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Diffstat (limited to 'drivers/misc/ocxl/link.c')
-rw-r--r--drivers/misc/ocxl/link.c779
1 files changed, 779 insertions, 0 deletions
diff --git a/drivers/misc/ocxl/link.c b/drivers/misc/ocxl/link.c
new file mode 100644
index 000000000..4cf4c55a5
--- /dev/null
+++ b/drivers/misc/ocxl/link.c
@@ -0,0 +1,779 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Copyright 2017 IBM Corp.
+#include <linux/sched/mm.h>
+#include <linux/mutex.h>
+#include <linux/mm.h>
+#include <linux/mm_types.h>
+#include <linux/mmu_context.h>
+#include <linux/mmu_notifier.h>
+#include <linux/irqdomain.h>
+#include <asm/copro.h>
+#include <asm/pnv-ocxl.h>
+#include <asm/xive.h>
+#include <misc/ocxl.h>
+#include "ocxl_internal.h"
+#include "trace.h"
+
+
+#define SPA_PASID_BITS 15
+#define SPA_PASID_MAX ((1 << SPA_PASID_BITS) - 1)
+#define SPA_PE_MASK SPA_PASID_MAX
+#define SPA_SPA_SIZE_LOG 22 /* Each SPA is 4 Mb */
+
+#define SPA_CFG_SF (1ull << (63-0))
+#define SPA_CFG_TA (1ull << (63-1))
+#define SPA_CFG_HV (1ull << (63-3))
+#define SPA_CFG_UV (1ull << (63-4))
+#define SPA_CFG_XLAT_hpt (0ull << (63-6)) /* Hashed page table (HPT) mode */
+#define SPA_CFG_XLAT_roh (2ull << (63-6)) /* Radix on HPT mode */
+#define SPA_CFG_XLAT_ror (3ull << (63-6)) /* Radix on Radix mode */
+#define SPA_CFG_PR (1ull << (63-49))
+#define SPA_CFG_TC (1ull << (63-54))
+#define SPA_CFG_DR (1ull << (63-59))
+
+#define SPA_XSL_TF (1ull << (63-3)) /* Translation fault */
+#define SPA_XSL_S (1ull << (63-38)) /* Store operation */
+
+#define SPA_PE_VALID 0x80000000
+
+struct ocxl_link;
+
+struct pe_data {
+ struct mm_struct *mm;
+ /* callback to trigger when a translation fault occurs */
+ void (*xsl_err_cb)(void *data, u64 addr, u64 dsisr);
+ /* opaque pointer to be passed to the above callback */
+ void *xsl_err_data;
+ struct rcu_head rcu;
+ struct ocxl_link *link;
+ struct mmu_notifier mmu_notifier;
+};
+
+struct spa {
+ struct ocxl_process_element *spa_mem;
+ int spa_order;
+ struct mutex spa_lock;
+ struct radix_tree_root pe_tree; /* Maps PE handles to pe_data */
+ char *irq_name;
+ int virq;
+ void __iomem *reg_dsisr;
+ void __iomem *reg_dar;
+ void __iomem *reg_tfc;
+ void __iomem *reg_pe_handle;
+ /*
+ * The following field are used by the memory fault
+ * interrupt handler. We can only have one interrupt at a
+ * time. The NPU won't raise another interrupt until the
+ * previous one has been ack'd by writing to the TFC register
+ */
+ struct xsl_fault {
+ struct work_struct fault_work;
+ u64 pe;
+ u64 dsisr;
+ u64 dar;
+ struct pe_data pe_data;
+ } xsl_fault;
+};
+
+/*
+ * A opencapi link can be used be by several PCI functions. We have
+ * one link per device slot.
