paca[boot_cpuid]);
fixup_boot_paca();
/*
* Configure exception handlers. This include setting up trampolines
* if needed, setting exception endian mode, etc...
*/
configure_exceptions();
/* Apply all the dynamic patching */
apply_feature_fixups();
setup_feature_keys();
/* Initialize the hash table or TLB handling */
early_init_mmu();
/*
* At this point, we can let interrupts switch to virtual mode
* (the MMU has been setup), so adjust the MSR in the PACA to
* have IR and DR set and enable AIL if it exists
*/
cpu_ready_for_interrupts();
DBG(" <- early_setup()\n");
#ifdef CONFIG_PPC_EARLY_DEBUG_BOOTX
/*
* This needs to be done *last* (after the above DBG() even)
*
* Right after we return from this function, we turn on the MMU
* which means the real-mode access trick that btext does will
* no longer work, it needs to switch to using a real MMU
* mapping. This call will ensure that it does
*/
btext_map();
#endif /* CONFIG_PPC_EARLY_DEBUG_BOOTX */
}
#ifdef CONFIG_SMP
void early_setup_secondary(void)
{
/* Mark interrupts disabled in PACA */
get_paca()->soft_enabled = 0;
/* Initialize the hash table or TLB handling */
early_init_mmu_secondary();
/*
* At this point, we can let interrupts switch to virtual mode
* (the MMU has been setup), so adjust the MSR in the PACA to
* have IR and DR set.
*/
cpu_ready_for_interrupts();
}
#endif /* CONFIG_SMP */
#if defined(CONFIG_SMP) || defined(CONFIG_KEXEC_CORE)
static bool use_spinloop(void)
{
if (!IS_ENABLED(CONFIG_PPC_BOOK3E))
return true;
/*
* When book3e boots from kexec, the ePAPR spin table does
* not get used.
*/
return of_property_read_bool(of_chosen, "linux,booted-from-kexec");
}
void smp_release_cpus(void)
{
unsigned long *ptr;
int i;
if (!use_spinloop())
return;
DBG(" -> smp_release_cpus()\n");
/* All secondary cpus are spinning on a common spinloop, release them
* all now so they can start to spin on their individual paca
* spinloops. For non SMP kernels, the secondary cpus never get out
* of the common spinloop.
*/
ptr = (unsigned long *)((unsigned long)&__secondary_hold_spinloop
- PHYSICAL_START);
*ptr = ppc_function_entry(generic_secondary_smp_init);
/* And wait a bit for them to catch up */
for (i = 0; i < 100000; i++) {
mb();
HMT_low();
if (spinning_secondaries == 0)
break;
udelay(1);
}
DBG("spinning_secondaries = %d\n", spinning_secondaries);
DBG(" <- smp_release_cpus()\n");
}
#endif /* CONFIG_SMP || CONFIG_KEXEC_CORE */
/*
* Initialize some remaining members of the ppc64_caches and systemcfg
* structures
* (at least until we get rid of them completely). This is mostly some
* cache informations about the CPU that will be used by cache flush
* routines and/or provided to userland
*/
static void init_cache_info(struct ppc_cache_info *info, u32 size, u32 lsize,
u32 bsize, u32 sets)
{
info->size = size;
info->sets = sets;
info->line_size = lsize;
info->block_size = bsize;
info->log_block_size = __ilog2(bsize);
if (bsize)
info->blocks_per_page = PAGE_SIZE / bsize;
else
info->blocks_per_page = 0;
if (sets == 0)
info->assoc = 0xffff;
else
info->assoc = size / (sets * lsize);
}
static bool __init parse_cache_info(struct device_node *np,
bool icache,
struct ppc_cache_info *info)
{
static const char *ipropnames[] __initdata = {
"i-cache-size",
"i-cache-sets",
"i-cache-block-size",
"i-cache-line-size",
};
static const char *dpropnames[] __initdata = {
"d-cache-size",
"d-cache-sets",
"d-cache-block-size",
"d-cache-line-size",
};
const char **propnames = icache ? ipropnames : dpropnames;
const __be32 *sizep, *lsizep, *bsizep, *setsp;
u32 size, lsize, bsize, sets;
bool success = true;
size = 0;
sets = -1u;
lsize = bsize = cur_cpu_spec->dcache_bsize;
sizep = of_get_property(np, propnames[0], NULL);
if (sizep != NULL)
size = be32_to_cpu(*sizep);
setsp = of_get_property(np, propnames[1], NULL);
if (setsp != NULL)
sets = be32_to_cpu(*setsp);
bsizep = of_get_property(np, propnames[2], NULL);
lsizep = of_get_property(np, propnames[3], NULL);
if (bsizep == NULL)
bsizep = lsizep;
if (lsizep != NULL)
lsize = be32_to_cpu(*lsizep);
if (bsizep != NULL)
bsize = be32_to_cpu(*bsizep);
if (sizep == NULL || bsizep == NULL || lsizep == NULL)
success = false;
/*
* OF is weird .. it represents fully associative caches
* as "1 way" which doesn't make much sense and doesn't
* leave room for direct mapped. We'll assume that 0
* in OF means direct mapped for that reason.
