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ae96e0cdc7
kmap() has been deprecated in favor of the kmap_local_page() due to high cost, restricted mapping space, the overhead of a global lock for synchronization, and making the process sleep in the absence of free slots. kmap_local_page() is faster than kmap() and offers thread-local and CPU-local mappings, take pagefaults in a local kmap region and preserves preemption by saving the mappings of outgoing tasks and restoring those of the incoming one during a context switch. The mappings are kept thread local in the functions “dmirror_do_read” and “dmirror_do_write” in test_hmm.c Therefore, replace kmap() with kmap_local_page() and use mempcy_from/to_page() to avoid open coding kmap_local_page() + memcpy() + kunmap_local(). Remove the unused variable “tmp”. Link: https://lkml.kernel.org/r/20230610175712.GA348514@sumitra.com Signed-off-by: Sumitra Sharma <sumitraartsy@gmail.com> Suggested-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Reviewed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Deepak R Varma <drv@mailo.com> Cc: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
1554 lines
38 KiB
C
1554 lines
38 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* This is a module to test the HMM (Heterogeneous Memory Management)
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* mirror and zone device private memory migration APIs of the kernel.
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* Userspace programs can register with the driver to mirror their own address
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* space and can use the device to read/write any valid virtual address.
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*/
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#include <linux/init.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/cdev.h>
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#include <linux/device.h>
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#include <linux/memremap.h>
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#include <linux/mutex.h>
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#include <linux/rwsem.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/highmem.h>
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#include <linux/delay.h>
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#include <linux/pagemap.h>
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#include <linux/hmm.h>
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#include <linux/vmalloc.h>
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#include <linux/swap.h>
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#include <linux/swapops.h>
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#include <linux/sched/mm.h>
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#include <linux/platform_device.h>
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#include <linux/rmap.h>
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#include <linux/mmu_notifier.h>
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#include <linux/migrate.h>
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#include "test_hmm_uapi.h"
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#define DMIRROR_NDEVICES 4
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#define DMIRROR_RANGE_FAULT_TIMEOUT 1000
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#define DEVMEM_CHUNK_SIZE (256 * 1024 * 1024U)
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#define DEVMEM_CHUNKS_RESERVE 16
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/*
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* For device_private pages, dpage is just a dummy struct page
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* representing a piece of device memory. dmirror_devmem_alloc_page
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* allocates a real system memory page as backing storage to fake a
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* real device. zone_device_data points to that backing page. But
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* for device_coherent memory, the struct page represents real
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* physical CPU-accessible memory that we can use directly.
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*/
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#define BACKING_PAGE(page) (is_device_private_page((page)) ? \
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(page)->zone_device_data : (page))
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static unsigned long spm_addr_dev0;
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module_param(spm_addr_dev0, long, 0644);
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MODULE_PARM_DESC(spm_addr_dev0,
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"Specify start address for SPM (special purpose memory) used for device 0. By setting this Coherent device type will be used. Make sure spm_addr_dev1 is set too. Minimum SPM size should be DEVMEM_CHUNK_SIZE.");
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static unsigned long spm_addr_dev1;
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module_param(spm_addr_dev1, long, 0644);
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MODULE_PARM_DESC(spm_addr_dev1,
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"Specify start address for SPM (special purpose memory) used for device 1. By setting this Coherent device type will be used. Make sure spm_addr_dev0 is set too. Minimum SPM size should be DEVMEM_CHUNK_SIZE.");
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static const struct dev_pagemap_ops dmirror_devmem_ops;
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static const struct mmu_interval_notifier_ops dmirror_min_ops;
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static dev_t dmirror_dev;
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struct dmirror_device;
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struct dmirror_bounce {
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void *ptr;
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unsigned long size;
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unsigned long addr;
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unsigned long cpages;
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};
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#define DPT_XA_TAG_ATOMIC 1UL
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#define DPT_XA_TAG_WRITE 3UL
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/*
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* Data structure to track address ranges and register for mmu interval
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* notifier updates.
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*/
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struct dmirror_interval {
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struct mmu_interval_notifier notifier;
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struct dmirror *dmirror;
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};
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/*
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* Data attached to the open device file.
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* Note that it might be shared after a fork().
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*/
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struct dmirror {
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struct dmirror_device *mdevice;
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struct xarray pt;
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struct mmu_interval_notifier notifier;
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struct mutex mutex;
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};
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/*
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* ZONE_DEVICE pages for migration and simulating device memory.
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*/
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struct dmirror_chunk {
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struct dev_pagemap pagemap;
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struct dmirror_device *mdevice;
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bool remove;
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};
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/*
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* Per device data.
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*/
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struct dmirror_device {
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struct cdev cdevice;
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unsigned int zone_device_type;
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struct device device;
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unsigned int devmem_capacity;
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unsigned int devmem_count;
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struct dmirror_chunk **devmem_chunks;
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struct mutex devmem_lock; /* protects the above */
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unsigned long calloc;
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unsigned long cfree;
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struct page *free_pages;
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spinlock_t lock; /* protects the above */
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};
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static struct dmirror_device dmirror_devices[DMIRROR_NDEVICES];
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static int dmirror_bounce_init(struct dmirror_bounce *bounce,
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unsigned long addr,
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unsigned long size)
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{
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bounce->addr = addr;
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bounce->size = size;
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bounce->cpages = 0;
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bounce->ptr = vmalloc(size);
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if (!bounce->ptr)
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return -ENOMEM;
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return 0;
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}
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static bool dmirror_is_private_zone(struct dmirror_device *mdevice)
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{
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return (mdevice->zone_device_type ==
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HMM_DMIRROR_MEMORY_DEVICE_PRIVATE) ? true : false;
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}
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static enum migrate_vma_direction
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dmirror_select_device(struct dmirror *dmirror)
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{
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return (dmirror->mdevice->zone_device_type ==
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HMM_DMIRROR_MEMORY_DEVICE_PRIVATE) ?
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MIGRATE_VMA_SELECT_DEVICE_PRIVATE :
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MIGRATE_VMA_SELECT_DEVICE_COHERENT;
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}
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static void dmirror_bounce_fini(struct dmirror_bounce *bounce)
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{
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vfree(bounce->ptr);
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}
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static int dmirror_fops_open(struct inode *inode, struct file *filp)
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{
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struct cdev *cdev = inode->i_cdev;
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struct dmirror *dmirror;
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int ret;
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/* Mirror this process address space */
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dmirror = kzalloc(sizeof(*dmirror), GFP_KERNEL);
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if (dmirror == NULL)
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return -ENOMEM;
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dmirror->mdevice = container_of(cdev, struct dmirror_device, cdevice);
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mutex_init(&dmirror->mutex);
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xa_init(&dmirror->pt);
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ret = mmu_interval_notifier_insert(&dmirror->notifier, current->mm,
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0, ULONG_MAX & PAGE_MASK, &dmirror_min_ops);
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if (ret) {
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kfree(dmirror);
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return ret;
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}
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filp->private_data = dmirror;
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return 0;
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}
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static int dmirror_fops_release(struct inode *inode, struct file *filp)
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{
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struct dmirror *dmirror = filp->private_data;
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mmu_interval_notifier_remove(&dmirror->notifier);
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xa_destroy(&dmirror->pt);
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kfree(dmirror);
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return 0;
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}
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static struct dmirror_chunk *dmirror_page_to_chunk(struct page *page)
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{
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return container_of(page->pgmap, struct dmirror_chunk, pagemap);
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}
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static struct dmirror_device *dmirror_page_to_device(struct page *page)
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{
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return dmirror_page_to_chunk(page)->mdevice;
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}
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static int dmirror_do_fault(struct dmirror *dmirror, struct hmm_range *range)
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{
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unsigned long *pfns = range->hmm_pfns;
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unsigned long pfn;
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for (pfn = (range->start >> PAGE_SHIFT);
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pfn < (range->end >> PAGE_SHIFT);
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pfn++, pfns++) {
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struct page *page;
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void *entry;
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/*
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* Since we asked for hmm_range_fault() to populate pages,
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* it shouldn't return an error entry on success.