+ *
+ * A linked list of opencapi links should suffice, as there's a
+ * limited number of opencapi slots on a system and lookup is only
+ * done when the device is probed
+ */
+struct ocxl_link {
+ struct list_head list;
+ struct kref ref;
+ int domain;
+ int bus;
+ int dev;
+ void __iomem *arva; /* ATSD register virtual address */
+ spinlock_t atsd_lock; /* to serialize shootdowns */
+ atomic_t irq_available;
+ struct spa *spa;
+ void *platform_data;
+};
+static LIST_HEAD(links_list);
+static DEFINE_MUTEX(links_list_lock);
+
+enum xsl_response {
+ CONTINUE,
+ ADDRESS_ERROR,
+ RESTART,
+};
+
+
+static void read_irq(struct spa *spa, u64 *dsisr, u64 *dar, u64 *pe)
+{
+ u64 reg;
+
+ *dsisr = in_be64(spa->reg_dsisr);
+ *dar = in_be64(spa->reg_dar);
+ reg = in_be64(spa->reg_pe_handle);
+ *pe = reg & SPA_PE_MASK;
+}
+
+static void ack_irq(struct spa *spa, enum xsl_response r)
+{
+ u64 reg = 0;
+
+ /* continue is not supported */
+ if (r == RESTART)
+ reg = PPC_BIT(31);
+ else if (r == ADDRESS_ERROR)
+ reg = PPC_BIT(30);
+ else
+ WARN(1, "Invalid irq response %d\n", r);
+
+ if (reg) {
+ trace_ocxl_fault_ack(spa->spa_mem, spa->xsl_fault.pe,
+ spa->xsl_fault.dsisr, spa->xsl_fault.dar, reg);
+ out_be64(spa->reg_tfc, reg);
+ }
+}
+
+static void xsl_fault_handler_bh(struct work_struct *fault_work)
+{
+ vm_fault_t flt = 0;
+ unsigned long access, flags, inv_flags = 0;
+ enum xsl_response r;
+ struct xsl_fault *fault = container_of(fault_work, struct xsl_fault,
+ fault_work);
+ struct spa *spa = container_of(fault, struct spa, xsl_fault);
+
+ int rc;
+
+ /*
+ * We must release a reference on mm_users whenever exiting this
+ * function (taken in the memory fault interrupt handler)
+ */
+ rc = copro_handle_mm_fault(fault->pe_data.mm, fault->dar, fault->dsisr,
+ &flt);
+ if (rc) {
+ pr_debug("copro_handle_mm_fault failed: %d\n", rc);
+ if (fault->pe_data.xsl_err_cb) {
+ fault->pe_data.xsl_err_cb(
+ fault->pe_data.xsl_err_data,
+ fault->dar, fault->dsisr);
+ }
+ r = ADDRESS_ERROR;
+ goto ack;
+ }
+
+ if (!radix_enabled()) {
+ /*
+ * update_mmu_cache() will not have loaded the hash
+ * since current->trap is not a 0x400 or 0x300, so
+ * just call hash_page_mm() here.
+ */
+ access = _PAGE_PRESENT | _PAGE_READ;
+ if (fault->dsisr & SPA_XSL_S)
+ access |= _PAGE_WRITE;
+
+ if (get_region_id(fault->dar) != USER_REGION_ID)
+ access |= _PAGE_PRIVILEGED;
+
+ local_irq_save(flags);
+ hash_page_mm(fault->pe_data.mm, fault->dar, access, 0x300,
+ inv_flags);
+ local_irq_restore(flags);
+ }
+ r = RESTART;
+ack:
+ mmput(fault->pe_data.mm);
+ ack_irq(spa, r);
+}
+
+static irqreturn_t xsl_fault_handler(int irq, void *data)
+{
+ struct ocxl_link *link = (struct ocxl_link *) data;
+ struct spa *spa = link->spa;
+ u64 dsisr, dar, pe_handle;
+ struct pe_data *pe_data;
+ struct ocxl_process_element *pe;
+ int pid;
+ bool schedule = false;
+
+ read_irq(spa, &dsisr, &dar, &pe_handle);
+ trace_ocxl_fault(spa->spa_mem, pe_handle, dsisr, dar, -1);
+
+ WARN_ON(pe_handle > SPA_PE_MASK);
+ pe = spa->spa_mem + pe_handle;
+ pid = be32_to_cpu(pe->pid);
+ /* We could be reading all null values here if the PE is being
+ * removed while an interrupt kicks in. It's not supposed to
+ * happen if the driver notified the AFU to terminate the
+ * PASID, and the AFU waited for pending operations before
+ * acknowledging. But even if it happens, we won't find a
+ * memory context below and fail silently, so it should be ok.
