The extraction of MMU related code is the basis of MPU support.
This commit starts this work by firstly splitting the page table
related code to mmu/pt.c, so that we will not end up with again
massive mm.c files.
Introduce a mmu specific directory and setup the Makefiles for it.
Move the page table related functions and macros from arch/arm/mm.c
to arch/arm/mmu/pt.c.
Take the opportunity to fix the in-code comment coding styles when
possible, and drop the unnecessary #include headers in the original
arch/arm/mm.c.
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
---
v8:
- Add Julien's Reviewed-by tag.
v7:
- Do not move pte_of_xenaddr() to mmu/pt.c.
- Do not expose global variable phys_offset.
v6:
- Rework the original patch "[v5,07/13] xen/arm: Extract MMU-specific
code", only split the page table related code out in this patch.
---
xen/arch/arm/Makefile | 1 +
xen/arch/arm/mm.c | 717 -------------------------------------
xen/arch/arm/mmu/Makefile | 1 +
xen/arch/arm/mmu/pt.c | 736 ++++++++++++++++++++++++++++++++++++++
4 files changed, 738 insertions(+), 717 deletions(-)
create mode 100644 xen/arch/arm/mmu/Makefile
create mode 100644 xen/arch/arm/mmu/pt.c
diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index 7bf07e9920..c45b08b31e 100644
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -1,5 +1,6 @@
obj-$(CONFIG_ARM_32) += arm32/
obj-$(CONFIG_ARM_64) += arm64/
+obj-$(CONFIG_MMU) += mmu/
obj-$(CONFIG_ACPI) += acpi/
obj-$(CONFIG_HAS_PCI) += pci/
ifneq ($(CONFIG_NO_PLAT),y)
diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index c34cc94c90..fd02493564 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -9,22 +9,14 @@
*/
#include <xen/domain_page.h>
-#include <xen/errno.h>
#include <xen/grant_table.h>
#include <xen/guest_access.h>
-#include <xen/init.h>
#include <xen/libfdt/libfdt.h>
#include <xen/mm.h>
-#include <xen/pfn.h>
-#include <xen/pmap.h>
-#include <xen/sched.h>
#include <xen/sizes.h>
-#include <xen/types.h>
-#include <xen/vmap.h>
#include <xsm/xsm.h>
-#include <asm/fixmap.h>
#include <asm/setup.h>
#include <public/memory.h>
@@ -35,19 +27,6 @@
#undef mfn_to_virt
#define mfn_to_virt(mfn) __mfn_to_virt(mfn_x(mfn))
-#ifdef NDEBUG
-static inline void
-__attribute__ ((__format__ (__printf__, 1, 2)))
-mm_printk(const char *fmt, ...) {}
-#else
-#define mm_printk(fmt, args...) \
- do \
- { \
- dprintk(XENLOG_ERR, fmt, ## args); \
- WARN(); \
- } while (0)
-#endif
-
/* Static start-of-day pagetables that we use before the allocators
* are up. These are used by all CPUs during bringup before switching
* to the CPUs own pagetables.
@@ -92,12 +71,10 @@ DEFINE_BOOT_PAGE_TABLES(boot_third, XEN_NR_ENTRIES(2));
*/
#ifdef CONFIG_ARM_64
-#define HYP_PT_ROOT_LEVEL 0
DEFINE_PAGE_TABLE(xen_pgtable);
static DEFINE_PAGE_TABLE(xen_first);
#define THIS_CPU_PGTABLE xen_pgtable
#else
-#define HYP_PT_ROOT_LEVEL 1
/* Per-CPU pagetable pages */
/* xen_pgtable == root of the trie (zeroeth level on 64-bit, first on 32-bit) */
DEFINE_PER_CPU(lpae_t *, xen_pgtable);
@@ -200,179 +177,6 @@ static void __init __maybe_unused build_assertions(void)
#undef CHECK_DIFFERENT_SLOT
}
-static lpae_t *xen_map_table(mfn_t mfn)
-{
- /*
- * During early boot, map_domain_page() may be unusable. Use the
- * PMAP to map temporarily a page-table.
- */
- if ( system_state == SYS_STATE_early_boot )
- return pmap_map(mfn);
-
- return map_domain_page(mfn);
-}
-
-static void xen_unmap_table(const lpae_t *table)
-{
- /*
- * During early boot, xen_map_table() will not use map_domain_page()
- * but the PMAP.