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*/
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WARN_ON(*pfns & HMM_PFN_ERROR);
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WARN_ON(!(*pfns & HMM_PFN_VALID));
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page = hmm_pfn_to_page(*pfns);
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WARN_ON(!page);
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entry = page;
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if (*pfns & HMM_PFN_WRITE)
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entry = xa_tag_pointer(entry, DPT_XA_TAG_WRITE);
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else if (WARN_ON(range->default_flags & HMM_PFN_WRITE))
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return -EFAULT;
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entry = xa_store(&dmirror->pt, pfn, entry, GFP_ATOMIC);
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if (xa_is_err(entry))
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return xa_err(entry);
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}
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return 0;
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}
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static void dmirror_do_update(struct dmirror *dmirror, unsigned long start,
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unsigned long end)
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{
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unsigned long pfn;
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void *entry;
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/*
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* The XArray doesn't hold references to pages since it relies on
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* the mmu notifier to clear page pointers when they become stale.
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* Therefore, it is OK to just clear the entry.
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*/
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xa_for_each_range(&dmirror->pt, pfn, entry, start >> PAGE_SHIFT,
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end >> PAGE_SHIFT)
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xa_erase(&dmirror->pt, pfn);
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}
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static bool dmirror_interval_invalidate(struct mmu_interval_notifier *mni,
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const struct mmu_notifier_range *range,
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unsigned long cur_seq)
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{
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struct dmirror *dmirror = container_of(mni, struct dmirror, notifier);
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/*
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* Ignore invalidation callbacks for device private pages since
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* the invalidation is handled as part of the migration process.
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*/
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if (range->event == MMU_NOTIFY_MIGRATE &&
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range->owner == dmirror->mdevice)
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return true;
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if (mmu_notifier_range_blockable(range))
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mutex_lock(&dmirror->mutex);
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else if (!mutex_trylock(&dmirror->mutex))
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return false;
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mmu_interval_set_seq(mni, cur_seq);
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dmirror_do_update(dmirror, range->start, range->end);
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mutex_unlock(&dmirror->mutex);
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return true;
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}
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static const struct mmu_interval_notifier_ops dmirror_min_ops = {
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.invalidate = dmirror_interval_invalidate,
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};
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static int dmirror_range_fault(struct dmirror *dmirror,
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struct hmm_range *range)
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{
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struct mm_struct *mm = dmirror->notifier.mm;
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unsigned long timeout =
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jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);
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int ret;
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while (true) {
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if (time_after(jiffies, timeout)) {
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ret = -EBUSY;
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goto out;
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}
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range->notifier_seq = mmu_interval_read_begin(range->notifier);
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mmap_read_lock(mm);
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ret = hmm_range_fault(range);
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mmap_read_unlock(mm);
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if (ret) {
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if (ret == -EBUSY)
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continue;
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goto out;
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}
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mutex_lock(&dmirror->mutex);
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if (mmu_interval_read_retry(range->notifier,
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range->notifier_seq)) {
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mutex_unlock(&dmirror->mutex);
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continue;
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}
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break;
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}
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ret = dmirror_do_fault(dmirror, range);
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mutex_unlock(&dmirror->mutex);
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out:
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return ret;
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}
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static int dmirror_fault(struct dmirror *dmirror, unsigned long start,
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unsigned long end, bool write)
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{
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struct mm_struct *mm = dmirror->notifier.mm;
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unsigned long addr;
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unsigned long pfns[64];
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struct hmm_range range = {
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.notifier = &dmirror->notifier,
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.hmm_pfns = pfns,
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.pfn_flags_mask = 0,
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.default_flags =
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HMM_PFN_REQ_FAULT | (write ? HMM_PFN_REQ_WRITE : 0),
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.dev_private_owner = dmirror->mdevice,
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};
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int ret = 0;
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/* Since the mm is for the mirrored process, get a reference first. */
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if (!mmget_not_zero(mm))
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return 0;
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for (addr = start; addr < end; addr = range.end) {
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range.start = addr;
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range.end = min(addr + (ARRAY_SIZE(pfns) << PAGE_SHIFT), end);
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ret = dmirror_range_fault(dmirror, &range);
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if (ret)
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break;
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}
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mmput(mm);
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return ret;
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}
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static int dmirror_do_read(struct dmirror *dmirror, unsigned long start,
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unsigned long end, struct dmirror_bounce *bounce)
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{
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unsigned long pfn;
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void *ptr;
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ptr = bounce->ptr + ((start - bounce->addr) & PAGE_MASK);
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for (pfn = start >> PAGE_SHIFT; pfn < (end >> PAGE_SHIFT); pfn++) {
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void *entry;
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struct page *page;
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entry = xa_load(&dmirror->pt, pfn);
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page = xa_untag_pointer(entry);
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if (!page)
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return -ENOENT;
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memcpy_from_page(ptr, page, 0, PAGE_SIZE);
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ptr += PAGE_SIZE;
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bounce->cpages++;
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}
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return 0;
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}
