^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) ** Tablewalk MMU emulator
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) **
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) ** by Toshiyasu Morita
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) **
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) ** Started 1/16/98 @ 2:22 am
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/mman.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/ptrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/delay.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/memblock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/bitops.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/sched/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <asm/setup.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <asm/traps.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <asm/page.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include <asm/sun3mmu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <asm/segment.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #include <asm/oplib.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <asm/mmu_context.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #include <asm/dvma.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #undef DEBUG_MMU_EMU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) #define DEBUG_PROM_MAPS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) ** Defines
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) #define CONTEXTS_NUM 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) #define SEGMAPS_PER_CONTEXT_NUM 2048
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) #define PAGES_PER_SEGMENT 16
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) #define PMEGS_NUM 256
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) #define PMEG_MASK 0xFF
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) ** Globals
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) unsigned long m68k_vmalloc_end;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) EXPORT_SYMBOL(m68k_vmalloc_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) unsigned long pmeg_vaddr[PMEGS_NUM];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) unsigned char pmeg_alloc[PMEGS_NUM];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) unsigned char pmeg_ctx[PMEGS_NUM];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) /* pointers to the mm structs for each task in each
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) context. 0xffffffff is a marker for kernel context */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) static struct mm_struct *ctx_alloc[CONTEXTS_NUM] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) [0] = (struct mm_struct *)0xffffffff
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) /* has this context been mmdrop'd? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) static unsigned char ctx_avail = CONTEXTS_NUM-1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) /* array of pages to be marked off for the rom when we do mem_init later */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) /* 256 pages lets the rom take up to 2mb of physical ram.. I really
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) hope it never wants mote than that. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) unsigned long rom_pages[256];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) /* Print a PTE value in symbolic form. For debugging. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) void print_pte (pte_t pte)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) #if 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) /* Verbose version. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) unsigned long val = pte_val (pte);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) pr_cont(" pte=%lx [addr=%lx",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) val, (val & SUN3_PAGE_PGNUM_MASK) << PAGE_SHIFT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) if (val & SUN3_PAGE_VALID) pr_cont(" valid");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) if (val & SUN3_PAGE_WRITEABLE) pr_cont(" write");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) if (val & SUN3_PAGE_SYSTEM) pr_cont(" sys");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) if (val & SUN3_PAGE_NOCACHE) pr_cont(" nocache");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) if (val & SUN3_PAGE_ACCESSED) pr_cont(" accessed");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) if (val & SUN3_PAGE_MODIFIED) pr_cont(" modified");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) switch (val & SUN3_PAGE_TYPE_MASK) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) case SUN3_PAGE_TYPE_MEMORY: pr_cont(" memory"); break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) case SUN3_PAGE_TYPE_IO: pr_cont(" io"); break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) case SUN3_PAGE_TYPE_VME16: pr_cont(" vme16"); break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) case SUN3_PAGE_TYPE_VME32: pr_cont(" vme32"); break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) pr_cont("]\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) /* Terse version. More likely to fit on a line. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) unsigned long val = pte_val (pte);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) char flags[7], *type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) flags[0] = (val & SUN3_PAGE_VALID) ? 'v' : '-';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) flags[1] = (val & SUN3_PAGE_WRITEABLE) ? 'w' : '-';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) flags[2] = (val & SUN3_PAGE_SYSTEM) ? 's' : '-';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) flags[3] = (val & SUN3_PAGE_NOCACHE) ? 'x' : '-';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) flags[4] = (val & SUN3_PAGE_ACCESSED) ? 'a' : '-';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) flags[5] = (val & SUN3_PAGE_MODIFIED) ? 'm' : '-';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) flags[6] = '\0';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) switch (val & SUN3_PAGE_TYPE_MASK) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) case SUN3_PAGE_TYPE_MEMORY: type = "memory"; break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) case SUN3_PAGE_TYPE_IO: type = "io" ; break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) case SUN3_PAGE_TYPE_VME16: type = "vme16" ; break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) case SUN3_PAGE_TYPE_VME32: type = "vme32" ; break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) default: type = "unknown?"; break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) pr_cont(" pte=%08lx [%07lx %s %s]\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) val, (val & SUN3_PAGE_PGNUM_MASK) << PAGE_SHIFT, flags, type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) /* Print the PTE value for a given virtual address. For debugging. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) void print_pte_vaddr (unsigned long vaddr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) pr_cont(" vaddr=%lx [%02lx]", vaddr, sun3_get_segmap (vaddr));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) print_pte (__pte (sun3_get_pte (vaddr)));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) * Initialise the MMU emulator.