/* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 2004, 2005 MIPS Technologies, Inc. All rights reserved. * Copyright (C) 2013 Imagination Technologies Ltd. * * VPE spport module for loading a MIPS SP program into VPE1. The SP * environment is rather simple since there are no TLBs. It needs * to be relocatable (or partiall linked). Initialize your stack in * the startup-code. The loader looks for the symbol __start and sets * up the execution to resume from there. To load and run, simply do * a cat SP 'binary' to the /dev/vpe1 device. */ #include <linux/kernel.h> #include <linux/device.h> #include <linux/fs.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/list.h> #include <linux/vmalloc.h> #include <linux/elf.h> #include <linux/seq_file.h> #include <linux/syscalls.h> #include <linux/moduleloader.h> #include <linux/interrupt.h> #include <linux/poll.h> #include <linux/bootmem.h> #include <asm/mipsregs.h> #include <asm/mipsmtregs.h> #include <asm/cacheflush.h> #include <linux/atomic.h> #include <asm/mips_mt.h> #include <asm/processor.h> #include <asm/vpe.h> #ifndef ARCH_SHF_SMALL #define ARCH_SHF_SMALL 0 #endif /* If this is set, the section belongs in the init part of the module */ #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1)) struct vpe_control vpecontrol = { .vpe_list_lock = __SPIN_LOCK_UNLOCKED(vpe_list_lock), .vpe_list = LIST_HEAD_INIT(vpecontrol.vpe_list), .tc_list_lock = __SPIN_LOCK_UNLOCKED(tc_list_lock), .tc_list = LIST_HEAD_INIT(vpecontrol.tc_list) }; /* get the vpe associated with this minor */ struct vpe *get_vpe(int minor) { struct vpe *res, *v; if (!cpu_has_mipsmt) return NULL; res = NULL; spin_lock(&vpecontrol.vpe_list_lock); list_for_each_entry(v, &vpecontrol.vpe_list, list) { if (v->minor == VPE_MODULE_MINOR) { res = v; break; } } spin_unlock(&vpecontrol.vpe_list_lock); return res; } /* get the vpe associated with this minor */ struct tc *get_tc(int index) { struct tc *res, *t; res = NULL; spin_lock(&vpecontrol.tc_list_lock); list_for_each_entry(t, &vpecontrol.tc_list, list) { if (t->index == index) { res = t; break; } } spin_unlock(&vpecontrol.tc_list_lock); return res; } /* allocate a vpe and associate it with this minor (or index) */ struct vpe *alloc_vpe(int minor) { struct vpe *v; v = kzalloc(sizeof(struct vpe), GFP_KERNEL); if (v == NULL) goto out; INIT_LIST_HEAD(&v->tc); spin_lock(&vpecontrol.vpe_list_lock); list_add_tail(&v->list, &vpecontrol.vpe_list); spin_unlock(&vpecontrol.vpe_list_lock); INIT_LIST_HEAD(&v->notify); v->minor = VPE_MODULE_MINOR; out: return v; } /* allocate a tc. At startup only tc0 is running, all other can be halted. */ struct tc *alloc_tc(int index) { struct tc *tc; tc = kzalloc(sizeof(struct tc), GFP_KERNEL); if (tc == NULL) goto out; INIT_LIST_HEAD(&tc->tc); tc->index = index; spin_lock(&vpecontrol.tc_list_lock); list_add_tail(&tc->list, &vpecontrol.tc_list); spin_unlock(&vpecontrol.tc_list_lock); out: return tc; } /* clean up and free everything */ void release_vpe(struct vpe *v) { list_del(&v->list); if (v->load_addr) release_progmem(v); kfree(v); } /* Find some VPE program space */ void *alloc_progmem(unsigned long len) { void *addr; #ifdef CONFIG_MIPS_VPE_LOADER_TOM /* * This means you must tell Linux to use less memory than you * physically have, for example by passing a mem= boot argument. */ addr = pfn_to_kaddr(max_low_pfn); memset(addr, 0, len); #else /* simple grab some mem for now */ addr = kzalloc(len, GFP_KERNEL); #endif return addr; } void release_progmem(void *ptr) { #ifndef CONFIG_MIPS_VPE_LOADER_TOM kfree(ptr); #endif } /* Update size with this section: return offset. */ static long get_offset(unsigned long *size, Elf_Shdr *sechdr) { long ret; ret = ALIGN(*size, sechdr->sh_addralign ? : 1); *size = ret + sechdr->sh_size; return ret; } /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld might -- code, read-only data, read-write data, small data. Tally sizes, and place the offsets into sh_entsize fields: high bit means it belongs in init. */ static void layout_sections(struct module *mod, const Elf_Ehdr *hdr, Elf_Shdr *sechdrs, const char *secstrings) { static unsigned long const masks[][2] = { /* NOTE: all executable code must be the first section * in this array; otherwise modify the text_size * finder in the two loops below */ {SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL}, {SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL}, {SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL}, {ARCH_SHF_SMALL | SHF_ALLOC, 0} }; unsigned int m, i; for (i = 0; i < hdr->e_shnum; i++) sechdrs[i].sh_entsize = ~0UL; for (m = 0; m < ARRAY_SIZE(masks); ++m) { for (i = 0; i < hdr->e_shnum; ++i) { Elf_Shdr *s = &sechdrs[i]; if ((s->sh_flags & masks[m][0]) != masks[m][0] || (s->sh_flags & masks[m][1]) || s->sh_entsize != ~0UL) continue; s->sh_entsize = get_offset((unsigned long *)&mod->core_size, s); } if (m == 0) mod->core_text_size = mod->core_size; } } /* from module-elf32.c, but subverted a little */ struct mips_hi16 { struct mips_hi16 *next; Elf32_Addr *addr; Elf32_Addr value; }; static struct mips_hi16 *mips_hi16_list; static unsigned int gp_offs, gp_addr; static int apply_r_mips_none(struct module *me, uint32_t *location, Elf32_Addr v) { return 0; } static int apply_r_mips_gprel16(struct module *me, uint32_t *location, Elf32_Addr v) { int rel; if (!(*location & 0xffff)) { rel = (int)v - gp_addr; } else { /* .sbss + gp(relative) + offset */ /* kludge! */ rel = (int)(short)((int)v + gp_offs + (int)(short)(*location & 0xffff) - gp_addr); } if ((rel > 32768) || (rel < -32768)) { pr_debug("VPE loader: apply_r_mips_gprel16: relative address 0x%x out of range of gp register\n", rel); return -ENOEXEC; } *location = (*location & 0xffff0000) | (rel & 0xffff); return 0; } static int apply_r_mips_pc16(struct module *me, uint32_t *location, Elf32_Addr v) { int rel; rel = (((unsigned int)v - (unsigned int)location)); rel >>= 2; /* because the offset is in _instructions_ not bytes. */ rel -= 1; /* and one instruction less due to the branch delay slot. */ if ((rel > 32768) || (rel < -32768)) { pr_debug("VPE loader: apply_r_mips_pc16: relative address out of range 0x%x\n", rel); return -ENOEXEC; } *location = (*location & 0xffff0000) | (rel & 0xffff); return 0; } static int apply_r_mips_32(struct module *me, uint32_t *location, Elf32_Addr v) { *location += v; return 0; } static int apply_r_mips_26(struct module *me, uint32_t *location, Elf32_Addr v) { if (v % 4) { pr_debug("VPE loader: apply_r_mips_26: unaligned relocation\n"); return -ENOEXEC; } /* * Not desperately convinced this is a good check of an overflow condition * anyway. But it gets in the way of handling undefined weak symbols which * we want to set to zero. * if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) { * printk(KERN_ERR * "module %s: relocation overflow\n", * me->name); * return -ENOEXEC; * } */ *location = (*location & ~0x03ffffff) | ((*location + (v >> 2)) & 0x03ffffff); return 0; } static int apply_r_mips_hi16(struct module *me, uint32_t *location, Elf32_Addr v) { struct mips_hi16 *n; /* * We cannot relocate this one now because we don't know the value of * the carry we need to add. Save the information, and let LO16 do the * actual relocation. */ n = kmalloc(sizeof(*n), GFP_KERNEL); if (!n) return -ENOMEM; n->addr = location; n->value = v; n->next = mips_hi16_list; mips_hi16_list = n; return 0; } static int apply_r_mips_lo16(struct module *me, uint32_t *location, Elf32_Addr v) { unsigned long insnlo = *location; Elf32_Addr val, vallo; struct mips_hi16 *l, *next; /* Sign extend the addend we extract from the lo insn. */ vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000; if (mips_hi16_list != NULL) { l = mips_hi16_list; while (l != NULL) { unsigned long insn; /* * The value for the HI16 had best be the same. */ if (v != l->value) { pr_debug("VPE loader: apply_r_mips_lo16/hi16: inconsistent value information\n"); goto out_free; } /* * Do the HI16 relocation. Note that we actually don't * need to know anything about the LO16 itself, except * where to find the low 16 bits of the addend needed * by the LO16. */ insn = *l->addr; val = ((insn & 0xffff) << 16) + vallo; val += v; /* * Account for the sign extension that will happen in * the low bits. */ val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff; insn = (insn & ~0xffff) | val; *l->addr = insn; next = l->next; kfree(l); l = next; } mips_hi16_list = NULL; } /* * Ok, we're done with the HI16 relocs. Now deal with the LO16. */ val = v + vallo; insnlo = (insnlo & ~0xffff) | (val & 0xffff); *location = insnlo; return 0; out_free: while (l != NULL) { next = l->next; kfree(l); l = next; } mips_hi16_list = NULL; return -ENOEXEC; } static int (*reloc_handlers[]) (struct module *me, uint32_t *location, Elf32_Addr v) = { [R_MIPS_NONE] = apply_r_mips_none, [R_MIPS_32] = apply_r_mips_32, [R_MIPS_26] = apply_r_mips_26, [R_MIPS_HI16] = apply_r_mips_hi16, [R_MIPS_LO16] = apply_r_mips_lo16, [R_MIPS_GPREL16] = apply_r_mips_gprel16, [R_MIPS_PC16] = apply_r_mips_pc16 }; static char *rstrs[] = { [R_MIPS_NONE] = "MIPS_NONE", [R_MIPS_32] = "MIPS_32", [R_MIPS_26] = "MIPS_26", [R_MIPS_HI16] = "MIPS_HI16", [R_MIPS_LO16] = "MIPS_LO16", [R_MIPS_GPREL16] = "MIPS_GPREL16", [R_MIPS_PC16] = "MIPS_PC16" }; static int apply_relocations(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, unsigned int relsec, struct module *me) { Elf32_Rel *rel = (void *) sechdrs[relsec].sh_addr; Elf32_Sym *sym; uint32_t *location; unsigned int i; Elf32_Addr v; int res; for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { Elf32_Word r_info = rel[i].r_info; /* This is where to make the change */ location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr + rel[i].r_offset; /* This is the symbol it is referring to */ sym = (Elf32_Sym *)sechdrs[symindex].sh_addr + ELF32_R_SYM(r_info); if (!sym->st_value) { pr_debug("%s: undefined weak symbol %s\n", me->name, strtab + sym->st_name); /* just print the warning, dont barf */ } v = sym->st_value; res = reloc_handlers[ELF32_R_TYPE(r_info)](me, location, v); if (res) { char *r = rstrs[ELF32_R_TYPE(r_info)]; pr_warn("VPE loader: .text+0x%x relocation type %s for symbol \"%s\" failed\n", rel[i].r_offset, r ? r : "UNKNOWN", strtab + sym->st_name); return res; } } return 0; } static inline void