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xp_sn2.c
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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  */
27 
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
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())
60  else if (is_shub2())
62 
63  return xpSuccess;
64 }
65 
66 static 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
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
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
105 xp_remote_memcpy_sn2(unsigned long dst_pa, const unsigned long src_pa,
106  size_t len)
107 {
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
127 xp_cpu_to_nasid_sn2(int cpuid)
128 {
129  return cpuid_to_nasid(cpuid);
130 }
131 
132 static enum xp_retval
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
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
166 {
167  BUG_ON(!is_shub());
168 
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
185 {
186  BUG_ON(!is_shub());
187 
188  xp_unregister_nofault_code_sn2();
189 }
190