git.saurik.com Git - apple/xnu.git/blame_incremental

... / ...

Commit	Line	Data
	1	/*
	2	* Copyright (c) 2013 Apple Inc. All rights reserved.
	3	*
	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
	25	*
	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
	27	*/
	28	#include <mach/mach_types.h>
	29	#include <mach/host_info.h>
	30	#include <kern/locks.h>
	31	#include <kern/ecc.h>
	32	#include <kern/spl.h>
	33	#include <pexpert/pexpert.h>
	34	#include <libkern/OSAtomic.h>
	35
	36	/*
	37	* ECC data. Not really KPCs, but this still seems like the
	38	* best home for this code.
	39	*
	40	* Circular buffer of events. When we fill up, drop data.
	41	*/
	42	#define ECC_EVENT_BUFFER_COUNT 5
	43	struct ecc_event ecc_data[ECC_EVENT_BUFFER_COUNT];
	44	static uint32_t ecc_data_next_read;
	45	static uint32_t ecc_data_next_write;
	46	static boolean_t ecc_data_empty = TRUE; // next read == next write : empty or full?
	47	static LCK_GRP_DECLARE(ecc_data_lock_group, "ecc-data");
	48	static LCK_SPIN_DECLARE(ecc_data_lock, &ecc_data_lock_group);
	49	static uint32_t ecc_correction_count;
	50
	51	uint32_t
	52	ecc_log_get_correction_count()
	53	{
	54	return ecc_correction_count;
	55	}
	56
	57	kern_return_t
	58	ecc_log_record_event(const struct ecc_event *ev)
	59	{
	60	spl_t x;
	61
	62	if (ev->count > ECC_EVENT_INFO_DATA_ENTRIES) {
	63	panic("Count of %u on ecc event is too large.", (unsigned)ev->count);
	64	}
	65
	66	x = splhigh();
	67	lck_spin_lock(&ecc_data_lock);
	68
	69	ecc_correction_count++;
	70
	71	if (ecc_data_next_read == ecc_data_next_write && !ecc_data_empty) {
	72	lck_spin_unlock(&ecc_data_lock);
	73	splx(x);
	74	return KERN_FAILURE;
	75	}
	76
	77	bcopy(ev, &ecc_data[ecc_data_next_write], sizeof(*ev));
	78	ecc_data_next_write++;
	79	ecc_data_next_write %= ECC_EVENT_BUFFER_COUNT;
	80	ecc_data_empty = FALSE;
	81
	82	lck_spin_unlock(&ecc_data_lock);
	83	splx(x);
	84
	85	return KERN_SUCCESS;
	86	}
	87
	88
	89	kern_return_t
	90	ecc_log_get_next_event(struct ecc_event *ev)
	91	{
	92	spl_t x;
	93
	94	x = splhigh();
	95	lck_spin_lock(&ecc_data_lock);
	96
	97	if (ecc_data_empty) {
	98	assert(ecc_data_next_write == ecc_data_next_read);
	99
	100	lck_spin_unlock(&ecc_data_lock);
	101	splx(x);
	102	return KERN_FAILURE;
	103	}
	104
	105	bcopy(&ecc_data[ecc_data_next_read], ev, sizeof(*ev));
	106	ecc_data_next_read++;
	107	ecc_data_next_read %= ECC_EVENT_BUFFER_COUNT;
	108
	109	if (ecc_data_next_read == ecc_data_next_write) {
	110	ecc_data_empty = TRUE;
	111	}
	112
	113	lck_spin_unlock(&ecc_data_lock);
	114	splx(x);
	115
	116	return KERN_SUCCESS;
	117	}