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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 | // SPDX-License-Identifier: GPL-2.0 /* * linux/arch/cris/arch-v10/mm/init.c * */ #include <linux/mmzone.h> #include <linux/init.h> #include <linux/bootmem.h> #include <linux/mm.h> #include <asm/pgtable.h> #include <asm/page.h> #include <asm/types.h> #include <asm/mmu.h> #include <asm/io.h> #include <asm/mmu_context.h> #include <arch/svinto.h> extern void tlb_init(void); /* * The kernel is already mapped with a kernel segment at kseg_c so * we don't need to map it with a page table. However head.S also * temporarily mapped it at kseg_4 so we should set up the ksegs again, * clear the TLB and do some other paging setup stuff. */ void __init paging_init(void) { int i; unsigned long zones_size[MAX_NR_ZONES]; printk("Setting up paging and the MMU.\n"); /* clear out the init_mm.pgd that will contain the kernel's mappings */ for(i = 0; i < PTRS_PER_PGD; i++) swapper_pg_dir[i] = __pgd(0); /* make sure the current pgd table points to something sane * (even if it is most probably not used until the next * switch_mm) */ per_cpu(current_pgd, smp_processor_id()) = init_mm.pgd; /* initialise the TLB (tlb.c) */ tlb_init(); /* see README.mm for details on the KSEG setup */ #ifdef CONFIG_CRIS_LOW_MAP /* Etrax-100 LX version 1 has a bug so that we cannot map anything * across the 0x80000000 boundary, so we need to shrink the user-virtual * area to 0x50000000 instead of 0xb0000000 and map things slightly * different. The unused areas are marked as paged so that we can catch * freak kernel accesses there. * * The ARTPEC chip is mapped at 0xa so we pass that segment straight * through. We cannot vremap it because the vmalloc area is below 0x8 * and Juliette needs an uncached area above 0x8. * * Same thing with 0xc and 0x9, which is memory-mapped I/O on some boards. * We map them straight over in LOW_MAP, but use vremap in LX version 2. */ #define CACHED_BOOTROM (KSEG_F | 0x08000000UL) *R_MMU_KSEG = ( IO_STATE(R_MMU_KSEG, seg_f, seg ) | /* bootrom */ IO_STATE(R_MMU_KSEG, seg_e, page ) | IO_STATE(R_MMU_KSEG, seg_d, page ) | IO_STATE(R_MMU_KSEG, seg_c, page ) | IO_STATE(R_MMU_KSEG, seg_b, seg ) | /* kernel reg area */ IO_STATE(R_MMU_KSEG, seg_a, page ) | IO_STATE(R_MMU_KSEG, seg_9, seg ) | /* LED's on some boards */ IO_STATE(R_MMU_KSEG, seg_8, seg ) | /* CSE0/1, flash and I/O */ IO_STATE(R_MMU_KSEG, seg_7, page ) | /* kernel vmalloc area */ IO_STATE(R_MMU_KSEG, seg_6, seg ) | /* kernel DRAM area */ IO_STATE(R_MMU_KSEG, seg_5, seg ) | /* cached flash */ IO_STATE(R_MMU_KSEG, seg_4, page ) | /* user area */ IO_STATE(R_MMU_KSEG, seg_3, page ) | /* user area */ IO_STATE(R_MMU_KSEG, seg_2, page ) | /* user area */ IO_STATE(R_MMU_KSEG, seg_1, page ) | /* user area */ IO_STATE(R_MMU_KSEG, seg_0, page ) ); /* user area */ *R_MMU_KBASE_HI = ( IO_FIELD(R_MMU_KBASE_HI, base_f, 0x3 ) | IO_FIELD(R_MMU_KBASE_HI, base_e, 0x0 ) | IO_FIELD(R_MMU_KBASE_HI, base_d, 0x0 ) | IO_FIELD(R_MMU_KBASE_HI, base_c, 0x0 ) | IO_FIELD(R_MMU_KBASE_HI, base_b, 0xb ) | IO_FIELD(R_MMU_KBASE_HI, base_a, 0x0 ) | IO_FIELD(R_MMU_KBASE_HI, base_9, 0x9 ) | IO_FIELD(R_MMU_KBASE_HI, base_8, 0x8 ) ); *R_MMU_KBASE_LO = ( IO_FIELD(R_MMU_KBASE_LO, base_7, 0x0 ) | IO_FIELD(R_MMU_KBASE_LO, base_6, 0x4 ) | IO_FIELD(R_MMU_KBASE_LO, base_5, 0x0 ) | IO_FIELD(R_MMU_KBASE_LO, base_4, 0x0 ) | IO_FIELD(R_MMU_KBASE_LO, base_3, 0x0 ) | IO_FIELD(R_MMU_KBASE_LO, base_2, 0x0 ) | IO_FIELD(R_MMU_KBASE_LO, base_1, 0x0 ) | IO_FIELD(R_MMU_KBASE_LO, base_0, 0x0 ) ); #else /* This code is for the corrected Etrax-100 LX version 2... */ #define CACHED_BOOTROM (KSEG_A | 0x08000000UL) *R_MMU_KSEG = ( IO_STATE(R_MMU_KSEG, seg_f, seg ) | /* cached flash */ IO_STATE(R_MMU_KSEG, seg_e, seg ) | /* uncached flash */ IO_STATE(R_MMU_KSEG, seg_d, page ) | /* vmalloc area */ IO_STATE(R_MMU_KSEG, seg_c, seg ) | /* kernel area */ IO_STATE(R_MMU_KSEG, seg_b, seg ) | /* kernel reg area */ IO_STATE(R_MMU_KSEG, seg_a, seg ) | /* bootrom */ IO_STATE(R_MMU_KSEG, seg_9, page ) | /* user area */ IO_STATE(R_MMU_KSEG, seg_8, page ) | IO_STATE(R_MMU_KSEG, seg_7, page ) | IO_STATE(R_MMU_KSEG, seg_6, page ) | IO_STATE(R_MMU_KSEG, seg_5, page ) | IO_STATE(R_MMU_KSEG, seg_4, page ) | IO_STATE(R_MMU_KSEG, seg_3, page ) | IO_STATE(R_MMU_KSEG, seg_2, page ) | IO_STATE(R_MMU_KSEG, seg_1, page ) | IO_STATE(R_MMU_KSEG, seg_0, page ) ); *R_MMU_KBASE_HI = ( IO_FIELD(R_MMU_KBASE_HI, base_f, 0x0 ) | IO_FIELD(R_MMU_KBASE_HI, base_e, 0x8 ) | IO_FIELD(R_MMU_KBASE_HI, base_d, 0x0 ) | IO_FIELD(R_MMU_KBASE_HI, base_c, 0x4 ) | IO_FIELD(R_MMU_KBASE_HI, base_b, 0xb ) | IO_FIELD(R_MMU_KBASE_HI, base_a, 0x3 ) | IO_FIELD(R_MMU_KBASE_HI, base_9, 0x0 ) | IO_FIELD(R_MMU_KBASE_HI, base_8, 0x0 ) ); *R_MMU_KBASE_LO = ( IO_FIELD(R_MMU_KBASE_LO, base_7, 0x0 ) | IO_FIELD(R_MMU_KBASE_LO, base_6, 0x0 ) | IO_FIELD(R_MMU_KBASE_LO, base_5, 0x0 ) | IO_FIELD(R_MMU_KBASE_LO, base_4, 0x0 ) | IO_FIELD(R_MMU_KBASE_LO, base_3, 0x0 ) | IO_FIELD(R_MMU_KBASE_LO, base_2, 0x0 ) | IO_FIELD(R_MMU_KBASE_LO, base_1, 0x0 ) | IO_FIELD(R_MMU_KBASE_LO, base_0, 0x0 ) ); #endif *R_MMU_CONTEXT = ( IO_FIELD(R_MMU_CONTEXT, page_id, 0 ) ); /* The MMU has been enabled ever since head.S but just to make * it totally obvious we do it here as well. */ *R_MMU_CTRL = ( IO_STATE(R_MMU_CTRL, inv_excp, enable ) | IO_STATE(R_MMU_CTRL, acc_excp, enable ) | IO_STATE(R_MMU_CTRL, we_excp, enable ) ); *R_MMU_ENABLE = IO_STATE(R_MMU_ENABLE, mmu_enable, enable); /* * initialize the bad page table and bad page to point * to a couple of allocated pages */ empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE); memset((void *)empty_zero_page, 0, PAGE_SIZE); /* All pages are DMA'able in Etrax, so put all in the DMA'able zone */ zones_size[0] = ((unsigned long)high_memory - PAGE_OFFSET) >> PAGE_SHIFT; for (i = 1; i < MAX_NR_ZONES; i++) zones_size[i] = 0; /* Use free_area_init_node instead of free_area_init, because the former * is designed for systems where the DRAM starts at an address substantially * higher than 0, like us (we start at PAGE_OFFSET). This saves space in the * mem_map page array. */ free_area_init_node(0, zones_size, PAGE_OFFSET >> PAGE_SHIFT, 0); } /* Initialize remaps of some I/O-ports. It is important that this * is called before any driver is initialized. */ static int __init init_ioremap(void) { /* Give the external I/O-port addresses their values */ #ifdef CONFIG_CRIS_LOW_MAP /* Simply a linear map (see the KSEG map above in paging_init) */ port_cse1_addr = (volatile unsigned long *)(MEM_CSE1_START | MEM_NON_CACHEABLE); port_csp0_addr = (volatile unsigned long *)(MEM_CSP0_START | MEM_NON_CACHEABLE); port_csp4_addr = (volatile unsigned long *)(MEM_CSP4_START | MEM_NON_CACHEABLE); #else /* Note that nothing blows up just because we do this remapping * it's ok even if the ports are not used or connected * to anything (or connected to a non-I/O thing) */ port_cse1_addr = (volatile unsigned long *) ioremap((unsigned long)(MEM_CSE1_START | MEM_NON_CACHEABLE), 16); port_csp0_addr = (volatile unsigned long *) ioremap((unsigned long)(MEM_CSP0_START | MEM_NON_CACHEABLE), 16); port_csp4_addr = (volatile unsigned long *) ioremap((unsigned long)(MEM_CSP4_START | MEM_NON_CACHEABLE), 16); #endif return 0; } __initcall(init_ioremap); /* Helper function for the two below */ static inline void flush_etrax_cacherange(void *startadr, int length) { /* CACHED_BOOTROM is mapped to the boot-rom area (cached) which * we can use to get fast dummy-reads of cachelines */ volatile short *flushadr = (volatile short *)(((unsigned long)startadr & ~PAGE_MASK) | CACHED_BOOTROM); length = length > 8192 ? 8192 : length; /* No need to flush more than cache size */ while(length > 0) { *flushadr; /* dummy read to flush */ flushadr += (32/sizeof(short)); /* a cacheline is 32 bytes */ length -= 32; } } /* Due to a bug in Etrax100(LX) all versions, receiving DMA buffers * will occasionally corrupt certain CPU writes if the DMA buffers * happen to be hot in the cache. * * As a workaround, we have to flush the relevant parts of the cache * before (re) inserting any receiving descriptor into the DMA HW. */ void prepare_rx_descriptor(struct etrax_dma_descr *desc) { flush_etrax_cacherange((void *)desc->buf, desc->sw_len ? desc->sw_len : 65536); } /* Do the same thing but flush the entire cache */ void flush_etrax_cache(void) { flush_etrax_cacherange(0, 8192); } |