diff options
Diffstat (limited to 'arch/powerpc/platforms/powernv/npu-dma.c')
-rw-r--r-- | arch/powerpc/platforms/powernv/npu-dma.c | 571 |
1 files changed, 14 insertions, 557 deletions
diff --git a/arch/powerpc/platforms/powernv/npu-dma.c b/arch/powerpc/platforms/powernv/npu-dma.c index c321fdbc2200..c16249d251f1 100644 --- a/arch/powerpc/platforms/powernv/npu-dma.c +++ b/arch/powerpc/platforms/powernv/npu-dma.c @@ -19,18 +19,25 @@ #include "pci.h" -/* - * spinlock to protect initialisation of an npu_context for a particular - * mm_struct. - */ -static DEFINE_SPINLOCK(npu_context_lock); - static struct pci_dev *get_pci_dev(struct device_node *dn) { struct pci_dn *pdn = PCI_DN(dn); + struct pci_dev *pdev; - return pci_get_domain_bus_and_slot(pci_domain_nr(pdn->phb->bus), + pdev = pci_get_domain_bus_and_slot(pci_domain_nr(pdn->phb->bus), pdn->busno, pdn->devfn); + + /* + * pci_get_domain_bus_and_slot() increased the reference count of + * the PCI device, but callers don't need that actually as the PE + * already holds a reference to the device. Since callers aren't + * aware of the reference count change, call pci_dev_put() now to + * avoid leaks. + */ + if (pdev) + pci_dev_put(pdev); + + return pdev; } /* Given a NPU device get the associated PCI device. */ @@ -359,15 +366,6 @@ struct npu_comp { /* An NPU descriptor, valid for POWER9 only */ struct npu { int index; - __be64 *mmio_atsd_regs[NV_NMMU_ATSD_REGS]; - unsigned int mmio_atsd_count; - - /* Bitmask for MMIO register usage */ - unsigned long mmio_atsd_usage; - - /* Do we need to explicitly flush the nest mmu? */ - bool nmmu_flush; - struct npu_comp npucomp; }; @@ -624,534 +622,8 @@ struct iommu_table_group *pnv_npu_compound_attach(struct pnv_ioda_pe *pe) } #endif /* CONFIG_IOMMU_API */ -/* Maximum number of nvlinks per npu */ -#define NV_MAX_LINKS 6 - -/* Maximum index of npu2 hosts in the system. Always < NV_MAX_NPUS */ -static int max_npu2_index; - -struct npu_context { - struct mm_struct *mm; - struct pci_dev *npdev[NV_MAX_NPUS][NV_MAX_LINKS]; - struct mmu_notifier mn; - struct kref kref; - bool nmmu_flush; - - /* Callback to stop translation requests on a given GPU */ - void (*release_cb)(struct npu_context *context, void *priv); - - /* - * Private pointer passed to the above callback for usage by - * device drivers. - */ - void *priv; -}; - -struct mmio_atsd_reg { - struct npu *npu; - int reg; -}; - -/* - * Find a free MMIO ATSD register and mark it in use. Return -ENOSPC - * if none are available. - */ -static int get_mmio_atsd_reg(struct npu *npu) -{ - int i; - - for (i = 0; i < npu->mmio_atsd_count; i++) { - if (!test_bit(i, &npu->mmio_atsd_usage)) - if (!test_and_set_bit_lock(i, &npu->mmio_atsd_usage)) - return i; - } - - return -ENOSPC; -} - -static void put_mmio_atsd_reg(struct npu *npu, int reg) -{ - clear_bit_unlock(reg, &npu->mmio_atsd_usage); -} - -/* MMIO ATSD register offsets */ -#define XTS_ATSD_LAUNCH 0 -#define XTS_ATSD_AVA 1 -#define XTS_ATSD_STAT 2 - -static unsigned long get_atsd_launch_val(unsigned long pid, unsigned long psize) -{ - unsigned long launch = 0; - - if (psize == MMU_PAGE_COUNT) { - /* IS set to invalidate entire matching PID */ - launch |= PPC_BIT(12); - } else { - /* AP set to invalidate region of psize */ - launch |= (u64)mmu_get_ap(psize) << PPC_BITLSHIFT(17); - } - - /* PRS set to process-scoped */ - launch |= PPC_BIT(13); - - /* PID */ - launch |= pid << PPC_BITLSHIFT(38); - - /* Leave "No flush" (bit 39) 0 so every ATSD performs a flush */ - - return launch; -} - -static void mmio_atsd_regs_write(struct mmio_atsd_reg - mmio_atsd_reg[NV_MAX_NPUS], unsigned long offset, - unsigned long val) -{ - struct npu *npu; - int i, reg; - - for (i = 0; i <= max_npu2_index; i++) { - reg = mmio_atsd_reg[i].reg; - if (reg < 0) - continue; - - npu = mmio_atsd_reg[i].npu; - __raw_writeq_be(val, npu->mmio_atsd_regs[reg] + offset); - } -} - -static void mmio_invalidate_pid(struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS], - unsigned long pid) -{ - unsigned long launch = get_atsd_launch_val(pid, MMU_PAGE_COUNT); - - /* Invalidating the entire process doesn't use a va */ - mmio_atsd_regs_write(mmio_atsd_reg, XTS_ATSD_LAUNCH, launch); -} - -static void mmio_invalidate_range(struct mmio_atsd_reg - mmio_atsd_reg[NV_MAX_NPUS], unsigned long pid, - unsigned long start, unsigned long psize) -{ - unsigned long launch = get_atsd_launch_val(pid, psize); - - /* Write all VAs first */ - mmio_atsd_regs_write(mmio_atsd_reg, XTS_ATSD_AVA, start); - - /* Issue one barrier for all address writes */ - eieio(); - - /* Launch */ - mmio_atsd_regs_write(mmio_atsd_reg, XTS_ATSD_LAUNCH, launch); -} - -#define mn_to_npu_context(x) container_of(x, struct npu_context, mn) - -static void mmio_invalidate_wait( - struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS]) -{ - struct npu *npu; - int i, reg; - - /* Wait for all invalidations to complete */ - for (i = 0; i <= max_npu2_index; i++) { - if (mmio_atsd_reg[i].reg < 0) - continue; - - /* Wait for completion */ - npu = mmio_atsd_reg[i].npu; - reg = mmio_atsd_reg[i].reg; - while (__raw_readq(npu->mmio_atsd_regs[reg] + XTS_ATSD_STAT)) - cpu_relax(); - } -} - -/* - * Acquires all the address translation shootdown (ATSD) registers required to - * launch an ATSD on all links this npu_context is active on. - */ -static void acquire_atsd_reg(struct npu_context *npu_context, - struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS]) -{ - int i, j; - struct npu *npu; - struct pci_dev *npdev; - - for (i = 0; i <= max_npu2_index; i++) { - mmio_atsd_reg[i].reg = -1; - for (j = 0; j < NV_MAX_LINKS; j++) { - /* - * There are no ordering requirements with respect to - * the setup of struct npu_context, but to ensure - * consistent behaviour we need to ensure npdev[][] is - * only read once. - */ - npdev = READ_ONCE(npu_context->npdev[i][j]); - if (!npdev) - continue; - - npu = pci_bus_to_host(npdev->bus)->npu; - if (!npu) - continue; - - mmio_atsd_reg[i].npu = npu; - mmio_atsd_reg[i].reg = get_mmio_atsd_reg(npu); - while (mmio_atsd_reg[i].reg < 0) { - mmio_atsd_reg[i].reg = get_mmio_atsd_reg(npu); - cpu_relax(); - } - break; - } - } -} - -/* - * Release previously acquired ATSD registers. To avoid deadlocks the registers - * must be released in the same order they were acquired above in - * acquire_atsd_reg. - */ -static void release_atsd_reg(struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS]) -{ - int i; - - for (i = 0; i <= max_npu2_index; i++) { - /* - * We can't rely on npu_context->npdev[][] being the same here - * as when acquire_atsd_reg() was called, hence we use the - * values stored in mmio_atsd_reg during the acquire phase - * rather than