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-rw-r--r--drivers/misc/cxl/irq.c453
1 files changed, 453 insertions, 0 deletions
diff --git a/drivers/misc/cxl/irq.c b/drivers/misc/cxl/irq.c
new file mode 100644
index 000000000..ce08a9f22
--- /dev/null
+++ b/drivers/misc/cxl/irq.c
@@ -0,0 +1,453 @@
+/*
+ * 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_psl9(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_psl9_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_PSL9_DSISR_An_TF) {
+ pr_devel("CXL interrupt: Scheduling translation fault handling for later (pe: %i)\n", ctx->pe);
+ return schedule_cxl_fault(ctx, dsisr, dar);
+ }
+
+ if (dsisr & CXL_PSL9_DSISR_An_PE)
+ return cxl_ops->handle_psl_slice_error(ctx, dsisr,
+ irq_info->errstat);
+ if (dsisr & CXL_PSL9_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_PSL9_DSISR_An_OC)
+ pr_devel("CXL interrupt: OS Context Warning\n");
+
+ WARN(1, "Unhandled CXL PSL IRQ\n");
+ return IRQ_HANDLED;
+}
+
+irqreturn_t cxl_irq_psl8(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 = true;
+ 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);
+}
+
+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;
+
+ 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;
+}
+
+void cxl_afu_decode_psl_serr(struct cxl_afu *afu, u64 serr)
+{
+ dev_crit(&afu->dev,
+ "PSL Slice error received. Check AFU for root cause.\n");
+ dev_crit(&afu->dev, "PSL_SERR_An: 0x%016llx\n", serr);
+ if (serr & CXL_PSL_SERR_An_afuto)
+ dev_crit(&afu->dev, "AFU MMIO Timeout\n");
+ if (serr & CXL_PSL_SERR_An_afudis)
+ dev_crit(&afu->dev,
+ "MMIO targeted Accelerator that was not enabled\n");
+ if (serr & CXL_PSL_SERR_An_afuov)
+ dev_crit(&afu->dev, "AFU CTAG Overflow\n");
+ if (serr & CXL_PSL_SERR_An_badsrc)
+ dev_crit(&afu->dev, "Bad Interrupt Source\n");
+ if (serr & CXL_PSL_SERR_An_badctx)
+ dev_crit(&afu->dev, "Bad Context Handle\n");
+ if (serr & CXL_PSL_SERR_An_llcmdis)
+ dev_crit(&afu->dev, "LLCMD to Disabled AFU\n");
+ if (serr & CXL_PSL_SERR_An_llcmdto)
+ dev_crit(&afu->dev, "LLCMD Timeout to AFU\n");
+ if (serr & CXL_PSL_SERR_An_afupar)
+ dev_crit(&afu->dev, "AFU MMIO Parity Error\n");
+ if (serr & CXL_PSL_SERR_An_afudup)
+ dev_crit(&afu->dev, "AFU MMIO Duplicate CTAG Error\n");
+ if (serr & CXL_PSL_SERR_An_AE)
+ dev_crit(&afu->dev,
+ "AFU asserted JDONE with JERROR in AFU Directed Mode\n");
+}
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