| /* |
| * Copyright 2014 IBM Corp. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| #include <linux/interrupt.h> |
| #include <linux/workqueue.h> |
| #include <linux/sched.h> |
| #include <linux/wait.h> |
| #include <linux/slab.h> |
| #include <linux/pid.h> |
| #include <asm/cputable.h> |
| #include <misc/cxl-base.h> |
| |
| #include "cxl.h" |
| #include "trace.h" |
| |
| static int afu_irq_range_start(void) |
| { |
| if (cpu_has_feature(CPU_FTR_HVMODE)) |
| return 1; |
| return 0; |
| } |
| |
| static irqreturn_t schedule_cxl_fault(struct cxl_context *ctx, u64 dsisr, u64 dar) |
| { |
| ctx->dsisr = dsisr; |
| ctx->dar = dar; |
| schedule_work(&ctx->fault_work); |
| return IRQ_HANDLED; |
| } |
| |
| irqreturn_t cxl_irq(int irq, struct cxl_context *ctx, struct cxl_irq_info *irq_info) |
| { |
| u64 dsisr, dar; |
| |
| dsisr = irq_info->dsisr; |
| dar = irq_info->dar; |
| |
| trace_cxl_psl_irq(ctx, irq, dsisr, dar); |
| |
| pr_devel("CXL interrupt %i for afu pe: %i DSISR: %#llx DAR: %#llx\n", irq, ctx->pe, dsisr, dar); |
| |
| if (dsisr & CXL_PSL_DSISR_An_DS) { |
| /* |
| * We don't inherently need to sleep to handle this, but we do |
| * need to get a ref to the task's mm, which we can't do from |
| * irq context without the potential for a deadlock since it |
| * takes the task_lock. An alternate option would be to keep a |
| * reference to the task's mm the entire time it has cxl open, |
| * but to do that we need to solve the issue where we hold a |
| * ref to the mm, but the mm can hold a ref to the fd after an |
| * mmap preventing anything from being cleaned up. |
| */ |
| pr_devel("Scheduling segment miss handling for later pe: %i\n", ctx->pe); |
| return schedule_cxl_fault(ctx, dsisr, dar); |
| } |
| |
| if (dsisr & CXL_PSL_DSISR_An_M) |
| pr_devel("CXL interrupt: PTE not found\n"); |
| if (dsisr & CXL_PSL_DSISR_An_P) |
| pr_devel("CXL interrupt: Storage protection violation\n"); |
| if (dsisr & CXL_PSL_DSISR_An_A) |
| pr_devel("CXL interrupt: AFU lock access to write through or cache inhibited storage\n"); |
| if (dsisr & CXL_PSL_DSISR_An_S) |
| pr_devel("CXL interrupt: Access was afu_wr or afu_zero\n"); |
| if (dsisr & CXL_PSL_DSISR_An_K) |
| pr_devel("CXL interrupt: Access not permitted by virtual page class key protection\n"); |
| |
| if (dsisr & CXL_PSL_DSISR_An_DM) { |
| /* |
| * In some cases we might be able to handle the fault |
| * immediately if hash_page would succeed, but we still need |
| * the task's mm, which as above we can't get without a lock |
| */ |
| pr_devel("Scheduling page fault handling for later pe: %i\n", ctx->pe); |
| return schedule_cxl_fault(ctx, dsisr, dar); |
| } |
| if (dsisr & CXL_PSL_DSISR_An_ST) |
| WARN(1, "CXL interrupt: Segment Table PTE not found\n"); |
| if (dsisr & CXL_PSL_DSISR_An_UR) |
| pr_devel("CXL interrupt: AURP PTE not found\n"); |
| if (dsisr & CXL_PSL_DSISR_An_PE) |
| return cxl_ops->handle_psl_slice_error(ctx, dsisr, |
| irq_info->errstat); |
| if (dsisr & CXL_PSL_DSISR_An_AE) { |
| pr_devel("CXL interrupt: AFU Error 0x%016llx\n", irq_info->afu_err); |
| |
| if (ctx->pending_afu_err) { |
| /* |
| * This shouldn't happen - the PSL treats these errors |
| * as fatal and will have reset the AFU, so there's not |
| * much point buffering multiple AFU errors. |
| * OTOH if we DO ever see a storm of these come in it's |
| * probably best that we log them somewhere: |
| */ |
| dev_err_ratelimited(&ctx->afu->dev, "CXL AFU Error " |
| "undelivered to pe %i: 0x%016llx\n", |
| ctx->pe, irq_info->afu_err); |
| } else { |
| spin_lock(&ctx->lock); |
| ctx->afu_err = irq_info->afu_err; |
| ctx->pending_afu_err = 1; |