save_gp_address(unsigned int secbase, unsigned int rel) { gp_addr = secbase + rel; gp_offs = gp_addr - (secbase & 0xffff0000); } /* end module-elf32.c */ /* Change all symbols so that sh_value encodes the pointer directly. */ static void simplify_symbols(Elf_Shdr *sechdrs, unsigned int symindex, const char *strtab, const char *secstrings, unsigned int nsecs, struct module *mod) { Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr; unsigned long secbase, bssbase = 0; unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym); int size; /* find the .bss section for COMMON symbols */ for (i = 0; i < nsecs; i++) { if (strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) == 0) { bssbase = sechdrs[i].sh_addr; break; } } for (i = 1; i < n; i++) { switch (sym[i].st_shndx) { case SHN_COMMON: /* Allocate space for the symbol in the .bss section. st_value is currently size. We want it to have the address of the symbol. */ size = sym[i].st_value; sym[i].st_value = bssbase; bssbase += size; break; case SHN_ABS: /* Don't need to do anything */ break; case SHN_UNDEF: /* ret = -ENOENT; */ break; case SHN_MIPS_SCOMMON: pr_debug("simplify_symbols: ignoring SHN_MIPS_SCOMMON symbol <%s> st_shndx %d\n", strtab + sym[i].st_name, sym[i].st_shndx); /* .sbss section */ break; default: secbase = sechdrs[sym[i].st_shndx].sh_addr; if (strncmp(strtab + sym[i].st_name, "_gp", 3) == 0) save_gp_address(secbase, sym[i].st_value); sym[i].st_value += secbase; break; } } } #ifdef DEBUG_ELFLOADER static void dump_elfsymbols(Elf_Shdr *sechdrs, unsigned int symindex, const char *strtab, struct module *mod) { Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr; unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym); pr_debug("dump_elfsymbols: n %d\n", n); for (i = 1; i < n; i++) { pr_debug(" i %d name <%s> 0x%x\n", i, strtab + sym[i].st_name, sym[i].st_value); } } #endif static int find_vpe_symbols(struct vpe *v, Elf_Shdr *sechdrs, unsigned int symindex, const char *strtab, struct module *mod) { Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr; unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym); for (i = 1; i < n; i++) { if (strcmp(strtab + sym[i].st_name, "__start") == 0) v->__start = sym[i].st_value; if (strcmp(strtab + sym[i].st_name, "vpe_shared") == 0) v->shared_ptr = (void *)sym[i].st_value; } if ((v->__start == 0) || (v->shared_ptr == NULL)) return -1; return 0; } /* * Allocates a VPE with some program code space(the load address), copies the * contents of the program (p)buffer performing relocatations/etc, free's it * when finished. */ static int vpe_elfload(struct vpe *v) { Elf_Ehdr *hdr; Elf_Shdr *sechdrs; long err = 0; char *secstrings, *strtab = NULL; unsigned int len, i, symindex = 0, strindex = 0, relocate = 0; struct module mod; /* so we can re-use the relocations code */ memset(&mod, 0, sizeof(struct module)); strcpy(mod.name, "VPE loader"); hdr = (Elf_Ehdr *) v->pbuffer; len = v->plen; /* Sanity checks against insmoding binaries or wrong arch, weird elf version */ if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0 || (hdr->e_type != ET_REL && hdr->e_type != ET_EXEC) || !elf_check_arch(hdr) || hdr->e_shentsize != sizeof(*sechdrs)) { pr_warn("VPE loader: program wrong arch or weird elf version\n"); return -ENOEXEC; } if (hdr->e_type == ET_REL) relocate = 1; if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) { pr_err("VPE loader: program length %u truncated\n", len); return -ENOEXEC; } /* Convenience variables */ sechdrs = (void *)hdr + hdr->e_shoff; secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; sechdrs[0].sh_addr = 0; /* And these should exist, but gcc whinges if we don't init them */ symindex = strindex = 0; if (relocate) { for (i = 1; i < hdr->e_shnum; i++) { if ((sechdrs[i].sh_type != SHT_NOBITS) && (len < sechdrs[i].sh_offset + sechdrs[i].sh_size)) { pr_err("VPE program length %u truncated\n", len); return -ENOEXEC; } /* Mark all sections sh_addr with their address in the temporary image. */ sechdrs[i].sh_addr = (size_t) hdr + sechdrs[i].sh_offset; /* Internal symbols and strings. */ if (sechdrs[i].sh_type == SHT_SYMTAB) { symindex = i; strindex = sechdrs[i].sh_link; strtab = (char *)hdr + sechdrs[strindex].sh_offset; } } layout_sections(&mod, hdr, sechdrs, secstrings); } v->load_addr = alloc_progmem(mod.core_size); if (!v->load_addr) return -ENOMEM; pr_info("VPE loader: loading to %p\n", v->load_addr); if (relocate) { for (i = 0; i < hdr->e_shnum; i++) { void *dest; if (!(sechdrs[i].sh_flags & SHF_ALLOC)) continue; dest = v->load_addr + sechdrs[i].sh_entsize; if (sechdrs[i].sh_type != SHT_NOBITS) memcpy(dest, (void *)sechdrs[i].sh_addr, sechdrs[i].sh_size); /* Update sh_addr to point to copy in image. */ sechdrs[i].sh_addr = (unsigned long)dest; pr_debug(" section sh_name %s sh_addr 0x%x\n", secstrings + sechdrs[i].sh_name, sechdrs[i].sh_addr); } /* Fix up syms, so that st_value is a pointer to location. */ simplify_symbols(sechdrs, symindex, strtab, secstrings, hdr->e_shnum, &mod); /* Now do relocations. */ for (i = 1; i < hdr->e_shnum; i++) { const char *strtab = (char *)sechdrs[strindex].sh_addr; unsigned int info = sechdrs[i].sh_info; /* Not a valid relocation section? */ if (info >= hdr->e_shnum) continue; /* Don't bother with non-allocated sections */ if (!(sechdrs[info].sh_flags & SHF_ALLOC)) continue; if (sechdrs[i].sh_type == SHT_REL) err = apply_relocations(sechdrs, strtab, symindex, i, &mod); else if (sechdrs[i].sh_type == SHT_RELA) err = apply_relocate_add(sechdrs, strtab, symindex, i, &mod); if (err < 0) return err; } } else { struct elf_phdr *phdr = (struct elf_phdr *) ((char *)hdr + hdr->e_phoff); for (i = 0; i < hdr->e_phnum; i++) { if (phdr->p_type == PT_LOAD) { memcpy((void *)phdr->p_paddr, (char *)hdr + phdr->p_offset, phdr->p_filesz); memset((void *)phdr->p_paddr + phdr->p_filesz, 0, phdr->p_memsz - phdr->p_filesz); } phdr++; } for (i = 0; i < hdr->e_shnum; i++) { /* Internal symbols and strings. */ if (sechdrs[i].sh_type == SHT_SYMTAB) { symindex = i; strindex = sechdrs[i].sh_link; strtab = (char *)hdr + sechdrs[strindex].sh_offset; /* * mark symtab's address for when we try * to find the magic symbols */ sechdrs[i].sh_addr = (size_t) hdr + sechdrs[i].sh_offset; } } } /* make sure it's physically written out */ flush_icache_range((unsigned long)v->load_addr, (unsigned long)v->load_addr + v->len); if ((find_vpe_symbols(v, sechdrs, symindex, strtab, &mod)) < 0) { if (v->__start == 0) { pr_warn("VPE loader: program does not contain a __start symbol\n"); return -ENOEXEC; } if (v->shared_ptr == NULL) pr_warn("VPE loader: program does not contain vpe_shared symbol.\n" " Unable to use AMVP (AP/SP) facilities.