driver/rdma.c


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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 "rdma.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 = pud_offset(pgd, address);
    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 address) {
    unsigned long pfn;

    address = (address >> PAGE_SHIFT) << PAGE_SHIFT;
    pfn = pcidriver_follow_pte(current->mm, address);

    return pfn;
}

EXPORT_SYMBOL(pcidriver_resolve_bar);