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linux-stable/arch/mips/kernel/vpe.c
Ralf Baechle 8292366341 [MIPS] vpe: Use p_paddr instead of p_vaddr loader. 
This subtle difference makes ELF overlays work.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-29 19:35:33 +00:00

1587 lines
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/*
* Copyright (C) 2004, 2005 MIPS Technologies, Inc. All rights reserved.
*
* This program is free software; you can distribute it and/or modify it
* under the terms of the GNU General Public License (Version 2) as
* published by the Free Software Foundation.
*
* This program is distributed in the hope 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.
*/
/*
* VPE support module
*
* Provides support for loading a MIPS SP program on VPE1.
* The SP enviroment is rather simple, no tlb's. It needs to be relocatable
* (or partially linked). You should initialise your stack in the startup
* code. This loader looks for the symbol __start and sets up
* execution to resume from there. The MIPS SDE kit contains suitable examples.
*
* To load and run, simply cat a SP 'program file' to /dev/vpe1.
* i.e cat spapp >/dev/vpe1.
*/
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <asm/uaccess.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 <asm/atomic.h>
#include <asm/cpu.h>
#include <asm/mips_mt.h>
#include <asm/processor.h>
#include <asm/system.h>
#include <asm/vpe.h>
#include <asm/kspd.h>
#include <asm/mips_mt.h>
typedef void *vpe_handle;
#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))
/*
* The number of TCs and VPEs physically available on the core
*/
static int hw_tcs, hw_vpes;
static char module_name[] = "vpe";
static int major;
static const int minor = 1; /* fixed for now */
#ifdef CONFIG_MIPS_APSP_KSPD
static struct kspd_notifications kspd_events;
static int kspd_events_reqd = 0;
#endif
/* grab the likely amount of memory we will need. */
#ifdef CONFIG_MIPS_VPE_LOADER_TOM
#define P_SIZE (2 * 1024 * 1024)
#else
/* add an overhead to the max kmalloc size for non-striped symbols/etc */
#define P_SIZE (256 * 1024)
#endif
extern unsigned long physical_memsize;
#define MAX_VPES 16
#define VPE_PATH_MAX 256
enum vpe_state {
VPE_STATE_UNUSED = 0,
VPE_STATE_INUSE,
VPE_STATE_RUNNING
};
enum tc_state {
TC_STATE_UNUSED = 0,
TC_STATE_INUSE,
TC_STATE_RUNNING,
TC_STATE_DYNAMIC
};
struct vpe {
enum vpe_state state;
/* (device) minor associated with this vpe */
int minor;
/* elfloader stuff */
void *load_addr;
unsigned long len;
char *pbuffer;
unsigned long plen;
unsigned int uid, gid;
char cwd[VPE_PATH_MAX];
unsigned long __start;
/* tc's associated with this vpe */
struct list_head tc;
/* The list of vpe's */
struct list_head list;
/* shared symbol address */
void *shared_ptr;
/* the list of who wants to know when something major happens */
struct list_head notify;
unsigned int ntcs;
};
struct tc {
enum tc_state state;
int index;
struct vpe *pvpe; /* parent VPE */
struct list_head tc; /* The list of TC's with this VPE */
struct list_head list; /* The global list of tc's */
};
struct {
/* Virtual processing elements */
struct list_head vpe_list;
/* Thread contexts */
struct list_head tc_list;
} vpecontrol = {
.vpe_list = LIST_HEAD_INIT(vpecontrol.vpe_list),
.tc_list = LIST_HEAD_INIT(vpecontrol.tc_list)
};
static void release_progmem(void *ptr);
extern void save_gp_address(unsigned int secbase, unsigned int rel);
/* get the vpe associated with this minor */
struct vpe *get_vpe(int minor)
{
struct vpe *v;
if (!cpu_has_mipsmt)
return NULL;
list_for_each_entry(v, &vpecontrol.vpe_list, list) {
if (v->minor == minor)
return v;
}
return NULL;
}
/* get the vpe associated with this minor */
struct tc *get_tc(int index)
{
struct tc *t;
