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280 lines
6.7 KiB
280 lines
6.7 KiB
/*
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* Copyright 2017 IBM Corp.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/hugetlb.h>
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#include <linux/sched/mm.h>
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#include <asm/pnv-pci.h>
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#include <misc/cxllib.h>
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#include "cxl.h"
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#define CXL_INVALID_DRA ~0ull
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#define CXL_DUMMY_READ_SIZE 128
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#define CXL_DUMMY_READ_ALIGN 8
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#define CXL_CAPI_WINDOW_START 0x2000000000000ull
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#define CXL_CAPI_WINDOW_LOG_SIZE 48
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#define CXL_XSL_CONFIG_CURRENT_VERSION CXL_XSL_CONFIG_VERSION1
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bool cxllib_slot_is_supported(struct pci_dev *dev, unsigned long flags)
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{
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int rc;
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u32 phb_index;
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u64 chip_id, capp_unit_id;
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/* No flags currently supported */
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if (flags)
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return false;
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if (!cpu_has_feature(CPU_FTR_HVMODE))
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return false;
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if (!cxl_is_power9())
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return false;
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if (cxl_slot_is_switched(dev))
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return false;
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/* on p9, some pci slots are not connected to a CAPP unit */
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rc = cxl_calc_capp_routing(dev, &chip_id, &phb_index, &capp_unit_id);
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if (rc)
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return false;
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return true;
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}
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EXPORT_SYMBOL_GPL(cxllib_slot_is_supported);
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static DEFINE_MUTEX(dra_mutex);
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static u64 dummy_read_addr = CXL_INVALID_DRA;
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static int allocate_dummy_read_buf(void)
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{
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u64 buf, vaddr;
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size_t buf_size;
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/*
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* Dummy read buffer is 128-byte long, aligned on a
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* 256-byte boundary and we need the physical address.
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*/
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buf_size = CXL_DUMMY_READ_SIZE + (1ull << CXL_DUMMY_READ_ALIGN);
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buf = (u64) kzalloc(buf_size, GFP_KERNEL);
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if (!buf)
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return -ENOMEM;
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vaddr = (buf + (1ull << CXL_DUMMY_READ_ALIGN) - 1) &
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(~0ull << CXL_DUMMY_READ_ALIGN);
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WARN((vaddr + CXL_DUMMY_READ_SIZE) > (buf + buf_size),
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"Dummy read buffer alignment issue");
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dummy_read_addr = virt_to_phys((void *) vaddr);
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return 0;
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}
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int cxllib_get_xsl_config(struct pci_dev *dev, struct cxllib_xsl_config *cfg)
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{
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int rc;
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u32 phb_index;
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u64 chip_id, capp_unit_id;
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if (!cpu_has_feature(CPU_FTR_HVMODE))
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return -EINVAL;
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mutex_lock(&dra_mutex);
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if (dummy_read_addr == CXL_INVALID_DRA) {
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rc = allocate_dummy_read_buf();
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if (rc) {
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mutex_unlock(&dra_mutex);
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return rc;
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}
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}
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mutex_unlock(&dra_mutex);
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rc = cxl_calc_capp_routing(dev, &chip_id, &phb_index, &capp_unit_id);
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if (rc)
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return rc;
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rc = cxl_get_xsl9_dsnctl(capp_unit_id, &cfg->dsnctl);
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if (rc)
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return rc;
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if (cpu_has_feature(CPU_FTR_POWER9_DD1)) {
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/* workaround for DD1 - nbwind = capiind */
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cfg->dsnctl |= ((u64)0x02 << (63-47));
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}
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cfg->version = CXL_XSL_CONFIG_CURRENT_VERSION;
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cfg->log_bar_size = CXL_CAPI_WINDOW_LOG_SIZE;
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cfg->bar_addr = CXL_CAPI_WINDOW_START;
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cfg->dra = dummy_read_addr;
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return 0;
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}
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EXPORT_SYMBOL_GPL(cxllib_get_xsl_config);
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int cxllib_switch_phb_mode(struct pci_dev *dev, enum cxllib_mode mode,
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unsigned long flags)
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{
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int rc = 0;
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if (!cpu_has_feature(CPU_FTR_HVMODE))
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return -EINVAL;
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switch (mode) {
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case CXL_MODE_PCI:
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/*
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* We currently don't support going back to PCI mode
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* However, we'll turn the invalidations off, so that
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* the firmware doesn't have to ack them and can do
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* things like reset, etc.. with no worries.
