drivers/misc/sgi-gru/gruhandles.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *              GRU KERNEL MCS INSTRUCTIONS
   4  *
   5  *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include "gru.h"
  10 #include "grulib.h"
  11 #include "grutables.h"
  12
  13 /* 10 sec */
  14 #ifdef CONFIG_IA64
  15 #include <asm/processor.h>
  16 #define GRU_OPERATION_TIMEOUT   (((cycles_t) local_cpu_data->itc_freq)*10)
  17 #define CLKS2NSEC(c)            ((c) *1000000000 / local_cpu_data->itc_freq)
  18 #else
  19 #include <linux/sync_core.h>
  20 #include <asm/tsc.h>
  21 #define GRU_OPERATION_TIMEOUT   ((cycles_t) tsc_khz*10*1000)
  22 #define CLKS2NSEC(c)            ((c) * 1000000 / tsc_khz)
  23 #endif
  24
  25 /* Extract the status field from a kernel handle */
  26 #define GET_MSEG_HANDLE_STATUS(h)       (((*(unsigned long *)(h)) >> 16) & 3)
  27
  28 struct mcs_op_statistic mcs_op_statistics[mcsop_last];
  29
  30 static void update_mcs_stats(enum mcs_op op, unsigned long clks)
  31 {
  32         unsigned long nsec;
  33
  34         nsec = CLKS2NSEC(clks);
  35         atomic_long_inc(&mcs_op_statistics[op].count);
  36         atomic_long_add(nsec, &mcs_op_statistics[op].total);
  37         if (mcs_op_statistics[op].max < nsec)
  38                 mcs_op_statistics[op].max = nsec;
  39 }
  40
  41 static void start_instruction(void *h)
  42 {
  43         unsigned long *w0 = h;
  44
  45         wmb();          /* setting CMD/STATUS bits must be last */
  46         *w0 = *w0 | 0x20001;
  47         gru_flush_cache(h);
  48 }
  49
  50 static void report_instruction_timeout(void *h)
  51 {
  52         unsigned long goff = GSEGPOFF((unsigned long)h);
  53         char *id = "???";
  54
  55         if (TYPE_IS(CCH, goff))
  56                 id = "CCH";
  57         else if (TYPE_IS(TGH, goff))
  58                 id = "TGH";
  59         else if (TYPE_IS(TFH, goff))
  60                 id = "TFH";
  61
  62         panic(KERN_ALERT "GRU %p (%s) is malfunctioning\n", h, id);
  63 }
  64
  65 static int wait_instruction_complete(void *h, enum mcs_op opc)
  66 {
  67         int status;
  68         unsigned long start_time = get_cycles();
  69
  70         while (1) {
  71                 cpu_relax();
  72                 status = GET_MSEG_HANDLE_STATUS(h);
  73                 if (status != CCHSTATUS_ACTIVE)
  74                         break;
  75                 if (GRU_OPERATION_TIMEOUT < (get_cycles() - start_time)) {
  76                         report_instruction_timeout(h);
  77                         start_time = get_cycles();
  78                 }
  79         }
  80         if (gru_options & OPT_STATS)
  81                 update_mcs_stats(opc, get_cycles() - start_time);
  82         return status;
  83 }
  84
  85 int cch_allocate(struct gru_context_configuration_handle *cch)
  86 {
  87         int ret;
  88
  89         cch->opc = CCHOP_ALLOCATE;
  90         start_instruction(cch);
  91         ret = wait_instruction_complete(cch, cchop_allocate);
  92
  93         /*
  94          * Stop speculation into the GSEG being mapped by the previous ALLOCATE.
  95          * The GSEG memory does not exist until the ALLOCATE completes.
  96          */
  97         sync_core();
  98         return ret;
  99 }
 100
 101 int cch_start(struct gru_context_configuration_handle *cch)
 102 {
 103         cch->opc = CCHOP_START;
 104         start_instruction(cch);
 105         return wait_instruction_complete(cch, cchop_start);
 106 }
 107
 108 int cch_interrupt(struct gru_context_configuration_handle *cch)
 109 {
 110         cch->opc = CCHOP_INTERRUPT;
 111         start_instruction(cch);
 112         return wait_instruction_complete(cch, cchop_interrupt);
 113 }
 114
 115 int cch_deallocate(struct gru_context_configuration_handle *cch)
 116 {
 117         int ret;
 118
 119         cch->opc = CCHOP_DEALLOCATE;
 120         start_instruction(cch);
 121         ret = wait_instruction_complete(cch, cchop_deallocate);
 122
 123         /*
 124          * Stop speculation into the GSEG being unmapped by the previous
 125          * DEALLOCATE.
 126          */
 127         sync_core();
 128         return ret;
 129 }
 130
 131 int cch_interrupt_sync(struct gru_context_configuration_handle
 132                                      *cch)
 133 {
 134         cch->opc = CCHOP_INTERRUPT_SYNC;
 135         start_instruction(cch);
 136         return wait_instruction_complete(cch, cchop_interrupt_sync);
 137 }
 138
 139 int tgh_invalidate(struct gru_tlb_global_handle *tgh,
 140                                  unsigned long vaddr, unsigned long vaddrmask,
 141                                  int asid, int pagesize, int global, int n,
 142                                  unsigned short ctxbitmap)
 143 {
 144         tgh->vaddr = vaddr;
 145         tgh->asid = asid;
 146         tgh->pagesize = pagesize;
 147         tgh->n = n;
 148         tgh->global = global;
 149         tgh->vaddrmask = vaddrmask;
 150         tgh->ctxbitmap = ctxbitmap;
 151         tgh->opc = TGHOP_TLBINV;
 152         start_instruction(tgh);
 153         return wait_instruction_complete(tgh, tghop_invalidate);
 154 }
 155
 156 int tfh_write_only(struct gru_tlb_fault_handle *tfh,
 157                                   unsigned long paddr, int gaa,
 158                                   unsigned long vaddr, int asid, int dirty,
 159                                   int pagesize)
 160 {
 161         tfh->fillasid = asid;
 162         tfh->fillvaddr = vaddr;
 163         tfh->pfn = paddr >> GRU_PADDR_SHIFT;
 164         tfh->gaa = gaa;
 165         tfh->dirty = dirty;
 166         tfh->pagesize = pagesize;
 167         tfh->opc = TFHOP_WRITE_ONLY;
 168         start_instruction(tfh);
 169         return wait_instruction_complete(tfh, tfhop_write_only);
 170 }
 171
 172 void tfh_write_restart(struct gru_tlb_fault_handle *tfh,
 173                                      unsigned long paddr, int gaa,
 174                                      unsigned long vaddr, int asid, int dirty,
 175                                      int pagesize)
 176 {
 177         tfh->fillasid = asid;
 178         tfh->fillvaddr = vaddr;
 179         tfh->pfn = paddr >> GRU_PADDR_SHIFT;
 180         tfh->gaa = gaa;
 181         tfh->dirty = dirty;
 182         tfh->pagesize = pagesize;
 183         tfh->opc = TFHOP_WRITE_RESTART;
 184         start_instruction(tfh);
 185 }
 186
 187 void tfh_user_polling_mode(struct gru_tlb_fault_handle *tfh)
 188 {
 189         tfh->opc = TFHOP_USER_POLLING_MODE;
 190         start_instruction(tfh);
 191 }
 192
 193 void tfh_exception(struct gru_tlb_fault_handle *tfh)
 194 {
 195         tfh->opc = TFHOP_EXCEPTION;
 196         start_instruction(tfh);
 197 }
 198