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static int dmirror_read(struct dmirror *dmirror, struct hmm_dmirror_cmd *cmd)
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{
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struct dmirror_bounce bounce;
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unsigned long start, end;
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unsigned long size = cmd->npages << PAGE_SHIFT;
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int ret;
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start = cmd->addr;
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end = start + size;
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if (end < start)
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return -EINVAL;
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ret = dmirror_bounce_init(&bounce, start, size);
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if (ret)
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return ret;
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while (1) {
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mutex_lock(&dmirror->mutex);
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ret = dmirror_do_read(dmirror, start, end, &bounce);
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mutex_unlock(&dmirror->mutex);
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if (ret != -ENOENT)
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break;
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start = cmd->addr + (bounce.cpages << PAGE_SHIFT);
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ret = dmirror_fault(dmirror, start, end, false);
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if (ret)
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break;
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cmd->faults++;
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}
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if (ret == 0) {
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if (copy_to_user(u64_to_user_ptr(cmd->ptr), bounce.ptr,
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bounce.size))
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ret = -EFAULT;
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}
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cmd->cpages = bounce.cpages;
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dmirror_bounce_fini(&bounce);
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return ret;
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}
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static int dmirror_do_write(struct dmirror *dmirror, unsigned long start,
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unsigned long end, struct dmirror_bounce *bounce)
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{
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unsigned long pfn;
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void *ptr;
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ptr = bounce->ptr + ((start - bounce->addr) & PAGE_MASK);
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for (pfn = start >> PAGE_SHIFT; pfn < (end >> PAGE_SHIFT); pfn++) {
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void *entry;
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struct page *page;
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entry = xa_load(&dmirror->pt, pfn);
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page = xa_untag_pointer(entry);
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if (!page || xa_pointer_tag(entry) != DPT_XA_TAG_WRITE)
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return -ENOENT;
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memcpy_to_page(page, 0, ptr, PAGE_SIZE);
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ptr += PAGE_SIZE;
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bounce->cpages++;
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}
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return 0;
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}
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static int dmirror_write(struct dmirror *dmirror, struct hmm_dmirror_cmd *cmd)
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{
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struct dmirror_bounce bounce;
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unsigned long start, end;
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unsigned long size = cmd->npages << PAGE_SHIFT;
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int ret;
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start = cmd->addr;
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end = start + size;
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if (end < start)
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return -EINVAL;
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ret = dmirror_bounce_init(&bounce, start, size);
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if (ret)
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return ret;
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if (copy_from_user(bounce.ptr, u64_to_user_ptr(cmd->ptr),
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bounce.size)) {
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ret = -EFAULT;
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goto fini;
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}
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while (1) {
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mutex_lock(&dmirror->mutex);
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ret = dmirror_do_write(dmirror, start, end, &bounce);
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mutex_unlock(&dmirror->mutex);
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if (ret != -ENOENT)
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break;
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start = cmd->addr + (bounce.cpages << PAGE_SHIFT);
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ret = dmirror_fault(dmirror, start, end, true);
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if (ret)
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break;
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cmd->faults++;
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}
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fini:
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cmd->cpages = bounce.cpages;
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dmirror_bounce_fini(&bounce);
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return ret;
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}
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static int dmirror_allocate_chunk(struct dmirror_device *mdevice,
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struct page **ppage)
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{
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struct dmirror_chunk *devmem;
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struct resource *res = NULL;
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unsigned long pfn;
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unsigned long pfn_first;
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unsigned long pfn_last;
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void *ptr;
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int ret = -ENOMEM;
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|
|
devmem = kzalloc(sizeof(*devmem), GFP_KERNEL);
|
|
if (!devmem)
|
|
return ret;
|
|
|
|
switch (mdevice->zone_device_type) {
|
|
case HMM_DMIRROR_MEMORY_DEVICE_PRIVATE:
|
|
res = request_free_mem_region(&iomem_resource, DEVMEM_CHUNK_SIZE,
|
|
"hmm_dmirror");
|
|
if (IS_ERR_OR_NULL(res))
|
|
goto err_devmem;
|
|
devmem->pagemap.range.start = res->start;
|
|
devmem->pagemap.range.end = res->end;
|
|
devmem->pagemap.type = MEMORY_DEVICE_PRIVATE;
|
|
break;
|
|
case HMM_DMIRROR_MEMORY_DEVICE_COHERENT:
|
|
devmem->pagemap.range.start = (MINOR(mdevice->cdevice.dev) - 2) ?
|
|
spm_addr_dev0 :
|
|
spm_addr_dev1;
|
|
devmem->pagemap.range.end = devmem->pagemap.range.start +
|
|
DEVMEM_CHUNK_SIZE - 1;
|
|
devmem->pagemap.type = MEMORY_DEVICE_COHERENT;
|
|
break;
|
|
default:
|
|
ret = -EINVAL;
|
|
goto err_devmem;
|
|
}
|
|
|
|
devmem->pagemap.nr_range = 1;
|
|
devmem->pagemap.ops = &dmirror_devmem_ops;
|
|
devmem->pagemap.owner = mdevice;
|
|
|
|
mutex_lock(&mdevice->devmem_lock);
|
|
|
|
if (mdevice->devmem_count == mdevice->devmem_capacity) {
|
|
struct dmirror_chunk **new_chunks;
|
|
unsigned int new_capacity;
|
|
|
|
new_capacity = mdevice->devmem_capacity +
|
|
DEVMEM_CHUNKS_RESERVE;
|
|
new_chunks = krealloc(mdevice->devmem_chunks,
|
|
sizeof(new_chunks[0]) * new_capacity,
|
|
GFP_KERNEL);
|
|
if (!new_chunks)
|
|
goto err_release;
|
|
mdevice->devmem_capacity = new_capacity;
|
|
mdevice->devmem_chunks = new_chunks;
|
|
}
|
|
ptr = memremap_pages(&devmem->pagemap, numa_node_id());
|
|
if (IS_ERR_OR_NULL(ptr)) {
|
|
if (ptr)
|
|
ret = PTR_ERR(ptr);
|
|
else
|
|
ret = -EFAULT;
|
|
goto err_release;
|
|
}
|
|
|
|
devmem->mdevice = mdevice;
|
|
pfn_first = devmem->pagemap.range.start >> PAGE_SHIFT;
|
|
pfn_last = pfn_first + (range_len(&devmem->pagemap.range) >> PAGE_SHIFT);
|
|
mdevice->devmem_chunks[mdevice->devmem_count++] = devmem;
|
|
|
|
mutex_unlock(&mdevice->devmem_lock);
|
|
|
|
pr_info("added new %u MB chunk (total %u chunks, %u MB) PFNs [0x%lx 0x%lx)\n",
|
|
DEVMEM_CHUNK_SIZE / (1024 * 1024),
|
|
mdevice->devmem_count,
|
|
mdevice->devmem_count * (DEVMEM_CHUNK_SIZE / (1024 * 1024)),
|
|
pfn_first, pfn_last);
|
|
|
|
spin_lock(&mdevice->lock);
|
|
for (pfn = pfn_first; pfn < pfn_last; pfn++) {
|
|
struct page *page = pfn_to_page(pfn);
|
|
|
|
page->zone_device_data = mdevice->free_pages;
|
|
mdevice->free_pages = page;
|
|
}
|
|
if (ppage) {
|
|
*ppage = mdevice->free_pages;
|
|
mdevice->free_pages = (*ppage)->zone_device_data;
|
|
mdevice->calloc++;
|
|
}
|
|
spin_unlock(&mdevice->lock);
|
|
|
|
return 0;
|
|
|
|
err_release:
|
|
mutex_unlock(&mdevice->devmem_lock);
|
|
if (res && devmem->pagemap.type == MEMORY_DEVICE_PRIVATE)
|
|
release_mem_region(devmem->pagemap.range.start,
|
|
range_len(&devmem->pagemap.range));
|
|
err_devmem:
|
|
kfree(devmem);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct page *dmirror_devmem_alloc_page(struct dmirror_device *mdevice)
|
|
{
|
|
struct page *dpage = NULL;
|
|
struct page *rpage = NULL;
|
|
|
|
/*
|
|
* For ZONE_DEVICE private type, this is a fake device so we allocate
|
|
* real system memory to store our device memory.
|
|
* For ZONE_DEVICE coherent type we use the actual dpage to store the
|
|
* data and ignore rpage.
