mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 11:19:37 +00:00
![Ralf Baechle](/assets/img/avatar_default.png)
Nobody is maintaining SMTC anymore and there also seems to be no userbase. Which is a pity - the SMTC technology primarily developed by Kevin D. Kissell <kevink@paralogos.com> is an ingenious demonstration for the MT ASE's power and elegance. Based on Markos Chandras <Markos.Chandras@imgtec.com> patch https://patchwork.linux-mips.org/patch/6719/ which while very similar did no longer apply cleanly when I tried to merge it plus some additional post-SMTC cleanup - SMTC was a feature as tricky to remove as it was to merge once upon a time. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
521 lines
11 KiB
C
521 lines
11 KiB
C
/*
|
|
* 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.
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/device.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/export.h>
|
|
|
|
#include <asm/mipsregs.h>
|
|
#include <asm/mipsmtregs.h>
|
|
#include <asm/mips_mt.h>
|
|
#include <asm/vpe.h>
|
|
|
|
static int major;
|
|
|
|
/* The number of TCs and VPEs physically available on the core */
|
|
static int hw_tcs, hw_vpes;
|
|
|
|
/* We are prepared so configure and start the VPE... */
|
|
int vpe_run(struct vpe *v)
|
|
{
|
|
unsigned long flags, val, dmt_flag;
|
|
struct vpe_notifications *notifier;
|
|
unsigned int vpeflags;
|
|
struct tc *t;
|
|
|
|
/* check we are the Master VPE */
|
|
local_irq_save(flags);
|
|
val = read_c0_vpeconf0();
|
|
if (!(val & VPECONF0_MVP)) {
|
|
pr_warn("VPE loader: only Master VPE's are able to config MT\n");
|
|
local_irq_restore(flags);
|
|
|
|
return -1;
|
|
}
|
|
|
|
dmt_flag = dmt();
|
|
vpeflags = dvpe();
|
|
|
|
if (list_empty(&v->tc)) {
|
|
evpe(vpeflags);
|
|
emt(dmt_flag);
|
|
local_irq_restore(flags);
|
|
|
|
pr_warn("VPE loader: No TC's associated with VPE %d\n",
|
|
v->minor);
|
|
|
|
return -ENOEXEC;
|
|
}
|
|
|
|
t = list_first_entry(&v->tc, struct tc, tc);
|
|
|
|
/* 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);
|
|
|
|
pr_warn("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);
|
|
|
|
/*
|
|
* SMVP kernels manage VPE enable independently, but uniprocessor
|
|
* kernels need to turn it on, even if that wasn't the pre-dvpe() state.
|
|
*/
|
|
#ifdef CONFIG_SMP
|
|
evpe(vpeflags);
|
|
#else
|
|
evpe(EVPE_ENABLE);
|
|
#endif
|
|
emt(dmt_flag);
|
|
local_irq_restore(flags);
|
|
|
|
list_for_each_entry(notifier, &v->notify, list)
|
|
notifier->start(VPE_MODULE_MINOR);
|
|
|
|
return 0;
|
|
}
|
|
|
|
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);
|
|
mips_ihb();
|
|
|
|
clear_c0_mvpcontrol(MVPCONTROL_VPC);
|
|
evpe(vpflags);
|
|
emt(mtflags);
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
/* module wrapper entry points */
|
|
/* give me a vpe */
|
|
void *vpe_alloc(void)
|
|
{
|
|
int i;
|
|
struct vpe *v;
|
|
|
|
/* find a vpe */
|
|
