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#include <linux/version.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <linux/wait.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/hugetlb.h>
#include <linux/cdev.h>
#include <linux/version.h>
#include "base.h"
static unsigned long pcidriver_follow_pte(struct mm_struct *mm, unsigned long address)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
spinlock_t *ptl;
unsigned long pfn = 0;
pgd = pgd_offset(mm, address);
if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
return 0;
// pud_offset compatibility with pgd_t* broken from Kernel Version 4.12 onwards. See: https://github.com/torvalds/linux/commit/048456dcf2c56ad6f6248e2899dda92fb6a613f6
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,12,0)
p4d_t *p4d;
p4d = p4d_offset(pgd, address);
pud = pud_offset(p4d, address);
#else
pud = pud_offset(pgd, address);
#endif
if (pud_none(*pud) || unlikely(pud_bad(*pud)))
return 0;
pmd = pmd_offset(pud, address);
if (pmd_none(*pmd))
return 0;
// Seems not available out of kernel tree. See: https://lkml.indiana.edu/hypermail/linux/kernel/2307.3/08004.html
pte = pte_offset_map_lock(mm, pmd, address, &ptl);
if (!pte_none(*pte))
pfn = (pte_pfn(*pte) << PAGE_SHIFT);
pte_unmap_unlock(pte, ptl);
return pfn;
}
unsigned long pcidriver_resolve_bar(unsigned long bar_address) {
int dev, bar;
unsigned long pfn;
unsigned long address;
unsigned long offset;
address = (bar_address >> PAGE_SHIFT) << PAGE_SHIFT;
offset = bar_address - address;
pfn = pcidriver_follow_pte(current->mm, address);
for (dev = 0; dev < MAXDEVICES; dev++)
{
pcidriver_privdata_t *privdata = pcidriver_get_privdata(dev);
if (!privdata) continue;
for (bar = 0; bar < 6; bar++)
{
unsigned long start = pci_resource_start(privdata->pdev, bar);
unsigned long end = start + pci_resource_len(privdata->pdev, bar);
if ((pfn >= start)&&(pfn < end))
return pfn + offset;
}
pcidriver_put_privdata(privdata);
}
return 0;
}
EXPORT_SYMBOL(pcidriver_resolve_bar);
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