|
|
*/
|
|
if (dmirror_is_private_zone(mdevice)) {
|
|
rpage = alloc_page(GFP_HIGHUSER);
|
|
if (!rpage)
|
|
return NULL;
|
|
}
|
|
spin_lock(&mdevice->lock);
|
|
|
|
if (mdevice->free_pages) {
|
|
dpage = mdevice->free_pages;
|
|
mdevice->free_pages = dpage->zone_device_data;
|
|
mdevice->calloc++;
|
|
spin_unlock(&mdevice->lock);
|
|
} else {
|
|
spin_unlock(&mdevice->lock);
|
|
if (dmirror_allocate_chunk(mdevice, &dpage))
|
|
goto error;
|
|
}
|
|
|
|
zone_device_page_init(dpage);
|
|
dpage->zone_device_data = rpage;
|
|
return dpage;
|
|
|
|
error:
|
|
if (rpage)
|
|
__free_page(rpage);
|
|
return NULL;
|
|
}
|
|
|
|
static void dmirror_migrate_alloc_and_copy(struct migrate_vma *args,
|
|
struct dmirror *dmirror)
|
|
{
|
|
struct dmirror_device *mdevice = dmirror->mdevice;
|
|
const unsigned long *src = args->src;
|
|
unsigned long *dst = args->dst;
|
|
unsigned long addr;
|
|
|
|
for (addr = args->start; addr < args->end; addr += PAGE_SIZE,
|
|
src++, dst++) {
|
|
struct page *spage;
|
|
struct page *dpage;
|
|
struct page *rpage;
|
|
|
|
if (!(*src & MIGRATE_PFN_MIGRATE))
|
|
continue;
|
|
|
|
/*
|
|
* Note that spage might be NULL which is OK since it is an
|
|
* unallocated pte_none() or read-only zero page.
|
|
*/
|
|
spage = migrate_pfn_to_page(*src);
|
|
if (WARN(spage && is_zone_device_page(spage),
|
|
"page already in device spage pfn: 0x%lx\n",
|
|
page_to_pfn(spage)))
|
|
continue;
|
|
|
|
dpage = dmirror_devmem_alloc_page(mdevice);
|
|
if (!dpage)
|
|
continue;
|
|
|
|
rpage = BACKING_PAGE(dpage);
|
|
if (spage)
|
|
copy_highpage(rpage, spage);
|
|
else
|
|
clear_highpage(rpage);
|
|
|
|
/*
|
|
* Normally, a device would use the page->zone_device_data to
|
|
* point to the mirror but here we use it to hold the page for
|
|
* the simulated device memory and that page holds the pointer
|
|
* to the mirror.
|
|
*/
|
|
rpage->zone_device_data = dmirror;
|
|
|
|
pr_debug("migrating from sys to dev pfn src: 0x%lx pfn dst: 0x%lx\n",
|
|
page_to_pfn(spage), page_to_pfn(dpage));
|
|
*dst = migrate_pfn(page_to_pfn(dpage));
|
|
if ((*src & MIGRATE_PFN_WRITE) ||
|
|
(!spage && args->vma->vm_flags & VM_WRITE))
|
|
*dst |= MIGRATE_PFN_WRITE;
|
|
}
|
|
}
|
|
|
|
static int dmirror_check_atomic(struct dmirror *dmirror, unsigned long start,
|
|
unsigned long end)
|
|
{
|
|
unsigned long pfn;
|
|
|
|
for (pfn = start >> PAGE_SHIFT; pfn < (end >> PAGE_SHIFT); pfn++) {
|
|
void *entry;
|
|
|
|
entry = xa_load(&dmirror->pt, pfn);
|
|
if (xa_pointer_tag(entry) == DPT_XA_TAG_ATOMIC)
|
|
return -EPERM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int dmirror_atomic_map(unsigned long start, unsigned long end,
|
|
struct page **pages, struct dmirror *dmirror)
|
|
{
|
|
unsigned long pfn, mapped = 0;
|
|
int i;
|
|
|
|
/* Map the migrated pages into the device's page tables. */
|
|
mutex_lock(&dmirror->mutex);
|
|
|
|
for (i = 0, pfn = start >> PAGE_SHIFT; pfn < (end >> PAGE_SHIFT); pfn++, i++) {
|
|
void *entry;
|
|
|
|
if (!pages[i])
|
|
continue;
|
|
|
|
entry = pages[i];
|
|
entry = xa_tag_pointer(entry, DPT_XA_TAG_ATOMIC);
|
|
entry = xa_store(&dmirror->pt, pfn, entry, GFP_ATOMIC);
|
|
if (xa_is_err(entry)) {
|
|
mutex_unlock(&dmirror->mutex);
|
|
return xa_err(entry);
|
|
}
|
|
|
|
mapped++;
|
|
}
|
|
|
|
mutex_unlock(&dmirror->mutex);
|
|
return mapped;
|
|
}
|
|
|
|
static int dmirror_migrate_finalize_and_map(struct migrate_vma *args,
|
|
struct dmirror *dmirror)
|
|
{
|
|
unsigned long start = args->start;
|
|
unsigned long end = args->end;
|
|
const unsigned long *src = args->src;
|
|
const unsigned long *dst = args->dst;
|
|
unsigned long pfn;
|
|
|
|
/* Map the migrated pages into the device's page tables. */
|
|
mutex_lock(&dmirror->mutex);
|
|
|
|
for (pfn = start >> PAGE_SHIFT; pfn < (end >> PAGE_SHIFT); pfn++,
|
|
src++, dst++) {
|
|
struct page *dpage;
|
|
void *entry;
|
|
|
|
if (!(*src & MIGRATE_PFN_MIGRATE))
|
|
continue;
|
|
|
|
dpage = migrate_pfn_to_page(*dst);
|
|
if (!dpage)
|
|
continue;
|
|
|
|
entry = BACKING_PAGE(dpage);
|
|
if (*dst & MIGRATE_PFN_WRITE)
|
|
entry = xa_tag_pointer(entry, DPT_XA_TAG_WRITE);
|
|
entry = xa_store(&dmirror->pt, pfn, entry, GFP_ATOMIC);
|
|
if (xa_is_err(entry)) {
|
|
mutex_unlock(&dmirror->mutex);
|
|
return xa_err(entry);
|
|
}
|
|
}
|
|
|
|
mutex_unlock(&dmirror->mutex);
|
|
return 0;
|
|
}
|
|
|
|
static int dmirror_exclusive(struct dmirror *dmirror,
|
|
struct hmm_dmirror_cmd *cmd)
|
|
{
|
|
unsigned long start, end, addr;
|
|
unsigned long size = cmd->npages << PAGE_SHIFT;
|
|
struct mm_struct *mm = dmirror->notifier.mm;
|
|
struct page *pages[64];
|
|
struct dmirror_bounce bounce;
|
|
unsigned long next;
|
|
int ret;
|
|
|
|
start = cmd->addr;
|
|
end = start + size;
|
|
if (end < start)
|
|
return -EINVAL;
|
|
|
|
/* Since the mm is for the mirrored process, get a reference first. */
|
|
if (!mmget_not_zero(mm))
|
|
return -EINVAL;
|
|
|
|
mmap_read_lock(mm);
|
|
for (addr = start; addr < end; addr = next) {
|
|
unsigned long mapped = 0;
|
|
int i;
|
|
|
|
if (end < addr + (ARRAY_SIZE(pages) << PAGE_SHIFT))
|
|
next = end;
|
|
else
|
|
next = addr + (ARRAY_SIZE(pages) << PAGE_SHIFT);
|
|
|
|
ret = make_device_exclusive_range(mm, addr, next, pages, NULL);
|
|
/*
|
|
* Do dmirror_atomic_map() iff all pages are marked for
|
|
* exclusive access to avoid accessing uninitialized
|
|
* fields of pages.
