[PATCH] Add v850 support for new module loader

Add v850 support for new module loader

arch/v850/kernel/Makefile

@@ -15,7 +15,7 @@ obj-y += intv.o entry.o process.o syscalls.o time.o semaphore.o setup.o \
 	 signal.o irq.o mach.o ptrace.o bug.o
 export-objs += v850_ksyms.o rte_mb_a_pci.o
 
-obj-$(CONFIG_MODULES)		+= v850_ksyms.o
+obj-$(CONFIG_MODULES)		+= module.o v850_ksyms.o
 # chip-specific code
 obj-$(CONFIG_V850E_MA1)		+= ma.o	nb85e_utils.o nb85e_timer_d.o
 obj-$(CONFIG_V850E_NB85E)	+= nb85e_intc.o

arch/v850/kernel/entry.S

@@ -922,10 +922,10 @@ C_DATA(sys_call_table):
 	.long CSYM(sys_adjtimex)
 	.long CSYM(sys_ni_syscall)	// 125 - sys_mprotect
 	.long CSYM(sys_sigprocmask)
-	.long CSYM(sys_create_module)
+	.long CSYM(sys_ni_syscall)	// sys_create_module
 	.long CSYM(sys_init_module)
 	.long CSYM(sys_delete_module)
-	.long CSYM(sys_get_kernel_syms) // 130
+	.long CSYM(sys_ni_syscall)	// 130 - sys_get_kernel_syms
 	.long CSYM(sys_quotactl)
 	.long CSYM(sys_getpgid)
 	.long CSYM(sys_fchdir)
@@ -962,7 +962,7 @@ C_DATA(sys_call_table):
 	.long CSYM(sys_setresuid)
 	.long CSYM(sys_getresuid)	// 165
 	.long CSYM(sys_ni_syscall)	// for vm86
-	.long CSYM(sys_query_module)
+	.long CSYM(sys_ni_syscall)	// sys_query_module
 	.long CSYM(sys_poll)
 	.long CSYM(sys_nfsservctl)
 	.long CSYM(sys_setresgid)	// 170

