powerpc: Move module.c over to arch/powerpc

... and rename it to module_32.c since it is the 32-bit version.
The 32-bit and 64-bit ABIs are sufficiently different that having
a merged version isn't really practical.

Signed-off-by: Paul Mackerras <paulus@samba.org>

2 files changed, 323 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 754c227835bb..b86d380f01b4 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -36,6 +36,8 @@ obj64-$(CONFIG_PPC_MULTIPLATFORM) += nvram_64.o
 obj-$(CONFIG_CRASH_DUMP)        += crash_dump.o
 obj-$(CONFIG_6xx)               += idle_6xx.o l2cr_6xx.o cpu_setup_6xx.o
 obj-$(CONFIG_TAU)               += tau_6xx.o
+obj32-$(CONFIG_SOFTWARE_SUSPEND) += swsusp_32.o
+obj32-$(CONFIG_MODULES)         += module_32.o
 
 ifeq ($(CONFIG_PPC_MERGE),y)
 
@@ -78,6 +80,7 @@ smpobj-$(CONFIG_SMP)		+= smp.o
 
 endif
 
+obj-$(CONFIG_PPC32)             += $(obj32-y)
 obj-$(CONFIG_PPC64)             += $(obj64-y)
 
 extra-$(CONFIG_PPC_FPU)         += fpu.o
diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c
new file mode 100644
index 000000000000..92f4e5f64f02
--- /dev/null
+++ b/arch/powerpc/kernel/module_32.c
@@ -0,0 +1,320 @@
+/*  Kernel module help for PPC.
+    Copyright (C) 2001 Rusty Russell.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+#include <linux/module.h>
+#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 <linux/cache.h>
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(fmt , ...)
+#endif
+
+LIST_HEAD(module_bug_list);
+
+void *module_alloc(unsigned long size)
+{
+        if (size == 0)
+                return NULL;
+        return vmalloc(size);
+}
+
+/* Free memory returned from module_alloc */
+void module_free(struct module *mod, void *module_region)
+{
+        vfree(module_region);
+        /* FIXME: If module_region == mod->init_region, trim exception
+           table entries. */
+}
+
+/* Count how many different relocations (different symbol, different
+   addend) */
+static unsigned int count_relocs(const Elf32_Rela *rela, unsigned int num)
+{
+        unsigned int i, j, ret = 0;
+
+        /* Sure, this is order(n^2), but it's usually short, and not
+           time critical */
+        for (i = 0; i < num; i++) {
+                for (j = 0; j < i; j++) {
+                        /* If this addend appeared before, it's
+                           already been counted */
+                        if (ELF32_R_SYM(rela[i].r_info)
+                            == ELF32_R_SYM(rela[j].r_info)
+                            && rela[i].r_addend == rela[j].r_addend)
+                                break;
+                }
+                if (j == i) ret++;
+        }
+        return ret;
+}
+
+/* Get the potential trampolines size required of the init and
+   non-init sections */
+static unsigned long get_plt_size(const Elf32_Ehdr *hdr,
+                                  const Elf32_Shdr *sechdrs,
+                                  const char *secstrings,
+                                  int is_init)
+{
+        unsigned long ret = 0;
+        unsigned i;
+
+        /* Everything marked ALLOC (this includes the exported
+           symbols) */
+        for (i = 1; i < hdr->e_shnum; i++) {
+                /* If it's called *.init*, and we're not init, we're
+                   not interested */
+                if ((strstr(secstrings + sechdrs[i].sh_name, ".init") != 0)
+                    != is_init)
+                        continue;
+
+                /* We don't want to look at debug sections. */
+                if (strstr(secstrings + sechdrs[i].sh_name, ".debug") != 0)
+                        continue;
+
+                if (sechdrs[i].sh_type == SHT_RELA) {
+                        DEBUGP("Found relocations in section %u\n", i);
+                        DEBUGP("Ptr: %p.  Number: %u\n",
+                               (void *)hdr + sechdrs[i].sh_offset,
+                               sechdrs[i].sh_size / sizeof(Elf32_Rela));
+                        ret += count_relocs((void *)hdr
+                                             + sechdrs[i].sh_offset,
+                                             sechdrs[i].sh_size
+                                             / sizeof(Elf32_Rela))