|
|
*/
|
|
if (ret == (next - addr) >> PAGE_SHIFT)
|
|
mapped = dmirror_atomic_map(addr, next, pages, dmirror);
|
|
for (i = 0; i < ret; i++) {
|
|
if (pages[i]) {
|
|
unlock_page(pages[i]);
|
|
put_page(pages[i]);
|
|
}
|
|
}
|
|
|
|
if (addr + (mapped << PAGE_SHIFT) < next) {
|
|
mmap_read_unlock(mm);
|
|
mmput(mm);
|
|
return -EBUSY;
|
|
}
|
|
}
|
|
mmap_read_unlock(mm);
|
|
mmput(mm);
|
|
|
|
/* Return the migrated data for verification. */
|
|
ret = dmirror_bounce_init(&bounce, start, size);
|
|
if (ret)
|
|
return ret;
|
|
mutex_lock(&dmirror->mutex);
|
|
ret = dmirror_do_read(dmirror, start, end, &bounce);
|
|
mutex_unlock(&dmirror->mutex);
|
|
if (ret == 0) {
|
|
if (copy_to_user(u64_to_user_ptr(cmd->ptr), bounce.ptr,
|
|
bounce.size))
|
|
ret = -EFAULT;
|
|
}
|
|
|
|
cmd->cpages = bounce.cpages;
|
|
dmirror_bounce_fini(&bounce);
|
|
return ret;
|
|
}
|
|
|
|
static vm_fault_t dmirror_devmem_fault_alloc_and_copy(struct migrate_vma *args,
|
|
struct dmirror *dmirror)
|
|
{
|
|
const unsigned long *src = args->src;
|
|
unsigned long *dst = args->dst;
|
|
unsigned long start = args->start;
|
|
unsigned long end = args->end;
|
|
unsigned long addr;
|
|
|
|
for (addr = start; addr < end; addr += PAGE_SIZE,
|
|
src++, dst++) {
|
|
struct page *dpage, *spage;
|
|
|
|
spage = migrate_pfn_to_page(*src);
|
|
if (!spage || !(*src & MIGRATE_PFN_MIGRATE))
|
|
continue;
|
|
|
|
if (WARN_ON(!is_device_private_page(spage) &&
|
|
!is_device_coherent_page(spage)))
|
|
continue;
|
|
spage = BACKING_PAGE(spage);
|
|
dpage = alloc_page_vma(GFP_HIGHUSER_MOVABLE, args->vma, addr);
|
|
if (!dpage)
|
|
continue;
|
|
pr_debug("migrating from dev to sys pfn src: 0x%lx pfn dst: 0x%lx\n",
|
|
page_to_pfn(spage), page_to_pfn(dpage));
|
|
|
|
lock_page(dpage);
|
|
xa_erase(&dmirror->pt, addr >> PAGE_SHIFT);
|
|
copy_highpage(dpage, spage);
|
|
*dst = migrate_pfn(page_to_pfn(dpage));
|
|
if (*src & MIGRATE_PFN_WRITE)
|
|
*dst |= MIGRATE_PFN_WRITE;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static unsigned long
|
|
dmirror_successful_migrated_pages(struct migrate_vma *migrate)
|
|
{
|
|
unsigned long cpages = 0;
|
|
unsigned long i;
|
|
|
|
for (i = 0; i < migrate->npages; i++) {
|
|
if (migrate->src[i] & MIGRATE_PFN_VALID &&
|
|
migrate->src[i] & MIGRATE_PFN_MIGRATE)
|
|
cpages++;
|
|
}
|
|
return cpages;
|
|
}
|
|
|
|
static int dmirror_migrate_to_system(struct dmirror *dmirror,
|
|
struct hmm_dmirror_cmd *cmd)
|
|
{
|
|
unsigned long start, end, addr;
|
|
unsigned long size = cmd->npages << PAGE_SHIFT;
|
|
struct mm_struct *mm = dmirror->notifier.mm;
|
|
struct vm_area_struct *vma;
|
|
unsigned long src_pfns[64] = { 0 };
|
|
unsigned long dst_pfns[64] = { 0 };
|
|
struct migrate_vma args = { 0 };
|
|
unsigned long next;
|
|
int ret;
|
|
|
|
start = cmd->addr;
|
|
end = start + size;
|
|
if (end < start)
|
|
return -EINVAL;
|
|
|
|
/* Since the mm is for the mirrored process, get a reference first. */
|
|
if (!mmget_not_zero(mm))
|
|
return -EINVAL;
|
|
|
|
cmd->cpages = 0;
|
|
mmap_read_lock(mm);
|
|
for (addr = start; addr < end; addr = next) {
|
|
vma = vma_lookup(mm, addr);
|
|
if (!vma || !(vma->vm_flags & VM_READ)) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
next = min(end, addr + (ARRAY_SIZE(src_pfns) << PAGE_SHIFT));
|
|
if (next > vma->vm_end)
|
|
next = vma->vm_end;
|
|
|
|
args.vma = vma;
|
|
args.src = src_pfns;
|
|
args.dst = dst_pfns;
|
|
args.start = addr;
|
|
args.end = next;
|
|
args.pgmap_owner = dmirror->mdevice;
|
|
args.flags = dmirror_select_device(dmirror);
|
|
|
|
ret = migrate_vma_setup(&args);
|
|
if (ret)
|
|
goto out;
|
|
|
|
pr_debug("Migrating from device mem to sys mem\n");
|
|
dmirror_devmem_fault_alloc_and_copy(&args, dmirror);
|
|
|
|
migrate_vma_pages(&args);
|
|
cmd->cpages += dmirror_successful_migrated_pages(&args);
|
|
migrate_vma_finalize(&args);
|
|
}
|
|
out:
|
|
mmap_read_unlock(mm);
|
|
mmput(mm);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int dmirror_migrate_to_device(struct dmirror *dmirror,
|
|
struct hmm_dmirror_cmd *cmd)
|
|
{
|
|
unsigned long start, end, addr;
|
|
unsigned long size = cmd->npages << PAGE_SHIFT;
|
|
struct mm_struct *mm = dmirror->notifier.mm;
|
|
struct vm_area_struct *vma;
|
|
unsigned long src_pfns[64] = { 0 };
|
|
unsigned long dst_pfns[64] = { 0 };
|
|
struct dmirror_bounce bounce;
|
|
struct migrate_vma args = { 0 };
|
|
unsigned long next;
|
|
int ret;
|
|
|
|
start = cmd->addr;
|
|
end = start + size;
|
|
if (end < start)
|
|
return -EINVAL;
|
|
|
|
/* Since the mm is for the mirrored process, get a reference first. */
|
|
if (!mmget_not_zero(mm))
|
|
return -EINVAL;
|
|
|
|
mmap_read_lock(mm);
|
|
for (addr = start; addr < end; addr = next) {
|
|
vma = vma_lookup(mm, addr);
|
|
if (!vma || !(vma->vm_flags & VM_READ)) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
next = min(end, addr + (ARRAY_SIZE(src_pfns) << PAGE_SHIFT));
|
|
if (next > vma->vm_end)
|
|
next = vma->vm_end;
|
|
|
|
args.vma = vma;
|
|
args.src = src_pfns;
|
|
args.dst = dst_pfns;
|
|
args.start = addr;
|
|
args.end = next;
|
|
args.pgmap_owner = dmirror->mdevice;
|
|
args.flags = MIGRATE_VMA_SELECT_SYSTEM;
|
|
ret = migrate_vma_setup(&args);
|
|
if (ret)
|
|
goto out;
|
|
|
|
pr_debug("Migrating from sys mem to device mem\n");
|
|
dmirror_migrate_alloc_and_copy(&args, dmirror);
|
|
migrate_vma_pages(&args);
|
|
dmirror_migrate_finalize_and_map(&args, dmirror);
|
|
migrate_vma_finalize(&args);
|
|
}
|
|
mmap_read_unlock(mm);
|
|
mmput(mm);
|
|
|
|
/*
|
|
* Return the migrated data for verification.