arch/v850/kernel/module.c

+/*
+ * arch/v850/kernel/module.c -- Architecture-specific module functions
+ *
+ *  Copyright (C) 2002  NEC Corporation
+ *  Copyright (C) 2002  Miles Bader <miles@gnu.org>
+ *  Copyright (C) 2001  Rusty Russell
+ *
+ * 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.
+ *
+ * Written by Miles Bader <miles@gnu.org>
+ *
+ * Derived in part from arch/ppc/kernel/module.c
+ */
+
+#include <linux/kernel.h>
+#include <linux/vmalloc.h>
+#include <linux/moduleloader.h>
+#include <linux/elf.h>
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(fmt , ...)
+#endif
+
+void *module_alloc (unsigned long size)
+{
+	return size == 0 ? 0 : vmalloc (size);
+}
+
+void module_free (struct module *mod, void *module_region)
+{
+	vfree (module_region);
+	/* FIXME: If module_region == mod->init_region, trim exception
+           table entries. */
+}
+
+int module_finalize (const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
+		     struct module *mod)
+{
+	return 0;
+}
+
+/* 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;
+
+		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 v850_plt_entry);
+		}
+	}
+
+	return ret;
+}
+
+long module_core_size (const Elf32_Ehdr *hdr, const Elf32_Shdr *sechdrs,
+		       const char *secstrings, struct module *mod)
+{
+	mod->arch.core_plt_offset = (mod->core_size + 3) & ~3;
+	return mod->core_size + get_plt_size (hdr, sechdrs, secstrings, 1);
+}
+
+long module_init_size (const Elf32_Ehdr *hdr, const Elf32_Shdr *sechdrs,
+		       const char *secstrings, struct module *mod)
+{
+	mod->arch.init_plt_offset = (mod->init_size + 3) & ~3;
+	return mod->init_size + get_plt_size (hdr, sechdrs, secstrings, 1);
+}
+
+int apply_relocate (Elf32_Shdr *sechdrs, const char *strtab,
+		    unsigned int symindex, unsigned int relsec,
+		    struct module *mod)
+{
+	printk ("Barf\n");
+	return -ENOEXEC;
+}
+
+/* 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, struct module *mod)
+{
+	struct v850_plt_entry *entry;
+	/* Instructions used to do the indirect jump.  */
+	uint32_t tramp[2];
+
+	/* We have to trash a register, so we assume that any control
+	   transfer more than 21-bits away must be a function call
+	   (so we can use a call-clobbered register).  */
+	tramp[0] = 0x0621 + ((val & 0xffff) << 16);   /* mov sym, r1 ... */
+	tramp[1] = ((val >> 16) & 0xffff) + 0x610000; /* ...; jmp r1 */
+
+	/* Init, or core PLT? */
+	if (location >= mod->module_core
+	    && location < mod->module_core + mod->arch.core_plt_offset)
+		entry = mod->module_core + mod->arch.core_plt_offset;
+	else
+		entry = mod->module_init + mod->arch.init_plt_offset;
+
+	/* Find this entry, or if that fails, the next avail. entry */
+	while (entry->tramp[0])
+		if (entry->tramp[0] == tramp[0] && entry->tramp[1] == tramp[1])
+			return (uint32_t)entry;
+		else
+			entry++;
+
+	entry->tramp[0] = tramp[0];
+	entry->tramp[1] = tramp[1];
+
+	return (uint32_t)entry;
+}
+
+int apply_relocate_add (Elf32_Shdr *sechdrs, const char *strtab,
+			unsigned int symindex, unsigned int relsec,
+			struct module *mod)
+{
+	unsigned int i;
+	Elf32_Rela *rela = (void *)sechdrs[relsec].sh_offset;
+
+	DEBUGP ("Applying 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 */
+		uint32_t *loc
+			= ((void *)sechdrs[sechdrs[relsec].sh_info].sh_offset
+			   + rela[i].r_offset);
+		/* This is the symbol it is referring to */
+		Elf32_Sym *sym
+			= ((Elf32_Sym *)sechdrs[symindex].sh_offset
+			   + ELF32_R_SYM (rela[i].r_info));
+		uint32_t val = sym->st_value;
+
+		if (! val) {
+			printk (KERN_WARNING "%s: Unknown symbol %s\n",
+				mod->name, strtab + sym->st_name);
+			return -ENOENT;
+		}
+
+		val += rela[i].r_addend;
+
+		switch (ELF32_R_TYPE (rela[i].r_info)) {
+		case R_V850_32:
+			/* We write two shorts instead of a long because even
+			   32-bit insns only need half-word alignment, but
+			   32-bit data writes need to be long-word aligned.  */
+			val += ((uint16_t *)loc)[0];
+			val += ((uint16_t *)loc)[1] << 16;
+			((uint16_t *)loc)[0] = val & 0xffff;
+			((uint16_t *)loc)[1] = (val >> 16) & 0xffff;
+			break;
+
+		case R_V850_22_PCREL:
+			/* Maybe jump indirectly via a PLT table entry.  */
+			if ((int32_t)(val - (uint32_t)loc) > 0x1fffff
+			    || (int32_t)(val - (uint32_t)loc) < -0x200000)
+				val = do_plt_call (loc, val, mod);
+
+			val -= (uint32_t)loc;
+
+			/* We write two shorts instead of a long because
+			   even 32-bit insns only need half-word alignment,
+			   but 32-bit data writes need to be long-word
+			   aligned.  */
+			((uint16_t *)loc)[0] =
+				(*(uint16_t *)loc & 0xffc0) /* opcode + reg */
+				| ((val >> 16) & 0xffc03f); /* offs high */
+			((uint16_t *)loc)[1] =
+				(val & 0xffff);		    /* offs low */
+			break;
+
+		default:
+			printk (KERN_ERR "module %s: Unknown reloc: %u\n",
+				mod->name, ELF32_R_TYPE (rela[i].r_info));
+			return -ENOEXEC;
+		}
+	}
+
+	return 0;
+}

