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b1db551324
The POWER9 core supports a new feature: ASB_Notify which requires the support of the Special Purpose Register: TIDR. The ASB_Notify command, generated by the AFU, will attempt to wake-up the host thread identified by the particular LPID:PID:TID. This patch assign a unique TIDR (thread id) for the current thread which will be used in the process element entry. Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Reviewed-by: Philippe Bergheaud <felix@linux.vnet.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Reviewed-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
367 lines
9.0 KiB
C
367 lines
9.0 KiB
C
/*
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* Copyright 2014 IBM Corp.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/bitmap.h>
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#include <linux/sched.h>
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#include <linux/pid.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/debugfs.h>
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#include <linux/slab.h>
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#include <linux/idr.h>
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#include <linux/sched/mm.h>
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#include <linux/mmu_context.h>
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#include <asm/cputable.h>
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#include <asm/current.h>
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#include <asm/copro.h>
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#include "cxl.h"
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/*
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* Allocates space for a CXL context.
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*/
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struct cxl_context *cxl_context_alloc(void)
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{
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return kzalloc(sizeof(struct cxl_context), GFP_KERNEL);
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}
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/*
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* Initialises a CXL context.
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*/
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int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master)
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{
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int i;
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ctx->afu = afu;
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ctx->master = master;
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ctx->pid = NULL; /* Set in start work ioctl */
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mutex_init(&ctx->mapping_lock);
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ctx->mapping = NULL;
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ctx->tidr = 0;
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ctx->assign_tidr = false;
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if (cxl_is_power8()) {
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spin_lock_init(&ctx->sste_lock);
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/*
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* Allocate the segment table before we put it in the IDR so that we
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* can always access it when dereferenced from IDR. For the same
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* reason, the segment table is only destroyed after the context is
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* removed from the IDR. Access to this in the IOCTL is protected by
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* Linux filesytem symantics (can't IOCTL until open is complete).
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*/
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i = cxl_alloc_sst(ctx);
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if (i)
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return i;
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}
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INIT_WORK(&ctx->fault_work, cxl_handle_fault);
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init_waitqueue_head(&ctx->wq);
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spin_lock_init(&ctx->lock);
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ctx->irq_bitmap = NULL;
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ctx->pending_irq = false;
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ctx->pending_fault = false;
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ctx->pending_afu_err = false;
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INIT_LIST_HEAD(&ctx->irq_names);
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INIT_LIST_HEAD(&ctx->extra_irq_contexts);
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/*
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* When we have to destroy all contexts in cxl_context_detach_all() we
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* end up with afu_release_irqs() called from inside a
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* idr_for_each_entry(). Hence we need to make sure that anything
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* dereferenced from this IDR is ok before we allocate the IDR here.
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* This clears out the IRQ ranges to ensure this.
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*/
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for (i = 0; i < CXL_IRQ_RANGES; i++)
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ctx->irqs.range[i] = 0;
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mutex_init(&ctx->status_mutex);
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ctx->status = OPENED;
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/*
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* Allocating IDR! We better make sure everything's setup that
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* dereferences from it.
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*/
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mutex_lock(&afu->contexts_lock);
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idr_preload(GFP_KERNEL);
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i = idr_alloc(&ctx->afu->contexts_idr, ctx, ctx->afu->adapter->min_pe,
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ctx->afu->num_procs, GFP_NOWAIT);
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idr_preload_end();
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mutex_unlock(&afu->contexts_lock);
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if (i < 0)
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return i;
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ctx->pe = i;
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if (cpu_has_feature(CPU_FTR_HVMODE)) {
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ctx->elem = &ctx->afu->native->spa[i];
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ctx->external_pe = ctx->pe;
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} else {
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ctx->external_pe = -1; /* assigned when attaching */
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}
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ctx->pe_inserted = false;
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/*
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* take a ref on the afu so that it stays alive at-least till
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* this context is reclaimed inside reclaim_ctx.