re-reading npdev[][]. - */ - if (mmio_atsd_reg[i].reg < 0) - continue; - - put_mmio_atsd_reg(mmio_atsd_reg[i].npu, mmio_atsd_reg[i].reg); - } -} - -/* - * Invalidate a virtual address range - */ -static void mmio_invalidate(struct npu_context *npu_context, - unsigned long start, unsigned long size) -{ - struct mmio_atsd_reg mmio_atsd_reg[NV_MAX_NPUS]; - unsigned long pid = npu_context->mm->context.id; - unsigned long atsd_start = 0; - unsigned long end = start + size - 1; - int atsd_psize = MMU_PAGE_COUNT; - - /* - * Convert the input range into one of the supported sizes. If the range - * doesn't fit, use the next larger supported size. Invalidation latency - * is high, so over-invalidation is preferred to issuing multiple - * invalidates. - * - * A 4K page size isn't supported by NPU/GPU ATS, so that case is - * ignored. - */ - if (size == SZ_64K) { - atsd_start = start; - atsd_psize = MMU_PAGE_64K; - } else if (ALIGN_DOWN(start, SZ_2M) == ALIGN_DOWN(end, SZ_2M)) { - atsd_start = ALIGN_DOWN(start, SZ_2M); - atsd_psize = MMU_PAGE_2M; - } else if (ALIGN_DOWN(start, SZ_1G) == ALIGN_DOWN(end, SZ_1G)) { - atsd_start = ALIGN_DOWN(start, SZ_1G); - atsd_psize = MMU_PAGE_1G; - } - - if (npu_context->nmmu_flush) - /* - * Unfortunately the nest mmu does not support flushing specific - * addresses so we have to flush the whole mm once before - * shooting down the GPU translation. - */ - flush_all_mm(npu_context->mm); - - /* - * Loop over all the NPUs this process is active on and launch - * an invalidate. - */ - acquire_atsd_reg(npu_context, mmio_atsd_reg); - - if (atsd_psize == MMU_PAGE_COUNT) - mmio_invalidate_pid(mmio_atsd_reg, pid); - else - mmio_invalidate_range(mmio_atsd_reg, pid, atsd_start, - atsd_psize); - - mmio_invalidate_wait(mmio_atsd_reg); - - /* - * The GPU requires two flush ATSDs to ensure all entries have been - * flushed. We use PID 0 as it will never be used for a process on the - * GPU. - */ - mmio_invalidate_pid(mmio_atsd_reg, 0); - mmio_invalidate_wait(mmio_atsd_reg); - mmio_invalidate_pid(mmio_atsd_reg, 0); - mmio_invalidate_wait(mmio_atsd_reg); - - release_atsd_reg(mmio_atsd_reg); -} - -static void pnv_npu2_mn_release(struct mmu_notifier *mn, - struct mm_struct *mm) -{ - struct npu_context *npu_context = mn_to_npu_context(mn); - - /* Call into device driver to stop requests to the NMMU */ - if (npu_context->release_cb) - npu_context->release_cb(npu_context, npu_context->priv); - - /* - * There should be no more translation requests for this PID, but we - * need to ensure any entries for it are removed from the TLB. - */ - mmio_invalidate(npu_context, 0, ~0UL); -} - -static void pnv_npu2_mn_invalidate_range(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, unsigned long end) -{ - struct npu_context *npu_context = mn_to_npu_context(mn); - mmio_invalidate(npu_context, start, end - start); -} - -static const struct mmu_notifier_ops nv_nmmu_notifier_ops = { - .release = pnv_npu2_mn_release, - .invalidate_range = pnv_npu2_mn_invalidate_range, -}; - -/* - * Call into OPAL to setup the nmmu context for the current task in - * the NPU. This must be called to setup the context tables before the - * GPU issues ATRs. pdev should be a pointed to PCIe GPU device. - * - * A release callback should be registered to allow a device driver to - * be notified that it should not launch any