list_for_each_entry(t, &vpecontrol.tc_list, list) {
if (t->index == index)
return t;
}
return NULL;
}
struct tc *get_tc_unused(void)
{
struct tc *t;
list_for_each_entry(t, &vpecontrol.tc_list, list) {
if (t->state == TC_STATE_UNUSED)
return t;
}
return NULL;
}
/* allocate a vpe and associate it with this minor (or index) */
struct vpe *alloc_vpe(int minor)
{
struct vpe *v;
if ((v = kzalloc(sizeof(struct vpe), GFP_KERNEL)) == NULL) {
return NULL;
}
INIT_LIST_HEAD(&v->tc);
list_add_tail(&v->list, &vpecontrol.vpe_list);
INIT_LIST_HEAD(&v->notify);
v->minor = minor;
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;
if ((tc = kzalloc(sizeof(struct tc), GFP_KERNEL)) == NULL)
goto out;
INIT_LIST_HEAD(&tc->tc);
tc->index = index;
list_add_tail(&tc->list, &vpecontrol.tc_list);
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);
}
void dump_mtregs(void)
{
unsigned long val;
val = read_c0_config3();
printk("config3 0x%lx MT %ld\n", val,
(val & CONFIG3_MT) >> CONFIG3_MT_SHIFT);
val = read_c0_mvpcontrol();
printk("MVPControl 0x%lx, STLB %ld VPC %ld EVP %ld\n", val,
(val & MVPCONTROL_STLB) >> MVPCONTROL_STLB_SHIFT,
(val & MVPCONTROL_VPC) >> MVPCONTROL_VPC_SHIFT,
(val & MVPCONTROL_EVP));
val = read_c0_mvpconf0();
printk("mvpconf0 0x%lx, PVPE %ld PTC %ld M %ld\n", val,
(val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT,
val & MVPCONF0_PTC, (val & MVPCONF0_M) >> MVPCONF0_M_SHIFT);
}
/* Find some VPE program space */
static void *alloc_progmem(unsigned long len)
{
#ifdef CONFIG_MIPS_VPE_LOADER_TOM
/* this means you must tell linux to use less memory than you physically have */
return pfn_to_kaddr(max_pfn);
#else
// simple grab some mem for now
return kmalloc(len, GFP_KERNEL);
#endif
}
static 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];
// || strncmp(secstrings + s->sh_name, ".init", 5) == 0)
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(&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) ) {
printk(KERN_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) ) {
printk(KERN_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) {
printk(KERN_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;
/* Sign extend the addend we extract from the lo insn. */
vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
if (mips_hi16_list != NULL) {
struct mips_hi16 *l;
l = mips_hi16_list;
while (l != NULL) {
struct mips_hi16 *next;
unsigned long insn;
/*
* The value for the HI16 had best be the same.
*/
if (v != l->value) {
printk(KERN_DEBUG "VPE loader: "
"apply_r_mips_lo16/hi16: "
"inconsistent value information\n");
return -ENOEXEC;
}
/*
* 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;
}
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"
};
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) {
printk(KERN_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)];
printk(KERN_WARNING "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;
}
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:
printk(KERN_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);
printk(KERN_DEBUG "dump_elfsymbols: n %d\n", n);
for (i = 1; i < n; i++) {
printk(KERN_DEBUG " i %d name <%s> 0x%x\n", i,
strtab + sym[i].st_name, sym[i].st_value);
}
}
#endif
/* We are prepared so configure and start the VPE... */
static int vpe_run(struct vpe * v)
{
unsigned long flags, val, dmt_flag;
struct vpe_notifications *n;
unsigned int vpeflags;
struct tc *t;
/* check we are the Master VPE */
local_irq_save(flags);
val = read_c0_vpeconf0();
if (!(val & VPECONF0_MVP)) {
printk(KERN_WARNING
"VPE loader: only Master VPE's are allowed to configure MT\n");
local_irq_restore(flags);
return -1;
}
dmt_flag = dmt();
vpeflags = dvpe();
if (!list_empty(&v->tc)) {
if ((t = list_entry(v->tc.next, struct tc, tc)) == NULL) {
