Re: [PATCH 3/4] powerpc/powernv: remove dead NPU DMA code

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 23/05/2019 17:49, Christoph Hellwig wrote:
> None of these routines were ever used since they were added to the
> kernel.


It is still being used exactly in the way as it was explained before in
previous respins. Thanks.


> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  arch/powerpc/include/asm/book3s/64/mmu.h |   2 -
>  arch/powerpc/include/asm/powernv.h       |  22 -
>  arch/powerpc/mm/book3s64/mmu_context.c   |   1 -
>  arch/powerpc/platforms/powernv/npu-dma.c | 556 -----------------------
>  4 files changed, 581 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h
> index 74d24201fc4f..23b83d3593e2 100644
> --- a/arch/powerpc/include/asm/book3s/64/mmu.h
> +++ b/arch/powerpc/include/asm/book3s/64/mmu.h
> @@ -116,8 +116,6 @@ typedef struct {
>  	/* Number of users of the external (Nest) MMU */
>  	atomic_t copros;
>  
> -	/* NPU NMMU context */
> -	struct npu_context *npu_context;
>  	struct hash_mm_context *hash_context;
>  
>  	unsigned long vdso_base;
> diff --git a/arch/powerpc/include/asm/powernv.h b/arch/powerpc/include/asm/powernv.h
> index 05b552418519..40f868c5e93c 100644
> --- a/arch/powerpc/include/asm/powernv.h
> +++ b/arch/powerpc/include/asm/powernv.h
> @@ -11,35 +11,13 @@
>  #define _ASM_POWERNV_H
>  
>  #ifdef CONFIG_PPC_POWERNV
> -#define NPU2_WRITE 1
>  extern void powernv_set_nmmu_ptcr(unsigned long ptcr);
> -extern struct npu_context *pnv_npu2_init_context(struct pci_dev *gpdev,
> -			unsigned long flags,
> -			void (*cb)(struct npu_context *, void *),
> -			void *priv);
> -extern void pnv_npu2_destroy_context(struct npu_context *context,
> -				struct pci_dev *gpdev);
> -extern int pnv_npu2_handle_fault(struct npu_context *context, uintptr_t *ea,
> -				unsigned long *flags, unsigned long *status,
> -				int count);
>  
>  void pnv_program_cpu_hotplug_lpcr(unsigned int cpu, u64 lpcr_val);
>  
>  void pnv_tm_init(void);
>  #else
>  static inline void powernv_set_nmmu_ptcr(unsigned long ptcr) { }
> -static inline struct npu_context *pnv_npu2_init_context(struct pci_dev *gpdev,
> -			unsigned long flags,
> -			struct npu_context *(*cb)(struct npu_context *, void *),
> -			void *priv) { return ERR_PTR(-ENODEV); }
> -static inline void pnv_npu2_destroy_context(struct npu_context *context,
> -					struct pci_dev *gpdev) { }
> -
> -static inline int pnv_npu2_handle_fault(struct npu_context *context,
> -					uintptr_t *ea, unsigned long *flags,
> -					unsigned long *status, int count) {
> -	return -ENODEV;
> -}
>  
>  static inline void pnv_tm_init(void) { }
>  #endif
> diff --git a/arch/powerpc/mm/book3s64/mmu_context.c b/arch/powerpc/mm/book3s64/mmu_context.c
> index cb2b08635508..0dd3e631cf3e 100644
> --- a/arch/powerpc/mm/book3s64/mmu_context.c
> +++ b/arch/powerpc/mm/book3s64/mmu_context.c
> @@ -140,7 +140,6 @@ static int radix__init_new_context(struct mm_struct *mm)
>  	 */
>  	asm volatile("ptesync;isync" : : : "memory");
>  
> -	mm->context.npu_context = NULL;
>  	mm->context.hash_context = NULL;
>  
>  	return index;
> diff --git a/arch/powerpc/platforms/powernv/npu-dma.c b/arch/powerpc/platforms/powernv/npu-dma.c
> index 495550432f3d..4ed24132bb7c 100644
> --- a/arch/powerpc/platforms/powernv/npu-dma.c
> +++ b/arch/powerpc/platforms/powernv/npu-dma.c
> @@ -22,12 +22,6 @@
>  
>  #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);
> @@ -362,15 +356,6 @@ 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;
>  };
>  
> @@ -627,534 +612,8 @@ 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;
> @@ -1163,33 +622,18 @@ 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;
>  }
>  
> 

-- 
Alexey