- */
- if ( system_state == SYS_STATE_early_boot )
- pmap_unmap(table);
- else
- unmap_domain_page(table);
-}
-
-void dump_pt_walk(paddr_t ttbr, paddr_t addr,
- unsigned int root_level,
- unsigned int nr_root_tables)
-{
- static const char *level_strs[4] = { "0TH", "1ST", "2ND", "3RD" };
- const mfn_t root_mfn = maddr_to_mfn(ttbr);
- DECLARE_OFFSETS(offsets, addr);
- lpae_t pte, *mapping;
- unsigned int level, root_table;
-
-#ifdef CONFIG_ARM_32
- BUG_ON(root_level < 1);
-#endif
- BUG_ON(root_level > 3);
-
- if ( nr_root_tables > 1 )
- {
- /*
- * Concatenated root-level tables. The table number will be
- * the offset at the previous level. It is not possible to
- * concatenate a level-0 root.
- */
- BUG_ON(root_level == 0);
- root_table = offsets[root_level - 1];
- printk("Using concatenated root table %u\n", root_table);
- if ( root_table >= nr_root_tables )
- {
- printk("Invalid root table offset\n");
- return;
- }
- }
- else
- root_table = 0;
-
- mapping = xen_map_table(mfn_add(root_mfn, root_table));
-
- for ( level = root_level; ; level++ )
- {
- if ( offsets[level] > XEN_PT_LPAE_ENTRIES )
- break;
-
- pte = mapping[offsets[level]];
-
- printk("%s[0x%03x] = 0x%"PRIx64"\n",
- level_strs[level], offsets[level], pte.bits);
-
- if ( level == 3 || !pte.walk.valid || !pte.walk.table )
- break;
-
- /* For next iteration */
- xen_unmap_table(mapping);
- mapping = xen_map_table(lpae_get_mfn(pte));
- }
-
- xen_unmap_table(mapping);
-}
-
-void dump_hyp_walk(vaddr_t addr)
-{
- uint64_t ttbr = READ_SYSREG64(TTBR0_EL2);
-
- printk("Walking Hypervisor VA 0x%"PRIvaddr" "
- "on CPU%d via TTBR 0x%016"PRIx64"\n",
- addr, smp_processor_id(), ttbr);
-
- dump_pt_walk(ttbr, addr, HYP_PT_ROOT_LEVEL, 1);
-}
-
-lpae_t mfn_to_xen_entry(mfn_t mfn, unsigned int attr)
-{
- lpae_t e = (lpae_t) {
- .pt = {
- .valid = 1, /* Mappings are present */
- .table = 0, /* Set to 1 for links and 4k maps */
- .ai = attr,
- .ns = 1, /* Hyp mode is in the non-secure world */
- .up = 1, /* See below */
- .ro = 0, /* Assume read-write */
- .af = 1, /* No need for access tracking */
- .ng = 1, /* Makes TLB flushes easier */
- .contig = 0, /* Assume non-contiguous */
- .xn = 1, /* No need to execute outside .text */
- .avail = 0, /* Reference count for domheap mapping */
- }};
- /*
- * For EL2 stage-1 page table, up (aka AP[1]) is RES1 as the translation
- * regime applies to only one exception level (see D4.4.4 and G4.6.1
- * in ARM DDI 0487B.a). If this changes, remember to update the
- * hard-coded values in head.S too.
- */
-
- switch ( attr )
- {
- case MT_NORMAL_NC:
- /*
- * ARM ARM: Overlaying the shareability attribute (DDI
- * 0406C.b B3-1376 to 1377)
- *
- * A memory region with a resultant memory type attribute of Normal,
- * and a resultant cacheability attribute of Inner Non-cacheable,
- * Outer Non-cacheable, must have a resultant shareability attribute
- * of Outer Shareable, otherwise shareability is UNPREDICTABLE.
- *
- * On ARMv8 sharability is ignored and explicitly treated as Outer
- * Shareable for Normal Inner Non_cacheable, Outer Non-cacheable.
- */
- e.pt.sh = LPAE_SH_OUTER;
- break;
- case MT_DEVICE_nGnRnE:
- case MT_DEVICE_nGnRE:
- /*
- * Shareability is ignored for non-Normal memory, Outer is as
- * good as anything.
- *
- * On ARMv8 sharability is ignored and explicitly treated as Outer
- * Shareable for any device memory type.
