module.c

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/*
 * Copyright 2004-2009 Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later
 */

#define pr_fmt(fmt) "module %s: " fmt, mod->name

#include <linux/moduleloader.h>
#include <linux/elf.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <asm/dma.h>
#include <asm/cacheflush.h>
#include <asm/uaccess.h>

/* Transfer the section to the L1 memory */
int
module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
              char *secstrings, struct module *mod)
{
    /*
     * XXX: sechdrs are vmalloced in kernel/module.c
     * and would be vfreed just after module is loaded,
     * so we hack to keep the only information we needed
     * in mod->arch to correctly free L1 I/D sram later.
     * NOTE: this breaks the semantic of mod->arch structure.
     */
    Elf_Shdr *s, *sechdrs_end = sechdrs + hdr->e_shnum;
    void *dest;

    for (s = sechdrs; s < sechdrs_end; ++s) {
        const char *shname = secstrings + s->sh_name;

        if (s->sh_size == 0)
            continue;

        if (!strcmp(".l1.text", shname) ||
            (!strcmp(".text", shname) &&
             (hdr->e_flags & EF_BFIN_CODE_IN_L1))) {

            dest = l1_inst_sram_alloc(s->sh_size);
            mod->arch.text_l1 = dest;
            if (dest == NULL) {
                pr_err("L1 inst memory allocation failed\n");
                return -1;
            }
            dma_memcpy(dest, (void *)s->sh_addr, s->sh_size);

        } else if (!strcmp(".l1.data", shname) ||
                   (!strcmp(".data", shname) &&
                    (hdr->e_flags & EF_BFIN_DATA_IN_L1))) {

            dest = l1_data_sram_alloc(s->sh_size);
            mod->arch.data_a_l1 = dest;
            if (dest == NULL) {
                pr_err("L1 data memory allocation failed\n");
                return -1;
            }
            memcpy(dest, (void *)s->sh_addr, s->sh_size);

        } else if (!strcmp(".l1.bss", shname) ||
                   (!strcmp(".bss", shname) &&
                    (hdr->e_flags & EF_BFIN_DATA_IN_L1))) {

            dest = l1_data_sram_zalloc(s->sh_size);
            mod->arch.bss_a_l1 = dest;
            if (dest == NULL) {
                pr_err("L1 data memory allocation failed\n");
                return -1;
            }

        } else if (!strcmp(".l1.data.B", shname)) {

            dest = l1_data_B_sram_alloc(s->sh_size);
            mod->arch.data_b_l1 = dest;
            if (dest == NULL) {
                pr_err("L1 data memory allocation failed\n");
                return -1;
            }
            memcpy(dest, (void *)s->sh_addr, s->sh_size);

        } else if (!strcmp(".l1.bss.B", shname)) {

            dest = l1_data_B_sram_alloc(s->sh_size);
            mod->arch.bss_b_l1 = dest;
            if (dest == NULL) {
                pr_err("L1 data memory allocation failed\n");
                return -1;
            }
            memset(dest, 0, s->sh_size);

        } else if (!strcmp(".l2.text", shname) ||
                   (!strcmp(".text", shname) &&
                    (hdr->e_flags & EF_BFIN_CODE_IN_L2))) {

            dest = l2_sram_alloc(s->sh_size);
            mod->arch.text_l2 = dest;
            if (dest == NULL) {
                pr_err("L2 SRAM allocation failed\n");
                return -1;
            }
            memcpy(dest, (void *)s->sh_addr, s->sh_size);

        } else if (!strcmp(".l2.data", shname) ||
                   (!strcmp(".data", shname) &&
                    (hdr->e_flags & EF_BFIN_DATA_IN_L2))) {

            dest = l2_sram_alloc(s->sh_size);
            mod->arch.data_l2 = dest;
            if (dest == NULL) {
                pr_err("L2 SRAM allocation failed\n");
                return -1;
            }
            memcpy(dest, (void *)s->sh_addr, s->sh_size);

        } else if (!strcmp(".l2.bss", shname) ||
                   (!strcmp(".bss", shname) &&
                    (hdr->e_flags & EF_BFIN_DATA_IN_L2))) {

            dest = l2_sram_zalloc(s->sh_size);
            mod->arch.bss_l2 = dest;
            if (dest == NULL) {
                pr_err("L2 SRAM allocation failed\n");
                return -1;
            }

