path: root/drivers/misc/sgi-xp/xpc_partition.c

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (c) 2004-2008 Silicon Graphics, Inc.  All Rights Reserved.
 */

/*
 * Cross Partition Communication (XPC) partition support.
 *
 *	This is the part of XPC that detects the presence/absence of
 *	other partitions. It provides a heartbeat and monitors the
 *	heartbeats of other partitions.
 *
 */

#include <linux/kernel.h>
#include <linux/sysctl.h>
#include <linux/cache.h>
#include <linux/mmzone.h>
#include <linux/nodemask.h>
#include <asm/uncached.h>
#include <asm/sn/bte.h>
#include <asm/sn/intr.h>
#include <asm/sn/sn_sal.h>
#include <asm/sn/nodepda.h>
#include <asm/sn/addrs.h>
#include "xpc.h"

/* XPC is exiting flag */
int xpc_exiting;

/* SH_IPI_ACCESS shub register value on startup */
static u64 xpc_sh1_IPI_access;
static u64 xpc_sh2_IPI_access0;
static u64 xpc_sh2_IPI_access1;
static u64 xpc_sh2_IPI_access2;
static u64 xpc_sh2_IPI_access3;

/* original protection values for each node */
u64 xpc_prot_vec[MAX_NUMNODES];

/* this partition's reserved page pointers */
struct xpc_rsvd_page *xpc_rsvd_page;
static u64 *xpc_part_nasids;
static u64 *xpc_mach_nasids;
struct xpc_vars *xpc_vars;
struct xpc_vars_part *xpc_vars_part;

static int xp_nasid_mask_bytes;	/* actual size in bytes of nasid mask */
static int xp_nasid_mask_words;	/* actual size in words of nasid mask */

struct xpc_partition *xpc_partitions;

/*
 * Generic buffer used to store a local copy of portions of a remote
 * partition's reserved page (either its header and part_nasids mask,
 * or its vars).
 */
char *xpc_remote_copy_buffer;
void *xpc_remote_copy_buffer_base;

/*
 * Guarantee that the kmalloc'd memory is cacheline aligned.
 */
void *
xpc_kmalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
{
	/* see if kmalloc will give us cachline aligned memory by default */
	*base = kmalloc(size, flags);
	if (*base == NULL)
		return NULL;

	if ((u64)*base == L1_CACHE_ALIGN((u64)*base))
		return *base;

	kfree(*base);

	/* nope, we'll have to do it ourselves */
	*base = kmalloc(size + L1_CACHE_BYTES, flags);
	if (*base == NULL)
		return NULL;

	return (void *)L1_CACHE_ALIGN((u64)*base);
}

/*
 * Given a nasid, get the physical address of the  partition's reserved page
 * for that nasid. This function returns 0 on any error.
 */
static u64
xpc_get_rsvd_page_pa(int nasid)
{
	bte_result_t bte_res;
	s64 status;
	u64 cookie = 0;
	u64 rp_pa = nasid;	/* seed with nasid */
	u64 len = 0;
	u64 buf = buf;
	u64 buf_len = 0;
	void *buf_base = NULL;

	while (1) {

		status = sn_partition_reserved_page_pa(buf, &cookie, &rp_pa,
						       &len);

		dev_dbg(xpc_part, "SAL returned with status=%li, cookie="
			"0x%016lx, address=0x%016lx, len=0x%016lx\n",
			status, cookie, rp_pa, len);

		if (status != SALRET_MORE_PASSES)
			break;

		if (L1_CACHE_ALIGN(len) > buf_len) {
			kfree(buf_base);
			buf_len = L1_CACHE_ALIGN(len);
			buf = (u64)xpc_kmalloc_cacheline_aligned(buf_len,
								 GFP_KERNEL,
								 &buf_base);
			if (buf_base == NULL) {
				dev_err(xpc_part, "unable to kmalloc "
					"len=0x%016lx\n", buf_len);
				status = SALRET_ERROR;
				break;
			}
		}

		bte_res = xp_bte_copy(rp_pa, buf, buf_len,
				      (BTE_NOTIFY | BTE_WACQUIRE), NULL);
		if (bte_res