+ */
+ if (!(dsisr & SPA_XSL_TF)) {
+ WARN(1, "Invalid xsl interrupt fault register %#llx\n", dsisr);
+ ack_irq(spa, ADDRESS_ERROR);
+ return IRQ_HANDLED;
+ }
+
+ rcu_read_lock();
+ pe_data = radix_tree_lookup(&spa->pe_tree, pe_handle);
+ if (!pe_data) {
+ /*
+ * Could only happen if the driver didn't notify the
+ * AFU about PASID termination before removing the PE,
+ * or the AFU didn't wait for all memory access to
+ * have completed.
+ *
+ * Either way, we fail early, but we shouldn't log an
+ * error message, as it is a valid (if unexpected)
+ * scenario
+ */
+ rcu_read_unlock();
+ pr_debug("Unknown mm context for xsl interrupt\n");
+ ack_irq(spa, ADDRESS_ERROR);
+ return IRQ_HANDLED;
+ }
+
+ if (!pe_data->mm) {
+ /*
+ * translation fault from a kernel context - an OpenCAPI
+ * device tried to access a bad kernel address
+ */
+ rcu_read_unlock();
+ pr_warn("Unresolved OpenCAPI xsl fault in kernel context\n");
+ ack_irq(spa, ADDRESS_ERROR);
+ return IRQ_HANDLED;
+ }
+ WARN_ON(pe_data->mm->context.id != pid);
+
+ if (mmget_not_zero(pe_data->mm)) {
+ spa->xsl_fault.pe = pe_handle;
+ spa->xsl_fault.dar = dar;
+ spa->xsl_fault.dsisr = dsisr;
+ spa->xsl_fault.pe_data = *pe_data;
+ schedule = true;
+ /* mm_users count released by bottom half */
+ }
+ rcu_read_unlock();
+ if (schedule)
+ schedule_work(&spa->xsl_fault.fault_work);
+ else
+ ack_irq(spa, ADDRESS_ERROR);
+ return IRQ_HANDLED;
+}
+
+static void unmap_irq_registers(struct spa *spa)
+{
+ pnv_ocxl_unmap_xsl_regs(spa->reg_dsisr, spa->reg_dar, spa->reg_tfc,
+ spa->reg_pe_handle);
+}
+
+static int map_irq_registers(struct pci_dev *dev, struct spa *spa)
+{
+ return pnv_ocxl_map_xsl_regs(dev, &spa->reg_dsisr, &spa->reg_dar,
+ &spa->reg_tfc, &spa->reg_pe_handle);
+}
+
+static int setup_xsl_irq(struct pci_dev *dev, struct ocxl_link *link)
+{
+ struct spa *spa = link->spa;
+ int rc;
+ int hwirq;
+
+ rc = pnv_ocxl_get_xsl_irq(dev, &hwirq);
+ if (rc)
+ return rc;
+
+ rc = map_irq_registers(dev, spa);
+ if (rc)
+ return rc;
+
+ spa->irq_name = kasprintf(GFP_KERNEL, "ocxl-xsl-%x-%x-%x",
+ link->domain, link->bus, link->dev);
+ if (!spa->irq_name) {
+ dev_err(&dev->dev, "Can't allocate name for xsl interrupt\n");
+ rc = -ENOMEM;
+ goto err_xsl;
+ }
+ /*
+ * At some point, we'll need to look into allowing a higher
+ * number of interrupts. Could we have an IRQ domain per link?