for (i = 1; i < MAX_VPES; i++) {
|
|
v = get_vpe(i);
|
|
if (v != NULL) {
|
|
v->state = VPE_STATE_INUSE;
|
|
return v;
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(vpe_alloc);
|
|
|
|
/* start running from here */
|
|
int vpe_start(void *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(void *vpe)
|
|
{
|
|
struct vpe *v = vpe;
|
|
struct tc *t;
|
|
unsigned int evpe_flags;
|
|
|
|
evpe_flags = dvpe();
|
|
|
|
t = list_entry(v->tc.next, struct tc, tc);
|
|
if (t != 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(void *vpe)
|
|
{
|
|
struct vpe *v = vpe;
|
|
struct tc *t;
|
|
unsigned int evpe_flags;
|
|
|
|
t = list_entry(v->tc.next, struct tc, tc);
|
|
if (t == 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);
|
|
|
|
/* halt the TC */
|
|
write_tc_c0_tchalt(TCHALT_H);
|
|
mips_ihb();
|
|
|
|
/* mark the TC unallocated */
|
|
write_tc_c0_tcstatus(read_tc_c0_tcstatus() & ~TCSTATUS_A);
|
|
|
|
v->state = VPE_STATE_UNUSED;
|
|
|
|
clear_c0_mvpcontrol(MVPCONTROL_VPC);
|
|
evpe(evpe_flags);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(vpe_free);
|
|
|
|
static ssize_t store_kill(struct device *dev, struct device_attribute *attr,
|
|
const char *buf, size_t len)
|
|
{
|
|
struct vpe *vpe = get_vpe(aprp_cpu_index());
|
|
struct vpe_notifications *notifier;
|
|
|
|
list_for_each_entry(notifier, &vpe->notify, list)
|
|
notifier->stop(aprp_cpu_index());
|
|
|
|
release_progmem(vpe->load_addr);
|
|
cleanup_tc(get_tc(aprp_cpu_index()));
|
|
vpe_stop(vpe);
|
|
vpe_free(vpe);
|
|
|
|
return len;
|
|
}
|
|
static DEVICE_ATTR(kill, S_IWUSR, NULL, store_kill);
|
|
|
|
static ssize_t ntcs_show(struct device *cd, struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct vpe *vpe = get_vpe(aprp_cpu_index());
|
|
|
|
return sprintf(buf, "%d\n", vpe->ntcs);
|
|
}
|
|
|
|
static ssize_t ntcs_store(struct device *dev, struct device_attribute *attr,
|
|
const char *buf, size_t len)
|
|
{
|
|
struct vpe *vpe = get_vpe(aprp_cpu_index());
|
|
unsigned long new;
|
|
int ret;
|
|
|
|
ret = kstrtoul(buf, 0, &new);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (new == 0 || new > (hw_tcs - aprp_cpu_index()))
|
|
return -EINVAL;
|
|
|
|
vpe->ntcs = new;
|
|
|
|
return len;
|
|
}
|
|
static DEVICE_ATTR_RW(ntcs);
|
|
|
|
static struct attribute *vpe_attrs[] = {
|
|
&dev_attr_kill.attr,
|
|
&dev_attr_ntcs.attr,
|
|
NULL,
|
|
};
|
|
ATTRIBUTE_GROUPS(vpe);
|
|
|
|
static void vpe_device_release(struct device *cd)
|
|
{
|
|
kfree(cd);
|
|
}
|
|
|
|
static struct class vpe_class = {
|
|
.name = "vpe",
|
|
.owner = THIS_MODULE,
|
|
.dev_release = vpe_device_release,
|
|
.dev_groups = vpe_groups,
|
|
};
|
|
|
|
static struct device vpe_device;
|
|
|
|
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) {
|
|
pr_warn("VPE loader: not a MIPS MT capable processor\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
if (vpelimit == 0) {
|
|
pr_warn("No VPEs reserved for AP/SP, not initialize VPE loader\n"