- */
- e.pt.sh = LPAE_SH_OUTER;
- break;
- default:
- e.pt.sh = LPAE_SH_INNER; /* Xen mappings are SMP coherent */
- break;
- }
-
- ASSERT(!(mfn_to_maddr(mfn) & ~PADDR_MASK));
-
- lpae_set_mfn(e, mfn);
-
- return e;
-}
-
-/* Map a 4k page in a fixmap entry */
-void set_fixmap(unsigned int map, mfn_t mfn, unsigned int flags)
-{
- int res;
-
- res = map_pages_to_xen(FIXMAP_ADDR(map), mfn, 1, flags);
- BUG_ON(res != 0);
-}
-
-/* Remove a mapping from a fixmap entry */
-void clear_fixmap(unsigned int map)
-{
- int res;
-
- res = destroy_xen_mappings(FIXMAP_ADDR(map), FIXMAP_ADDR(map) + PAGE_SIZE);
- BUG_ON(res != 0);
-}
-
void flush_page_to_ram(unsigned long mfn, bool sync_icache)
{
void *v = map_domain_page(_mfn(mfn));
@@ -733,527 +537,6 @@ void *__init arch_vmap_virt_end(void)
return (void *)(VMAP_VIRT_START + VMAP_VIRT_SIZE);
}
-/*
- * This function should only be used to remap device address ranges
- * TODO: add a check to verify this assumption
- */
-void *ioremap_attr(paddr_t start, size_t len, unsigned int attributes)
-{
- mfn_t mfn = _mfn(PFN_DOWN(start));
- unsigned int offs = start & (PAGE_SIZE - 1);
- unsigned int nr = PFN_UP(offs + len);
- void *ptr = __vmap(&mfn, nr, 1, 1, attributes, VMAP_DEFAULT);
-
- if ( ptr == NULL )
- return NULL;
-
- return ptr + offs;
-}
-
-void *ioremap(paddr_t pa, size_t len)
-{
- return ioremap_attr(pa, len, PAGE_HYPERVISOR_NOCACHE);
-}
-
-static int create_xen_table(lpae_t *entry)
-{
- mfn_t mfn;
- void *p;
- lpae_t pte;
-
- if ( system_state != SYS_STATE_early_boot )
- {
- struct page_info *pg = alloc_domheap_page(NULL, 0);
-
- if ( pg == NULL )
- return -ENOMEM;
-
- mfn = page_to_mfn(pg);
- }
- else
- mfn = alloc_boot_pages(1, 1);
-
- p = xen_map_table(mfn);
- clear_page(p);
- xen_unmap_table(p);
-
- pte = mfn_to_xen_entry(mfn, MT_NORMAL);
- pte.pt.table = 1;
- write_pte(entry, pte);
- /*
- * No ISB here. It is deferred to xen_pt_update() as the new table
- * will not be used for hardware translation table access as part of
- * the mapping update.
- */
-
- return 0;
-}
-
-#define XEN_TABLE_MAP_FAILED 0
-#define XEN_TABLE_SUPER_PAGE 1
-#define XEN_TABLE_NORMAL_PAGE 2
-
-/*
- * Take the currently mapped table, find the corresponding entry,
- * and map the next table, if available.
- *
- * The read_only parameters indicates whether intermediate tables should
- * be allocated when not present.
- *
- * Return values:
- * XEN_TABLE_MAP_FAILED: Either read_only was set and the entry
- * was empty, or allocating a new page failed.
- * XEN_TABLE_NORMAL_PAGE: next level mapped normally
- * XEN_TABLE_SUPER_PAGE: The next entry points to a superpage.