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*/
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cxl_afu_get(afu);
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return 0;
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}
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void cxl_context_set_mapping(struct cxl_context *ctx,
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struct address_space *mapping)
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{
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mutex_lock(&ctx->mapping_lock);
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ctx->mapping = mapping;
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mutex_unlock(&ctx->mapping_lock);
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}
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static int cxl_mmap_fault(struct vm_fault *vmf)
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{
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struct vm_area_struct *vma = vmf->vma;
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struct cxl_context *ctx = vma->vm_file->private_data;
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u64 area, offset;
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offset = vmf->pgoff << PAGE_SHIFT;
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pr_devel("%s: pe: %i address: 0x%lx offset: 0x%llx\n",
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__func__, ctx->pe, vmf->address, offset);
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if (ctx->afu->current_mode == CXL_MODE_DEDICATED) {
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area = ctx->afu->psn_phys;
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if (offset >= ctx->afu->adapter->ps_size)
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return VM_FAULT_SIGBUS;
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} else {
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area = ctx->psn_phys;
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if (offset >= ctx->psn_size)
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return VM_FAULT_SIGBUS;
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}
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mutex_lock(&ctx->status_mutex);
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if (ctx->status != STARTED) {
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mutex_unlock(&ctx->status_mutex);
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pr_devel("%s: Context not started, failing problem state access\n", __func__);
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if (ctx->mmio_err_ff) {
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if (!ctx->ff_page) {
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ctx->ff_page = alloc_page(GFP_USER);
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if (!ctx->ff_page)
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return VM_FAULT_OOM;
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memset(page_address(ctx->ff_page), 0xff, PAGE_SIZE);
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}
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get_page(ctx->ff_page);
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vmf->page = ctx->ff_page;
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vma->vm_page_prot = pgprot_cached(vma->vm_page_prot);
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return 0;
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}
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return VM_FAULT_SIGBUS;
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}
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vm_insert_pfn(vma, vmf->address, (area + offset) >> PAGE_SHIFT);
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mutex_unlock(&ctx->status_mutex);
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return VM_FAULT_NOPAGE;
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}
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static const struct vm_operations_struct cxl_mmap_vmops = {
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.fault = cxl_mmap_fault,
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};
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/*
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* Map a per-context mmio space into the given vma.
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*/
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int cxl_context_iomap(struct cxl_context *ctx, struct vm_area_struct *vma)
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{
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u64 start = vma->vm_pgoff << PAGE_SHIFT;
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u64 len = vma->vm_end - vma->vm_start;
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if (ctx->afu->current_mode == CXL_MODE_DEDICATED) {
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if (start + len > ctx->afu->adapter->ps_size)
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return -EINVAL;
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if (cxl_is_power9()) {
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/*
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* Make sure there is a valid problem state
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* area space for this AFU.
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*/
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if (ctx->master && !ctx->afu->psa) {
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pr_devel("AFU doesn't support mmio space\n");
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return -EINVAL;
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}
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/* Can't mmap until the AFU is enabled */
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if (!ctx->afu->enabled)
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return -EBUSY;
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}
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} else {
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if (start + len > ctx->psn_size)
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return -EINVAL;
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/* Make sure there is a valid per process space for this AFU */
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if ((ctx->master && !ctx->afu->psa) || (!ctx->afu->pp_psa)) {
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pr_devel("AFU doesn't support mmio space\n");
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return -EINVAL;
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}
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/* Can't mmap until the AFU is enabled */
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if (!ctx->afu->enabled)
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return -EBUSY;
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}
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pr_devel("%s: mmio physical: %llx pe: %i master:%i\n", __func__,
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ctx->psn_phys, ctx->pe , ctx->master);
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vma->vm_flags |= VM_IO | VM_PFNMAP;
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vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
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vma->vm_ops = &cxl_mmap_vmops;
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return 0;
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}
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/*
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* Detach a context from the hardware. This disables interrupts and doesn't
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* return until all outstanding interrupts for this context have completed. The
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* hardware should no longer access *ctx after this has returned.