evpe(vpeflags);
emt(dmt_flag);
local_irq_restore(flags);
printk(KERN_WARNING
"VPE loader: TC %d is already in use.\n",
t->index);
return -ENOEXEC;
}
} else {
evpe(vpeflags);
emt(dmt_flag);
local_irq_restore(flags);
printk(KERN_WARNING
"VPE loader: No TC's associated with VPE %d\n",
v->minor);
return -ENOEXEC;
}
/* Put MVPE's into 'configuration state' */
set_c0_mvpcontrol(MVPCONTROL_VPC);
settc(t->index);
/* should check it is halted, and not activated */
if ((read_tc_c0_tcstatus() & TCSTATUS_A) || !(read_tc_c0_tchalt() & TCHALT_H)) {
evpe(vpeflags);
emt(dmt_flag);
local_irq_restore(flags);
printk(KERN_WARNING "VPE loader: TC %d is already active!\n",
t->index);
return -ENOEXEC;
}
/* Write the address we want it to start running from in the TCPC register. */
write_tc_c0_tcrestart((unsigned long)v->__start);
write_tc_c0_tccontext((unsigned long)0);
/*
* Mark the TC as activated, not interrupt exempt and not dynamically
* allocatable
*/
val = read_tc_c0_tcstatus();
val = (val & ~(TCSTATUS_DA | TCSTATUS_IXMT)) | TCSTATUS_A;
write_tc_c0_tcstatus(val);
write_tc_c0_tchalt(read_tc_c0_tchalt() & ~TCHALT_H);
/*
* The sde-kit passes 'memsize' to __start in $a3, so set something
* here... Or set $a3 to zero and define DFLT_STACK_SIZE and
* DFLT_HEAP_SIZE when you compile your program
*/
mttgpr(6, v->ntcs);
mttgpr(7, physical_memsize);
/* set up VPE1 */
/*
* bind the TC to VPE 1 as late as possible so we only have the final
* VPE registers to set up, and so an EJTAG probe can trigger on it
*/
write_tc_c0_tcbind((read_tc_c0_tcbind() & ~TCBIND_CURVPE) | 1);
write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~(VPECONF0_VPA));
back_to_back_c0_hazard();
/* Set up the XTC bit in vpeconf0 to point at our tc */
write_vpe_c0_vpeconf0( (read_vpe_c0_vpeconf0() & ~(VPECONF0_XTC))
| (t->index << VPECONF0_XTC_SHIFT));
back_to_back_c0_hazard();
/* enable this VPE */
write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);
/* clear out any left overs from a previous program */
write_vpe_c0_status(0);
write_vpe_c0_cause(0);
/* take system out of configuration state */
clear_c0_mvpcontrol(MVPCONTROL_VPC);
#ifdef CONFIG_SMP
evpe(EVPE_ENABLE);
#else
evpe(vpeflags);
#endif
emt(dmt_flag);
local_irq_restore(flags);
list_for_each_entry(n, &v->notify, list)
n->start(minor);
return 0;
}
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, 4) != 0
|| (hdr->e_type != ET_REL && hdr->e_type != ET_EXEC)
|| !elf_check_arch(hdr)
|| hdr->e_shentsize != sizeof(*sechdrs)) {
printk(KERN_WARNING
"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)) {
printk(KERN_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) {
printk(KERN_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);
memset(v->load_addr, 0, mod.core_size);
printk("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;
printk(KERN_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)
continue;
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 the 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) {
printk(KERN_WARNING "VPE loader: program does not contain "
"a __start symbol\n");
return -ENOEXEC;
}
if (v->shared_ptr == NULL)
printk(KERN_WARNING "VPE loader: "
"program does not contain vpe_shared symbol.\n"
" Unable to use AMVP (AP/SP) facilities.\n");
}
printk(" elf loaded\n");
return 0;
}
static void cleanup_tc(struct tc *tc)
{
unsigned long flags;
unsigned int mtflags, vpflags;
int tmp;
local_irq_save(flags);
mtflags = dmt();
vpflags = dvpe();
/* Put MVPE's into 'configuration state' */
set_c0_mvpcontrol(MVPCONTROL_VPC);
settc(tc->index);
tmp = read_tc_c0_tcstatus();
/* mark not allocated and not dynamically allocatable */
tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
tmp |= TCSTATUS_IXMT; /* interrupt exempt */