- */
-static int xen_pt_next_level(bool read_only, unsigned int level,
- lpae_t **table, unsigned int offset)
-{
- lpae_t *entry;
- int ret;
- mfn_t mfn;
-
- entry = *table + offset;
-
- if ( !lpae_is_valid(*entry) )
- {
- if ( read_only )
- return XEN_TABLE_MAP_FAILED;
-
- ret = create_xen_table(entry);
- if ( ret )
- return XEN_TABLE_MAP_FAILED;
- }
-
- /* The function xen_pt_next_level is never called at the 3rd level */
- if ( lpae_is_mapping(*entry, level) )
- return XEN_TABLE_SUPER_PAGE;
-
- mfn = lpae_get_mfn(*entry);
-
- xen_unmap_table(*table);
- *table = xen_map_table(mfn);
-
- return XEN_TABLE_NORMAL_PAGE;
-}
-
-/* Sanity check of the entry */
-static bool xen_pt_check_entry(lpae_t entry, mfn_t mfn, unsigned int level,
- unsigned int flags)
-{
- /* Sanity check when modifying an entry. */
- if ( (flags & _PAGE_PRESENT) && mfn_eq(mfn, INVALID_MFN) )
- {
- /* We don't allow modifying an invalid entry. */
- if ( !lpae_is_valid(entry) )
- {
- mm_printk("Modifying invalid entry is not allowed.\n");
- return false;
- }
-
- /* We don't allow modifying a table entry */
- if ( !lpae_is_mapping(entry, level) )
- {
- mm_printk("Modifying a table entry is not allowed.\n");
- return false;
- }
-
- /* We don't allow changing memory attributes. */
- if ( entry.pt.ai != PAGE_AI_MASK(flags) )
- {
- mm_printk("Modifying memory attributes is not allowed (0x%x -> 0x%x).\n",
- entry.pt.ai, PAGE_AI_MASK(flags));
- return false;
- }
-
- /* We don't allow modifying entry with contiguous bit set. */
- if ( entry.pt.contig )
- {
- mm_printk("Modifying entry with contiguous bit set is not allowed.\n");
- return false;
- }
- }
- /* Sanity check when inserting a mapping */
- else if ( flags & _PAGE_PRESENT )
- {
- /* We should be here with a valid MFN. */
- ASSERT(!mfn_eq(mfn, INVALID_MFN));
-
- /*
- * We don't allow replacing any valid entry.
- *
- * Note that the function xen_pt_update() relies on this
- * assumption and will skip the TLB flush. The function will need
- * to be updated if the check is relaxed.
- */
- if ( lpae_is_valid(entry) )
- {
- if ( lpae_is_mapping(entry, level) )
- mm_printk("Changing MFN for a valid entry is not allowed (%#"PRI_mfn" -> %#"PRI_mfn").\n",
- mfn_x(lpae_get_mfn(entry)), mfn_x(mfn));
- else
- mm_printk("Trying to replace a table with a mapping.\n");
- return false;
- }
- }
- /* Sanity check when removing a mapping. */
- else if ( (flags & (_PAGE_PRESENT|_PAGE_POPULATE)) == 0 )
- {
- /* We should be here with an invalid MFN. */
- ASSERT(mfn_eq(mfn, INVALID_MFN));
-
- /* We don't allow removing a table */
- if ( lpae_is_table(entry, level) )
- {
- mm_printk("Removing a table is not allowed.\n");
- return false;
- }
-
- /* We don't allow removing a mapping with contiguous bit set. */
- if ( entry.pt.contig )
- {
- mm_printk("Removing entry with contiguous bit set is not allowed.\n");
- return false;
- }
- }
- /* Sanity check when populating the page-table. No check so far. */
- else
- {
- ASSERT(flags & _PAGE_POPULATE);
- /* We should be here with an invalid MFN */
- ASSERT(mfn_eq(mfn, INVALID_MFN));
- }
-
- return true;
-}
-
-/* Update an entry at the level @target. */
-static int xen_pt_update_entry(mfn_t root, unsigned long virt,
- mfn_t mfn, unsigned int target,
- unsigned int flags)
-{
- int rc;
- unsigned int level;
- lpae_t *table;
- /*
- * The intermediate page tables are read-only when the MFN is not valid
- * and we are not populating page table.
- * This means we either modify permissions or remove an entry.
- */
- bool read_only = mfn_eq(mfn, INVALID_MFN) && !(flags & _PAGE_POPULATE);
- lpae_t pte, *entry;
-
- /* convenience aliases */
- DECLARE_OFFSETS(offsets, (paddr_t)virt);
-
- /* _PAGE_POPULATE and _PAGE_PRESENT should never be set together. */
- ASSERT((flags & (_PAGE_POPULATE|_PAGE_PRESENT)) != (_PAGE_POPULATE|_PAGE_PRESENT));
-
- table = xen_map_table(root);
- for ( level = HYP_PT_ROOT_LEVEL; level < target; level++ )
- {
- rc = xen_pt_next_level(read_only, level, &table, offsets[level]);
- if ( rc == XEN_TABLE_MAP_FAILED )
- {
- /*
- * We are here because xen_pt_next_level has failed to map
- * the intermediate page table (e.g the table does not exist
- * and the pt is read-only). It is a valid case when
- * removing a mapping as it may not exist in the page table.
- * In this case, just ignore it.