+                                * sizeof(struct ppc_plt_entry);
+                }
+        }
+
+        return ret;
+}
+
+int module_frob_arch_sections(Elf32_Ehdr *hdr,
+                              Elf32_Shdr *sechdrs,
+                              char *secstrings,
+                              struct module *me)
+{
+        unsigned int i;
+
+        /* Find .plt and .init.plt sections */
+        for (i = 0; i < hdr->e_shnum; i++) {
+                if (strcmp(secstrings + sechdrs[i].sh_name, ".init.plt") == 0)
+                        me->arch.init_plt_section = i;
+                else if (strcmp(secstrings + sechdrs[i].sh_name, ".plt") == 0)
+                        me->arch.core_plt_section = i;
+        }
+        if (!me->arch.core_plt_section || !me->arch.init_plt_section) {
+                printk("Module doesn't contain .plt or .init.plt sections.\n");
+                return -ENOEXEC;
+        }
+
+        /* Override their sizes */
+        sechdrs[me->arch.core_plt_section].sh_size
+                = get_plt_size(hdr, sechdrs, secstrings, 0);
+        sechdrs[me->arch.init_plt_section].sh_size
+                = get_plt_size(hdr, sechdrs, secstrings, 1);
+        return 0;
+}
+
+int apply_relocate(Elf32_Shdr *sechdrs,
+                   const char *strtab,
+                   unsigned int symindex,
+                   unsigned int relsec,
+                   struct module *module)
+{
+        printk(KERN_ERR "%s: Non-ADD RELOCATION unsupported\n",
+               module->name);
+        return -ENOEXEC;
+}
+
+static inline int entry_matches(struct ppc_plt_entry *entry, Elf32_Addr val)
+{
+        if (entry->jump[0] == 0x3d600000 + ((val + 0x8000) >> 16)
+            && entry->jump[1] == 0x396b0000 + (val & 0xffff))
+                return 1;
+        return 0;
+}
+
+/* Set up a trampoline in the PLT to bounce us to the distant function */
+static uint32_t do_plt_call(void *location,
+                            Elf32_Addr val,
+                            Elf32_Shdr *sechdrs,
+                            struct module *mod)
+{
+        struct ppc_plt_entry *entry;
+
+        DEBUGP("Doing plt for call to 0x%x at 0x%x\n", val, (unsigned int)location);
+        /* Init, or core PLT? */
+        if (location >= mod->module_core
+            && location < mod->module_core + mod->core_size)
+                entry = (void *)sechdrs[mod->arch.core_plt_section].sh_addr;
+        else
+                entry = (void *)sechdrs[mod->arch.init_plt_section].sh_addr;
+
+        /* Find this entry, or if that fails, the next avail. entry */
+        while (entry->jump[0]) {
+                if (entry_matches(entry, val)) return (uint32_t)entry;
+                entry++;
+        }
+
+        /* Stolen from Paul Mackerras as well... */
+        entry->jump[0] = 0x3d600000+((val+0x8000)>>16); /* lis r11,sym@ha */
+        entry->jump[1] = 0x396b0000 + (val&0xffff);     /* addi r11,r11,sym@l*/
+        entry->jump[2] = 0x7d6903a6;                    /* mtctr r11 */
+        entry->jump[3] = 0x4e800420;                    /* bctr */
+
+        DEBUGP("Initialized plt for 0x%x at %p\n", val, entry);
+        return (uint32_t)entry;
+}
+
+int apply_relocate_add(Elf32_Shdr *sechdrs,
+                       const char *strtab,
+                       unsigned int symindex,
+                       unsigned int relsec,
+                       struct module *module)
+{
+        unsigned int i;
+        Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
+        Elf32_Sym *sym;
+        uint32_t *location;
+        uint32_t value;
+
+        DEBUGP("Applying ADD relocate section %u to %u\n", relsec,
+               sechdrs[relsec].sh_info);
+        for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
+                /* This is where to make the change */
+                location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+                        + rela[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(rela[i].r_info);
+                /* `Everything is relative'. */
+                value = sym->st_value + rela[i].r_addend;
+
+                switch (ELF32_R_TYPE(rela[i].r_info)) {
