![Jeremy Fitzhardinge](/assets/img/avatar_default.png)
Rusty, in his peevish way, complained that macros defining constants should have a name which somewhat accurately reflects the actual purpose of the constant. Aside from the fact that PTE_MASK gives no clue as to what's actually being masked, and is misleadingly similar to the functionally entirely different PMD_MASK, PUD_MASK and PGD_MASK, I don't really see what the problem is. But if this patch silences the incessent noise, then it will have achieved its goal (TODO: write test-case). Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
166 lines
4.6 KiB
C
166 lines
4.6 KiB
C
#ifndef __XEN_PAGE_H
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#define __XEN_PAGE_H
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#include <linux/pfn.h>
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#include <asm/uaccess.h>
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#include <asm/pgtable.h>
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#include <xen/features.h>
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/* Xen machine address */
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typedef struct xmaddr {
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phys_addr_t maddr;
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} xmaddr_t;
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/* Xen pseudo-physical address */
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typedef struct xpaddr {
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phys_addr_t paddr;
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} xpaddr_t;
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#define XMADDR(x) ((xmaddr_t) { .maddr = (x) })
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#define XPADDR(x) ((xpaddr_t) { .paddr = (x) })
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/**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/
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#define INVALID_P2M_ENTRY (~0UL)
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#define FOREIGN_FRAME_BIT (1UL<<31)
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#define FOREIGN_FRAME(m) ((m) | FOREIGN_FRAME_BIT)
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/* Maximum amount of memory we can handle in a domain in pages */
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#define MAX_DOMAIN_PAGES \
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((unsigned long)((u64)CONFIG_XEN_MAX_DOMAIN_MEMORY * 1024 * 1024 * 1024 / PAGE_SIZE))
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extern unsigned long get_phys_to_machine(unsigned long pfn);
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extern void set_phys_to_machine(unsigned long pfn, unsigned long mfn);
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static inline unsigned long pfn_to_mfn(unsigned long pfn)
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{
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if (xen_feature(XENFEAT_auto_translated_physmap))
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return pfn;
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return get_phys_to_machine(pfn) & ~FOREIGN_FRAME_BIT;
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}
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static inline int phys_to_machine_mapping_valid(unsigned long pfn)
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{
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if (xen_feature(XENFEAT_auto_translated_physmap))
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return 1;
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return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY;
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}
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static inline unsigned long mfn_to_pfn(unsigned long mfn)
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{
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unsigned long pfn;
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if (xen_feature(XENFEAT_auto_translated_physmap))
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return mfn;
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#if 0
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if (unlikely((mfn >> machine_to_phys_order) != 0))
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return max_mapnr;
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#endif
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pfn = 0;
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/*
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* The array access can fail (e.g., device space beyond end of RAM).
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* In such cases it doesn't matter what we return (we return garbage),
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* but we must handle the fault without crashing!
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*/
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__get_user(pfn, &machine_to_phys_mapping[mfn]);
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return pfn;
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}
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static inline xmaddr_t phys_to_machine(xpaddr_t phys)
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{
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unsigned offset = phys.paddr & ~PAGE_MASK;
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return XMADDR(PFN_PHYS((u64)pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
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}
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static inline xpaddr_t machine_to_phys(xmaddr_t machine)
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{
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unsigned offset = machine.maddr & ~PAGE_MASK;
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return XPADDR(PFN_PHYS((u64)mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
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}
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/*
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* We detect special mappings in one of two ways:
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* 1. If the MFN is an I/O page then Xen will set the m2p entry
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* to be outside our maximum possible pseudophys range.
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* 2. If the MFN belongs to a different domain then we will certainly
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* not have MFN in our p2m table. Conversely, if the page is ours,
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* then we'll have p2m(m2p(MFN))==MFN.
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* If we detect a special mapping then it doesn't have a 'struct page'.
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* We force !pfn_valid() by returning an out-of-range pointer.
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*
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* NB. These checks require that, for any MFN that is not in our reservation,
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* there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
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* we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
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* Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
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*
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* NB2. When deliberately mapping foreign pages into the p2m table, you *must*
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* use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
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* require. In all the cases we care about, the FOREIGN_FRAME bit is
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* masked (e.g., pfn_to_mfn()) so behaviour there is correct.
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*/
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static inline unsigned long mfn_to_local_pfn(unsigned long mfn)
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{
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extern unsigned long max_mapnr;
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unsigned long pfn = mfn_to_pfn(mfn);
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if ((pfn < max_mapnr)
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&& !xen_feature(XENFEAT_auto_translated_physmap)
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&& (get_phys_to_machine(pfn) != mfn))
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return max_mapnr; /* force !pfn_valid() */
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/* XXX fixme; not true with sparsemem */
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return pfn;
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}
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/* VIRT <-> MACHINE conversion */
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#define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v))))
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#define virt_to_mfn(v) (pfn_to_mfn(PFN_DOWN(__pa(v))))
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#define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT))
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static inline unsigned long pte_mfn(pte_t pte)
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{
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return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
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}
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static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)
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{
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pte_t pte;
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pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |
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(pgprot_val(pgprot) & __supported_pte_mask);
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return pte;
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}
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static inline pteval_t pte_val_ma(pte_t pte)
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{
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return pte.pte;
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}
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static inline pte_t __pte_ma(pteval_t x)
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{
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return (pte_t) { .pte = x };
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}
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#define pmd_val_ma(v) ((v).pmd)
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#ifdef __PAGETABLE_PUD_FOLDED
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#define pud_val_ma(v) ((v).pgd.pgd)
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#else
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#define pud_val_ma(v) ((v).pud)
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#endif
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#define __pmd_ma(x) ((pmd_t) { (x) } )
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#define pgd_val_ma(x) ((x).pgd)
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xmaddr_t arbitrary_virt_to_machine(void *address);
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void make_lowmem_page_readonly(void *vaddr);
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void make_lowmem_page_readwrite(void *vaddr);
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#endif /* __XEN_PAGE_H */
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