drivers/misc/sgi-xp/xpc_sn2.c

   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 Communication (XPC) sn2-based functions.
  11  *
  12  *     Architecture specific implementation of common functions.
  13  *
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <asm/uncached.h>
  18 #include <asm/sn/sn_sal.h>
  19 #include "xpc.h"
  20
  21 struct xpc_vars *xpc_vars;
  22 struct xpc_vars_part *xpc_vars_part;
  23
  24 static enum xp_retval
  25 xpc_rsvd_page_init_sn2(struct xpc_rsvd_page *rp)
  26 {
  27         AMO_t *amos_page;
  28         u64 nasid_array = 0;
  29         int i;
  30         int ret;
  31
  32         xpc_vars = XPC_RP_VARS(rp);
  33
  34         rp->sn.vars_pa = __pa(xpc_vars);
  35
  36         xpc_vars_part = XPC_RP_VARS_PART(rp);
  37
  38         /*
  39          * Before clearing xpc_vars, see if a page of AMOs had been previously
  40          * allocated. If not we'll need to allocate one and set permissions
  41          * so that cross-partition AMOs are allowed.
  42          *
  43          * The allocated AMO page needs MCA reporting to remain disabled after
  44          * XPC has unloaded.  To make this work, we keep a copy of the pointer
  45          * to this page (i.e., amos_page) in the struct xpc_vars structure,
  46          * which is pointed to by the reserved page, and re-use that saved copy
  47          * on subsequent loads of XPC. This AMO page is never freed, and its
  48          * memory protections are never restricted.
  49          */
  50         amos_page = xpc_vars->amos_page;
  51         if (amos_page == NULL) {
  52                 amos_page = (AMO_t *)TO_AMO(uncached_alloc_page(0, 1));
  53                 if (amos_page == NULL) {
  54                         dev_err(xpc_part, "can't allocate page of AMOs\n");
  55                         return xpNoMemory;
  56                 }
  57
  58                 /*
  59                  * Open up AMO-R/W to cpu.  This is done for Shub 1.1 systems
  60                  * when xpc_allow_IPI_ops() is called via xpc_hb_init().
  61                  */
  62                 if (!enable_shub_wars_1_1()) {
  63                         ret = sn_change_memprotect(ia64_tpa((u64)amos_page),
  64                                                    PAGE_SIZE,
  65                                                    SN_MEMPROT_ACCESS_CLASS_1,
  66                                                    &nasid_array);
  67                         if (ret != 0) {
  68                                 dev_err(xpc_part, "can't change memory "
  69                                         "protections\n");
  70                                 uncached_free_page(__IA64_UNCACHED_OFFSET |
  71                                                    TO_PHYS((u64)amos_page), 1);
  72                                 return xpSalError;
  73                         }
  74                 }
  75         }
  76
  77         /* clear xpc_vars */
  78         memset(xpc_vars, 0, sizeof(struct xpc_vars));
  79
  80         xpc_vars->version = XPC_V_VERSION;
  81         xpc_vars->act_nasid = cpuid_to_nasid(0);
  82         xpc_vars->act_phys_cpuid = cpu_physical_id(0);
  83         xpc_vars->vars_part_pa = __pa(xpc_vars_part);
  84         xpc_vars->amos_page_pa = ia64_tpa((u64)amos_page);
  85         xpc_vars->amos_page = amos_page;        /* save for next load of XPC */
  86
  87         /* clear xpc_vars_part */
  88         memset((u64 *)xpc_vars_part, 0, sizeof(struct xpc_vars_part) *
  89                xp_max_npartitions);
  90
  91         /* initialize the activate IRQ related AMO variables */
  92         for (i = 0; i < xp_nasid_mask_words; i++)
  93                 (void)xpc_IPI_init(XPC_ACTIVATE_IRQ_AMOS + i);
  94
  95         /* initialize the engaged remote partitions related AMO variables */
  96         (void)xpc_IPI_init(XPC_ENGAGED_PARTITIONS_AMO);
  97         (void)xpc_IPI_init(XPC_DISENGAGE_REQUEST_AMO);
  98
  99         return xpSuccess;
 100 }
 101
 102 void
 103 xpc_init_sn2(void)
 104 {
 105         xpc_rsvd_page_init = xpc_rsvd_page_init_sn2;
 106 }
 107
 108 void
 109 xpc_exit_sn2(void)
 110 {
 111 }