*/
if (sets == 1)
sets = 0;
else if (sets == 0)
sets = 1;
init_cache_info(info, size, lsize, bsize, sets);
return success;
}
void __init initialize_cache_info(void)
{
struct device_node *cpu = NULL, *l2, *l3 = NULL;
u32 pvr;
DBG(" -> initialize_cache_info()\n");
/*
* All shipping POWER8 machines have a firmware bug that
* puts incorrect information in the device-tree. This will
* be (hopefully) fixed for future chips but for now hard
* code the values if we are running on one of these
*/
pvr = PVR_VER(mfspr(SPRN_PVR));
if (pvr == PVR_POWER8 || pvr == PVR_POWER8E ||
pvr == PVR_POWER8NVL) {
/* size lsize blk sets */
init_cache_info(&ppc64_caches.l1i, 0x8000, 128, 128, 32);
init_cache_info(&ppc64_caches.l1d, 0x10000, 128, 128, 64);
init_cache_info(&ppc64_caches.l2, 0x80000, 128, 0, 512);
init_cache_info(&ppc64_caches.l3, 0x800000, 128, 0, 8192);
} else
cpu = of_find_node_by_type(NULL, "cpu");
/*
* We're assuming *all* of the CPUs have the same
* d-cache and i-cache sizes... -Peter
*/
if (cpu) {
if (!parse_cache_info(cpu, false, &ppc64_caches.l1d))
DBG("Argh, can't find dcache properties !\n");
if (!parse_cache_info(cpu, true, &ppc64_caches.l1i))
DBG("Argh, can't find icache properties !\n");
/*
* Try to find the L2 and L3 if any. Assume they are
* unified and use the D-side properties.
*/
l2 = of_find_next_cache_node(cpu);
of_node_put(cpu);
if (l2) {
parse_cache_info(l2, false, &ppc64_caches.l2);
l3 = of_find_next_cache_node(l2);
of_node_put(l2);
}
if (l3) {
parse_cache_info(l3, false, &ppc64_caches.l3);
of_node_put(l3);
}
}
/* For use by binfmt_elf */
dcache_bsize = ppc64_caches.l1d.block_size;
icache_bsize = ppc64_caches.l1i.block_size;
cur_cpu_spec->dcache_bsize = dcache_bsize;
cur_cpu_spec->icache_bsize = icache_bsize;
DBG(" <- initialize_cache_info()\n");
}
/* This returns the limit below which memory accesses to the linear
* mapping are guarnateed not to cause a TLB or SLB miss. This is
* used to allocate interrupt or emergency stacks for which our
* exception entry path doesn't deal with being interrupted.
*/
static __init u64 safe_stack_limit(void)
{
#ifdef CONFIG_PPC_BOOK3E
/* Freescale BookE bolts the entire linear mapping */
if (mmu_has_feature(MMU_FTR_TYPE_FSL_E))
return linear_map_top;
/* Other BookE, we assume the first GB is bolted */
return 1ul << 30;
#else
if (early_radix_enabled())
return ULONG_MAX;
/* BookS, the first segment is bolted */
if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
return 1UL << SID_SHIFT_1T;
return 1UL << SID_SHIFT;
#endif
}
void __init irqstack_early_init(void)
{
u64 limit = safe_stack_limit();
unsigned int i;
/*
* Interrupt stacks must be in the first segment since we
* cannot afford to take SLB misses on them. They are not
* accessed in realmode.
*/
for_each_possible_cpu(i) {
softirq_ctx[i] = (struct thread_info *)
__va(memblock_alloc_base(THREAD_SIZE,
THREAD_SIZE, limit));
hardirq_ctx[i] = (struct thread_info *)
__va(memblock_alloc_base(THREAD_SIZE,
THREAD_SIZE, limit));
}
}
#ifdef CONFIG_PPC_BOOK3E
void __init exc_lvl_early_init(void)
{
unsigned int i;
unsigned long sp;
for_each_possible_cpu(i) {
sp = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
critirq_ctx[i] = (struct thread_info *)__va(sp);
paca[i].crit_kstack = __va(sp + THREAD_SIZE);
sp = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
dbgirq_ctx[i] = (struct thread_info *)__va(sp);
paca[i].dbg_kstack = __va(sp + THREAD_SIZE);
sp = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
mcheckirq_ctx[i] = (struct thread_info *)__va(sp);
paca[i].mc_kstack = __va(sp + THREAD_SIZE);
}
if (cpu_has_feature(CPU_FTR_DEBUG_LVL_EXC))
patch_exception(0x040, exc_debug_debug_book3e);
}
#endif
/*
* Emergency stacks are used for a range of things, from asynchronous
* NMIs (system reset, machine check) to synchronous, process context.
