4a19138c65
Introduce physical to machine and machine to physical tracking mechanisms based on rbtrees for arm/xen and arm64/xen. We need it because any guests on ARM are an autotranslate guests, therefore a physical address is potentially different from a machine address. When programming a device to do DMA, we need to be extra-careful to use machine addresses rather than physical addresses to program the device. Therefore we need to know the physical to machine mappings. For the moment we assume that dom0 starts with a 1:1 physical to machine mapping, in other words physical addresses correspond to machine addresses. However when mapping a foreign grant reference, obviously the 1:1 model doesn't work anymore. So at the very least we need to be able to track grant mappings. We need locking to protect accesses to the two trees. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Changes in v8: - move pfn_to_mfn and mfn_to_pfn to page.h as static inline functions; - no need to walk the tree if phys_to_mach.rb_node is NULL; - correctly handle multipage p2m entries; - substitute the spin_lock with a rwlock.
128 lines
3.0 KiB
C
128 lines
3.0 KiB
C
#ifndef _ASM_ARM_XEN_PAGE_H
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#define _ASM_ARM_XEN_PAGE_H
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <linux/pfn.h>
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#include <linux/types.h>
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#include <xen/xen.h>
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#include <xen/interface/grant_table.h>
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#define phys_to_machine_mapping_valid(pfn) (1)
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#define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT))
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#define pte_mfn pte_pfn
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#define mfn_pte pfn_pte
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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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#define INVALID_P2M_ENTRY (~0UL)
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unsigned long __pfn_to_mfn(unsigned long pfn);
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unsigned long __mfn_to_pfn(unsigned long mfn);
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extern struct rb_root phys_to_mach;
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static inline unsigned long pfn_to_mfn(unsigned long pfn)
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{
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unsigned long mfn;
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if (phys_to_mach.rb_node != NULL) {
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mfn = __pfn_to_mfn(pfn);
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if (mfn != INVALID_P2M_ENTRY)
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return mfn;
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}
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if (xen_initial_domain())
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return pfn;
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else
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return 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 (phys_to_mach.rb_node != NULL) {
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pfn = __mfn_to_pfn(mfn);
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if (pfn != INVALID_P2M_ENTRY)
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return pfn;
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}
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if (xen_initial_domain())
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return mfn;
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else
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return INVALID_P2M_ENTRY;
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}
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#define mfn_to_local_pfn(mfn) mfn_to_pfn(mfn)
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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(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(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
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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_pfn(v) (PFN_DOWN(__pa(v)))
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#define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v)))
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#define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT))
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static inline xmaddr_t arbitrary_virt_to_machine(void *vaddr)
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{
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/* TODO: assuming it is mapped in the kernel 1:1 */
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return virt_to_machine(vaddr);
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}
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/* TODO: this shouldn't be here but it is because the frontend drivers
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* are using it (its rolled in headers) even though we won't hit the code path.
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* So for right now just punt with this.
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*/
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static inline pte_t *lookup_address(unsigned long address, unsigned int *level)
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{
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BUG();
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return NULL;
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}
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static inline int m2p_add_override(unsigned long mfn, struct page *page,
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struct gnttab_map_grant_ref *kmap_op)
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{
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return 0;
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}
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static inline int m2p_remove_override(struct page *page, bool clear_pte)
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{
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return 0;
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}
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bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
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bool __set_phys_to_machine_multi(unsigned long pfn, unsigned long mfn,
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unsigned long nr_pages);
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static inline bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
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{
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return __set_phys_to_machine(pfn, mfn);
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}
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#define xen_remap(cookie, size) ioremap_cached((cookie), (size));
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#endif /* _ASM_ARM_XEN_PAGE_H */
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