[mirror_ubuntu-artful-kernel.git] / arch / powerpc / kvm / book3s_hv_builtin.c

/*
 * 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 <asm/cputable.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>

/*
 * 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;

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);

static struct kvmppc_rma_info *rma_info;
static LIST_HEAD(free_rmas);
static DEFINE_SPINLOCK(rma_lock);

/* 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;
	}
}

/*
 * Called at boot time while the bootmem allocator is active,
 * to allocate contiguous physical memory for the real memory
 * areas for guests.
 */
void kvm_rma_init(void)
{
	unsigned long i;
	unsigned long j, npages;
	void *rma;
	struct page *pg;

	/* 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;
	}

	npages = kvm_rma_size >> PAGE_SHIFT;
	rma_info = alloc_bootmem(kvm_rma_count * sizeof(struct kvmppc_rma_info));
	for (i = 0; i < kvm_rma_count; ++i) {
		rma = alloc_bootmem_align(kvm_rma_size, kvm_rma_size);
		pr_info("Allocated KVM RMA at %p (%ld MB)\n", rma,
			kvm_rma_size >> 20);
		rma_info[i].base_virt = rma;
		rma_info[i].base_pfn = __pa(rma) >> PAGE_SHIFT;
		rma_info[i].npages = npages;
		list_add_tail(&rma_info[i].list, &free_rmas);
		atomic_set(&rma_info[i].use_count, 0);

		pg = pfn_to_page(rma_info[i].base_pfn);
		for (j = 0; j < npages; ++j) {
			atomic_inc(&pg->_count);
			++pg;
		}
	}
}

struct kvmppc_rma_info *kvm_alloc_rma(void)
{
	struct kvmppc_rma_info *ri;

	ri = NULL;
	spin_lock(&rma_lock);
	if (!list_empty(&free_rmas)) {
		ri = list_first_entry(&free_rmas, struct kvmppc_rma_info, list);
		list_del(&ri->list);
		atomic_inc(&ri->use_count);
	}
	spin_unlock(&rma_lock);
	return ri;
}
EXPORT_SYMBOL_GPL(kvm_alloc_rma);

void kvm_release_rma(struct kvmppc_rma_info *ri)
{
	if (atomic_dec_and_test(&ri->use_count)) {
		spin_lock(&rma_lock);
		list_add_tail(&ri->list, &free_rmas);
		spin_unlock(&rma_lock);