|
|
* Only for pages in device zone
|
|
*/
|
|
ret = dmirror_bounce_init(&bounce, start, size);
|
|
if (ret)
|
|
return ret;
|
|
mutex_lock(&dmirror->mutex);
|
|
ret = dmirror_do_read(dmirror, start, end, &bounce);
|
|
mutex_unlock(&dmirror->mutex);
|
|
if (ret == 0) {
|
|
if (copy_to_user(u64_to_user_ptr(cmd->ptr), bounce.ptr,
|
|
bounce.size))
|
|
ret = -EFAULT;
|
|
}
|
|
cmd->cpages = bounce.cpages;
|
|
dmirror_bounce_fini(&bounce);
|
|
return ret;
|
|
|
|
out:
|
|
mmap_read_unlock(mm);
|
|
mmput(mm);
|
|
return ret;
|
|
}
|
|
|
|
static void dmirror_mkentry(struct dmirror *dmirror, struct hmm_range *range,
|
|
unsigned char *perm, unsigned long entry)
|
|
{
|
|
struct page *page;
|
|
|
|
if (entry & HMM_PFN_ERROR) {
|
|
*perm = HMM_DMIRROR_PROT_ERROR;
|
|
return;
|
|
}
|
|
if (!(entry & HMM_PFN_VALID)) {
|
|
*perm = HMM_DMIRROR_PROT_NONE;
|
|
return;
|
|
}
|
|
|
|
page = hmm_pfn_to_page(entry);
|
|
if (is_device_private_page(page)) {
|
|
/* Is the page migrated to this device or some other? */
|
|
if (dmirror->mdevice == dmirror_page_to_device(page))
|
|
*perm = HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL;
|
|
else
|
|
*perm = HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE;
|
|
} else if (is_device_coherent_page(page)) {
|
|
/* Is the page migrated to this device or some other? */
|
|
if (dmirror->mdevice == dmirror_page_to_device(page))
|
|
*perm = HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL;
|
|
else
|
|
*perm = HMM_DMIRROR_PROT_DEV_COHERENT_REMOTE;
|
|
} else if (is_zero_pfn(page_to_pfn(page)))
|
|
*perm = HMM_DMIRROR_PROT_ZERO;
|
|
else
|
|
*perm = HMM_DMIRROR_PROT_NONE;
|
|
if (entry & HMM_PFN_WRITE)
|
|
*perm |= HMM_DMIRROR_PROT_WRITE;
|
|
else
|
|
*perm |= HMM_DMIRROR_PROT_READ;
|
|
if (hmm_pfn_to_map_order(entry) + PAGE_SHIFT == PMD_SHIFT)
|
|
*perm |= HMM_DMIRROR_PROT_PMD;
|
|
else if (hmm_pfn_to_map_order(entry) + PAGE_SHIFT == PUD_SHIFT)
|
|
*perm |= HMM_DMIRROR_PROT_PUD;
|
|
}
|
|
|
|
static bool dmirror_snapshot_invalidate(struct mmu_interval_notifier *mni,
|
|
const struct mmu_notifier_range *range,
|
|
unsigned long cur_seq)
|
|
{
|
|
struct dmirror_interval *dmi =
|
|
container_of(mni, struct dmirror_interval, notifier);
|
|
struct dmirror *dmirror = dmi->dmirror;
|
|
|
|
if (mmu_notifier_range_blockable(range))
|
|
mutex_lock(&dmirror->mutex);
|
|
else if (!mutex_trylock(&dmirror->mutex))
|
|
return false;
|
|
|
|
/*
|
|
* Snapshots only need to set the sequence number since any
|
|
* invalidation in the interval invalidates the whole snapshot.
|
|
*/
|
|
mmu_interval_set_seq(mni, cur_seq);
|
|
|
|
mutex_unlock(&dmirror->mutex);
|
|
return true;
|
|
}
|
|
|
|
static const struct mmu_interval_notifier_ops dmirror_mrn_ops = {
|
|
.invalidate = dmirror_snapshot_invalidate,
|
|
};
|
|
|
|
static int dmirror_range_snapshot(struct dmirror *dmirror,
|
|
struct hmm_range *range,
|
|
unsigned char *perm)
|
|
{
|
|
struct mm_struct *mm = dmirror->notifier.mm;
|
|
struct dmirror_interval notifier;
|
|
unsigned long timeout =
|
|
jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);
|
|
unsigned long i;
|
|
unsigned long n;
|
|
int ret = 0;
|
|
|
|
notifier.dmirror = dmirror;
|
|
range->notifier = ¬ifier.notifier;
|
|
|
|
ret = mmu_interval_notifier_insert(range->notifier, mm,
|
|
range->start, range->end - range->start,
|
|
&dmirror_mrn_ops);
|
|
if (ret)
|
|
return ret;
|
|
|
|
while (true) {
|
|
if (time_after(jiffies, timeout)) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
range->notifier_seq = mmu_interval_read_begin(range->notifier);
|
|
|
|
mmap_read_lock(mm);
|
|
ret = hmm_range_fault(range);
|
|
mmap_read_unlock(mm);
|
|
if (ret) {
|
|
if (ret == -EBUSY)
|
|
continue;
|
|
goto out;
|
|
}
|
|
|
|
mutex_lock(&dmirror->mutex);
|
|
if (mmu_interval_read_retry(range->notifier,
|
|
range->notifier_seq)) {
|
|
mutex_unlock(&dmirror->mutex);
|
|
continue;
|
|
}
|
|
break;
|
|
}
|
|
|
|
n = (range->end - range->start) >> PAGE_SHIFT;
|
|
for (i = 0; i < n; i++)
|
|
dmirror_mkentry(dmirror, range, perm + i, range->hmm_pfns[i]);
|
|
|
|
mutex_unlock(&dmirror->mutex);
|
|
out:
|
|
mmu_interval_notifier_remove(range->notifier);
|
|
return ret;
|
|
}
|
|
|
|
static int dmirror_snapshot(struct dmirror *dmirror,
|
|
struct hmm_dmirror_cmd *cmd)
|
|
{
|
|
struct mm_struct *mm = dmirror->notifier.mm;
|
|
unsigned long start, end;
|
|
unsigned long size = cmd->npages << PAGE_SHIFT;
|
|
unsigned long addr;
|
|
unsigned long next;
|
|
unsigned long pfns[64];
|
|
unsigned char perm[64];
|
|
char __user *uptr;
|
|
struct hmm_range range = {
|
|
.hmm_pfns = pfns,
|
|
.dev_private_owner = dmirror->mdevice,
|
|
};
|
|
int ret = 0;
|
|
|
|
start = cmd->addr;
|
|
end = start + size;
|
|
if (end < start)
|
|
return -EINVAL;
|
|
|
|
/* Since the mm is for the mirrored process, get a reference first. */
|
|
if (!mmget_not_zero(mm))
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* Register a temporary notifier to detect invalidations even if it
|
|
* overlaps with other mmu_interval_notifiers.
