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/*
* Copyright 2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*/
#include <linux/kvm_host.h>
#include <linux/preempt.h>
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/bootmem.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/sizes.h>
#include <asm/cputable.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include "book3s_hv_cma.h"
#define KVM_LINEAR_RMA 0
#define KVM_LINEAR_HPT 1
static void __init kvm_linear_init_one(ulong size, int count, int type);
static struct kvmppc_linear_info *kvm_alloc_linear(int type);
static void kvm_release_linear(struct kvmppc_linear_info *ri);
/*
* Hash page table alignment on newer cpus(CPU_FTR_ARCH_206)
* should be power of 2.
*/
#define HPT_ALIGN_PAGES ((1 << 18) >> PAGE_SHIFT) /* 256k */
/*
* By default we reserve 5% of memory for hash pagetable allocation.
*/
static unsigned long kvm_cma_resv_ratio = 5;
/*************** RMA *************/
/*
* This maintains a list of RMAs (real mode areas) for KVM guests to use.
* Each RMA has to be physically contiguous and of a size that the
* hardware supports. PPC970 and POWER7 support 64MB, 128MB and 256MB,
* and other larger sizes. Since we are unlikely to be allocate that
* much physically contiguous memory after the system is up and running,
* we preallocate a set of RMAs in early boot for KVM to use.
*/
static unsigned long kvm_rma_size = 64 << 20; /* 64MB */
static unsigned long kvm_rma_count;
/* Work out RMLS (real mode limit selector) field value for a given RMA size.
Assumes POWER7 or PPC970. */
static inline int lpcr_rmls(unsigned long rma_size)
{
switch (rma_size) {
case 32ul << 20: /* 32 MB */
if (cpu_has_feature(CPU_FTR_ARCH_206))
return 8; /* only supported on POWER7 */
return -1;
case 64ul << 20: /* 64 MB */
return 3;
case 128ul << 20: /* 128 MB */
return 7;
case 256ul << 20: /* 256 MB */
return 4;
case 1ul << 30: /* 1 GB */
return 2;
case 16ul << 30: /* 16 GB */
return 1;
case 256ul << 30: /* 256 GB */
return 0;
default:
return -1;
}
}
static int __init early_parse_rma_size(char *p)
{
if (!p)
return 1;
kvm_rma_size = memparse(p, &p);
return 0;
}
early_param("kvm_rma_size", early_parse_rma_size);
static int __init early_parse_rma_count(char *p)
{
if (!p)
return 1;
kvm_rma_count = simple_strtoul(p, NULL, 0);
return 0;
}
early_param("kvm_rma_count", early_parse_rma_count);
struct kvmppc_linear_info *kvm_alloc_rma(void)
{
return kvm_alloc_linear(KVM_LINEAR_RMA);
}
EXPORT_SYMBOL_GPL(kvm_alloc_rma);
void kvm_release_rma(struct kvmppc_linear_info *ri)
{
kvm_release_linear(ri);
}
EXPORT_SYMBOL_GPL(kvm_release_rma);
static int __init early_parse_kvm_cma_resv(char *p)
{
pr_debug("%s(%s)\n", __func__, p);
if (!p)
return -EINVAL;
return kstrtoul(p, 0, &kvm_cma_resv_ratio);
}
early_param("kvm_cma_resv_ratio", early_parse_kvm_cma_resv);
struct page *kvm_alloc_hpt(unsigned long nr_pages)
{
unsigned long align_pages = HPT_ALIGN_PAGES;
/* Old CPUs require HPT aligned on a multiple of its size */
if (!cpu_has_feature(CPU_FTR_ARCH_206))
align_pages = nr_pages;
return kvm_alloc_cma(nr_pages, align_pages);
}
EXPORT_SYMBOL_GPL(kvm_alloc_hpt);
void kvm_release_hpt(struct page *page, unsigned long nr_pages)
{
kvm_release_cma(page, nr_pages);
}
EXPORT_SYMBOL_GPL(kvm_release_hpt);
/*************** generic *************/
static LIST_HEAD(free_linears);
