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