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