        } else
            continue;

        s->sh_flags &= ~SHF_ALLOC;
        s->sh_addr = (unsigned long)dest;
    }

    return 0;
}

/*************************************************************************/
/* FUNCTION : apply_relocate_add                                         */
/* ABSTRACT : Blackfin specific relocation handling for the loadable     */
/*            modules. Modules are expected to be .o files.              */
/*            Arithmetic relocations are handled.                        */
/*            We do not expect LSETUP to be split and hence is not       */
/*            handled.                                                   */
/*            R_BFIN_BYTE and R_BFIN_BYTE2 are also not handled as the   */
/*            gas does not generate it.                                  */
/*************************************************************************/
int
apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
           unsigned int symindex, unsigned int relsec,
           struct module *mod)
{
    unsigned int i;
    Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
    Elf32_Sym *sym;
    unsigned long location, value, size;

    pr_debug("applying relocate section %u to %u\n",
        relsec, sechdrs[relsec].sh_info);

    for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
        /* This is where to make the change */
        location = sechdrs[sechdrs[relsec].sh_info].sh_addr +
                   rel[i].r_offset;

        /* This is the symbol it is referring to. Note that all
           undefined symbols have been resolved. */
        sym = (Elf32_Sym *) sechdrs[symindex].sh_addr
            + ELF32_R_SYM(rel[i].r_info);
        value = sym->st_value;
        value += rel[i].r_addend;

#ifdef CONFIG_SMP
        if (location >= COREB_L1_DATA_A_START) {
            pr_err("cannot relocate in L1: %u (SMP kernel)\n",
                ELF32_R_TYPE(rel[i].r_info));
            return -ENOEXEC;
        }
#endif

        pr_debug("location is %lx, value is %lx type is %d\n",
            location, value, ELF32_R_TYPE(rel[i].r_info));

        switch (ELF32_R_TYPE(rel[i].r_info)) {

        case R_BFIN_HUIMM16:
            value >>= 16;
        case R_BFIN_LUIMM16:
        case R_BFIN_RIMM16:
            size = 2;
            break;
        case R_BFIN_BYTE4_DATA:
            size = 4;
            break;

        case R_BFIN_PCREL24:
        case R_BFIN_PCREL24_JUMP_L:
        case R_BFIN_PCREL12_JUMP:
        case R_BFIN_PCREL12_JUMP_S:
        case R_BFIN_PCREL10:
            pr_err("unsupported relocation: %u (no -mlong-calls?)\n",
                ELF32_R_TYPE(rel[i].r_info));
            return -ENOEXEC;

        default:
            pr_err("unknown relocation: %u\n",
                ELF32_R_TYPE(rel[i].r_info));
            return -ENOEXEC;
        }

        switch (bfin_mem_access_type(location, size)) {
        case BFIN_MEM_ACCESS_CORE:
        case BFIN_MEM_ACCESS_CORE_ONLY:
            memcpy((void *)location, &value, size);
            break;
        case BFIN_MEM_ACCESS_DMA:
            dma_memcpy((void *)location, &value, size);
            break;
        case BFIN_MEM_ACCESS_ITEST:
            isram_memcpy((void *)location, &value, size);
            break;
        default:
            pr_err("invalid relocation for %#lx\n", location);
            return -ENOEXEC;
        }
    }

    return 0;
}

int
module_finalize(const Elf_Ehdr * hdr,
        const Elf_Shdr * sechdrs, struct module *mod)
{
    unsigned int i, strindex = 0, symindex = 0;
    char *secstrings;
    long err = 0;

    secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;

    for (i = 1; i < hdr->e_shnum; i++) {
        /* Internal symbols and strings. */
        if (sechdrs[i].sh_type == SHT_SYMTAB) {
            symindex = i;
            strindex = sechdrs[i].sh_link;
        }
    }

    for (i = 1; i < hdr->e_shnum; i++) {
        const char *strtab = (char *)sechdrs[strindex].sh_addr;
        unsigned int info = sechdrs[i].sh_info;
        const char *shname = secstrings + sechdrs[i].sh_name;

        /* Not a valid relocation section? */
        if (info >= hdr->e_shnum)
            continue;

        /* Only support RELA relocation types */
        if (sechdrs[i].sh_type != SHT_RELA)
            continue;

        if (!strcmp(".rela.l2.text", shname) ||
            !strcmp(".rela.l1.text", shname) ||
            (!strcmp(".rela.text", shname) &&
             (hdr->e_flags & (EF_BFIN_CODE_IN_L1 | EF_BFIN_CODE_IN_L2)))) {

            err = apply_relocate_add((Elf_Shdr *) sechdrs, strtab,
                       symindex, i, mod);
            if (err < 0)
                return -ENOEXEC;
        }
    }

    return 0;
}

void module_arch_cleanup(struct module *mod)
{
    l1_inst_sram_free(mod->arch.text_l1);
    l1_data_A_sram_free(mod->arch.data_a_l1);
    l1_data_A_sram_free(mod->arch.bss_a_l1);
    l1_data_B_sram_free(mod->arch.data_b_l1);
    l1_data_B_sram_free(mod->arch.bss_b_l1);
    l2_sram_free(mod->arch.text_l2);
    l2_sram_free(mod->arch.data_l2);
    l2_sram_free(mod->arch.bss_l2);
}