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kernel-ark/arch/powerpc/kernel/setup_64.c
Paul Mackerras aa04b4cc5b KVM: PPC: Allocate RMAs (Real Mode Areas) at boot for use by guests 
This adds infrastructure which will be needed to allow book3s_hv KVM to
run on older POWER processors, including PPC970, which don't support
the Virtual Real Mode Area (VRMA) facility, but only the Real Mode
Offset (RMO) facility.  These processors require a physically
contiguous, aligned area of memory for each guest.  When the guest does
an access in real mode (MMU off), the address is compared against a
limit value, and if it is lower, the address is ORed with an offset
value (from the Real Mode Offset Register (RMOR)) and the result becomes
the real address for the access.  The size of the RMA has to be one of
a set of supported values, which usually includes 64MB, 128MB, 256MB
and some larger powers of 2.

Since we are unlikely to be able to allocate 64MB or more of physically
contiguous memory after the kernel has been running for a while, we
allocate a pool of RMAs at boot time using the bootmem allocator.  The
size and number of the RMAs can be set using the kvm_rma_size=xx and
kvm_rma_count=xx kernel command line options.

KVM exports a new capability, KVM_CAP_PPC_RMA, to signal the availability
of the pool of preallocated RMAs.  The capability value is 1 if the
processor can use an RMA but doesn't require one (because it supports
the VRMA facility), or 2 if the processor requires an RMA for each guest.

This adds a new ioctl, KVM_ALLOCATE_RMA, which allocates an RMA from the
pool and returns a file descriptor which can be used to map the RMA.  It
also returns the size of the RMA in the argument structure.

Having an RMA means we will get multiple KMV_SET_USER_MEMORY_REGION
ioctl calls from userspace.  To cope with this, we now preallocate the
kvm->arch.ram_pginfo array when the VM is created with a size sufficient
for up to 64GB of guest memory.  Subsequently we will get rid of this
array and use memory associated with each memslot instead.

This moves most of the code that translates the user addresses into
host pfns (page frame numbers) out of kvmppc_prepare_vrma up one level
to kvmppc_core_prepare_memory_region.  Also, instead of having to look
up the VMA for each page in order to check the page size, we now check
that the pages we get are compound pages of 16MB.  However, if we are
adding memory that is mapped to an RMA, we don't bother with calling
get_user_pages_fast and instead just offset from the base pfn for the
RMA.

Typically the RMA gets added after vcpus are created, which makes it
inconvenient to have the LPCR (logical partition control register) value
in the vcpu->arch struct, since the LPCR controls whether the processor
uses RMA or VRMA for the guest.  This moves the LPCR value into the
kvm->arch struct and arranges for the MER (mediated external request)
bit, which is the only bit that varies between vcpus, to be set in
assembly code when going into the guest if there is a pending external
interrupt request.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12 13:16:57 +03:00

