1 files changed, 357 insertions, 0 deletions
diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
new file mode 100644
index 000000000..fa9ec2078
--- /dev/null
+++ b/arch/x86/include/asm/xen/page.h
@@ -0,0 +1,357 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_XEN_PAGE_H
+#define _ASM_X86_XEN_PAGE_H
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/pfn.h>
+#include <linux/mm.h>
+#include <linux/device.h>
+
+#include <asm/extable.h>
+#include <asm/page.h>
+
+#include <xen/interface/xen.h>
+#include <xen/interface/grant_table.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;
+
+#ifdef CONFIG_X86_64
+#define XEN_PHYSICAL_MASK	__sme_clr((1UL << 52) - 1)
+#else
+#define XEN_PHYSICAL_MASK	__PHYSICAL_MASK
+#endif
+
+#define XEN_PTE_MFN_MASK	((pteval_t)(((signed long)PAGE_MASK) & \
+					    XEN_PHYSICAL_MASK))
+
+#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<<(BITS_PER_LONG-1))
+#define IDENTITY_FRAME_BIT	(1UL<<(BITS_PER_LONG-2))
+#define FOREIGN_FRAME(m)	((m) | FOREIGN_FRAME_BIT)
+#define IDENTITY_FRAME(m)	((m) | IDENTITY_FRAME_BIT)
+
+#define P2M_PER_PAGE		(PAGE_SIZE / sizeof(unsigned long))
+
+extern unsigned long *machine_to_phys_mapping;
+extern unsigned long  machine_to_phys_nr;
+extern unsigned long *xen_p2m_addr;
+extern unsigned long  xen_p2m_size;
+extern unsigned long  xen_max_p2m_pfn;
+
+extern int xen_alloc_p2m_entry(unsigned long pfn);
+
+extern unsigned long get_phys_to_machine(unsigned long pfn);
+extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
+extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
+extern unsigned long __init set_phys_range_identity(unsigned long pfn_s,
+						    unsigned long pfn_e);
+
+#ifdef CONFIG_XEN_PV
+extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
+				   struct gnttab_map_grant_ref *kmap_ops,
+				   struct page **pages, unsigned int count);
+extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
+				     struct gnttab_unmap_grant_ref *kunmap_ops,
+				     struct page **pages, unsigned int count);
+#else
+static inline int
+set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
+			struct gnttab_map_grant_ref *kmap_ops,
+			struct page **pages, unsigned int count)
+{
+	return 0;
+}
+
+static inline int
+clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
+			  struct gnttab_unmap_grant_ref *kunmap_ops,
+			  struct page **pages, unsigned int count)
+{
+	return 0;
+}
+#endif
+
+/*
+ * Helper functions to write or read unsigned long values to/from
+ * memory, when the access may fault.
+ */
+static inline int xen_safe_write_ulong(unsigned long *addr, unsigned long val)
+{
+	int ret = 0;
+
+	asm volatile("1: mov %[val], %[ptr]\n"
+		     "2:\n"
+		     _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %[ret])
+		     : [ret] "+r" (ret), [ptr] "=m" (*addr)
+		     : [val] "r" (val));
+
+	return ret;
+}
+
+static inline int xen_safe_read_ulong(const unsigned long *addr,
+				      unsigned long *val)
+{
+	unsigned long rval = ~0ul;
+	int ret = 0;
+
+	asm volatile("1: mov %[ptr], %[rval]\n"
+		     "2:\n"
+		     _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %[ret])
+		     : [ret] "+r" (ret), [rval] "+r" (rval)
+		     : [ptr] "m" (*addr));
+	*val = rval;
+
+	return ret;
+}
+
+#ifdef CONFIG_XEN_PV
+/*
+ * When to use pfn_to_mfn(), __pfn_to_mfn() or get_phys_to_machine():
+ * - pfn_to_mfn() returns either INVALID_P2M_ENTRY or the mfn. No indicator
+ *   bits (identity or foreign) are set.
+ * - __pfn_to_mfn() returns the found entry of the p2m table. A possibly set
+ *   identity or foreign indicator will be still set. __pfn_to_mfn() is
+ *   encapsulating get_phys_to_machine() which is called in special cases only.
+ * - get_phys_to_machine() is to be called by __pfn_to_mfn() only in special
+ *   cases needing an extended handling.
+ */
+static inline unsigned long __pfn_to_mfn(unsigned long pfn)
+{
+	unsigned long mfn;
+
+	if (pfn < xen_p2m_size)
+		mfn = xen_p2m_addr[pfn];
+	else if (unlikely(pfn < xen_max_p2m_pfn))
+		return get_phys_to_machine(pfn);
+	else
+		return IDENTITY_FRAME(pfn);
+
+	if (unlikely(mfn == INVALID_P2M_ENTRY))
+		return get_phys_to_machine(pfn);
+
+	return mfn;
+}
+#else
+static inline unsigned long __pfn_to_mfn(unsigned long pfn)
+{
+	return pfn;
+}
+#endif
+
+static inline unsigned long pfn_to_mfn(unsigned long pfn)
+{
+	unsigned long mfn;
+
+	/*
+	 * Some x86 code are still using pfn_to_mfn instead of
+	 * pfn_to_mfn. This will have to be removed when we figured
+	 * out which call.