new translation requests - * as the final TLB invalidate is about to occur. - * - * Returns an error if there no contexts are currently available or a - * npu_context which should be passed to pnv_npu2_handle_fault(). - * - * mmap_sem must be held in write mode and must not be called from interrupt - * context. - */ -struct npu_context *pnv_npu2_init_context(struct pci_dev *gpdev, - unsigned long flags, - void (*cb)(struct npu_context *, void *), - void *priv) -{ - int rc; - u32 nvlink_index; - struct device_node *nvlink_dn; - struct mm_struct *mm = current->mm; - struct npu *npu; - struct npu_context *npu_context; - struct pci_controller *hose; - - /* - * At present we don't support GPUs connected to multiple NPUs and I'm - * not sure the hardware does either. - */ - struct pci_dev *npdev = pnv_pci_get_npu_dev(gpdev, 0); - - if (!npdev) - /* No nvlink associated with this GPU device */ - return ERR_PTR(-ENODEV); - - /* We only support DR/PR/HV in pnv_npu2_map_lpar_dev() */ - if (flags & ~(MSR_DR | MSR_PR | MSR_HV)) - return ERR_PTR(-EINVAL); - - nvlink_dn = of_parse_phandle(npdev->dev.of_node, "ibm,nvlink", 0); - if (WARN_ON(of_property_read_u32(nvlink_dn, "ibm,npu-link-index", - &nvlink_index))) - return ERR_PTR(-ENODEV); - - if (!mm || mm->context.id == 0) { - /* - * Kernel thread contexts are not supported and context id 0 is - * reserved on the GPU. - */ - return ERR_PTR(-EINVAL); - } - - hose = pci_bus_to_host(npdev->bus); - npu = hose->npu; - if (!npu) - return ERR_PTR(-ENODEV); - - /* - * We store the npu pci device so we can more easily get at the - * associated npus. - */ - spin_lock(&npu_context_lock); - npu_context = mm->context.npu_context; - if (npu_context) { - if (npu_context->release_cb != cb || - npu_context->priv != priv) { - spin_unlock(&npu_context_lock); - return ERR_PTR(-EINVAL); - } - - WARN_ON(!kref_get_unless_zero(&npu_context->kref)); - } - spin_unlock(&npu_context_lock); - - if (!npu_context) { - /* - * We can set up these fields without holding the - * npu_context_lock as the npu_context hasn't been returned to - * the caller meaning it can't be destroyed. Parallel allocation - * is protected against by mmap_sem. - */ - rc = -ENOMEM; - npu_context = kzalloc(sizeof(struct npu_context), GFP_KERNEL); - if (npu_context) { - kref_init(&npu_context->kref); - npu_context->mm = mm; - npu_context->mn.ops = &nv_nmmu_notifier_ops; - rc = __mmu_notifier_register(&npu_context->mn, mm); - } - - if (rc) { - kfree(npu_context); - return ERR_PTR(rc); - } - - mm->context.npu_context = npu_context; - } - - npu_context->release_cb = cb; - npu_context->priv = priv; - - /* - * npdev is a pci_dev pointer setup by the PCI code. We assign it to - * npdev[][] to indicate to the mmu notifiers that an invalidation - * should also be sent over this nvlink. The notifiers don't use any - * other fields in npu_context, so we just need to ensure that when they - * deference npu_context->npdev[][] it is either a valid pointer or - * NULL. - */ - WRITE_ONCE(npu_context->npdev[npu->index][nvlink_index], npdev); - - if (!npu->nmmu_flush) { - /* - * If we're not explicitly flushing ourselves we need to mark - * the thread for global flushes - */ - npu_context->nmmu_flush = false; - mm_context_add_copro(mm); - } else - npu_context->nmmu_flush = true; - - return npu_context; -} -EXPORT_SYMBOL(pnv_npu2_init_context); - -static