- */
- if ( flags & (_PAGE_PRESENT|_PAGE_POPULATE) )
- {
- mm_printk("%s: Unable to map level %u\n", __func__, level);
- rc = -ENOENT;
- goto out;
- }
- else
- {
- rc = 0;
- goto out;
- }
- }
- else if ( rc != XEN_TABLE_NORMAL_PAGE )
- break;
- }
-
- if ( level != target )
- {
- mm_printk("%s: Shattering superpage is not supported\n", __func__);
- rc = -EOPNOTSUPP;
- goto out;
- }
-
- entry = table + offsets[level];
-
- rc = -EINVAL;
- if ( !xen_pt_check_entry(*entry, mfn, level, flags) )
- goto out;
-
- /* If we are only populating page-table, then we are done. */
- rc = 0;
- if ( flags & _PAGE_POPULATE )
- goto out;
-
- /* We are removing the page */
- if ( !(flags & _PAGE_PRESENT) )
- memset(&pte, 0x00, sizeof(pte));
- else
- {
- /* We are inserting a mapping => Create new pte. */
- if ( !mfn_eq(mfn, INVALID_MFN) )
- {
- pte = mfn_to_xen_entry(mfn, PAGE_AI_MASK(flags));
-
- /*
- * First and second level pages set pte.pt.table = 0, but
- * third level entries set pte.pt.table = 1.
- */
- pte.pt.table = (level == 3);
- }
- else /* We are updating the permission => Copy the current pte. */
- pte = *entry;
-
- /* Set permission */
- pte.pt.ro = PAGE_RO_MASK(flags);
- pte.pt.xn = PAGE_XN_MASK(flags);
- /* Set contiguous bit */
- pte.pt.contig = !!(flags & _PAGE_CONTIG);
- }
-
- write_pte(entry, pte);
- /*
- * No ISB or TLB flush here. They are deferred to xen_pt_update()
- * as the entry will not be used as part of the mapping update.
- */
-
- rc = 0;
-
-out:
- xen_unmap_table(table);
-
- return rc;
-}
-
-/* Return the level where mapping should be done */
-static int xen_pt_mapping_level(unsigned long vfn, mfn_t mfn, unsigned long nr,
- unsigned int flags)
-{
- unsigned int level;
- unsigned long mask;
-
- /*
- * Don't take into account the MFN when removing mapping (i.e
- * MFN_INVALID) to calculate the correct target order.
- *
- * Per the Arm Arm, `vfn` and `mfn` must be both superpage aligned.
- * They are or-ed together and then checked against the size of
- * each level.
- *
- * `left` is not included and checked separately to allow
- * superpage mapping even if it is not properly aligned (the
- * user may have asked to map 2MB + 4k).
- */
- mask = !mfn_eq(mfn, INVALID_MFN) ? mfn_x(mfn) : 0;
- mask |= vfn;
-
- /*
- * Always use level 3 mapping unless the caller request block
- * mapping.
- */
- if ( likely(!(flags & _PAGE_BLOCK)) )
- level = 3;
- else if ( !(mask & (BIT(FIRST_ORDER, UL) - 1)) &&
- (nr >= BIT(FIRST_ORDER, UL)) )
- level = 1;
- else if ( !(mask & (BIT(SECOND_ORDER, UL) - 1)) &&
- (nr >= BIT(SECOND_ORDER, UL)) )
- level = 2;
- else
- level = 3;
-
- return level;
-}
-
-#define XEN_PT_4K_NR_CONTIG 16
-
-/*
- * Check whether the contiguous bit can be set. Return the number of
- * contiguous entry allowed. If not allowed, return 1.
- */
-static unsigned int xen_pt_check_contig(unsigned long vfn, mfn_t mfn,
- unsigned int level, unsigned long left,
- unsigned int flags)
-{
- unsigned long nr_contig;
-
- /*
- * Allow the contiguous bit to set when the caller requests block
- * mapping.
- */
- if ( !(flags & _PAGE_BLOCK) )
- return 1;
-
- /*
- * We don't allow to remove mapping with the contiguous bit set.
- * So shortcut the logic and directly return 1.
- */
- if ( mfn_eq(mfn, INVALID_MFN) )
- return 1;
-
- /*
- * The number of contiguous entries varies depending on the page
- * granularity used. The logic below assumes 4KB.
- */
- BUILD_BUG_ON(PAGE_SIZE != SZ_4K);
-
- /*
- * In order to enable the contiguous bit, we should have enough entries
- * to map left and both the virtual and physical address should be
- * aligned to the size of 16 translation tables entries.