arch/v850/kernel/v850_ksyms.c

@@ -27,6 +27,9 @@ EXPORT_SYMBOL (trap_table);
 extern void dump_thread (struct pt_regs *, struct user *);
 EXPORT_SYMBOL (dump_thread);
 EXPORT_SYMBOL (kernel_thread);
+EXPORT_SYMBOL (enable_irq);
+EXPORT_SYMBOL (disable_irq);
+EXPORT_SYMBOL (disable_irq_nosync);
 EXPORT_SYMBOL (__bug);
 
 /* Networking helper routines. */
@@ -46,7 +49,6 @@ EXPORT_SYMBOL_NOVERS (strchr);
 EXPORT_SYMBOL_NOVERS (strlen);
 EXPORT_SYMBOL_NOVERS (strnlen);
 EXPORT_SYMBOL_NOVERS (strpbrk);
-EXPORT_SYMBOL_NOVERS (strtok);
 EXPORT_SYMBOL_NOVERS (strrchr);
 EXPORT_SYMBOL_NOVERS (strstr);
 EXPORT_SYMBOL_NOVERS (memset);

include/asm-v850/elf.h

@@ -19,7 +19,8 @@ typedef struct user_fpu_struct elf_fpregset_t;
 /*
  * This is used to ensure we don't load something for the wrong architecture.
  */
-#define elf_check_arch(x) ( (x)->e_machine == EM_CYGNUS_V850 )
+#define elf_check_arch(x)  \
+  ((x)->e_machine == EM_V850 || (x)->e_machine == EM_CYGNUS_V850)
 
 /*
  * These are used to set parameters in the core dumps.

include/asm-v850/irq.h

@@ -52,6 +52,17 @@ typedef void (*irq_handler_t)(int irq, void *data, struct pt_regs *regs);
    interrupt.  */
 extern unsigned int handle_irq (int irq, struct pt_regs *regs);
 
+
+/* Enable interrupt handling on an irq.  */
+extern void enable_irq(unsigned int irq);
+
+/* Disable an irq and wait for completion.  */
+extern void disable_irq (unsigned int irq);
+
+/* Disable an irq without waiting. */
+extern void disable_irq_nosync (unsigned int irq);
+
+
 #endif /* !__ASSEMBLY__ */
 
 #endif /* __V850_IRQ_H__ */

include/asm-v850/module.h

@@ -3,20 +3,40 @@
  *
  *  Copyright (C) 2001,02  NEC Corporation
  *  Copyright (C) 2001,02  Miles Bader <miles@gnu.org>
+ *  Copyright (C) 2001  Rusty Russell
  *
  * 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.
  *
  * Written by Miles Bader <miles@gnu.org>
+ *
+ * Derived in part from include/asm-ppc/module.h
  */
 
 #ifndef __V850_MODULE_H__
 #define __V850_MODULE_H__
 
-#define arch_init_modules(x)	((void)0)
-#define module_arch_init(x)	(0)
-#define module_map(sz)		vmalloc (sz)
-#define module_unmap(sz)	vfree (sz)
+#define MODULE_SYMBOL_PREFIX "_"
+
+struct v850_plt_entry
+{
+	/* Indirect jump instruction sequence (6-byte mov + 2-byte jr).  */
+	unsigned long tramp[2];
+};
+
+struct mod_arch_specific
+{
+	/* How much of the core is actually taken up with core (then
+           we know the rest is for the PLT).  */
+	unsigned int core_plt_offset;
+
+	/* Same for init.  */
+	unsigned int init_plt_offset;
+};
+
+#define Elf_Shdr Elf32_Shdr
+#define Elf_Sym Elf32_Sym
+#define Elf_Ehdr Elf32_Ehdr
 
 #endif /* __V850_MODULE_H__ */