1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License.  See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
7 */
8
9/*
10 * Cross Partition (XP) sn2-based functions.
11 *
12 *      Architecture specific implementation of common functions.
13 */
14
15#include <linux/module.h>
16#include <linux/device.h>
17#include <asm/sn/bte.h>
18#include <asm/sn/sn_sal.h>
19#include "xp.h"
20
21/*
22 * The export of xp_nofault_PIOR needs to happen here since it is defined
23 * in drivers/misc/sgi-xp/xp_nofault.S. The target of the nofault read is
24 * defined here.
25 */
26EXPORT_SYMBOL_GPL(xp_nofault_PIOR);
27
28u64 xp_nofault_PIOR_target;
29EXPORT_SYMBOL_GPL(xp_nofault_PIOR_target);
30
31/*
32 * Register a nofault code region which performs a cross-partition PIO read.
33 * If the PIO read times out, the MCA handler will consume the error and
34 * return to a kernel-provided instruction to indicate an error. This PIO read
35 * exists because it is guaranteed to timeout if the destination is down
36 * (amo operations do not timeout on at least some CPUs on Shubs <= v1.2,
37 * which unfortunately we have to work around).
38 */
39static enum xp_retval
40xp_register_nofault_code_sn2(void)
41{
42	int ret;
43	u64 func_addr;
44	u64 err_func_addr;
45
46	func_addr = *(u64 *)xp_nofault_PIOR;
47	err_func_addr = *(u64 *)xp_error_PIOR;
48	ret = sn_register_nofault_code(func_addr, err_func_addr, err_func_addr,
49				       1, 1);
50	if (ret != 0) {
51		dev_err(xp, "can't register nofault code, error=%d\n", ret);
52		return xpSalError;
53	}
54	/*
55	 * Setup the nofault PIO read target. (There is no special reason why
56	 * SH_IPI_ACCESS was selected.)
57	 */
58	if (is_shub1())
59		xp_nofault_PIOR_target = SH1_IPI_ACCESS;
60	else if (is_shub2())
61		xp_nofault_PIOR_target = SH2_IPI_ACCESS0;
62
63	return xpSuccess;
64}
65
66static void
67xp_unregister_nofault_code_sn2(void)
68{
69	u64 func_addr = *(u64 *)xp_nofault_PIOR;
70	u64 err_func_addr = *(u64 *)xp_error_PIOR;
71
72	/* unregister the PIO read nofault code region */
73	(void)sn_register_nofault_code(func_addr, err_func_addr,
74				       err_func_addr, 1, 0);
75}
76
77/*
78 * Convert a virtual memory address to a physical memory address.
79 */
80static unsigned long
81xp_pa_sn2(void *addr)
82{
83	return __pa(addr);
84}
85
86/*
87 * Convert a global physical to a socket physical address.
88 */
89static unsigned long
90xp_socket_pa_sn2(unsigned long gpa)
91{
92	return gpa;
93}
94
95/*
96 * Wrapper for bte_copy().
97 *
98 *	dst_pa - physical address of the destination of the transfer.
99 *	src_pa - physical address of the source of the transfer.
100 *	len - number of bytes to transfer from source to destination.
101 *
102 * Note: xp_remote_memcpy_sn2() should never be called while holding a spinlock.
103 */
104static enum xp_retval
105xp_remote_memcpy_sn2(unsigned long dst_pa, const unsigned long src_pa,
106		     size_t len)
107{
108	bte_result_t ret;
109
110	ret = bte_copy(src_pa, dst_pa, len, (BTE_NOTIFY | BTE_WACQUIRE), NULL);
111	if (ret == BTE_SUCCESS)
112		return xpSuccess;
113
114	if (is_shub2()) {
115		dev_err(xp, "bte_copy() on shub2 failed, error=0x%x dst_pa="
116			"0x%016lx src_pa=0x%016lx len=%ld\\n", ret, dst_pa,
117			src_pa, len);
118	} else {
119		dev_err(xp, "bte_copy() failed, error=%d dst_pa=0x%016lx "
120			"src_pa=0x%016lx len=%ld\\n", ret, dst_pa, src_pa, len);
121	}
122
123	return xpBteCopyError;
124}
125
126static int
127xp_cpu_to_nasid_sn2(int cpuid)
128{
129	return cpuid_to_nasid(cpuid);
130}
131
132static enum xp_retval
133xp_expand_memprotect_sn2(unsigned long phys_addr, unsigned long size)
134{
135	u64 nasid_array = 0;
136	int ret;
137
138	ret = sn_change_memprotect(phys_addr, size, SN_MEMPROT_ACCESS_CLASS_1,
139				   &nasid_array);
140	if (ret != 0) {
141		dev_err(xp, "sn_change_memprotect(,, "
142			"SN_MEMPROT_ACCESS_CLASS_1,) failed ret=%d\n", ret);
143		return xpSalError;
144	}
145	return xpSuccess;
146}
147
148static enum xp_retval
149xp_restrict_memprotect_sn2(unsigned long phys_addr, unsigned long size)
150{
151	u64 nasid_array = 0;
152	int ret;
153
154	ret = sn_change_memprotect(phys_addr, size, SN_MEMPROT_ACCESS_CLASS_0,
155				   &nasid_array);
156	if (ret != 0) {
157		dev_err(xp, "sn_change_memprotect(,, "
158			"SN_MEMPROT_ACCESS_CLASS_0,) failed ret=%d\n", ret);
159		return xpSalError;
160	}
161	return xpSuccess;
162}
163
164enum xp_retval
165xp_init_sn2(void)
166{
167	BUG_ON(!is_shub());
168
169	xp_max_npartitions = XP_MAX_NPARTITIONS_SN2;
170	xp_partition_id = sn_partition_id;
171	xp_region_size = sn_region_size;
172
173	xp_pa = xp_pa_sn2;
174	xp_socket_pa = xp_socket_pa_sn2;
175	xp_remote_memcpy = xp_remote_memcpy_sn2;
176	xp_cpu_to_nasid = xp_cpu_to_nasid_sn2;
177	xp_expand_memprotect = xp_expand_memprotect_sn2;
178	xp_restrict_memprotect = xp_restrict_memprotect_sn2;
179
180	return xp_register_nofault_code_sn2();
181}
182
183void
184xp_exit_sn2(void)
185{
186	BUG_ON(!is_shub());
187
188	xp_unregister_nofault_code_sn2();
189}
190
191