+                case R_PPC_ADDR32:
+                        /* Simply set it */
+                        *(uint32_t *)location = value;
+                        break;
+
+                case R_PPC_ADDR16_LO:
+                        /* Low half of the symbol */
+                        *(uint16_t *)location = value;
+                        break;
+                
+                case R_PPC_ADDR16_HA:
+                        /* Sign-adjusted lower 16 bits: PPC ELF ABI says:
+                           (((x >> 16) + ((x & 0x8000) ? 1 : 0))) & 0xFFFF.
+                           This is the same, only sane.
+                         */
+                        *(uint16_t *)location = (value + 0x8000) >> 16;
+                        break;
+
+                case R_PPC_REL24:
+                        if ((int)(value - (uint32_t)location) < -0x02000000
+                            || (int)(value - (uint32_t)location) >= 0x02000000)
+                                value = do_plt_call(location, value,
+                                                    sechdrs, module);
+
+                        /* Only replace bits 2 through 26 */
+                        DEBUGP("REL24 value = %08X. location = %08X\n",
+                               value, (uint32_t)location);
+                        DEBUGP("Location before: %08X.\n",
+                               *(uint32_t *)location);
+                        *(uint32_t *)location
+                                = (*(uint32_t *)location & ~0x03fffffc)
+                                | ((value - (uint32_t)location)
+                                   & 0x03fffffc);
+                        DEBUGP("Location after: %08X.\n",
+                               *(uint32_t *)location);
+                        DEBUGP("ie. jump to %08X+%08X = %08X\n",
+                               *(uint32_t *)location & 0x03fffffc,
+                               (uint32_t)location,
+                               (*(uint32_t *)location & 0x03fffffc)
+                               + (uint32_t)location);
+                        break;
+
+                case R_PPC_REL32:
+                        /* 32-bit relative jump. */
+                        *(uint32_t *)location = value - (uint32_t)location;
+                        break;
+
+                default:
+                        printk("%s: unknown ADD relocation: %u\n",
+                               module->name,
+                               ELF32_R_TYPE(rela[i].r_info));
+                        return -ENOEXEC;
+                }
+        }
+        return 0;
+}
+
+int module_finalize(const Elf_Ehdr *hdr,
+                    const Elf_Shdr *sechdrs,
+                    struct module *me)
+{
+        char *secstrings;
+        unsigned int i;
+
+        me->arch.bug_table = NULL;
+        me->arch.num_bugs = 0;
+
+        /* Find the __bug_table section, if present */
+        secstrings = (char *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
+        for (i = 1; i < hdr->e_shnum; i++) {
+                if (strcmp(secstrings+sechdrs[i].sh_name, "__bug_table"))
+                        continue;
+                me->arch.bug_table = (void *) sechdrs[i].sh_addr;
+                me->arch.num_bugs = sechdrs[i].sh_size / sizeof(struct bug_entry);
+                break;
+        }
+
+        /*
+         * Strictly speaking this should have a spinlock to protect against
+         * traversals, but since we only traverse on BUG()s, a spinlock
+         * could potentially lead to deadlock and thus be counter-productive.
+         */
+        list_add(&me->arch.bug_list, &module_bug_list);
+
+        return 0;
+}
+
+void module_arch_cleanup(struct module *mod)
+{
+        list_del(&mod->arch.bug_list);
+}
+
+struct bug_entry *module_find_bug(unsigned long bugaddr)
+{
+        struct mod_arch_specific *mod;
+        unsigned int i;
+        struct bug_entry *bug;
+
+        list_for_each_entry(mod, &module_bug_list, bug_list) {
+                bug = mod->bug_table;
+                for (i = 0; i < mod->num_bugs; ++i, ++bug)
+                        if (bugaddr == bug->bug_addr)
+                                return bug;
+        }
+        return NULL;
+}