|
|
*/
|
|
uptr = u64_to_user_ptr(cmd->ptr);
|
|
for (addr = start; addr < end; addr = next) {
|
|
unsigned long n;
|
|
|
|
next = min(addr + (ARRAY_SIZE(pfns) << PAGE_SHIFT), end);
|
|
range.start = addr;
|
|
range.end = next;
|
|
|
|
ret = dmirror_range_snapshot(dmirror, &range, perm);
|
|
if (ret)
|
|
break;
|
|
|
|
n = (range.end - range.start) >> PAGE_SHIFT;
|
|
if (copy_to_user(uptr, perm, n)) {
|
|
ret = -EFAULT;
|
|
break;
|
|
}
|
|
|
|
cmd->cpages += n;
|
|
uptr += n;
|
|
}
|
|
mmput(mm);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void dmirror_device_evict_chunk(struct dmirror_chunk *chunk)
|
|
{
|
|
unsigned long start_pfn = chunk->pagemap.range.start >> PAGE_SHIFT;
|
|
unsigned long end_pfn = chunk->pagemap.range.end >> PAGE_SHIFT;
|
|
unsigned long npages = end_pfn - start_pfn + 1;
|
|
unsigned long i;
|
|
unsigned long *src_pfns;
|
|
unsigned long *dst_pfns;
|
|
|
|
src_pfns = kcalloc(npages, sizeof(*src_pfns), GFP_KERNEL);
|
|
dst_pfns = kcalloc(npages, sizeof(*dst_pfns), GFP_KERNEL);
|
|
|
|
migrate_device_range(src_pfns, start_pfn, npages);
|
|
for (i = 0; i < npages; i++) {
|
|
struct page *dpage, *spage;
|
|
|
|
spage = migrate_pfn_to_page(src_pfns[i]);
|
|
if (!spage || !(src_pfns[i] & MIGRATE_PFN_MIGRATE))
|
|
continue;
|
|
|
|
if (WARN_ON(!is_device_private_page(spage) &&
|
|
!is_device_coherent_page(spage)))
|
|
continue;
|
|
spage = BACKING_PAGE(spage);
|
|
dpage = alloc_page(GFP_HIGHUSER_MOVABLE | __GFP_NOFAIL);
|
|
lock_page(dpage);
|
|
copy_highpage(dpage, spage);
|
|
dst_pfns[i] = migrate_pfn(page_to_pfn(dpage));
|
|
if (src_pfns[i] & MIGRATE_PFN_WRITE)
|
|
dst_pfns[i] |= MIGRATE_PFN_WRITE;
|
|
}
|
|
migrate_device_pages(src_pfns, dst_pfns, npages);
|
|
migrate_device_finalize(src_pfns, dst_pfns, npages);
|
|
kfree(src_pfns);
|
|
kfree(dst_pfns);
|
|
}
|
|
|
|
/* Removes free pages from the free list so they can't be re-allocated */
|
|
static void dmirror_remove_free_pages(struct dmirror_chunk *devmem)
|
|
{
|
|
struct dmirror_device *mdevice = devmem->mdevice;
|
|
struct page *page;
|
|
|
|
for (page = mdevice->free_pages; page; page = page->zone_device_data)
|
|
if (dmirror_page_to_chunk(page) == devmem)
|
|
mdevice->free_pages = page->zone_device_data;
|
|
}
|
|
|
|
static void dmirror_device_remove_chunks(struct dmirror_device *mdevice)
|
|
{
|
|
unsigned int i;
|
|
|
|
mutex_lock(&mdevice->devmem_lock);
|
|
if (mdevice->devmem_chunks) {
|
|
for (i = 0; i < mdevice->devmem_count; i++) {
|
|
struct dmirror_chunk *devmem =
|
|
mdevice->devmem_chunks[i];
|
|
|
|
spin_lock(&mdevice->lock);
|
|
devmem->remove = true;
|
|
dmirror_remove_free_pages(devmem);
|
|
spin_unlock(&mdevice->lock);
|
|
|
|
dmirror_device_evict_chunk(devmem);
|
|
memunmap_pages(&devmem->pagemap);
|
|
if (devmem->pagemap.type == MEMORY_DEVICE_PRIVATE)
|
|
release_mem_region(devmem->pagemap.range.start,
|
|
range_len(&devmem->pagemap.range));
|
|
kfree(devmem);
|
|
}
|
|
mdevice->devmem_count = 0;
|
|
mdevice->devmem_capacity = 0;
|
|
mdevice->free_pages = NULL;
|
|
kfree(mdevice->devmem_chunks);
|
|
mdevice->devmem_chunks = NULL;
|
|
}
|
|
mutex_unlock(&mdevice->devmem_lock);
|
|
}
|
|
|
|
static long dmirror_fops_unlocked_ioctl(struct file *filp,
|
|
unsigned int command,
|
|
unsigned long arg)
|
|
{
|
|
void __user *uarg = (void __user *)arg;
|
|
struct hmm_dmirror_cmd cmd;
|
|
struct dmirror *dmirror;
|
|
int ret;
|
|
|
|
dmirror = filp->private_data;
|
|
if (!dmirror)
|
|
return -EINVAL;
|
|
|
|
if (copy_from_user(&cmd, uarg, sizeof(cmd)))
|
|
return -EFAULT;
|
|
|
|
if (cmd.addr & ~PAGE_MASK)
|
|
return -EINVAL;
|
|
if (cmd.addr >= (cmd.addr + (cmd.npages << PAGE_SHIFT)))
|
|
return -EINVAL;
|
|
|
|
cmd.cpages = 0;
|
|
cmd.faults = 0;
|
|
|
|
switch (command) {
|
|
case HMM_DMIRROR_READ:
|
|
ret = dmirror_read(dmirror, &cmd);
|
|
break;
|
|
|
|
case HMM_DMIRROR_WRITE:
|
|
ret = dmirror_write(dmirror, &cmd);
|
|
break;
|
|
|
|
case HMM_DMIRROR_MIGRATE_TO_DEV:
|
|
ret = dmirror_migrate_to_device(dmirror, &cmd);
|
|
break;
|
|
|
|
case HMM_DMIRROR_MIGRATE_TO_SYS:
|
|
ret = dmirror_migrate_to_system(dmirror, &cmd);
|
|
break;
|
|
|
|
case HMM_DMIRROR_EXCLUSIVE:
|
|
ret = dmirror_exclusive(dmirror, &cmd);
|
|
break;
|
|
|
|
case HMM_DMIRROR_CHECK_EXCLUSIVE:
|
|
ret = dmirror_check_atomic(dmirror, cmd.addr,
|
|
cmd.addr + (cmd.npages << PAGE_SHIFT));
|
|
break;
|
|
|
|
case HMM_DMIRROR_SNAPSHOT:
|
|
ret = dmirror_snapshot(dmirror, &cmd);
|
|
break;
|
|
|
|
case HMM_DMIRROR_RELEASE:
|
|
dmirror_device_remove_chunks(dmirror->mdevice);
|
|
ret = 0;
|
|
break;
|
|
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (copy_to_user(uarg, &cmd, sizeof(cmd)))
|
|
return -EFAULT;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int dmirror_fops_mmap(struct file *file, struct vm_area_struct *vma)
|
|
{
|
|
unsigned long addr;
|
|
|
|
for (addr = vma->vm_start; addr < vma->vm_end; addr += PAGE_SIZE) {
|
|
struct page *page;
|
|
int ret;
|
|
|
|