|
|
"Pass maxvpes=<n> argument as kernel argument\n");
|
|
|
|
return -ENODEV;
|
|
}
|
|
|
|
if (aprp_cpu_index() == 0) {
|
|
pr_warn("No TCs reserved for AP/SP, not initialize VPE loader\n"
|
|
"Pass maxtcs=<n> argument as kernel argument\n");
|
|
|
|
return -ENODEV;
|
|
}
|
|
|
|
major = register_chrdev(0, VPE_MODULE_NAME, &vpe_fops);
|
|
if (major < 0) {
|
|
pr_warn("VPE loader: unable to register character device\n");
|
|
return major;
|
|
}
|
|
|
|
err = class_register(&vpe_class);
|
|
if (err) {
|
|
pr_err("vpe_class registration failed\n");
|
|
goto out_chrdev;
|
|
}
|
|
|
|
device_initialize(&vpe_device);
|
|
vpe_device.class = &vpe_class,
|
|
vpe_device.parent = NULL,
|
|
dev_set_name(&vpe_device, "vpe1");
|
|
vpe_device.devt = MKDEV(major, VPE_MODULE_MINOR);
|
|
err = device_add(&vpe_device);
|
|
if (err) {
|
|
pr_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);
|
|
|
|
val = read_c0_mvpconf0();
|
|
hw_tcs = (val & MVPCONF0_PTC) + 1;
|
|
hw_vpes = ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
|
|
|
|
for (tc = aprp_cpu_index(); 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_dev;
|
|
}
|
|
|
|
local_irq_save(flags);
|
|
mtflags = dmt();
|
|
vpflags = dvpe();
|
|
set_c0_mvpcontrol(MVPCONTROL_VPC);
|
|
|
|
/* VPE's */
|
|
if (tc < hw_tcs) {
|
|
settc(tc);
|
|
|
|
v = alloc_vpe(tc);
|
|
if (v == NULL) {
|
|
pr_warn("VPE: unable to allocate VPE\n");
|
|
goto out_reenable;
|
|
}
|
|
|
|
v->ntcs = hw_tcs - aprp_cpu_index();
|
|
|
|
/* add the tc to the list of this vpe's tc's. */
|
|
list_add(&t->tc, &v->tc);
|
|
|
|
/* deactivate all but vpe0 */
|
|
if (tc >= aprp_cpu_index()) {
|
|
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 >= aprp_cpu_index()) {
|
|
unsigned long tmp;
|
|
|
|
settc(tc);
|
|
|
|
/*
|
|
* 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...
|
|
*/
|
|
tmp = read_tc_c0_tcbind();
|
|
if (tmp & TCBIND_CURVPE) {
|
|
/* tc is bound >vpe0 */
|
|
write_tc_c0_tcbind(tmp & ~TCBIND_CURVPE);
|
|
|
|
t->pvpe = get_vpe(0); /* set the parent vpe */
|
|
}
|
|
|
|
/* halt the TC */
|
|
write_tc_c0_tchalt(TCHALT_H);
|
|
mips_ihb();
|
|
|
|
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);
|
|
}
|
|
}
|
|
|
|
out_reenable:
|
|
/* release config state */
|
|
clear_c0_mvpcontrol(MVPCONTROL_VPC);
|
|
|
|
evpe(vpflags);
|
|
emt(mtflags);
|
|
local_irq_restore(flags);
|
|
|
|
return 0;
|
|
|
|
out_dev:
|
|
device_del(&vpe_device);
|
|
|
|
out_class:
|
|
class_unregister(&vpe_class);
|
|
|
|
out_chrdev:
|
|
unregister_chrdev(major, VPE_MODULE_NAME);
|
|
|
|
return err;
|
|
}
|
|
|
|
void __exit vpe_module_exit(void)
|
|
{
|
|
struct vpe *v, *n;
|
|
|
|
device_del(&vpe_device);
|
|
class_unregister(&vpe_class);
|
|
unregister_chrdev(major, VPE_MODULE_NAME);
|
|
|
|
/* No locking needed here */
|
|
list_for_each_entry_safe(v, n, &vpecontrol.vpe_list, list) {
|
|
if (v->state != VPE_STATE_UNUSED)
|
|
release_vpe(v);
|
|
}
|
|
}
|