write_tc_c0_tcstatus(tmp);
write_tc_c0_tchalt(TCHALT_H);
/* bind it to anything other than VPE1 */
// write_tc_c0_tcbind(read_tc_c0_tcbind() & ~TCBIND_CURVPE); // | TCBIND_CURVPE
clear_c0_mvpcontrol(MVPCONTROL_VPC);
evpe(vpflags);
emt(mtflags);
local_irq_restore(flags);
}
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 *not;
struct vpe *v;
int ret;
if (minor != iminor(inode)) {
/* assume only 1 device at the moment. */
printk(KERN_WARNING "VPE loader: only vpe1 is supported\n");
return -ENODEV;
}
if ((v = get_vpe(tclimit)) == NULL) {
printk(KERN_WARNING "VPE loader: unable to get vpe\n");
return -ENODEV;
}
state = xchg(&v->state, VPE_STATE_INUSE);
if (state != VPE_STATE_UNUSED) {
printk(KERN_DEBUG "VPE loader: tc in use dumping regs\n");
list_for_each_entry(not, &v->notify, list) {
not->stop(tclimit);
}
release_progmem(v->load_addr);
cleanup_tc(get_tc(tclimit));
}
/* this of-course trashes what was there before... */
v->pbuffer = vmalloc(P_SIZE);
v->plen = P_SIZE;
v->load_addr = NULL;
v->len = 0;
v->uid = filp->f_uid;
v->gid = filp->f_gid;
#ifdef CONFIG_MIPS_APSP_KSPD
/* get kspd to tell us when a syscall_exit happens */
if (!kspd_events_reqd) {
kspd_notify(&kspd_events);
kspd_events_reqd++;
}
#endif
v->cwd[0] = 0;
ret = getcwd(v->cwd, VPE_PATH_MAX);
if (ret < 0)
printk(KERN_WARNING "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)
{
struct vpe *v;
Elf_Ehdr *hdr;
int ret = 0;
v = get_vpe(tclimit);
if (v == NULL)
return -ENODEV;
hdr = (Elf_Ehdr *) v->pbuffer;
if (memcmp(hdr->e_ident, ELFMAG, 4) == 0) {
if (vpe_elfload(v) >= 0) {
vpe_run(v);
} else {
printk(KERN_WARNING "VPE loader: ELF load failed.\n");
ret = -ENOEXEC;
}
} else {
printk(KERN_WARNING "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
loose 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;
// cleanup any temp buffers
if (v->pbuffer)
vfree(v->pbuffer);
v->plen = 0;
return ret;
}
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->f_path.dentry->d_inode) != minor)
return -ENODEV;
v = get_vpe(tclimit);
if (v == NULL)
return -ENODEV;
if (v->pbuffer == NULL) {
printk(KERN_ERR "VPE loader: no buffer for program\n");
return -ENOMEM;
}
if ((count + v->len) > v->plen) {
printk(KERN_WARNING
"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;
}
static const struct file_operations vpe_fops = {
.owner = THIS_MODULE,
.open = vpe_open,
.release = vpe_release,
.write = vpe_write
};
/* module wrapper entry points */
/* give me a vpe */
vpe_handle vpe_alloc(void)
{
int i;
struct vpe *v;
/* find a vpe */
for (i = 1; i < MAX_VPES; i++) {
if ((v = get_vpe(i)) != NULL) {
v->state = VPE_STATE_INUSE;
return v;
}
}
return NULL;
}
EXPORT_SYMBOL(vpe_alloc);
/* start running from here */
int vpe_start(vpe_handle vpe, unsigned long start)
{
struct vpe *v = vpe;
v->__start = start;
return vpe_run(v);
}
EXPORT_SYMBOL(vpe_start);
/* halt it for now */
int vpe_stop(vpe_handle vpe)
{
struct vpe *v = vpe;
struct tc *t;
unsigned int evpe_flags;
evpe_flags = dvpe();
if ((t = list_entry(v->tc.next, struct tc, tc)) != NULL) {
settc(t->index);
write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA);
}
evpe(evpe_flags);
return 0;
}
EXPORT_SYMBOL(vpe_stop);
/* I've done with it thank you */
int vpe_free(vpe_handle vpe)
{
struct vpe *v = vpe;
struct tc *t;
unsigned int evpe_flags;
if ((t = list_entry(v->tc.next, struct tc, tc)) == NULL) {
return -ENOEXEC;
}
evpe_flags = dvpe();
/* Put MVPE's into 'configuration state' */
set_c0_mvpcontrol(MVPCONTROL_VPC);
settc(t->index);
write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA);
/* mark the TC unallocated and halt'ed */
write_tc_c0_tcstatus(read_tc_c0_tcstatus() & ~TCSTATUS_A);
write_tc_c0_tchalt(TCHALT_H);
v->state = VPE_STATE_UNUSED;
clear_c0_mvpcontrol(MVPCONTROL_VPC);