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) void __init mmu_emu_init(unsigned long bootmem_end)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) unsigned long seg, num;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) int i,j;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) memset(rom_pages, 0, sizeof(rom_pages));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) memset(pmeg_vaddr, 0, sizeof(pmeg_vaddr));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) memset(pmeg_alloc, 0, sizeof(pmeg_alloc));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) memset(pmeg_ctx, 0, sizeof(pmeg_ctx));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) /* pmeg align the end of bootmem, adding another pmeg,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) * later bootmem allocations will likely need it */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) bootmem_end = (bootmem_end + (2 * SUN3_PMEG_SIZE)) & ~SUN3_PMEG_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) /* mark all of the pmegs used thus far as reserved */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) for (i=0; i < __pa(bootmem_end) / SUN3_PMEG_SIZE ; ++i)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) pmeg_alloc[i] = 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) /* I'm thinking that most of the top pmeg's are going to be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) used for something, and we probably shouldn't risk it */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) for(num = 0xf0; num <= 0xff; num++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) pmeg_alloc[num] = 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) /* liberate all existing mappings in the rest of kernel space */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) for(seg = bootmem_end; seg < 0x0f800000; seg += SUN3_PMEG_SIZE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) i = sun3_get_segmap(seg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) if(!pmeg_alloc[i]) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) #ifdef DEBUG_MMU_EMU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) pr_info("freed:");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) print_pte_vaddr (seg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) sun3_put_segmap(seg, SUN3_INVALID_PMEG);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) j = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) for (num=0, seg=0x0F800000; seg<0x10000000; seg+=16*PAGE_SIZE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) if (sun3_get_segmap (seg) != SUN3_INVALID_PMEG) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) #ifdef DEBUG_PROM_MAPS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) for(i = 0; i < 16; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) pr_info("mapped:");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) print_pte_vaddr (seg + (i*PAGE_SIZE));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) // the lowest mapping here is the end of our
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) // vmalloc region
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) if (!m68k_vmalloc_end)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) m68k_vmalloc_end = seg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) // mark the segmap alloc'd, and reserve any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) // of the first 0xbff pages the hardware is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) // already using... does any sun3 support > 24mb?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) pmeg_alloc[sun3_get_segmap(seg)] = 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) dvma_init();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) /* blank everything below the kernel, and we've got the base
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) mapping to start all the contexts off with... */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) for(seg = 0; seg < PAGE_OFFSET; seg += SUN3_PMEG_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) sun3_put_segmap(seg, SUN3_INVALID_PMEG);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) set_fs(MAKE_MM_SEG(3));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) for(seg = 0; seg < 0x10000000; seg += SUN3_PMEG_SIZE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) i = sun3_get_segmap(seg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) for(j = 1; j < CONTEXTS_NUM; j++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) (*(romvec->pv_setctxt))(j, (void *)seg, i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) set_fs(KERNEL_DS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) /* erase the mappings for a dead context. Uses the pg_dir for hints
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) as the pmeg tables proved somewhat unreliable, and unmapping all of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) TASK_SIZE was much slower and no more stable. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) /* todo: find a better way to keep track of the pmegs used by a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) context for when they're cleared */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) void clear_context(unsigned long context)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) unsigned char oldctx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) unsigned long i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) if(context) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) if(!ctx_alloc[context])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) panic("clear_context: context not allocated\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) ctx_alloc[context]->context = SUN3_INVALID_CONTEXT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) ctx_alloc[context] = (struct mm_struct *)0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) ctx_avail++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) oldctx = sun3_get_context();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) sun3_put_context(context);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) for(i = 0; i < SUN3_INVALID_PMEG; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) if((pmeg_ctx[i] == context) && (pmeg_alloc[i] == 1)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) sun3_put_segmap(pmeg_vaddr[i], SUN3_INVALID_PMEG);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) pmeg_ctx[i] = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) pmeg_alloc[i] = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) pmeg_vaddr[i] = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) sun3_put_context(oldctx);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) /* gets an empty context. if full, kills the next context listed to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) die first */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) /* This context invalidation scheme is, well, totally arbitrary, I'm
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) sure it could be much more intelligent... but it gets the job done
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) for now without much overhead in making it's decision. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) /* todo: come up with optimized scheme for flushing contexts */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) unsigned long get_free_context(struct mm_struct *mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) unsigned long new = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) static unsigned char next_to_die = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) if(!ctx_avail) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) /* kill someone to get our context */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) new = next_to_die;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) clear_context(new);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) next_to_die = (next_to_die + 1) & 0x7;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) if(!next_to_die)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) next_to_die++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) while(new < CONTEXTS_NUM) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) if(ctx_alloc[new])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) new++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) // check to make sure one was really free...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) if(new == CONTEXTS_NUM)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) panic("get_free_context: failed to find free context");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) ctx_alloc[new] = mm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) ctx_avail--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) return new;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) * Dynamically select a `spare' PMEG and use it to map virtual `vaddr' in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) * `context'. Maintain internal PMEG management structures. This doesn't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) * actually map the physical address, but does clear the old mappings.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) //todo: better allocation scheme? but is extra complexity worthwhile?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) //todo: only clear old entries if necessary? how to tell?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) inline void mmu_emu_map_pmeg (int context, int vaddr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) static unsigned char curr_pmeg = 128;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) /* Round address to PMEG boundary. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) vaddr &= ~SUN3_PMEG_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) /* Find a spare one. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) while (pmeg_alloc[curr_pmeg] == 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) ++curr_pmeg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) #ifdef DEBUG_MMU_EMU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) pr_info("mmu_emu_map_pmeg: pmeg %x to context %d vaddr %x\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) curr_pmeg, context, vaddr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) /* Invalidate old mapping for the pmeg, if any */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) if (pmeg_alloc[curr_pmeg] == 1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) sun3_put_context(pmeg_ctx[curr_pmeg]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) sun3_put_segmap (pmeg_vaddr[curr_pmeg], SUN3_INVALID_PMEG);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) sun3_put_context(context);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) /* Update PMEG management structures. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) // don't take pmeg's away from the kernel...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) if(vaddr >= PAGE_OFFSET) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) /* map kernel pmegs into all contexts */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) unsigned char i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) for(i = 0; i < CONTEXTS_NUM; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) sun3_put_context(i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) sun3_put_segmap (vaddr, curr_pmeg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) sun3_put_context(context);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) pmeg_alloc[curr_pmeg] = 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) pmeg_ctx[curr_pmeg] = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) pmeg_alloc[curr_pmeg] = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) pmeg_ctx[curr_pmeg] = context;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) sun3_put_segmap (vaddr, curr_pmeg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) pmeg_vaddr[curr_pmeg] = vaddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) /* Set hardware mapping and clear the old PTE entries. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) for (i=0; i<SUN3_PMEG_SIZE; i+=SUN3_PTE_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) sun3_put_pte (vaddr + i, SUN3_PAGE_SYSTEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) /* Consider a different one next time. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) ++curr_pmeg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) * Handle a pagefault at virtual address `vaddr'; check if there should be a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) * page there (specifically, whether the software pagetables indicate that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) * there is). This is necessary due to the limited size of the second-level
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) * Sun3 hardware pagetables (256 groups of 16 pages). If there should be a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) * mapping present, we select a `spare' PMEG and use it to create a mapping.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) * `read_flag' is nonzero for a read fault; zero for a write. Returns nonzero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) * if we successfully handled the fault.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) //todo: should we bump minor pagefault counter? if so, here or in caller?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) //todo: possibly inline this into bus_error030 in <asm/buserror.h> ?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) // kernel_fault is set when a kernel page couldn't be demand mapped,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) // and forces another try using the kernel page table. basically a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) // hack so that vmalloc would work correctly.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) int mmu_emu_handle_fault (unsigned long vaddr, int read_flag, int kernel_fault)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) unsigned long segment, offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) unsigned char context;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) pte_t *pte;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) pgd_t * crp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) if(current->mm == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) crp = swapper_pg_dir;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) context = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) context = current->mm->context;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) if(kernel_fault)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) crp = swapper_pg_dir;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) crp = current->mm->pgd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) #ifdef DEBUG_MMU_EMU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) pr_info("mmu_emu_handle_fault: vaddr=%lx type=%s crp=%p\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) vaddr, read_flag ? "read" : "write", crp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) segment = (vaddr >> SUN3_PMEG_SIZE_BITS) & 0x7FF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) offset = (vaddr >> SUN3_PTE_SIZE_BITS) & 0xF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) #ifdef DEBUG_MMU_EMU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) pr_info("mmu_emu_handle_fault: segment=%lx offset=%lx\n", segment,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) pte = (pte_t *) pgd_val (*(crp + segment));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) //todo: next line should check for valid pmd properly.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) if (!pte) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) // pr_info("mmu_emu_handle_fault: invalid pmd\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) pte = (pte_t *) __va ((unsigned long)(pte + offset));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) /* Make sure this is a valid page */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) if (!(pte_val (*pte) & SUN3_PAGE_VALID))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) /* Make sure there's a pmeg allocated for the page */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) if (sun3_get_segmap (vaddr&~SUN3_PMEG_MASK) == SUN3_INVALID_PMEG)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) mmu_emu_map_pmeg (context, vaddr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) /* Write the pte value to hardware MMU */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) sun3_put_pte (vaddr&PAGE_MASK, pte_val (*pte));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) /* Update software copy of the pte value */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) // I'm not sure this is necessary. If this is required, we ought to simply
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) // copy this out when we reuse the PMEG or at some other convenient time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) // Doing it here is fairly meaningless, anyway, as we only know about the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) // first access to a given page. --m
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) if (!read_flag) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) if (pte_val (*pte) & SUN3_PAGE_WRITEABLE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) pte_val (*pte) |= (SUN3_PAGE_ACCESSED
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) | SUN3_PAGE_MODIFIED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) return 0; /* Write-protect error. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) pte_val (*pte) |= SUN3_PAGE_ACCESSED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) #ifdef DEBUG_MMU_EMU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) pr_info("seg:%ld crp:%p ->", get_fs().seg, crp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) print_pte_vaddr (vaddr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) pr_cont("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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