void pnv_npu2_release_context(struct kref *kref) -{ - struct npu_context *npu_context = - container_of(kref, struct npu_context, kref); - - if (!npu_context->nmmu_flush) - mm_context_remove_copro(npu_context->mm); - - npu_context->mm->context.npu_context = NULL; -} - -/* - * Destroy a context on the given GPU. May free the npu_context if it is no - * longer active on any GPUs. Must not be called from interrupt context. - */ -void pnv_npu2_destroy_context(struct npu_context *npu_context, - struct pci_dev *gpdev) -{ - int removed; - struct npu *npu; - struct pci_dev *npdev = pnv_pci_get_npu_dev(gpdev, 0); - struct device_node *nvlink_dn; - u32 nvlink_index; - struct pci_controller *hose; - - if (WARN_ON(!npdev)) - return; - - hose = pci_bus_to_host(npdev->bus); - npu = hose->npu; - if (!npu) - return; - nvlink_dn = of_parse_phandle(npdev->dev.of_node, "ibm,nvlink", 0); - if (WARN_ON(of_property_read_u32(nvlink_dn, "ibm,npu-link-index", - &nvlink_index))) - return; - WRITE_ONCE(npu_context->npdev[npu->index][nvlink_index], NULL); - spin_lock(&npu_context_lock); - removed = kref_put(&npu_context->kref, pnv_npu2_release_context); - spin_unlock(&npu_context_lock); - - /* - * We need to do this outside of pnv_npu2_release_context so that it is - * outside the spinlock as mmu_notifier_destroy uses SRCU. - */ - if (removed) { - mmu_notifier_unregister(&npu_context->mn, - npu_context->mm); - - kfree(npu_context); - } - -} -EXPORT_SYMBOL(pnv_npu2_destroy_context); - -/* - * Assumes mmap_sem is held for the contexts associated mm. - */ -int pnv_npu2_handle_fault(struct npu_context *context, uintptr_t *ea, - unsigned long *flags, unsigned long *status, int count) -{ - u64 rc = 0, result = 0; - int i, is_write; - struct page *page[1]; - const char __user *u; - char c; - - /* mmap_sem should be held so the struct_mm must be present */ - struct mm_struct *mm = context->mm; - - WARN_ON(!rwsem_is_locked(&mm->mmap_sem)); - - for (i = 0; i < count; i++) { - is_write = flags[i] & NPU2_WRITE; - rc = get_user_pages_remote(NULL, mm, ea[i], 1, - is_write ? FOLL_WRITE : 0, - page, NULL, NULL); - - if (rc != 1) { - status[i] = rc; - result = -EFAULT; - continue; - } - - /* Make sure partition scoped tree gets a pte */ - u = page_address(page[0]); - if (__get_user(c, u)) - result = -EFAULT; - - status[i] = 0; - put_page(page[0]); - } - - return result; -} -EXPORT_SYMBOL(pnv_npu2_handle_fault); - int pnv_npu2_init(struct pci_controller *hose) { - unsigned int i; - u64 mmio_atsd; static int npu_index; struct npu *npu; int ret; @@ -1160,33 +632,18 @@ int pnv_npu2_init(struct pci_controller *hose) if (!npu) return -ENOMEM; - npu->nmmu_flush = of_property_read_bool(hose->dn, "ibm,nmmu-flush"); - - for (i = 0; i < ARRAY_SIZE(npu->mmio_atsd_regs) && - !of_property_read_u64_index(hose->dn, "ibm,mmio-atsd", - i, &mmio_atsd); i++) - npu->mmio_atsd_regs[i] = ioremap(mmio_atsd, 32); - - pr_info("NPU%d: Found %d MMIO ATSD registers", hose->global_number, i); - npu->mmio_atsd_count = i; - npu->mmio_atsd_usage = 0; npu_index++; if (WARN_ON(npu_index >= NV_MAX_NPUS)) { ret = -ENOSPC; goto fail_exit; } - max_npu2_index = npu_index; npu->index = npu_index; hose->npu = npu; return 0; fail_exit: - for (i = 0; i < npu->mmio_atsd_count; ++i) - iounmap(npu->mmio_atsd_regs[i]); - kfree(npu); - return ret; } |