evpe(evpe_flags);
return 0;
}
EXPORT_SYMBOL(vpe_free);
void *vpe_get_shared(int index)
{
struct vpe *v;
if ((v = get_vpe(index)) == NULL)
return NULL;
return v->shared_ptr;
}
EXPORT_SYMBOL(vpe_get_shared);
int vpe_getuid(int index)
{
struct vpe *v;
if ((v = get_vpe(index)) == NULL)
return -1;
return v->uid;
}
EXPORT_SYMBOL(vpe_getuid);
int vpe_getgid(int index)
{
struct vpe *v;
if ((v = get_vpe(index)) == NULL)
return -1;
return v->gid;
}
EXPORT_SYMBOL(vpe_getgid);
int vpe_notify(int index, struct vpe_notifications *notify)
{
struct vpe *v;
if ((v = get_vpe(index)) == NULL)
return -1;
list_add(&notify->list, &v->notify);
return 0;
}
EXPORT_SYMBOL(vpe_notify);
char *vpe_getcwd(int index)
{
struct vpe *v;
if ((v = get_vpe(index)) == NULL)
return NULL;
return v->cwd;
}
EXPORT_SYMBOL(vpe_getcwd);
#ifdef CONFIG_MIPS_APSP_KSPD
static void kspd_sp_exit( int sp_id)
{
cleanup_tc(get_tc(sp_id));
}
#endif
static ssize_t store_kill(struct device *dev, struct device_attribute *attr,
const char *buf, size_t len)
{
struct vpe *vpe = get_vpe(tclimit);
struct vpe_notifications *not;
list_for_each_entry(not, &vpe->notify, list) {
not->stop(tclimit);
}
release_progmem(vpe->load_addr);
cleanup_tc(get_tc(tclimit));
vpe_stop(vpe);
vpe_free(vpe);
return len;
}
static ssize_t show_ntcs(struct device *cd, struct device_attribute *attr,
char *buf)
{
struct vpe *vpe = get_vpe(tclimit);
return sprintf(buf, "%d\n", vpe->ntcs);
}
static ssize_t store_ntcs(struct device *dev, struct device_attribute *attr,
const char *buf, size_t len)
{
struct vpe *vpe = get_vpe(tclimit);
unsigned long new;
char *endp;
new = simple_strtoul(buf, &endp, 0);
if (endp == buf)
goto out_einval;
if (new == 0 || new > (hw_tcs - tclimit))
goto out_einval;
vpe->ntcs = new;
return len;
out_einval:
return -EINVAL;;
}
static struct device_attribute vpe_class_attributes[] = {
__ATTR(kill, S_IWUSR, NULL, store_kill),
__ATTR(ntcs, S_IRUGO | S_IWUSR, show_ntcs, store_ntcs),
{}
};
static void vpe_device_release(struct device *cd)
{
kfree(cd);
}
struct class vpe_class = {
.name = "vpe",
.owner = THIS_MODULE,
.dev_release = vpe_device_release,
.dev_attrs = vpe_class_attributes,
};
struct device vpe_device;
static int __init vpe_module_init(void)
{
unsigned int mtflags, vpflags;
unsigned long flags, val;
struct vpe *v = NULL;
struct tc *t;
int tc, err;
if (!cpu_has_mipsmt) {
printk("VPE loader: not a MIPS MT capable processor\n");
return -ENODEV;
}
if (vpelimit == 0) {
printk(KERN_WARNING "No VPEs reserved for AP/SP, not "
"initializing VPE loader.\nPass maxvpes=<n> argument as "
"kernel argument\n");
return -ENODEV;
}
if (tclimit == 0) {
printk(KERN_WARNING "No TCs reserved for AP/SP, not "
"initializing VPE loader.\nPass maxtcs=<n> argument as "
"kernel argument\n");
return -ENODEV;
}
major = register_chrdev(0, module_name, &vpe_fops);
if (major < 0) {
printk("VPE loader: unable to register character device\n");
return major;
}
err = class_register(&vpe_class);
if (err) {
printk(KERN_ERR "vpe_class registration failed\n");
goto out_chrdev;
}
device_initialize(&vpe_device);
vpe_device.class = &vpe_class,
vpe_device.parent = NULL,
strlcpy(vpe_device.bus_id, "vpe1", BUS_ID_SIZE);
vpe_device.devt = MKDEV(major, minor);
err = device_add(&vpe_device);
if (err) {
printk(KERN_ERR "Adding vpe_device failed\n");
goto out_class;
}
local_irq_save(flags);
mtflags = dmt();
vpflags = dvpe();
/* Put MVPE's into 'configuration state' */
set_c0_mvpcontrol(MVPCONTROL_VPC);
/* dump_mtregs(); */
val = read_c0_mvpconf0();
hw_tcs = (val & MVPCONF0_PTC) + 1;
hw_vpes = ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
for (tc = tclimit; tc < hw_tcs; tc++) {
/*
* Must re-enable multithreading temporarily or in case we
* reschedule send IPIs or similar we might hang.