676 lines
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/*
*
* 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.
*/
#undef DEBUG
#include <linux/module.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 <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/sections.h>
#include <asm/btext.h>
#include <asm/nvram.h>
#include <asm/setup.h>
#include <asm/system.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/mmu_context.h>
#include <asm/code-patching.h>
#include <asm/kvm_ppc.h>
#include "setup.h"
#ifdef DEBUG
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif
int boot_cpuid = 0;
int __initdata boot_cpu_count;
u64 ppc64_pft_size;
/* Pick defaults since we might want to patch instructions
* before we've read this from the device tree.
*/
struct ppc64_caches ppc64_caches = {
.dline_size = 0x40,
.log_dline_size = 6,
.iline_size = 0x40,
.log_iline_size = 6
};
EXPORT_SYMBOL_GPL(ppc64_caches);
/*
* These are used in binfmt_elf.c to put aux entries on the stack
* for each elf executable being started.
*/
int dcache_bsize;
int icache_bsize;
int ucache_bsize;
#ifdef CONFIG_SMP
static char *smt_enabled_cmdline;
/* Look for ibm,smt-enabled OF option */
static void 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 {
long smt;
int rc;
rc = strict_strtol(smt_enabled_cmdline, 10, &smt);
if (!rc)
smt_enabled_at_boot =
min(threads_per_core, (int)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);
#else
#define check_smt_enabled()
#endif /* CONFIG_SMP */
/*
* 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)
{
/* -------- printk is _NOT_ safe to use here ! ------- */
/* Identify CPU type */
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);
/* Initialize lockdep early or else spinlocks will blow */
lockdep_init();
/* -------- 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]);
/* Fix up paca fields required for the boot cpu */
get_paca()->cpu_start = 1;
/* Probe the machine type */
probe_machine();
setup_kdump_trampoline();
DBG("Found, Initializing memory management...\n");
/* Initialize the hash table or TLB handling */
early_init_mmu();
DBG(" <- early_setup()\n");
}
#ifdef CONFIG_SMP
void early_setup_secondary(void)
{
/* Mark interrupts enabled in PACA */
get_paca()->soft_enabled = 0;
/* Initialize the hash table or TLB handling */
early_init_mmu_secondary();
}
#endif /* CONFIG_SMP */
#if defined(CONFIG_SMP) || defined(CONFIG_KEXEC)
void smp_release_cpus(void)
{
unsigned long *ptr;
int i;
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 = __pa(generic_secondary_smp_init);
/* And wait a bit for them to catch up */
for (i = 0; i < 100000; i++) {
mb();
HMT_low();
if (boot_cpu_count == 0)
break;
udelay(1);
}
DBG("boot_cpu_count = %d\n", boot_cpu_count);
DBG(" <- smp_release_cpus()\n");
}
#endif /* CONFIG_SMP || CONFIG_KEXEC */
/*
* 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 initialize_cache_info(void)
{
struct device_node *np;
unsigned long num_cpus = 0;
DBG(" -> initialize_cache_info()\n");
for (np = NULL; (np = of_find_node_by_type(np, "cpu"));) {
num_cpus += 1;
/* We're assuming *all* of the CPUs have the same
* d-cache and i-cache sizes... -Peter
*/
if ( num_cpus == 1 ) {
const u32 *sizep, *lsizep;
u32 size, lsize;
size = 0;
lsize = cur_cpu_spec->dcache_bsize;
sizep = of_get_property(np, "d-cache-size", NULL);
if (sizep != NULL)
size = *sizep;
lsizep = of_get_property(np, "d-cache-block-size", NULL);
/* fallback if block size missing */
if (lsizep == NULL)
lsizep = of_get_property(np, "d-cache-line-size", NULL);
if (lsizep != NULL)
lsize = *lsizep;
if (sizep == 0 || lsizep == 0)
DBG("Argh, can't find dcache properties ! "
"sizep: %p, lsizep: %p\n", sizep, lsizep);
ppc64_caches.dsize = size;
ppc64_caches.dline_size = lsize;
ppc64_caches.log_dline_size = __ilog2(lsize);
ppc64_caches.dlines_per_page = PAGE_SIZE / lsize;
size = 0;
lsize = cur_cpu_spec->icache_bsize;
sizep = of_get_property(np, "i-cache-size", NULL);
if (sizep != NULL)
size = *sizep;
lsizep = of_get_property(np, "i-cache-block-size", NULL);
if (lsizep == NULL)
lsizep = of_get_property(np, "i-cache-line-size", NULL);
if (lsizep != NULL)
lsize = *lsizep;
if (sizep == 0 || lsizep == 0)
DBG("Argh, can't find icache properties ! "
"sizep: %p, lsizep: %p\n", sizep, lsizep);
ppc64_caches.isize = size;
ppc64_caches.iline_size = lsize;
ppc64_caches.log_iline_size = __ilog2(lsize);
ppc64_caches.ilines_per_page = PAGE_SIZE / lsize;
}
}
DBG(" <- initialize_cache_info()\n");
}
/*
* Do some initial setup of the system. The parameters are those which
* were passed in from the bootloader.
*/
void __init setup_system(void)
{
DBG(" -> setup_system()\n");
/* Apply the CPUs-specific and firmware specific fixups to kernel
* text (nop out sections not relevant to this CPU or this firmware)
*/
do_feature_fixups(cur_cpu_spec->cpu_features,
&__start___ftr_fixup, &__stop___ftr_fixup);
do_feature_fixups(cur_cpu_spec->mmu_features,
&__start___mmu_ftr_fixup, &__stop___mmu_ftr_fixup);
do_feature_fixups(powerpc_firmware_features,
&__start___fw_ftr_fixup, &__stop___fw_ftr_fixup);
do_lwsync_fixups(cur_cpu_spec->cpu_features,
&__start___lwsync_fixup, &__stop___lwsync_fixup);
/*
* Unflatten the device-tree passed by prom_init or kexec
*/
unflatten_device_tree();
/*
* Fill the ppc64_caches & systemcfg structures with informations
* retrieved from the device-tree.
*/
initialize_cache_info();
#ifdef CONFIG_PPC_RTAS
/*