+ */
+ spa->virq = irq_create_mapping(NULL, hwirq);
+ if (!spa->virq) {
+ dev_err(&dev->dev,
+ "irq_create_mapping failed for translation interrupt\n");
+ rc = -EINVAL;
+ goto err_name;
+ }
+
+ dev_dbg(&dev->dev, "hwirq %d mapped to virq %d\n", hwirq, spa->virq);
+
+ rc = request_irq(spa->virq, xsl_fault_handler, 0, spa->irq_name,
+ link);
+ if (rc) {
+ dev_err(&dev->dev,
+ "request_irq failed for translation interrupt: %d\n",
+ rc);
+ rc = -EINVAL;
+ goto err_mapping;
+ }
+ return 0;
+
+err_mapping:
+ irq_dispose_mapping(spa->virq);
+err_name:
+ kfree(spa->irq_name);
+err_xsl:
+ unmap_irq_registers(spa);
+ return rc;
+}
+
+static void release_xsl_irq(struct ocxl_link *link)
+{
+ struct spa *spa = link->spa;
+
+ if (spa->virq) {
+ free_irq(spa->virq, link);
+ irq_dispose_mapping(spa->virq);
+ }
+ kfree(spa->irq_name);
+ unmap_irq_registers(spa);
+}
+
+static int alloc_spa(struct pci_dev *dev, struct ocxl_link *link)
+{
+ struct spa *spa;
+
+ spa = kzalloc(sizeof(struct spa), GFP_KERNEL);
+ if (!spa)
+ return -ENOMEM;
+
+ mutex_init(&spa->spa_lock);
+ INIT_RADIX_TREE(&spa->pe_tree, GFP_KERNEL);
+ INIT_WORK(&spa->xsl_fault.fault_work, xsl_fault_handler_bh);
+
+ spa->spa_order = SPA_SPA_SIZE_LOG - PAGE_SHIFT;
+ spa->spa_mem = (struct ocxl_process_element *)
+ __get_free_pages(GFP_KERNEL | __GFP_ZERO, spa->spa_order);
+ if (!spa->spa_mem) {
+ dev_err(&dev->dev, "Can't allocate Shared Process Area\n");
+ kfree(spa);
+ return -ENOMEM;
+ }
+ pr_debug("Allocated SPA for %x:%x:%x at %p\n", link->domain, link->bus,
+ link->dev, spa->spa_mem);
+
+ link->spa = spa;
+ return 0;
+}
+
+static void free_spa(struct ocxl_link *link)
+{
+ struct spa *spa = link->spa;
+
+ pr_debug("Freeing SPA for %x:%x:%x\n", link->domain, link->bus,
+ link->dev);
+
+ if (spa && spa->spa_mem) {
+ free_pages((unsigned long) spa->spa_mem, spa->spa_order);
+ kfree(spa);
+ link->spa = NULL;
+ }
+}
+
+static int alloc_link(struct pci_dev *dev, int PE_mask, struct ocxl_link **out_link)
+{
+ struct ocxl_link *link;
+ int rc;
+
+ link = kzalloc(sizeof(struct ocxl_link), GFP_KERNEL);
+ if (!link)
+ return -ENOMEM;
+
+ kref_init(&link->ref);
+ link->domain = pci_domain_nr(dev->bus);
+ link->bus = dev->bus->number;
+ link->dev = PCI_SLOT(dev->devfn);
+ atomic_set(&link->irq_available, MAX_IRQ_PER_LINK);
+ spin_lock_init(&link->atsd_lock);
+
+ rc = alloc_spa(dev, link);
+ if (rc)
+ goto err_free;
+
+ rc = setup_xsl_irq(dev, link);
+ if (rc)
+ goto err_spa;
+
+ /* platform specific hook */
+ rc = pnv_ocxl_spa_setup(dev, link->spa->spa_mem, PE_mask,
+ &link->platform_data);
+ if (rc)
+ goto err_xsl_irq;
+
+ /* if link->arva is not defeined, MMIO registers are not used to
+ * generate TLB invalidate. PowerBus snooping is enabled.
+ * Otherwise, PowerBus snooping is disabled. TLB Invalidates are
+ * initiated using MMIO registers.