+	 */
+	if (xen_feature(XENFEAT_auto_translated_physmap))
+		return pfn;
+
+	mfn = __pfn_to_mfn(pfn);
+
+	if (mfn != INVALID_P2M_ENTRY)
+		mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);
+
+	return mfn;
+}
+
+static inline int phys_to_machine_mapping_valid(unsigned long pfn)
+{
+	if (xen_feature(XENFEAT_auto_translated_physmap))
+		return 1;
+
+	return __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY;
+}
+
+static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn)
+{
+	unsigned long pfn;
+	int ret;
+
+	if (unlikely(mfn >= machine_to_phys_nr))
+		return ~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!
+	 */
+	ret = xen_safe_read_ulong(&machine_to_phys_mapping[mfn], &pfn);
+	if (ret < 0)
+		return ~0;
+
+	return pfn;
+}
+
+static inline unsigned long mfn_to_pfn(unsigned long mfn)
+{
+	unsigned long pfn;
+
+	/*
+	 * Some x86 code are still using mfn_to_pfn instead of
+	 * gfn_to_pfn. This will have to be removed when we figure
+	 * out which call.
+	 */
+	if (xen_feature(XENFEAT_auto_translated_physmap))
+		return mfn;
+
+	pfn = mfn_to_pfn_no_overrides(mfn);
+	if (__pfn_to_mfn(pfn) != mfn)
+		pfn = ~0;
+
+	/*
+	 * pfn is ~0 if there are no entries in the m2p for mfn or the
+	 * entry doesn't map back to the mfn.
+	 */
+	if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn))
+		pfn = mfn;
+
+	return pfn;
+}
+
+static inline xmaddr_t phys_to_machine(xpaddr_t phys)
+{
+	unsigned offset = phys.paddr & ~PAGE_MASK;
+	return XMADDR(PFN_PHYS(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(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
+}
+
+/* Pseudo-physical <-> Guest conversion */
+static inline unsigned long pfn_to_gfn(unsigned long pfn)
+{
+	if (xen_feature(XENFEAT_auto_translated_physmap))
+		return pfn;
+	else
+		return pfn_to_mfn(pfn);
+}
+
+static inline unsigned long gfn_to_pfn(unsigned long gfn)
+{
+	if (xen_feature(XENFEAT_auto_translated_physmap))
+		return gfn;
+	else
+		return mfn_to_pfn(gfn);
+}
+
+/* Pseudo-physical <-> Bus conversion */
+#define pfn_to_bfn(pfn)		pfn_to_gfn(pfn)
+#define bfn_to_pfn(bfn)		gfn_to_pfn(bfn)
+
+/*
+ * 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 bfn_to_local_pfn(unsigned long mfn)
+{
+	unsigned long pfn;
+
+	if (xen_feature(XENFEAT_auto_translated_physmap))
+		return mfn;
+
+	pfn = mfn_to_pfn(mfn);
+	if (__pfn_to_mfn(pfn) != mfn)
+		return -1; /* force !pfn_valid() */
+	return pfn;
+}
+
+/* VIRT <-> MACHINE conversion */
+#define virt_to_machine(v)	(phys_to_machine(XPADDR(__pa(v))))
+#define virt_to_pfn(v)          (PFN_DOWN(__pa(v)))
+#define virt_to_mfn(v)		(pfn_to_mfn(virt_to_pfn(v)))
+#define mfn_to_virt(m)		(__va(mfn_to_pfn(m) << PAGE_SHIFT))
+
+/* VIRT <-> GUEST conversion */
+#define virt_to_gfn(v)		(pfn_to_gfn(virt_to_pfn(v)))
+#define gfn_to_virt(g)		(__va(gfn_to_pfn(g) << PAGE_SHIFT))
+
+static inline unsigned long pte_mfn(pte_t pte)
+{
+	return (pte.pte & XEN_PTE_MFN_MASK) >> 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) |
+			massage_pgprot(pgprot);
+
+	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 };
+}
+
+#define pmd_val_ma(v) ((v).pmd)
+#ifdef __PAGETABLE_PUD_FOLDED
+#define pud_val_ma(v) ((v).p4d.pgd.pgd)
+#else
+#define pud_val_ma(v) ((v).pud)
+#endif
+#define __pmd_ma(x)	((pmd_t) { (x) } )
+
+#ifdef __PAGETABLE_P4D_FOLDED
+#define p4d_val_ma(x)	((x).pgd.pgd)
+#else
+#define p4d_val_ma(x)	((x).p4d)
+#endif
+
+xmaddr_t arbitrary_virt_to_machine(void *address);
+unsigned long arbitrary_virt_to_mfn(void *vaddr);
+void make_lowmem_page_readonly(void *vaddr);
+void make_lowmem_page_readwrite(void *vaddr);
+
+static inline bool xen_arch_need_swiotlb(struct device *dev,
+					 phys_addr_t phys,
+					 dma_addr_t dev_addr)
+{
+	return false;
+}
+
+#endif /* _ASM_X86_XEN_PAGE_H */