1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2006 Chris Dearman (chris@mips.com), 4 */ 5 #include <linux/init.h> 6 #include <linux/kernel.h> 7 #include <linux/sched.h> 8 #include <linux/mm.h> 9 10 #include <asm/cpu-type.h> 11 #include <asm/mipsregs.h> 12 #include <asm/bcache.h> 13 #include <asm/cacheops.h> 14 #include <asm/page.h> 15 #include <asm/mmu_context.h> 16 #include <asm/r4kcache.h> 17 #include <asm/mips-cps.h> 18 #include <asm/bootinfo.h> 19 20 /* 21 * MIPS32/MIPS64 L2 cache handling 22 */ 23 24 /* 25 * Writeback and invalidate the secondary cache before DMA. 26 */ 27 static void mips_sc_wback_inv(unsigned long addr, unsigned long size) 28 { 29 blast_scache_range(addr, addr + size); 30 } 31 32 /* 33 * Invalidate the secondary cache before DMA. 34 */ 35 static void mips_sc_inv(unsigned long addr, unsigned long size) 36 { 37 unsigned long lsize = cpu_scache_line_size(); 38 unsigned long almask = ~(lsize - 1); 39 40 cache_op(Hit_Writeback_Inv_SD, addr & almask); 41 cache_op(Hit_Writeback_Inv_SD, (addr + size - 1) & almask); 42 blast_inv_scache_range(addr, addr + size); 43 } 44 45 static void mips_sc_enable(void) 46 { 47 /* L2 cache is permanently enabled */ 48 } 49 50 static void mips_sc_disable(void) 51 { 52 /* L2 cache is permanently enabled */ 53 } 54 55 static void mips_sc_prefetch_enable(void) 56 { 57 unsigned long pftctl; 58 59 if (mips_cm_revision() < CM_REV_CM2_5) 60 return; 61 62 /* 63 * If there is one or more L2 prefetch unit present then enable 64 * prefetching for both code & data, for all ports. 65 */ 66 pftctl = read_gcr_l2_pft_control(); 67 if (pftctl & CM_GCR_L2_PFT_CONTROL_NPFT) { 68 pftctl &= ~CM_GCR_L2_PFT_CONTROL_PAGEMASK; 69 pftctl |= PAGE_MASK & CM_GCR_L2_PFT_CONTROL_PAGEMASK; 70 pftctl |= CM_GCR_L2_PFT_CONTROL_PFTEN; 71 write_gcr_l2_pft_control(pftctl); 72 73 set_gcr_l2_pft_control_b(CM_GCR_L2_PFT_CONTROL_B_PORTID | 74 CM_GCR_L2_PFT_CONTROL_B_CEN); 75 } 76 } 77 78 static void mips_sc_prefetch_disable(void) 79 { 80 if (mips_cm_revision() < CM_REV_CM2_5) 81 return; 82 83 clear_gcr_l2_pft_control(CM_GCR_L2_PFT_CONTROL_PFTEN); 84 clear_gcr_l2_pft_control_b(CM_GCR_L2_PFT_CONTROL_B_PORTID | 85 CM_GCR_L2_PFT_CONTROL_B_CEN); 86 } 87 88 static bool mips_sc_prefetch_is_enabled(void) 89 { 90 unsigned long pftctl; 91 92 if (mips_cm_revision() < CM_REV_CM2_5) 93 return false; 94 95 pftctl = read_gcr_l2_pft_control(); 96 if (!(pftctl & CM_GCR_L2_PFT_CONTROL_NPFT)) 97 return false; 98 return !!(pftctl & CM_GCR_L2_PFT_CONTROL_PFTEN); 99 } 100 101 static struct bcache_ops mips_sc_ops = { 102 .bc_enable = mips_sc_enable, 103 .bc_disable = mips_sc_disable, 104 .bc_wback_inv = mips_sc_wback_inv, 105 .bc_inv = mips_sc_inv, 106 .bc_prefetch_enable = mips_sc_prefetch_enable, 107 .bc_prefetch_disable = mips_sc_prefetch_disable, 108 .bc_prefetch_is_enabled = mips_sc_prefetch_is_enabled, 109 }; 110 111 /* 112 * Check if the L2 cache controller is activated on a particular platform. 113 * MTI's L2 controller and the L2 cache controller of Broadcom's BMIPS 114 * cores both use c0_config2's bit 12 as "L2 Bypass" bit, that is the 115 * cache being disabled. However there is no guarantee for this to be 116 * true on all platforms. In an act of stupidity the spec defined bits 117 * 12..15 as implementation defined so below function will eventually have 118 * to be replaced by a platform specific probe. 