	}
}
EXPORT_SYMBOL_GPL(kvm_release_rma);
Commit	Line	Data
aa04b4cc PM	1	/*
	2	* Copyright 2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License, version 2, as
	6	* published by the Free Software Foundation.
	7	*/
	8
	9	#include <linux/kvm_host.h>
	10	#include <linux/preempt.h>
66b15db6	11	#include <linux/export.h>
aa04b4cc PM	12	#include <linux/sched.h>
	13	#include <linux/spinlock.h>
	14	#include <linux/bootmem.h>
	15	#include <linux/init.h>
	16
	17	#include <asm/cputable.h>
	18	#include <asm/kvm_ppc.h>
	19	#include <asm/kvm_book3s.h>
	20
	21	/*
	22	* This maintains a list of RMAs (real mode areas) for KVM guests to use.
	23	* Each RMA has to be physically contiguous and of a size that the
	24	* hardware supports. PPC970 and POWER7 support 64MB, 128MB and 256MB,
	25	* and other larger sizes. Since we are unlikely to be allocate that
	26	* much physically contiguous memory after the system is up and running,
	27	* we preallocate a set of RMAs in early boot for KVM to use.
	28	*/
	29	static unsigned long kvm_rma_size = 64 << 20; /* 64MB */
	30	static unsigned long kvm_rma_count;
	31
	32	static int __init early_parse_rma_size(char *p)
	33	{
	34	if (!p)
	35	return 1;
	36
	37	kvm_rma_size = memparse(p, &p);
	38
	39	return 0;
	40	}
	41	early_param("kvm_rma_size", early_parse_rma_size);
	42
	43	static int __init early_parse_rma_count(char *p)
	44	{
	45	if (!p)
	46	return 1;
	47
	48	kvm_rma_count = simple_strtoul(p, NULL, 0);
	49
	50	return 0;
	51	}
	52	early_param("kvm_rma_count", early_parse_rma_count);
	53
	54	static struct kvmppc_rma_info *rma_info;
	55	static LIST_HEAD(free_rmas);
	56	static DEFINE_SPINLOCK(rma_lock);
	57
	58	/* Work out RMLS (real mode limit selector) field value for a given RMA size.
9e368f29	59	Assumes POWER7 or PPC970. */
aa04b4cc PM	60	static inline int lpcr_rmls(unsigned long rma_size)
	61	{
	62	switch (rma_size) {
	63	case 32ul << 20: /* 32 MB */
9e368f29 PM	64	if (cpu_has_feature(CPU_FTR_ARCH_206))
	65	return 8; /* only supported on POWER7 */
	66	return -1;
aa04b4cc PM	67	case 64ul << 20: /* 64 MB */
	68	return 3;
	69	case 128ul << 20: /* 128 MB */
	70	return 7;
	71	case 256ul << 20: /* 256 MB */
	72	return 4;
	73	case 1ul << 30: /* 1 GB */
	74	return 2;
	75	case 16ul << 30: /* 16 GB */
	76	return 1;
	77	case 256ul << 30: /* 256 GB */
	78	return 0;
	79	default:
	80	return -1;
	81	}
	82	}
	83
	84	/*
	85	* Called at boot time while the bootmem allocator is active,
	86	* to allocate contiguous physical memory for the real memory
	87	* areas for guests.
	88	*/
	89	void kvm_rma_init(void)
	90	{
	91	unsigned long i;
	92	unsigned long j, npages;
	93	void *rma;
	94	struct page *pg;
	95
9e368f29 PM	96	/* Only do this on PPC970 in HV mode */
	97	if (!cpu_has_feature(CPU_FTR_HVMODE) \|\|
	98	!cpu_has_feature(CPU_FTR_ARCH_201))
aa04b4cc PM	99	return;
	100
	101	if (!kvm_rma_size \|\| !kvm_rma_count)
	102	return;
	103
	104	/* Check that the requested size is one supported in hardware */
	105	if (lpcr_rmls(kvm_rma_size) < 0) {
	106	pr_err("RMA size of 0x%lx not supported\n", kvm_rma_size);
	107	return;
	108	}
	109
	110	npages = kvm_rma_size >> PAGE_SHIFT;
	111	rma_info = alloc_bootmem(kvm_rma_count * sizeof(struct kvmppc_rma_info));
	112	for (i = 0; i < kvm_rma_count; ++i) {
	113	rma = alloc_bootmem_align(kvm_rma_size, kvm_rma_size);
	114	pr_info("Allocated KVM RMA at %p (%ld MB)\n", rma,
	115	kvm_rma_size >> 20);
	116	rma_info[i].base_virt = rma;
	117	rma_info[i].base_pfn = __pa(rma) >> PAGE_SHIFT;
	118	rma_info[i].npages = npages;
	119	list_add_tail(&rma_info[i].list, &free_rmas);
	120	atomic_set(&rma_info[i].use_count, 0);
	121
	122	pg = pfn_to_page(rma_info[i].base_pfn);
	123	for (j = 0; j < npages; ++j) {
	124	atomic_inc(&pg->_count);
	125	++pg;
	126	}
	127	}
	128	}
	129
	130	struct kvmppc_rma_info *kvm_alloc_rma(void)
	131	{
	132	struct kvmppc_rma_info *ri;
	133
	134	ri = NULL;
	135	spin_lock(&rma_lock);
	136	if (!list_empty(&free_rmas)) {
	137	ri = list_first_entry(&free_rmas, struct kvmppc_rma_info, list);
	138	list_del(&ri->list);
	139	atomic_inc(&ri->use_count);
	140	}
	141	spin_unlock(&rma_lock);
	142	return ri;
	143	}
	144	EXPORT_SYMBOL_GPL(kvm_alloc_rma);
	145
	146	void kvm_release_rma(struct kvmppc_rma_info *ri)
	147	{
	148	if (atomic_dec_and_test(&ri->use_count)) {
	149	spin_lock(&rma_lock);
	150	list_add_tail(&ri->list, &free_rmas);
	151	spin_unlock(&rma_lock);
	152
	153	}
	154	}
	155	EXPORT_SYMBOL_GPL(kvm_release_rma);
	156