* We set preempt_count to zero, even though that isn't necessarily correct. To
* get the right value we'd need to copy it from the previous thread_info, but
* doing that might fault causing more problems.
* TODO: what to do with accounting?
*/
static void emerg_stack_init_thread_info(struct thread_info *ti, int cpu)
{
ti->task = NULL;
ti->cpu = cpu;
ti->preempt_count = 0;
ti->local_flags = 0;
ti->flags = 0;
klp_init_thread_info(ti);
}
/*
* Stack space used when we detect a bad kernel stack pointer, and
* early in SMP boots before relocation is enabled. Exclusive emergency
* stack for machine checks.
*/
void __init emergency_stack_init(void)
{
u64 limit;
unsigned int i;
/*
* Emergency stacks must be under 256MB, we cannot afford to take
* SLB misses on them. The ABI also requires them to be 128-byte
* aligned.
*
* Since we use these as temporary stacks during secondary CPU
* bringup, machine check, system reset, and HMI, we need to get
* at them in real mode. This means they must also be within the RMO
* region.
*
* The IRQ stacks allocated elsewhere in this file are zeroed and
* initialized in kernel/irq.c. These are initialized here in order
* to have emergency stacks available as early as possible.
*/
limit = min(safe_stack_limit(), ppc64_rma_size);
for_each_possible_cpu(i) {
struct thread_info *ti;
ti = __va(memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit));
memset(ti, 0, THREAD_SIZE);
emerg_stack_init_thread_info(ti, i);
paca[i].emergency_sp = (void *)ti + THREAD_SIZE;
#ifdef CONFIG_PPC_BOOK3S_64
/* emergency stack for NMI exception handling. */
ti = __va(memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit));
memset(ti, 0, THREAD_SIZE);
emerg_stack_init_thread_info(ti, i);
paca[i].nmi_emergency_sp = (void *)ti + THREAD_SIZE;
/* emergency stack for machine check exception handling. */
ti = __va(memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit));
memset(ti, 0, THREAD_SIZE);
emerg_stack_init_thread_info(ti, i);
paca[i].mc_emergency_sp = (void *)ti + THREAD_SIZE;
#endif
}
}
#ifdef CONFIG_SMP
#define PCPU_DYN_SIZE ()
static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align)
{
return __alloc_bootmem_node(NODE_DATA(early_cpu_to_node(cpu)), size, align,
__pa(MAX_DMA_ADDRESS));
}
static void __init pcpu_fc_free(void *ptr, size_t size)
{
free_bootmem(__pa(ptr), size);
}
static int pcpu_cpu_distance(unsigned int from, unsigned int to)
{
if (early_cpu_to_node(from) == early_cpu_to_node(to))
return LOCAL_DISTANCE;
else
return REMOTE_DISTANCE;
}
unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
EXPORT_SYMBOL(__per_cpu_offset);
void __init setup_per_cpu_areas(void)
{
const size_t dyn_size = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE;
size_t atom_size;
unsigned long delta;
unsigned int cpu;
int rc;
/*
* Linear mapping is one of 4K, 1M and 16M. For 4K, no need
* to group units. For larger mappings, use 1M atom which
* should be large enough to contain a number of units.
*/
if (mmu_linear_psize == MMU_PAGE_4K)
atom_size = PAGE_SIZE;
else
atom_size = 1 << 20;
rc = pcpu_embed_first_chunk(0, dyn_size, atom_size, pcpu_cpu_distance,
pcpu_fc_alloc, pcpu_fc_free);
if (rc < 0)
panic("cannot initialize percpu area (err=%d)", rc);
delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
for_each_possible_cpu(cpu) {
__per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
paca[cpu].data_offset = __per_cpu_offset[cpu];
}
}
#endif
#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
unsigned long memory_block_size_bytes(void)
{
if (ppc_md.memory_block_size)
return ppc_md.memory_block_size();
return MIN_MEMORY_BLOCK_SIZE;
}
#endif
#if defined(CONFIG_PPC_INDIRECT_PIO) || defined(CONFIG_PPC_INDIRECT_MMIO)
struct ppc_pci_io ppc_pci_io;
EXPORT_SYMBOL(ppc_pci_io);
#endif
#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
u64 hw_nmi_get_sample_period(int watchdog_thresh)
{
return ppc_proc_freq * watchdog_thresh;
}
#endif
/*
* The perf based hardlockup detector breaks PMU event based branches, so
* disable it by default. Book3S has a soft-nmi hardlockup detector based
* on the decrementer interrupt, so it does not suffer from this problem.
*
* It is likely to get false positives in VM guests, so disable it there
* by default too.
*/
static int __init disable_hardlockup_detector(void)
{
#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
hardlockup_detector_disable();
#else
if (firmware_has_feature(FW_FEATURE_LPAR))
hardlockup_detector_disable();
#endif
return 0;
}
early_initcall(disable_hardlockup_detector);