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*/
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int __detach_context(struct cxl_context *ctx)
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{
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enum cxl_context_status status;
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mutex_lock(&ctx->status_mutex);
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status = ctx->status;
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ctx->status = CLOSED;
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mutex_unlock(&ctx->status_mutex);
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if (status != STARTED)
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return -EBUSY;
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/* Only warn if we detached while the link was OK.
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* If detach fails when hw is down, we don't care.
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*/
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WARN_ON(cxl_ops->detach_process(ctx) &&
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cxl_ops->link_ok(ctx->afu->adapter, ctx->afu));
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flush_work(&ctx->fault_work); /* Only needed for dedicated process */
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/*
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* Wait until no further interrupts are presented by the PSL
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* for this context.
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*/
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if (cxl_ops->irq_wait)
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cxl_ops->irq_wait(ctx);
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/* release the reference to the group leader and mm handling pid */
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put_pid(ctx->pid);
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cxl_ctx_put();
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/* Decrease the attached context count on the adapter */
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cxl_adapter_context_put(ctx->afu->adapter);
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/* Decrease the mm count on the context */
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cxl_context_mm_count_put(ctx);
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if (ctx->mm)
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mm_context_remove_copro(ctx->mm);
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ctx->mm = NULL;
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return 0;
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}
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/*
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* Detach the given context from the AFU. This doesn't actually
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* free the context but it should stop the context running in hardware
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* (ie. prevent this context from generating any further interrupts
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* so that it can be freed).
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*/
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void cxl_context_detach(struct cxl_context *ctx)
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{
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int rc;
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rc = __detach_context(ctx);
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if (rc)
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return;
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afu_release_irqs(ctx, ctx);
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wake_up_all(&ctx->wq);
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}
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/*
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* Detach all contexts on the given AFU.
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*/
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void cxl_context_detach_all(struct cxl_afu *afu)
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{
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struct cxl_context *ctx;
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int tmp;
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mutex_lock(&afu->contexts_lock);
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idr_for_each_entry(&afu->contexts_idr, ctx, tmp) {
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/*
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* Anything done in here needs to be setup before the IDR is
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* created and torn down after the IDR removed
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*/
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cxl_context_detach(ctx);
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/*
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* We are force detaching - remove any active PSA mappings so
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* userspace cannot interfere with the card if it comes back.
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* Easiest way to exercise this is to unbind and rebind the
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* driver via sysfs while it is in use.
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*/
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mutex_lock(&ctx->mapping_lock);
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if (ctx->mapping)
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unmap_mapping_range(ctx->mapping, 0, 0, 1);
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mutex_unlock(&ctx->mapping_lock);
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}
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mutex_unlock(&afu->contexts_lock);
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}
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static void reclaim_ctx(struct rcu_head *rcu)
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{
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struct cxl_context *ctx = container_of(rcu, struct cxl_context, rcu);
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if (cxl_is_power8())
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free_page((u64)ctx->sstp);
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if (ctx->ff_page)
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__free_page(ctx->ff_page);
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ctx->sstp = NULL;
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kfree(ctx->irq_bitmap);
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/* Drop ref to the afu device taken during cxl_context_init */
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cxl_afu_put(ctx->afu);
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kfree(ctx);
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}
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void cxl_context_free(struct cxl_context *ctx)
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{
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if (ctx->kernelapi && ctx->mapping)
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cxl_release_mapping(ctx);
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mutex_lock(&ctx->afu->contexts_lock);
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idr_remove(&ctx->afu->contexts_idr, ctx->pe);
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mutex_unlock(&ctx->afu->contexts_lock);
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call_rcu(&ctx->rcu, reclaim_ctx);
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}
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void cxl_context_mm_count_get(struct cxl_context *ctx)
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{
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if (ctx->mm)
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atomic_inc(&ctx->mm->mm_count);
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}
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void cxl_context_mm_count_put(struct cxl_context *ctx)
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{
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if (ctx->mm)
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mmdrop(ctx->mm);
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}
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