119 */ 120 static inline int mips_sc_is_activated(struct cpuinfo_mips *c) 121 { 122 unsigned int config2 = read_c0_config2(); 123 unsigned int tmp; 124 125 /* Check the bypass bit (L2B) */ 126 switch (current_cpu_type()) { 127 case CPU_34K: 128 case CPU_74K: 129 case CPU_1004K: 130 case CPU_1074K: 131 case CPU_INTERAPTIV: 132 case CPU_PROAPTIV: 133 case CPU_P5600: 134 case CPU_BMIPS5000: 135 case CPU_QEMU_GENERIC: 136 case CPU_P6600: 137 if (config2 & (1 << 12)) 138 return 0; 139 } 140 141 tmp = (config2 >> 4) & 0x0f; 142 if (0 < tmp && tmp <= 7) 143 c->scache.linesz = 2 << tmp; 144 else 145 return 0; 146 return 1; 147 } 148 149 static int __init mips_sc_probe_cm3(void) 150 { 151 struct cpuinfo_mips *c = ¤t_cpu_data; 152 unsigned long cfg = read_gcr_l2_config(); 153 unsigned long sets, line_sz, assoc; 154 155 if (cfg & CM_GCR_L2_CONFIG_BYPASS) 156 return 0; 157 158 sets = cfg & CM_GCR_L2_CONFIG_SET_SIZE; 159 sets >>= __ffs(CM_GCR_L2_CONFIG_SET_SIZE); 160 if (sets) 161 c->scache.sets = 64 << sets; 162 163 line_sz = cfg & CM_GCR_L2_CONFIG_LINE_SIZE; 164 line_sz >>= __ffs(CM_GCR_L2_CONFIG_LINE_SIZE); 165 if (line_sz) 166 c->scache.linesz = 2 << line_sz; 167 168 assoc = cfg & CM_GCR_L2_CONFIG_ASSOC; 169 assoc >>= __ffs(CM_GCR_L2_CONFIG_ASSOC); 170 c->scache.ways = assoc + 1; 171 c->scache.waysize = c->scache.sets * c->scache.linesz; 172 c->scache.waybit = __ffs(c->scache.waysize); 173 174 if (c->scache.linesz) { 175 c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT; 176 c->options |= MIPS_CPU_INCLUSIVE_CACHES; 177 return 1; 178 } 179 180 return 0; 181 } 182 183 static inline int __init mips_sc_probe(void) 184 { 185 struct cpuinfo_mips *c = ¤t_cpu_data; 186 unsigned int config1, config2; 187 unsigned int tmp; 188 189 /* Mark as not present until probe completed */ 190 c->scache.flags |= MIPS_CACHE_NOT_PRESENT; 191 192 if (mips_cm_revision() >= CM_REV_CM3) 193 return mips_sc_probe_cm3(); 194 195 /* Ignore anything but MIPSxx processors */ 196 if (!(c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 | 197 MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 | 198 MIPS_CPU_ISA_M32R5 | MIPS_CPU_ISA_M64R5 | 199 MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R6))) 200 return 0; 201 202 /* Does this MIPS32/MIPS64 CPU have a config2 register? */ 203 config1 = read_c0_config1(); 204 if (!(config1 & MIPS_CONF_M)) 205 return 0; 206 207 config2 = read_c0_config2(); 208 209 if (!mips_sc_is_activated(c)) 210 return 0; 211 212 tmp = (config2 >> 8) & 0x0f; 213 if (tmp <= 7) 214 c->scache.sets = 64 << tmp; 215 else 216 return 0; 217 218 tmp = (config2 >> 0) & 0x0f; 219 if (tmp <= 7) 220 c->scache.ways = tmp + 1; 221 else 222 return 0; 223 224 if (current_cpu_type() == CPU_XBURST) { 225 switch (mips_machtype) { 226 /* 227 * According to config2 it would be 5-ways, but that is 228 * contradicted by all documentation. 229 */ 230 case MACH_INGENIC_JZ4770: 231 c->scache.ways = 4; 232 break; 233 234 /* 235 * According to config2 it would be 5-ways and 512-sets, 236 * but that is contradicted by all documentation. 237 */ 238 case MACH_INGENIC_X1000: 239 c->scache.sets = 256; 240 c->scache.ways = 4; 241 break; 242 } 243 } 244 245 c->scache.waysize = c->scache.sets * c->scache.linesz; 246 c->scache.waybit = __ffs(c->scache.waysize); 247 248 c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT; 249 250 return 1; 251 } 252 253 int mips_sc_init(void) 254 { 255 int found = mips_sc_probe(); 256 if (found) { 257 mips_sc_enable(); 258 mips_sc_prefetch_enable(); 259 bcops = &mips_sc_ops; 260 } 261 return found; 262 } 263