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