| spin_unlock(&ctx->lock); |
| |
| wake_up_all(&ctx->wq); |
| } |
| |
| cxl_ops->ack_irq(ctx, CXL_PSL_TFC_An_A, 0); |
| return IRQ_HANDLED; |
| } |
| if (dsisr & CXL_PSL_DSISR_An_OC) |
| pr_devel("CXL interrupt: OS Context Warning\n"); |
| |
| WARN(1, "Unhandled CXL PSL IRQ\n"); |
| return IRQ_HANDLED; |
| } |
| |
| static irqreturn_t cxl_irq_afu(int irq, void *data) |
| { |
| struct cxl_context *ctx = data; |
| irq_hw_number_t hwirq = irqd_to_hwirq(irq_get_irq_data(irq)); |
| int irq_off, afu_irq = 0; |
| __u16 range; |
| int r; |
| |
| /* |
| * Look for the interrupt number. |
| * On bare-metal, we know range 0 only contains the PSL |
| * interrupt so we could start counting at range 1 and initialize |
| * afu_irq at 1. |
| * In a guest, range 0 also contains AFU interrupts, so it must |
| * be counted for. Therefore we initialize afu_irq at 0 to take into |
| * account the PSL interrupt. |
| * |
| * For code-readability, it just seems easier to go over all |
| * the ranges on bare-metal and guest. The end result is the same. |
| */ |
| for (r = 0; r < CXL_IRQ_RANGES; r++) { |
| irq_off = hwirq - ctx->irqs.offset[r]; |
| range = ctx->irqs.range[r]; |
| if (irq_off >= 0 && irq_off < range) { |
| afu_irq += irq_off; |
| break; |
| } |
| afu_irq += range; |
| } |
| if (unlikely(r >= CXL_IRQ_RANGES)) { |
| WARN(1, "Received AFU IRQ out of range for pe %i (virq %i hwirq %lx)\n", |
| ctx->pe, irq, hwirq); |
| return IRQ_HANDLED; |
| } |
| |
| trace_cxl_afu_irq(ctx, afu_irq, irq, hwirq); |
| pr_devel("Received AFU interrupt %i for pe: %i (virq %i hwirq %lx)\n", |
| afu_irq, ctx->pe, irq, hwirq); |
| |
| if (unlikely(!ctx->irq_bitmap)) { |
| WARN(1, "Received AFU IRQ for context with no IRQ bitmap\n"); |
| return IRQ_HANDLED; |
| } |
| spin_lock(&ctx->lock); |
| set_bit(afu_irq - 1, ctx->irq_bitmap); |
| ctx->pending_irq = true; |
| spin_unlock(&ctx->lock); |
| |
| wake_up_all(&ctx->wq); |
| |
| return IRQ_HANDLED; |
| } |
| |
| unsigned int cxl_map_irq(struct cxl *adapter, irq_hw_number_t hwirq, |
| irq_handler_t handler, void *cookie, const char *name) |
| { |
| unsigned int virq; |
| int result; |
| |
| /* IRQ Domain? */ |
| virq = irq_create_mapping(NULL, hwirq); |
| if (!virq) { |
| dev_warn(&adapter->dev, "cxl_map_irq: irq_create_mapping failed\n"); |
| return 0; |
| } |
| |
| if (cxl_ops->setup_irq) |
| cxl_ops->setup_irq(adapter, hwirq, virq); |
| |
| pr_devel("hwirq %#lx mapped to virq %u\n", hwirq, virq); |
| |
| result = request_irq(virq, handler, 0, name, cookie); |
| if (result) { |
| dev_warn(&adapter->dev, "cxl_map_irq: request_irq failed: %i\n", result); |
| return 0; |
| } |
| |
| return virq; |
| } |
| |
| void cxl_unmap_irq(unsigned int virq, void *cookie) |
| { |
| free_irq(virq, cookie); |
| irq_dispose_mapping(virq); |
| } |
| |
| int cxl_register_one_irq(struct cxl *adapter, |
| irq_handler_t handler, |
| void *cookie, |
| irq_hw_number_t *dest_hwirq, |
| unsigned int *dest_virq, |
| const char *name) |
| { |
| int hwirq, virq; |
| |
| if ((hwirq = cxl_ops->alloc_one_irq(adapter)) < 0) |
| return hwirq; |
| |
| if (!(virq = cxl_map_irq(adapter, hwirq, handler, cookie, name))) |
| goto err; |
| |
| *dest_hwirq = hwirq; |
| *dest_virq = virq; |
| |
| return 0; |
| |
| err: |
| cxl_ops->release_one_irq(adapter, hwirq); |
| return -ENOMEM; |
| } |
| |
| void afu_irq_name_free(struct cxl_context *ctx) |
| { |
| struct cxl_irq_name *irq_name, *tmp; |
| |
| list_for_each_entry_safe(irq_name, tmp, &ctx->irq_names, list) { |
| kfree(irq_name->name); |
| list_del(&irq_name->list); |
| kfree(irq_name); |
| } |
| } |
| |
| int afu_allocate_irqs(struct cxl_context *ctx, u32 count) |
| { |
