arch/blackfin/kernel/cplb-nompu/cplbmgr.c

   1 /*
   2  * Based on:     arch/blackfin/kernel/cplb-mpu/cplbmgr.c
   3  * Author:       Michael McTernan <mmcternan@airvana.com>
   4  *
   5  * Description:  CPLB miss handler.
   6  *
   7  * Modified:
   8  *               Copyright 2008 Airvana Inc.
   9  *               Copyright 2008-2009 Analog Devices Inc.
  10  *
  11  * Licensed under the GPL-2 or later
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <asm/blackfin.h>
  16 #include <asm/cplbinit.h>
  17 #include <asm/cplb.h>
  18 #include <asm/mmu_context.h>
  19 #include <asm/traps.h>
  20
  21 /*
  22  * WARNING
  23  *
  24  * This file is compiled with certain -ffixed-reg options.  We have to
  25  * make sure not to call any functions here that could clobber these
  26  * registers.
  27  */
  28
  29 int nr_dcplb_miss[NR_CPUS], nr_icplb_miss[NR_CPUS];
  30 int nr_dcplb_supv_miss[NR_CPUS], nr_icplb_supv_miss[NR_CPUS];
  31 int nr_cplb_flush[NR_CPUS], nr_dcplb_prot[NR_CPUS];
  32
  33 #ifdef CONFIG_EXCPT_IRQ_SYSC_L1
  34 #define MGR_ATTR __attribute__((l1_text))
  35 #else
  36 #define MGR_ATTR
  37 #endif
  38
  39 static inline void write_dcplb_data(int cpu, int idx, unsigned long data,
  40                                     unsigned long addr)
  41 {
  42         _disable_dcplb();
  43         bfin_write32(DCPLB_DATA0 + idx * 4, data);
  44         bfin_write32(DCPLB_ADDR0 + idx * 4, addr);
  45         _enable_dcplb();
  46
  47 #ifdef CONFIG_CPLB_INFO
  48         dcplb_tbl[cpu][idx].addr = addr;
  49         dcplb_tbl[cpu][idx].data = data;
  50 #endif
  51 }
  52
  53 static inline void write_icplb_data(int cpu, int idx, unsigned long data,
  54                                     unsigned long addr)
  55 {
  56         _disable_icplb();
  57         bfin_write32(ICPLB_DATA0 + idx * 4, data);
  58         bfin_write32(ICPLB_ADDR0 + idx * 4, addr);
  59         _enable_icplb();
  60
  61 #ifdef CONFIG_CPLB_INFO
  62         icplb_tbl[cpu][idx].addr = addr;
  63         icplb_tbl[cpu][idx].data = data;
  64 #endif
  65 }
  66
  67 /* Counters to implement round-robin replacement.  */
  68 static int icplb_rr_index[NR_CPUS] PDT_ATTR;
  69 static int dcplb_rr_index[NR_CPUS] PDT_ATTR;
  70
  71 /*
  72  * Find an ICPLB entry to be evicted and return its index.
