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