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* So always return EPERM (can't go back to PCI) or
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* EBUSY if we couldn't even turn off snooping
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*/
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rc = pnv_phb_to_cxl_mode(dev, OPAL_PHB_CAPI_MODE_SNOOP_OFF);
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if (rc)
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rc = -EBUSY;
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else
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rc = -EPERM;
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break;
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case CXL_MODE_CXL:
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/* DMA only supported on TVT1 for the time being */
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if (flags != CXL_MODE_DMA_TVT1)
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return -EINVAL;
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rc = pnv_phb_to_cxl_mode(dev, OPAL_PHB_CAPI_MODE_DMA_TVT1);
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if (rc)
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return rc;
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rc = pnv_phb_to_cxl_mode(dev, OPAL_PHB_CAPI_MODE_SNOOP_ON);
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break;
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default:
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rc = -EINVAL;
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}
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return rc;
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}
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EXPORT_SYMBOL_GPL(cxllib_switch_phb_mode);
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/*
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* When switching the PHB to capi mode, the TVT#1 entry for
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* the Partitionable Endpoint is set in bypass mode, like
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* in PCI mode.
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* Configure the device dma to use TVT#1, which is done
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* by calling dma_set_mask() with a mask large enough.
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*/
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int cxllib_set_device_dma(struct pci_dev *dev, unsigned long flags)
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{
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int rc;
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if (flags)
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return -EINVAL;
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rc = dma_set_mask(&dev->dev, DMA_BIT_MASK(64));
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return rc;
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}
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EXPORT_SYMBOL_GPL(cxllib_set_device_dma);
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int cxllib_get_PE_attributes(struct task_struct *task,
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unsigned long translation_mode,
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struct cxllib_pe_attributes *attr)
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{
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struct mm_struct *mm = NULL;
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if (translation_mode != CXL_TRANSLATED_MODE &&
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translation_mode != CXL_REAL_MODE)
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return -EINVAL;
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attr->sr = cxl_calculate_sr(false,
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task == NULL,
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translation_mode == CXL_REAL_MODE,
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true);
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attr->lpid = mfspr(SPRN_LPID);
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if (task) {
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mm = get_task_mm(task);
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if (mm == NULL)
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return -EINVAL;
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/*
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* Caller is keeping a reference on mm_users for as long
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* as XSL uses the memory context
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*/
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attr->pid = mm->context.id;
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mmput(mm);
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} else {
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attr->pid = 0;
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}
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attr->tid = 0;
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return 0;
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}
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EXPORT_SYMBOL_GPL(cxllib_get_PE_attributes);
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static int get_vma_info(struct mm_struct *mm, u64 addr,
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u64 *vma_start, u64 *vma_end,
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unsigned long *page_size)
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{
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struct vm_area_struct *vma = NULL;
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int rc = 0;
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down_read(&mm->mmap_sem);
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vma = find_vma(mm, addr);
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if (!vma) {
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rc = -EFAULT;
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goto out;
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}
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*page_size = vma_kernel_pagesize(vma);
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*vma_start = vma->vm_start;
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*vma_end = vma->vm_end;
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out:
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up_read(&mm->mmap_sem);
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return rc;
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}
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int cxllib_handle_fault(struct mm_struct *mm, u64 addr, u64 size, u64 flags)
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{
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int rc;
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u64 dar, vma_start, vma_end;
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unsigned long page_size;
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if (mm == NULL)
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return -EFAULT;
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/*
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* The buffer we have to process can extend over several pages
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* and may also cover several VMAs.
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* We iterate over all the pages. The page size could vary
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* between VMAs.
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*/
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rc = get_vma_info(mm, addr, &vma_start, &vma_end, &page_size);
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if (rc)
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return rc;
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for (dar = (addr & ~(page_size - 1)); dar < (addr + size);
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dar += page_size) {
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if (dar < vma_start || dar >= vma_end) {
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/*
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* We don't hold the mm->mmap_sem semaphore
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* while iterating, since the semaphore is
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* required by one of the lower-level page
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* fault processing functions and it could
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* create a deadlock.
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*
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* It means the VMAs can be altered between 2
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* loop iterations and we could theoretically
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* miss a page (however unlikely). But that's
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* not really a problem, as the driver will
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* retry access, get another page fault on the
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* missing page and call us again.
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*/
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rc = get_vma_info(mm, dar, &vma_start, &vma_end,
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&page_size);
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if (rc)
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return rc;
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}
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rc = cxl_handle_mm_fault(mm, flags, dar);
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if (rc)
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return -EFAULT;
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}
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return 0;
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}
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EXPORT_SYMBOL_GPL(cxllib_handle_fault);
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