Orange Pi5 kernel

/*
 * 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);
<------>}
}