\n"); } pr_info(" elf loaded\n"); return 0; } static int getcwd(char *buff, int size) { mm_segment_t old_fs; int ret; old_fs = get_fs(); set_fs(KERNEL_DS); ret = sys_getcwd(buff, size); set_fs(old_fs); return ret; } /* checks VPE is unused and gets ready to load program */ static int vpe_open(struct inode *inode, struct file *filp) { enum vpe_state state; struct vpe_notifications *notifier; struct vpe *v; int ret; if (VPE_MODULE_MINOR != iminor(inode)) { /* assume only 1 device at the moment. */ pr_warn("VPE loader: only vpe1 is supported\n"); return -ENODEV; } v = get_vpe(aprp_cpu_index()); if (v == NULL) { pr_warn("VPE loader: unable to get vpe\n"); return -ENODEV; } state = xchg(&v->state, VPE_STATE_INUSE); if (state != VPE_STATE_UNUSED) { pr_debug("VPE loader: tc in use dumping regs\n"); list_for_each_entry(notifier, &v->notify, list) notifier->stop(aprp_cpu_index()); release_progmem(v->load_addr); cleanup_tc(get_tc(aprp_cpu_index())); } /* this of-course trashes what was there before... */ v->pbuffer = vmalloc(P_SIZE); if (!v->pbuffer) { pr_warn("VPE loader: unable to allocate memory\n"); return -ENOMEM; } v->plen = P_SIZE; v->load_addr = NULL; v->len = 0; v->cwd[0] = 0; ret = getcwd(v->cwd, VPE_PATH_MAX); if (ret < 0) pr_warn("VPE loader: open, getcwd returned %d\n", ret); v->shared_ptr = NULL; v->__start = 0; return 0; } static int vpe_release(struct inode *inode, struct file *filp) { #if defined(CONFIG_MIPS_VPE_LOADER_MT) || defined(CONFIG_MIPS_VPE_LOADER_CMP) struct vpe *v; Elf_Ehdr *hdr; int ret = 0; v = get_vpe(aprp_cpu_index()); if (v == NULL) return -ENODEV; hdr = (Elf_Ehdr *) v->pbuffer; if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) == 0) { if (vpe_elfload(v) >= 0) { vpe_run(v); } else { pr_warn("VPE loader: ELF load failed.\n"); ret = -ENOEXEC; } } else { pr_warn("VPE loader: only elf files are supported\n"); ret = -ENOEXEC; } /* It's good to be able to run the SP and if it chokes have a look at the /dev/rt?. But if we reset the pointer to the shared struct we lose what has happened. So perhaps if garbage is sent to the vpe device, use it as a trigger for the reset. Hopefully a nice executable will be along shortly. */ if (ret < 0) v->shared_ptr = NULL; vfree(v->pbuffer); v->plen = 0; return ret; #else pr_warn("VPE loader: ELF load failed.\n"); return -ENOEXEC; #endif } static ssize_t vpe_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) { size_t ret = count; struct vpe *v; if (iminor(file_inode(file)) != VPE_MODULE_MINOR) return -ENODEV; v = get_vpe(aprp_cpu_index()); if (v == NULL) return -ENODEV; if ((count + v->len) > v->plen) { pr_warn("VPE loader: elf size too big. Perhaps strip uneeded symbols\n"); return -ENOMEM; } count -= copy_from_user(v->pbuffer + v->len, buffer, count); if (!count) return -EFAULT; v->len += count; return ret; } const struct file_operations vpe_fops = { .owner = THIS_MODULE, .open = vpe_open, .release = vpe_release, .write = vpe_write, .llseek = noop_llseek, }; void *vpe_get_shared(int index) { struct vpe *v = get_vpe(index); if (v == NULL) return NULL; return v->shared_ptr; } EXPORT_SYMBOL(vpe_get_shared); int vpe_notify(int index, struct vpe_notifications *notify) { struct vpe *v = get_vpe(index); if (v == NULL) return -1; list_add(¬ify->list, &v->notify); return 0; } EXPORT_SYMBOL(vpe_notify); char *vpe_getcwd(int index) { struct vpe *v = get_vpe(index); if (v == NULL) return NULL; return v->cwd; } EXPORT_SYMBOL(vpe_getcwd); module_init(vpe_module_init); module_exit(vpe_module_exit); MODULE_DESCRIPTION("MIPS VPE Loader"); MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc."); MODULE_LICENSE("GPL");