/alps/pcitool

#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;

    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);