+ */
+ pnv_ocxl_map_lpar(dev, mfspr(SPRN_LPID), 0, &link->arva);
+
+ *out_link = link;
+ return 0;
+
+err_xsl_irq:
+ release_xsl_irq(link);
+err_spa:
+ free_spa(link);
+err_free:
+ kfree(link);
+ return rc;
+}
+
+static void free_link(struct ocxl_link *link)
+{
+ release_xsl_irq(link);
+ free_spa(link);
+ kfree(link);
+}
+
+int ocxl_link_setup(struct pci_dev *dev, int PE_mask, void **link_handle)
+{
+ int rc = 0;
+ struct ocxl_link *link;
+
+ mutex_lock(&links_list_lock);
+ list_for_each_entry(link, &links_list, list) {
+ /* The functions of a device all share the same link */
+ if (link->domain == pci_domain_nr(dev->bus) &&
+ link->bus == dev->bus->number &&
+ link->dev == PCI_SLOT(dev->devfn)) {
+ kref_get(&link->ref);
+ *link_handle = link;
+ goto unlock;
+ }
+ }
+ rc = alloc_link(dev, PE_mask, &link);
+ if (rc)
+ goto unlock;
+
+ list_add(&link->list, &links_list);
+ *link_handle = link;
+unlock:
+ mutex_unlock(&links_list_lock);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(ocxl_link_setup);
+
+static void release_xsl(struct kref *ref)
+{
+ struct ocxl_link *link = container_of(ref, struct ocxl_link, ref);
+
+ if (link->arva) {
+ pnv_ocxl_unmap_lpar(link->arva);
+ link->arva = NULL;
+ }
+
+ list_del(&link->list);
+ /* call platform code before releasing data */
+ pnv_ocxl_spa_release(link->platform_data);
+ free_link(link);
+}
+
+void ocxl_link_release(struct pci_dev *dev, void *link_handle)
+{
+ struct ocxl_link *link = (struct ocxl_link *) link_handle;
+
+ mutex_lock(&links_list_lock);
+ kref_put(&link->ref, release_xsl);
+ mutex_unlock(&links_list_lock);
+}
+EXPORT_SYMBOL_GPL(ocxl_link_release);
+
+static void invalidate_range(struct mmu_notifier *mn,
+ struct mm_struct *mm,
+ unsigned long start, unsigned long end)
+{
+ struct pe_data *pe_data = container_of(mn, struct pe_data, mmu_notifier);
+ struct ocxl_link *link = pe_data->link;
+ unsigned long addr, pid, page_size = PAGE_SIZE;
+
+ pid = mm->context.id;
+ trace_ocxl_mmu_notifier_range(start, end, pid);
+
+ spin_lock(&link->atsd_lock);
+ for (addr = start; addr < end; addr += page_size)
+ pnv_ocxl_tlb_invalidate(link->arva, pid, addr, page_size);
+ spin_unlock(&link->atsd_lock);
+}
+
+static const struct mmu_notifier_ops ocxl_mmu_notifier_ops = {
+ .invalidate_range = invalidate_range,
+};
+
+static u64 calculate_cfg_state(bool kernel)
+{
+ u64 state;
+
+ state = SPA_CFG_DR;
+ if (mfspr(SPRN_LPCR) & LPCR_TC)
+ state |= SPA_CFG_TC;
+ if (radix_enabled())
+ state |= SPA_CFG_XLAT_ror;
+ else
+ state |= SPA_CFG_XLAT_hpt;
+ state |= SPA_CFG_HV;
+ if (kernel) {
+ if (mfmsr() & MSR_SF)
+ state |= SPA_CFG_SF;
+ } else {
+ state |= SPA_CFG_PR;
+ if (!test_tsk_thread_flag(current, TIF_32BIT))
+ state |= SPA_CFG_SF;
+ }
+ return state;
+}
+
+int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr,
+ u64 amr, u16 bdf, struct mm_struct *mm,
+ void (*xsl_err_cb)(void *data, u64 addr, u64 dsisr),
+ void *xsl_err_data)
+{
+ struct ocxl_link *link = (struct ocxl_link *) link_handle;
+ struct spa *spa = link->spa;
+ struct ocxl_process_element *pe;
+ int pe_handle, rc = 0;
+ struct pe_data *pe_data;
