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Diffstat (limited to 'include/asm-x86/xen/page.h')
| -rw-r--r-- | include/asm-x86/xen/page.h | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/include/asm-x86/xen/page.h b/include/asm-x86/xen/page.h new file mode 100644 index 00000000000..01799305f02 --- /dev/null +++ b/include/asm-x86/xen/page.h @@ -0,0 +1,168 @@ +#ifndef __XEN_PAGE_H +#define __XEN_PAGE_H + +#include <linux/pfn.h> + +#include <asm/uaccess.h> +#include <asm/pgtable.h> + +#include <xen/features.h> + +/* Xen machine address */ +typedef struct xmaddr { + phys_addr_t maddr; +} xmaddr_t; + +/* Xen pseudo-physical address */ +typedef struct xpaddr { + phys_addr_t paddr; +} xpaddr_t; + +#define XMADDR(x) ((xmaddr_t) { .maddr = (x) }) +#define XPADDR(x) ((xpaddr_t) { .paddr = (x) }) + +/**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/ +#define INVALID_P2M_ENTRY (~0UL) +#define FOREIGN_FRAME_BIT (1UL<<31) +#define FOREIGN_FRAME(m) ((m) | FOREIGN_FRAME_BIT) + +extern unsigned long *phys_to_machine_mapping; + +static inline unsigned long pfn_to_mfn(unsigned long pfn) +{ + if (xen_feature(XENFEAT_auto_translated_physmap)) + return pfn; + + return phys_to_machine_mapping[(unsigned int)(pfn)] & + ~FOREIGN_FRAME_BIT; +} + +static inline int phys_to_machine_mapping_valid(unsigned long pfn) +{ + if (xen_feature(XENFEAT_auto_translated_physmap)) + return 1; + + return (phys_to_machine_mapping[pfn] != INVALID_P2M_ENTRY); +} + +static inline unsigned long mfn_to_pfn(unsigned long mfn) +{ + unsigned long pfn; + + if (xen_feature(XENFEAT_auto_translated_physmap)) + return mfn; + +#if 0 + if (unlikely((mfn >> machine_to_phys_order) != 0)) + return max_mapnr; +#endif + + pfn = 0; + /* + * The array access can fail (e.g., device space beyond end of RAM). + * In such cases it doesn't matter what we return (we return garbage), + * but we must handle the fault without crashing! + */ + __get_user(pfn, &machine_to_phys_mapping[mfn]); + + return pfn; +} + +static inline xmaddr_t phys_to_machine(xpaddr_t phys) +{ + unsigned offset = phys.paddr & ~PAGE_MASK; + return XMADDR(PFN_PHYS((u64)pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset); +} + +static inline xpaddr_t machine_to_phys(xmaddr_t machine) +{ + unsigned offset = machine.maddr & ~PAGE_MASK; + return XPADDR(PFN_PHYS((u64)mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset); +} + +/* + * We detect special mappings in one of two ways: + * 1. If the MFN is an I/O page then Xen will set the m2p entry + * to be outside our maximum possible pseudophys range. + * 2. If the MFN belongs to a different domain then we will certainly + * not have MFN in our p2m table. Conversely, if the page is ours, + * then we'll have p2m(m2p(MFN))==MFN. + * If we detect a special mapping then it doesn't have a 'struct page'. + * We force !pfn_valid() by returning an out-of-range pointer. + * + * NB. These checks require that, for any MFN that is not in our reservation, + * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if + * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN. + * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety. + * + * NB2. When deliberately mapping foreign pages into the p2m table, you *must* + * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we + * require. In all the cases we care about, the FOREIGN_FRAME bit is + * masked (e.g., pfn_to_mfn()) so behaviour there is correct. + */ +static inline unsigned long mfn_to_local_pfn(unsigned long mfn) +{ + extern unsigned long max_mapnr; + unsigned long pfn = mfn_to_pfn(mfn); + if ((pfn < max_mapnr) + && !xen_feature(XENFEAT_auto_translated_physmap) + && (phys_to_machine_mapping[pfn] != mfn)) + return max_mapnr; /* force !pfn_valid() */ + return pfn; +} + +static inline void set_phys_to_machine(unsigned long pfn, unsigned long mfn) +{ + if (xen_feature(XENFEAT_auto_translated_physmap)) { + BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY); + return; + } + phys_to_machine_mapping[pfn] = mfn; +} + +/* VIRT <-> MACHINE conversion */ +#define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v)))) +#define virt_to_mfn(v) (pfn_to_mfn(PFN_DOWN(__pa(v)))) +#define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT)) + +static inline unsigned long pte_mfn(pte_t pte) +{ + return (pte.pte & ~_PAGE_NX) >> PAGE_SHIFT; +} + +static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot) +{ + pte_t pte; + + pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) | + (pgprot_val(pgprot) & __supported_pte_mask); + + return pte; +} + +static inline pteval_t pte_val_ma(pte_t pte) +{ + return pte.pte; +} + +static inline pte_t __pte_ma(pteval_t x) +{ + return (pte_t) { .pte = x }; +} + +#ifdef CONFIG_X86_PAE +#define pmd_val_ma(v) ((v).pmd) +#define pud_val_ma(v) ((v).pgd.pgd) +#define __pmd_ma(x) ((pmd_t) { (x) } ) +#else /* !X86_PAE */ +#define pmd_val_ma(v) ((v).pud.pgd.pgd) +#endif /* CONFIG_X86_PAE */ + +#define pgd_val_ma(x) ((x).pgd) + + +xmaddr_t arbitrary_virt_to_machine(unsigned long address); +void make_lowmem_page_readonly(void *vaddr); +void make_lowmem_page_readwrite(void *vaddr); + +#endif /* __XEN_PAGE_H */ |