diff options
Diffstat (limited to 'arch/mips/kernel/vpe-mt.c')
| -rw-r--r-- | arch/mips/kernel/vpe-mt.c | 523 |
1 files changed, 523 insertions, 0 deletions
diff --git a/arch/mips/kernel/vpe-mt.c b/arch/mips/kernel/vpe-mt.c new file mode 100644 index 000000000000..949ae0e17018 --- /dev/null +++ b/arch/mips/kernel/vpe-mt.c @@ -0,0 +1,523 @@ +/* + * 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); + + /* + * SMTC/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); + + /* 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... + */ + 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); + } +} |