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  */
26 EXPORT_SYMBOL_GPL(xp_nofault_PIOR);
27 
28 u64 xp_nofault_PIOR_target;
29 EXPORT_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  */
39 static enum xp_retval
xp_register_nofault_code_sn2(void)40 xp_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 
66 static void
xp_unregister_nofault_code_sn2(void)67 xp_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  */
80 static unsigned long
xp_pa_sn2(void * addr)81 xp_pa_sn2(void *addr)
82 {
83 	return __pa(addr);
84 }
85 
86 /*
87  * Convert a global physical to a socket physical address.
88  */
89 static unsigned long
xp_socket_pa_sn2(unsigned long gpa)90 xp_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  */
104 static enum xp_retval
xp_remote_memcpy_sn2(unsigned long dst_pa,const unsigned long src_pa,size_t len)105 xp_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 
126 static int
xp_cpu_to_nasid_sn2(int cpuid)127 xp_cpu_to_nasid_sn2(int cpuid)
128 {
129 	return cpuid_to_nasid(cpuid);
130 }
131 
132 static enum xp_retval
xp_expand_memprotect_sn2(unsigned long phys_addr,unsigned long size)133 xp_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 
148 static enum xp_retval
xp_restrict_memprotect_sn2(unsigned long phys_addr,unsigned long size)149 xp_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 
164 enum xp_retval
xp_init_sn2(void)165 xp_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 
183 void
xp_exit_sn2(void)184 xp_exit_sn2(void)
185 {
186 	BUG_ON(!is_shub());
187 
188 	xp_unregister_nofault_code_sn2();
189 }
190 
191