+
+ BUILD_BUG_ON(sizeof(struct ocxl_process_element) != 128);
+ if (pasid > SPA_PASID_MAX)
+ return -EINVAL;
+
+ mutex_lock(&spa->spa_lock);
+ pe_handle = pasid & SPA_PE_MASK;
+ pe = spa->spa_mem + pe_handle;
+
+ if (pe->software_state) {
+ rc = -EBUSY;
+ goto unlock;
+ }
+
+ pe_data = kmalloc(sizeof(*pe_data), GFP_KERNEL);
+ if (!pe_data) {
+ rc = -ENOMEM;
+ goto unlock;
+ }
+
+ pe_data->mm = mm;
+ pe_data->xsl_err_cb = xsl_err_cb;
+ pe_data->xsl_err_data = xsl_err_data;
+ pe_data->link = link;
+ pe_data->mmu_notifier.ops = &ocxl_mmu_notifier_ops;
+
+ memset(pe, 0, sizeof(struct ocxl_process_element));
+ pe->config_state = cpu_to_be64(calculate_cfg_state(pidr == 0));
+ pe->pasid = cpu_to_be32(pasid << (31 - 19));
+ pe->bdf = cpu_to_be16(bdf);
+ pe->lpid = cpu_to_be32(mfspr(SPRN_LPID));
+ pe->pid = cpu_to_be32(pidr);
+ pe->tid = cpu_to_be32(tidr);
+ pe->amr = cpu_to_be64(amr);
+ pe->software_state = cpu_to_be32(SPA_PE_VALID);
+
+ /*
+ * For user contexts, register a copro so that TLBIs are seen
+ * by the nest MMU. If we have a kernel context, TLBIs are
+ * already global.
+ */
+ if (mm) {
+ mm_context_add_copro(mm);
+ if (link->arva) {
+ /* Use MMIO registers for the TLB Invalidate
+ * operations.
+ */
+ trace_ocxl_init_mmu_notifier(pasid, mm->context.id);
+ mmu_notifier_register(&pe_data->mmu_notifier, mm);
+ }
+ }
+
+ /*
+ * Barrier is to make sure PE is visible in the SPA before it
+ * is used by the device. It also helps with the global TLBI
+ * invalidation
+ */
+ mb();
+ radix_tree_insert(&spa->pe_tree, pe_handle, pe_data);
+
+ /*
+ * The mm must stay valid for as long as the device uses it. We
+ * lower the count when the context is removed from the SPA.
+ *
+ * We grab mm_count (and not mm_users), as we don't want to
+ * end up in a circular dependency if a process mmaps its
+ * mmio, therefore incrementing the file ref count when
+ * calling mmap(), and forgets to unmap before exiting. In
+ * that scenario, when the kernel handles the death of the
+ * process, the file is not cleaned because unmap was not
+ * called, and the mm wouldn't be freed because we would still
+ * have a reference on mm_users. Incrementing mm_count solves
+ * the problem.
+ */
+ if (mm)
+ mmgrab(mm);
+ trace_ocxl_context_add(current->pid, spa->spa_mem, pasid, pidr, tidr);
+unlock:
+ mutex_unlock(&spa->spa_lock);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(ocxl_link_add_pe);
+
+int ocxl_link_update_pe(void *link_handle, int pasid, __u16 tid)
+{
+ struct ocxl_link *link = (struct ocxl_link *) link_handle;
+ struct spa *spa = link->spa;
+ struct ocxl_process_element *pe;
+ int pe_handle, rc;
+
+ if (pasid > SPA_PASID_MAX)
+ return -EINVAL;
+
+ pe_handle = pasid & SPA_PE_MASK;
+ pe = spa->spa_mem + pe_handle;
+
+ mutex_lock(&spa->spa_lock);
+
+ pe->tid = cpu_to_be32(tid);
+
+ /*
+ * The barrier makes sure the PE is updated
+ * before we clear the NPU context cache below, so that the
+ * old PE cannot be reloaded erroneously.
+ */
+ mb();
+
+ /*
+ * hook to platform code
+ * On powerpc, the entry needs to be cleared from the context
+ * cache of the NPU.