page = alloc_page(GFP_KERNEL | __GFP_ZERO);
|
|
if (!page)
|
|
return -ENOMEM;
|
|
|
|
ret = vm_insert_page(vma, addr, page);
|
|
if (ret) {
|
|
__free_page(page);
|
|
return ret;
|
|
}
|
|
put_page(page);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations dmirror_fops = {
|
|
.open = dmirror_fops_open,
|
|
.release = dmirror_fops_release,
|
|
.mmap = dmirror_fops_mmap,
|
|
.unlocked_ioctl = dmirror_fops_unlocked_ioctl,
|
|
.llseek = default_llseek,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static void dmirror_devmem_free(struct page *page)
|
|
{
|
|
struct page *rpage = BACKING_PAGE(page);
|
|
struct dmirror_device *mdevice;
|
|
|
|
if (rpage != page)
|
|
__free_page(rpage);
|
|
|
|
mdevice = dmirror_page_to_device(page);
|
|
spin_lock(&mdevice->lock);
|
|
|
|
/* Return page to our allocator if not freeing the chunk */
|
|
if (!dmirror_page_to_chunk(page)->remove) {
|
|
mdevice->cfree++;
|
|
page->zone_device_data = mdevice->free_pages;
|
|
mdevice->free_pages = page;
|
|
}
|
|
spin_unlock(&mdevice->lock);
|
|
}
|
|
|
|
static vm_fault_t dmirror_devmem_fault(struct vm_fault *vmf)
|
|
{
|
|
struct migrate_vma args = { 0 };
|
|
unsigned long src_pfns = 0;
|
|
unsigned long dst_pfns = 0;
|
|
struct page *rpage;
|
|
struct dmirror *dmirror;
|
|
vm_fault_t ret;
|
|
|
|
/*
|
|
* Normally, a device would use the page->zone_device_data to point to
|
|
* the mirror but here we use it to hold the page for the simulated
|
|
* device memory and that page holds the pointer to the mirror.
|
|
*/
|
|
rpage = vmf->page->zone_device_data;
|
|
dmirror = rpage->zone_device_data;
|
|
|
|
/* FIXME demonstrate how we can adjust migrate range */
|
|
args.vma = vmf->vma;
|
|
args.start = vmf->address;
|
|
args.end = args.start + PAGE_SIZE;
|
|
args.src = &src_pfns;
|
|
args.dst = &dst_pfns;
|
|
args.pgmap_owner = dmirror->mdevice;
|
|
args.flags = dmirror_select_device(dmirror);
|
|
args.fault_page = vmf->page;
|
|
|
|
if (migrate_vma_setup(&args))
|
|
return VM_FAULT_SIGBUS;
|
|
|
|
ret = dmirror_devmem_fault_alloc_and_copy(&args, dmirror);
|
|
if (ret)
|
|
return ret;
|
|
migrate_vma_pages(&args);
|
|
/*
|
|
* No device finalize step is needed since
|
|
* dmirror_devmem_fault_alloc_and_copy() will have already
|
|
* invalidated the device page table.
|
|
*/
|
|
migrate_vma_finalize(&args);
|
|
return 0;
|
|
}
|
|
|
|
static const struct dev_pagemap_ops dmirror_devmem_ops = {
|
|
.page_free = dmirror_devmem_free,
|
|
.migrate_to_ram = dmirror_devmem_fault,
|
|
};
|
|
|
|
static int dmirror_device_init(struct dmirror_device *mdevice, int id)
|
|
{
|
|
dev_t dev;
|
|
int ret;
|
|
|
|
dev = MKDEV(MAJOR(dmirror_dev), id);
|
|
mutex_init(&mdevice->devmem_lock);
|
|
spin_lock_init(&mdevice->lock);
|
|
|
|
cdev_init(&mdevice->cdevice, &dmirror_fops);
|
|
mdevice->cdevice.owner = THIS_MODULE;
|
|
device_initialize(&mdevice->device);
|
|
mdevice->device.devt = dev;
|
|
|
|
ret = dev_set_name(&mdevice->device, "hmm_dmirror%u", id);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = cdev_device_add(&mdevice->cdevice, &mdevice->device);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* Build a list of free ZONE_DEVICE struct pages */
|
|
return dmirror_allocate_chunk(mdevice, NULL);
|
|
}
|
|
|
|
static void dmirror_device_remove(struct dmirror_device *mdevice)
|
|
{
|
|
dmirror_device_remove_chunks(mdevice);
|
|
cdev_device_del(&mdevice->cdevice, &mdevice->device);
|
|
}
|
|
|
|
static int __init hmm_dmirror_init(void)
|
|
{
|
|
int ret;
|
|
int id = 0;
|
|
int ndevices = 0;
|
|
|
|
ret = alloc_chrdev_region(&dmirror_dev, 0, DMIRROR_NDEVICES,
|
|
"HMM_DMIRROR");
|
|
if (ret)
|
|
goto err_unreg;
|
|
|
|
memset(dmirror_devices, 0, DMIRROR_NDEVICES * sizeof(dmirror_devices[0]));
|
|
dmirror_devices[ndevices++].zone_device_type =
|
|
HMM_DMIRROR_MEMORY_DEVICE_PRIVATE;
|
|
dmirror_devices[ndevices++].zone_device_type =
|
|
HMM_DMIRROR_MEMORY_DEVICE_PRIVATE;
|
|
if (spm_addr_dev0 && spm_addr_dev1) {
|
|
dmirror_devices[ndevices++].zone_device_type =
|
|
HMM_DMIRROR_MEMORY_DEVICE_COHERENT;
|
|
dmirror_devices[ndevices++].zone_device_type =
|
|
HMM_DMIRROR_MEMORY_DEVICE_COHERENT;
|
|
}
|
|
for (id = 0; id < ndevices; id++) {
|
|
ret = dmirror_device_init(dmirror_devices + id, id);
|
|
if (ret)
|
|
goto err_chrdev;
|
|
}
|
|
|
|
pr_info("HMM test module loaded. This is only for testing HMM.\n");
|
|
return 0;
|
|
|
|
err_chrdev:
|
|
while (--id >= 0)
|
|
dmirror_device_remove(dmirror_devices + id);
|
|
unregister_chrdev_region(dmirror_dev, DMIRROR_NDEVICES);
|
|
err_unreg:
|
|
return ret;
|
|
}
|
|
|
|
static void __exit hmm_dmirror_exit(void)
|
|
{
|
|
int id;
|
|
|
|
for (id = 0; id < DMIRROR_NDEVICES; id++)
|
|
if (dmirror_devices[id].zone_device_type)
|
|
dmirror_device_remove(dmirror_devices + id);
|
|
unregister_chrdev_region(dmirror_dev, DMIRROR_NDEVICES);
|
|
}
|
|
|
|
module_init(hmm_dmirror_init);
|
|
module_exit(hmm_dmirror_exit);
|
|
MODULE_LICENSE("GPL");
|