* Initialize RTAS if available
*/
rtas_initialize();
#endif /* CONFIG_PPC_RTAS */
/*
* Check if we have an initrd provided via the device-tree
*/
check_for_initrd();
/*
* Do some platform specific early initializations, that includes
* setting up the hash table pointers. It also sets up some interrupt-mapping
* related options that will be used by finish_device_tree()
*/
if (ppc_md.init_early)
ppc_md.init_early();
/*
* We can discover serial ports now since the above did setup the
* hash table management for us, thus ioremap works. We do that early
* so that further code can be debugged
*/
find_legacy_serial_ports();
/*
* Register early console
*/
register_early_udbg_console();
/*
* Initialize xmon
*/
xmon_setup();
smp_setup_cpu_maps();
check_smt_enabled();
#ifdef CONFIG_SMP
/* Release secondary cpus out of their spinloops at 0x60 now that
* we can map physical -> logical CPU ids
*/
smp_release_cpus();
#endif
printk("Starting Linux PPC64 %s\n", init_utsname()->version);
printk("-----------------------------------------------------\n");
printk("ppc64_pft_size = 0x%llx\n", ppc64_pft_size);
printk("physicalMemorySize = 0x%llx\n", memblock_phys_mem_size());
if (ppc64_caches.dline_size != 0x80)
printk("ppc64_caches.dcache_line_size = 0x%x\n",
ppc64_caches.dline_size);
if (ppc64_caches.iline_size != 0x80)
printk("ppc64_caches.icache_line_size = 0x%x\n",
ppc64_caches.iline_size);
#ifdef CONFIG_PPC_STD_MMU_64
if (htab_address)
printk("htab_address = 0x%p\n", htab_address);
printk("htab_hash_mask = 0x%lx\n", htab_hash_mask);
#endif /* CONFIG_PPC_STD_MMU_64 */
if (PHYSICAL_START > 0)
printk("physical_start = 0x%llx\n",
(unsigned long long)PHYSICAL_START);
printk("-----------------------------------------------------\n");
DBG(" <- setup_system()\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 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
/* BookS, the first segment is bolted */
if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
return 1UL << SID_SHIFT_1T;
return 1UL << SID_SHIFT;
#endif
}
static 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.
*/
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
static void __init exc_lvl_early_init(void)
{
extern unsigned int interrupt_base_book3e;
extern unsigned int exc_debug_debug_book3e;
unsigned int i;
for_each_possible_cpu(i) {
critirq_ctx[i] = (struct thread_info *)
__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
dbgirq_ctx[i] = (struct thread_info *)
__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
mcheckirq_ctx[i] = (struct thread_info *)
__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
}
if (cpu_has_feature(CPU_FTR_DEBUG_LVL_EXC))
patch_branch(&interrupt_base_book3e + (0x040 / 4) + 1,
(unsigned long)&exc_debug_debug_book3e, 0);
}
#else
#define exc_lvl_early_init()
#endif
/*
* Stack space used when we detect a bad kernel stack pointer, and
* early in SMP boots before relocation is enabled.
*/
static 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, we need to get at them in real mode. This means they
* must also be within the RMO region.
*/
limit = min(safe_stack_limit(), ppc64_rma_size);
for_each_possible_cpu(i) {
unsigned long sp;
sp = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit);
sp += THREAD_SIZE;
paca[i].emergency_sp = __va(sp);
}
}
/*
* Called into from start_kernel this initializes bootmem, which is used
* to manage page allocation until mem_init is called.
*/
void __init setup_arch(char **cmdline_p)
{
ppc64_boot_msg(0x12, "Setup Arch");
*cmdline_p = cmd_line;
/*
* Set cache line size based on type of cpu as a default.
* Systems with OF can look in the properties on the cpu node(s)
* for a possibly more accurate value.
*/
dcache_bsize = ppc64_caches.dline_size;
icache_bsize = ppc64_caches.iline_size;
/* reboot on panic */
panic_timeout = 180;
if (ppc_md.panic)
setup_panic();
init_mm.start_code = (unsigned long)_stext;
init_mm.end_code = (unsigned long) _etext;
init_mm.end_data = (unsigned long) _edata;
init_mm.brk = klimit;
irqstack_early_init();
exc_lvl_early_init();
emergency_stack_init();
#ifdef CONFIG_PPC_STD_MMU_64
stabs_alloc();
#endif
/* set up the bootmem stuff with available memory */
do_init_bootmem();
sparse_init();
#ifdef CONFIG_DUMMY_CONSOLE
conswitchp = &dummy_con;
#endif
if (ppc_md.setup_arch)
ppc_md.setup_arch();
paging_init();
/* Initialize the MMU context management stuff */
mmu_context_init();
kvm_rma_init();
ppc64_boot_msg(0x15, "Setup Done");
}
/* ToDo: do something useful if ppc_md is not yet setup. */
#define PPC64_LINUX_FUNCTION 0x0f000000
#define PPC64_IPL_MESSAGE 0xc0000000
#define PPC64_TERM_MESSAGE 0xb0000000
static void ppc64_do_msg(unsigned int src, const char *msg)
{
if (ppc_md.progress) {
char buf[128];
sprintf(buf, "%08X\n", src);
ppc_md.progress(buf, 0);
snprintf(buf, 128, "%s", msg);
ppc_md.progress(buf, 0);
}
}
/* Print a boot progress message. */
void ppc64_boot_msg(unsigned int src, const char *msg)
{
ppc64_do_msg(PPC64_LINUX_FUNCTION|PPC64_IPL_MESSAGE|src, msg);
printk("[boot]%04x %s\n", src, msg);
}
#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(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 (cpu_to_node(from) == 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_PPC_INDIRECT_IO
struct ppc_pci_io ppc_pci_io;
EXPORT_SYMBOL(ppc_pci_io);
#endif /* CONFIG_PPC_INDIRECT_IO */
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