+ */
+ rc = pnv_ocxl_spa_remove_pe_from_cache(link->platform_data, pe_handle);
+ WARN_ON(rc);
+
+ mutex_unlock(&spa->spa_lock);
+ return rc;
+}
+
+int ocxl_link_remove_pe(void *link_handle, int pasid)
+{
+ struct ocxl_link *link = (struct ocxl_link *) link_handle;
+ struct spa *spa = link->spa;
+ struct ocxl_process_element *pe;
+ struct pe_data *pe_data;
+ int pe_handle, rc;
+
+ if (pasid > SPA_PASID_MAX)
+ return -EINVAL;
+
+ /*
+ * About synchronization with our memory fault handler:
+ *
+ * Before removing the PE, the driver is supposed to have
+ * notified the AFU, which should have cleaned up and make
+ * sure the PASID is no longer in use, including pending
+ * interrupts. However, there's no way to be sure...
+ *
+ * We clear the PE and remove the context from our radix
+ * tree. From that point on, any new interrupt for that
+ * context will fail silently, which is ok. As mentioned
+ * above, that's not expected, but it could happen if the
+ * driver or AFU didn't do the right thing.
+ *
+ * There could still be a bottom half running, but we don't
+ * need to wait/flush, as it is managing a reference count on
+ * the mm it reads from the radix tree.
+ */
+ pe_handle = pasid & SPA_PE_MASK;
+ pe = spa->spa_mem + pe_handle;
+
+ mutex_lock(&spa->spa_lock);
+
+ if (!(be32_to_cpu(pe->software_state) & SPA_PE_VALID)) {
+ rc = -EINVAL;
+ goto unlock;
+ }
+
+ trace_ocxl_context_remove(current->pid, spa->spa_mem, pasid,
+ be32_to_cpu(pe->pid), be32_to_cpu(pe->tid));
+
+ memset(pe, 0, sizeof(struct ocxl_process_element));
+ /*
+ * The barrier makes sure the PE is removed from the SPA
+ * before we clear the NPU context cache below, so that the
+ * old PE cannot be reloaded erroneously.
+ */
+ mb();
+
+ /*
+ * hook to platform code
+ * On powerpc, the entry needs to be cleared from the context
+ * cache of the NPU.
+ */
+ rc = pnv_ocxl_spa_remove_pe_from_cache(link->platform_data, pe_handle);
+ WARN_ON(rc);
+
+ pe_data = radix_tree_delete(&spa->pe_tree, pe_handle);
+ if (!pe_data) {
+ WARN(1, "Couldn't find pe data when removing PE\n");
+ } else {
+ if (pe_data->mm) {
+ if (link->arva) {
+ trace_ocxl_release_mmu_notifier(pasid,
+ pe_data->mm->context.id);
+ mmu_notifier_unregister(&pe_data->mmu_notifier,
+ pe_data->mm);
+ spin_lock(&link->atsd_lock);
+ pnv_ocxl_tlb_invalidate(link->arva,
+ pe_data->mm->context.id,
+ 0ull,
+ PAGE_SIZE);
+ spin_unlock(&link->atsd_lock);
+ }
+ mm_context_remove_copro(pe_data->mm);
+ mmdrop(pe_data->mm);
+ }
+ kfree_rcu(pe_data, rcu);
+ }
+unlock:
+ mutex_unlock(&spa->spa_lock);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(ocxl_link_remove_pe);
+
+int ocxl_link_irq_alloc(void *link_handle, int *hw_irq)
+{
+ struct ocxl_link *link = (struct ocxl_link *) link_handle;
+ int irq;
+
+ if (atomic_dec_if_positive(&link->irq_available) < 0)
+ return -ENOSPC;
+
+ irq = xive_native_alloc_irq();
+ if (!irq) {
+ atomic_inc(&link->irq_available);
+ return -ENXIO;
+ }
+
+ *hw_irq = irq;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(ocxl_link_irq_alloc);
+
+void ocxl_link_free_irq(void *link_handle, int hw_irq)
+{
+ struct ocxl_link *link = (struct ocxl_link *) link_handle;
+
+ xive_native_free_irq(hw_irq);
+ atomic_inc(&link->irq_available);
+}
+EXPORT_SYMBOL_GPL(ocxl_link_free_irq);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 02:59:04 +0000