*/
clear_c0_mvpcontrol(MVPCONTROL_VPC);
evpe(vpflags);
emt(mtflags);
local_irq_restore(flags);
t = alloc_tc(tc);
if (!t) {
err = -ENOMEM;
goto out;
}
local_irq_save(flags);
mtflags = dmt();
vpflags = dvpe();
set_c0_mvpcontrol(MVPCONTROL_VPC);
/* VPE's */
if (tc < hw_tcs) {
settc(tc);
if ((v = alloc_vpe(tc)) == NULL) {
printk(KERN_WARNING "VPE: unable to allocate VPE\n");
goto out_reenable;
}
v->ntcs = hw_tcs - tclimit;
/* add the tc to the list of this vpe's tc's. */
list_add(&t->tc, &v->tc);
/* deactivate all but vpe0 */
if (tc >= tclimit) {
unsigned long tmp = read_vpe_c0_vpeconf0();
tmp &= ~VPECONF0_VPA;
/* master VPE */
tmp |= VPECONF0_MVP;
write_vpe_c0_vpeconf0(tmp);
}
/* disable multi-threading with TC's */
write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & ~VPECONTROL_TE);
if (tc >= vpelimit) {
/*
* Set config to be the same as vpe0,
* particularly kseg0 coherency alg
*/
write_vpe_c0_config(read_c0_config());
}
}
/* TC's */
t->pvpe = v; /* set the parent vpe */
if (tc >= tclimit) {
unsigned long tmp;
settc(tc);
/* Any TC that is bound to VPE0 gets left as is - in case
we are running SMTC on VPE0. A TC that is bound to any
other VPE gets bound to VPE0, ideally I'd like to make
it homeless but it doesn't appear to let me bind a TC
to a non-existent VPE. Which is perfectly reasonable.
The (un)bound state is visible to an EJTAG probe so may
notify GDB...
*/
if (((tmp = read_tc_c0_tcbind()) & TCBIND_CURVPE)) {
/* tc is bound >vpe0 */
write_tc_c0_tcbind(tmp & ~TCBIND_CURVPE);
t->pvpe = get_vpe(0); /* set the parent vpe */
}
tmp = read_tc_c0_tcstatus();
/* mark not activated and not dynamically allocatable */
tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
tmp |= TCSTATUS_IXMT; /* interrupt exempt */
write_tc_c0_tcstatus(tmp);
write_tc_c0_tchalt(TCHALT_H);
}
}
out_reenable:
/* release config state */
clear_c0_mvpcontrol(MVPCONTROL_VPC);
evpe(vpflags);
emt(mtflags);
local_irq_restore(flags);
#ifdef CONFIG_MIPS_APSP_KSPD
kspd_events.kspd_sp_exit = kspd_sp_exit;
#endif
return 0;
out_class:
class_unregister(&vpe_class);
out_chrdev:
unregister_chrdev(major, module_name);
out:
return err;
}
static void __exit vpe_module_exit(void)
{
struct vpe *v, *n;
list_for_each_entry_safe(v, n, &vpecontrol.vpe_list, list) {
if (v->state != VPE_STATE_UNUSED) {
release_vpe(v);
}
}
device_del(&vpe_device);
unregister_chrdev(major, module_name);
}
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");
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