| int rc, r, i, j = 1; |
| struct cxl_irq_name *irq_name; |
| int alloc_count; |
| |
| /* |
| * In native mode, range 0 is reserved for the multiplexed |
| * PSL interrupt. It has been allocated when the AFU was initialized. |
| * |
| * In a guest, the PSL interrupt is not mutliplexed, but per-context, |
| * and is the first interrupt from range 0. It still needs to be |
| * allocated, so bump the count by one. |
| */ |
| if (cpu_has_feature(CPU_FTR_HVMODE)) |
| alloc_count = count; |
| else |
| alloc_count = count + 1; |
| |
| /* Initialize the list head to hold irq names */ |
| INIT_LIST_HEAD(&ctx->irq_names); |
| |
| if ((rc = cxl_ops->alloc_irq_ranges(&ctx->irqs, ctx->afu->adapter, |
| alloc_count))) |
| return rc; |
| |
| if (cpu_has_feature(CPU_FTR_HVMODE)) { |
| /* Multiplexed PSL Interrupt */ |
| ctx->irqs.offset[0] = ctx->afu->native->psl_hwirq; |
| ctx->irqs.range[0] = 1; |
| } |
| |
| ctx->irq_count = count; |
| ctx->irq_bitmap = kcalloc(BITS_TO_LONGS(count), |
| sizeof(*ctx->irq_bitmap), GFP_KERNEL); |
| if (!ctx->irq_bitmap) |
| goto out; |
| |
| /* |
| * Allocate names first. If any fail, bail out before allocating |
| * actual hardware IRQs. |
| */ |
| for (r = afu_irq_range_start(); r < CXL_IRQ_RANGES; r++) { |
| for (i = 0; i < ctx->irqs.range[r]; i++) { |
| irq_name = kmalloc(sizeof(struct cxl_irq_name), |
| GFP_KERNEL); |
| if (!irq_name) |
| goto out; |
| irq_name->name = kasprintf(GFP_KERNEL, "cxl-%s-pe%i-%i", |
| dev_name(&ctx->afu->dev), |
| ctx->pe, j); |
| if (!irq_name->name) { |
| kfree(irq_name); |
| goto out; |
| } |
| /* Add to tail so next look get the correct order */ |
| list_add_tail(&irq_name->list, &ctx->irq_names); |
| j++; |
| } |
| } |
| return 0; |
| |
| out: |
| cxl_ops->release_irq_ranges(&ctx->irqs, ctx->afu->adapter); |
| afu_irq_name_free(ctx); |
| return -ENOMEM; |
| } |
| |
| static void afu_register_hwirqs(struct cxl_context *ctx) |
| { |
| irq_hw_number_t hwirq; |
| struct cxl_irq_name *irq_name; |
| int r, i; |
| irqreturn_t (*handler)(int irq, void *data); |
| |
| /* We've allocated all memory now, so let's do the irq allocations */ |
| irq_name = list_first_entry(&ctx->irq_names, struct cxl_irq_name, list); |
| for (r = afu_irq_range_start(); r < CXL_IRQ_RANGES; r++) { |
| hwirq = ctx->irqs.offset[r]; |
| for (i = 0; i < ctx->irqs.range[r]; hwirq++, i++) { |
| if (r == 0 && i == 0) |
| /* |
| * The very first interrupt of range 0 is |
| * always the PSL interrupt, but we only |
| * need to connect a handler for guests, |
| * because there's one PSL interrupt per |
| * context. |
| * On bare-metal, the PSL interrupt is |
| * multiplexed and was setup when the AFU |
| * was configured. |
| */ |
| handler = cxl_ops->psl_interrupt; |
| else |
| handler = cxl_irq_afu; |
| cxl_map_irq(ctx->afu->adapter, hwirq, handler, ctx, |
| irq_name->name); |
| irq_name = list_next_entry(irq_name, list); |
| } |
| } |
| } |
| |
| int afu_register_irqs(struct cxl_context *ctx, u32 count) |
| { |
| int rc; |
| |
| rc = afu_allocate_irqs(ctx, count); |
| if (rc) |
| return rc; |
| |
| afu_register_hwirqs(ctx); |
| return 0; |
| } |
| |
| void afu_release_irqs(struct cxl_context *ctx, void *cookie) |
| { |
| irq_hw_number_t hwirq; |
| unsigned int virq; |
| int r, i; |
| |
| for (r = afu_irq_range_start(); r < CXL_IRQ_RANGES; r++) { |
| hwirq = ctx->irqs.offset[r]; |
| for (i = 0; i < ctx->irqs.range[r]; hwirq++, i++) { |
| virq = irq_find_mapping(NULL, hwirq); |
| if (virq) |
| cxl_unmap_irq(virq, cookie); |
| } |
| } |
| |
| afu_irq_name_free(ctx); |
| cxl_ops->release_irq_ranges(&ctx->irqs, ctx->afu->adapter); |
| |
| ctx->irq_count = 0; |
| } |