  73  */
  74 static int evict_one_icplb(int cpu)
  75 {
  76         int i = first_switched_icplb + icplb_rr_index[cpu];
  77         if (i >= MAX_CPLBS) {
  78                 i -= MAX_CPLBS - first_switched_icplb;
  79                 icplb_rr_index[cpu] -= MAX_CPLBS - first_switched_icplb;
  80         }
  81         icplb_rr_index[cpu]++;
  82         return i;
  83 }
  84
  85 static int evict_one_dcplb(int cpu)
  86 {
  87         int i = first_switched_dcplb + dcplb_rr_index[cpu];
  88         if (i >= MAX_CPLBS) {
  89                 i -= MAX_CPLBS - first_switched_dcplb;
  90                 dcplb_rr_index[cpu] -= MAX_CPLBS - first_switched_dcplb;
  91         }
  92         dcplb_rr_index[cpu]++;
  93         return i;
  94 }
  95
  96 MGR_ATTR static int icplb_miss(int cpu)
  97 {
  98         unsigned long addr = bfin_read_ICPLB_FAULT_ADDR();
  99         int status = bfin_read_ICPLB_STATUS();
 100         int idx;
 101         unsigned long i_data, base, addr1, eaddr;
 102
 103         nr_icplb_miss[cpu]++;
 104         if (unlikely(status & FAULT_USERSUPV))
 105                 nr_icplb_supv_miss[cpu]++;
 106
 107         base = 0;
 108         idx = 0;
 109         do {
 110                 eaddr = icplb_bounds[idx].eaddr;
 111                 if (addr < eaddr)
 112                         break;
 113                 base = eaddr;
 114         } while (++idx < icplb_nr_bounds);
 115
 116         if (unlikely(idx == icplb_nr_bounds))
 117                 return CPLB_NO_ADDR_MATCH;
 118
 119         i_data = icplb_bounds[idx].data;
 120         if (unlikely(i_data == 0))
 121                 return CPLB_NO_ADDR_MATCH;
 122
 123         addr1 = addr & ~(SIZE_4M - 1);
 124         addr &= ~(SIZE_1M - 1);
 125         i_data |= PAGE_SIZE_1MB;
 126         if (addr1 >= base && (addr1 + SIZE_4M) <= eaddr) {
 127                 /*
 128                  * This works because
 129                  * (PAGE_SIZE_4MB & PAGE_SIZE_1MB) == PAGE_SIZE_1MB.
 130                  */
 131                 i_data |= PAGE_SIZE_4MB;
 132                 addr = addr1;
 133         }
 134
 135         /* Pick entry to evict */
 136         idx = evict_one_icplb(cpu);
 137
 138         write_icplb_data(cpu, idx, i_data, addr);
 139
 140         return CPLB_RELOADED;
 141 }
 142
 143 MGR_ATTR static int dcplb_miss(int cpu)
 144 {
 145         unsigned long addr = bfin_read_DCPLB_FAULT_ADDR();
 146         int status = bfin_read_DCPLB_STATUS();
 147         int idx;
 148         unsigned long d_data, base, addr1, eaddr;
 149
 150         nr_dcplb_miss[cpu]++;
 151         if (unlikely(status & FAULT_USERSUPV))
 152                 nr_dcplb_supv_miss[cpu]++;
 153
 154         base = 0;
 155         idx = 0;
 156         do {
 157                 eaddr = dcplb_bounds[idx].eaddr;
 158                 if (addr < eaddr)
 159                         break;
 160                 base = eaddr;
 161         } while (++idx < dcplb_nr_bounds);
 162
 163         if (unlikely(idx == dcplb_nr_bounds))
 164                 return CPLB_NO_ADDR_MATCH;
 165
 166         d_data = dcplb_bounds[idx].data;
 167         if (unlikely(d_data == 0))
 168                 return CPLB_NO_ADDR_MATCH;
 169
 170         addr1 = addr & ~(SIZE_4M - 1);
 171         addr &= ~(SIZE_1M - 1);
 172         d_data |= PAGE_SIZE_1MB;
 173         if (addr1 >= base && (addr1 + SIZE_4M) <= eaddr) {
 174                 /*
 175                  * This works because
 176                  * (PAGE_SIZE_4MB & PAGE_SIZE_1MB) == PAGE_SIZE_1MB.
 177                  */
 178                 d_data |= PAGE_SIZE_4MB;
 179                 addr = addr1;
 180         }
 181
 182         /* Pick entry to evict */
 183         idx = evict_one_dcplb(cpu);
 184
 185         write_dcplb_data(cpu, idx, d_data, addr);
 186
 187         return CPLB_RELOADED;
 188 }
 189
 190 MGR_ATTR int cplb_hdr(int seqstat, struct pt_regs *regs)
 191 {
 192         int cause = seqstat & 0x3f;
 193         unsigned int cpu = raw_smp_processor_id();
 194         switch (cause) {
 195         case VEC_CPLB_I_M:
 196                 return icplb_miss(cpu);
 197         case VEC_CPLB_M:
 198                 return dcplb_miss(cpu);
 199         default:
 200                 return CPLB_UNKNOWN_ERR;
 201         }
 202 }