static DEFINE_SPINLOCK(linear_lock);
static void __init kvm_linear_init_one(ulong size, int count, int type)
{
unsigned long i;
unsigned long j, npages;
void *linear;
struct page *pg;
const char *typestr;
struct kvmppc_linear_info *linear_info;
if (!count)
return;
typestr = (type == KVM_LINEAR_RMA) ? "RMA" : "HPT";
npages = size >> PAGE_SHIFT;
linear_info = alloc_bootmem(count * sizeof(struct kvmppc_linear_info));
for (i = 0; i < count; ++i) {
linear = alloc_bootmem_align(size, size);
pr_debug("Allocated KVM %s at %p (%ld MB)\n", typestr, linear,
size >> 20);
linear_info[i].base_virt = linear;
linear_info[i].base_pfn = __pa(linear) >> PAGE_SHIFT;
linear_info[i].npages = npages;
linear_info[i].type = type;
list_add_tail(&linear_info[i].list, &free_linears);
atomic_set(&linear_info[i].use_count, 0);
pg = pfn_to_page(linear_info[i].base_pfn);
for (j = 0; j < npages; ++j) {
atomic_inc(&pg->_count);
++pg;
}
}
}
static struct kvmppc_linear_info *kvm_alloc_linear(int type)
{
struct kvmppc_linear_info *ri, *ret;
ret = NULL;
spin_lock(&linear_lock);
list_for_each_entry(ri, &free_linears, list) {
if (ri->type != type)
continue;
list_del(&ri->list);
atomic_inc(&ri->use_count);
memset(ri->base_virt, 0, ri->npages << PAGE_SHIFT);
ret = ri;
break;
}
spin_unlock(&linear_lock);
return ret;
}
static void kvm_release_linear(struct kvmppc_linear_info *ri)
{
if (atomic_dec_and_test(&ri->use_count)) {
spin_lock(&linear_lock);
list_add_tail(&ri->list, &free_linears);
spin_unlock(&linear_lock);
}
}
/*
* Called at boot time while the bootmem allocator is active,
* to allocate contiguous physical memory for the hash page
* tables for guests.
*/
void __init kvm_linear_init(void)
{
/* RMA */
/* Only do this on PPC970 in HV mode */
if (!cpu_has_feature(CPU_FTR_HVMODE) ||
!cpu_has_feature(CPU_FTR_ARCH_201))
return;
if (!kvm_rma_size || !kvm_rma_count)
return;
/* Check that the requested size is one supported in hardware */
if (lpcr_rmls(kvm_rma_size) < 0) {
pr_err("RMA size of 0x%lx not supported\n", kvm_rma_size);
return;
}
kvm_linear_init_one(kvm_rma_size, kvm_rma_count, KVM_LINEAR_RMA);
}
/**
* kvm_cma_reserve() - reserve area for kvm hash pagetable
*
* This function reserves memory from early allocator. It should be
* called by arch specific code once the early allocator (memblock or bootmem)
* has been activated and all other subsystems have already allocated/reserved
* memory.
*/
void __init kvm_cma_reserve(void)
{
unsigned long align_size;
struct memblock_region *reg;
phys_addr_t selected_size = 0;
/*
* We cannot use memblock_phys_mem_size() here, because
* memblock_analyze() has not been called yet.
*/
for_each_memblock(memory, reg)
selected_size += memblock_region_memory_end_pfn(reg) -
memblock_region_memory_base_pfn(reg);
selected_size = (selected_size * kvm_cma_resv_ratio / 100) << PAGE_SHIFT;
if (selected_size) {
pr_debug("%s: reserving %ld MiB for global area\n", __func__,
(unsigned long)selected_size / SZ_1M);
/*
* Old CPUs require HPT aligned on a multiple of its size. So for them
* make the alignment as max size we could request.
*/
if (!cpu_has_feature(CPU_FTR_ARCH_206))
align_size = __rounddown_pow_of_two(selected_size);
else
align_size = HPT_ALIGN_PAGES << PAGE_SHIFT;
kvm_cma_declare_contiguous(selected_size, align_size);
}
}
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