- */
- nr_contig = BIT(XEN_PT_LEVEL_ORDER(level), UL) * XEN_PT_4K_NR_CONTIG;
-
- if ( (left < nr_contig) || ((mfn_x(mfn) | vfn) & (nr_contig - 1)) )
- return 1;
-
- return XEN_PT_4K_NR_CONTIG;
-}
-
-static DEFINE_SPINLOCK(xen_pt_lock);
-
-static int xen_pt_update(unsigned long virt,
- mfn_t mfn,
- /* const on purpose as it is used for TLB flush */
- const unsigned long nr_mfns,
- unsigned int flags)
-{
- int rc = 0;
- unsigned long vfn = virt >> PAGE_SHIFT;
- unsigned long left = nr_mfns;
-
- /*
- * For arm32, page-tables are different on each CPUs. Yet, they share
- * some common mappings. It is assumed that only common mappings
- * will be modified with this function.
- *
- * XXX: Add a check.
- */
- const mfn_t root = maddr_to_mfn(READ_SYSREG64(TTBR0_EL2));
-
- /*
- * The hardware was configured to forbid mapping both writeable and
- * executable.
- * When modifying/creating mapping (i.e _PAGE_PRESENT is set),
- * prevent any update if this happen.
- */
- if ( (flags & _PAGE_PRESENT) && !PAGE_RO_MASK(flags) &&
- !PAGE_XN_MASK(flags) )
- {
- mm_printk("Mappings should not be both Writeable and Executable.\n");
- return -EINVAL;
- }
-
- if ( flags & _PAGE_CONTIG )
- {
- mm_printk("_PAGE_CONTIG is an internal only flag.\n");
- return -EINVAL;
- }
-
- if ( !IS_ALIGNED(virt, PAGE_SIZE) )
- {
- mm_printk("The virtual address is not aligned to the page-size.\n");
- return -EINVAL;
- }
-
- spin_lock(&xen_pt_lock);
-
- while ( left )
- {
- unsigned int order, level, nr_contig, new_flags;
-
- level = xen_pt_mapping_level(vfn, mfn, left, flags);
- order = XEN_PT_LEVEL_ORDER(level);
-
- ASSERT(left >= BIT(order, UL));
-
- /*
- * Check if we can set the contiguous mapping and update the
- * flags accordingly.
- */
- nr_contig = xen_pt_check_contig(vfn, mfn, level, left, flags);
- new_flags = flags | ((nr_contig > 1) ? _PAGE_CONTIG : 0);
-
- for ( ; nr_contig > 0; nr_contig-- )
- {
- rc = xen_pt_update_entry(root, vfn << PAGE_SHIFT, mfn, level,
- new_flags);
- if ( rc )
- break;
-
- vfn += 1U << order;
- if ( !mfn_eq(mfn, INVALID_MFN) )
- mfn = mfn_add(mfn, 1U << order);
-
- left -= (1U << order);
- }
-
- if ( rc )
- break;
- }
-
- /*
- * The TLBs flush can be safely skipped when a mapping is inserted
- * as we don't allow mapping replacement (see xen_pt_check_entry()).
- * Although we still need an ISB to ensure any DSB in
- * write_pte() will complete because the mapping may be used soon
- * after.
- *
- * For all the other cases, the TLBs will be flushed unconditionally
- * even if the mapping has failed. This is because we may have
- * partially modified the PT. This will prevent any unexpected
- * behavior afterwards.
- */
- if ( !((flags & _PAGE_PRESENT) && !mfn_eq(mfn, INVALID_MFN)) )
- flush_xen_tlb_range_va(virt, PAGE_SIZE * nr_mfns);
- else
- isb();
-
- spin_unlock(&xen_pt_lock);
-
- return rc;
-}
-
-int map_pages_to_xen(unsigned long virt,
- mfn_t mfn,
- unsigned long nr_mfns,
- unsigned int flags)
-{
- return xen_pt_update(virt, mfn, nr_mfns, flags);
-}
-
-int __init populate_pt_range(unsigned long virt, unsigned long nr_mfns)
-{
- return xen_pt_update(virt, INVALID_MFN, nr_mfns, _PAGE_POPULATE);
-}
-
-int destroy_xen_mappings(unsigned long s, unsigned long e)
-{
- ASSERT(IS_ALIGNED(s, PAGE_SIZE));
- ASSERT(IS_ALIGNED(e, PAGE_SIZE));
- ASSERT(s <= e);
- return xen_pt_update(s, INVALID_MFN, (e - s) >> PAGE_SHIFT, 0);
-}
-
-int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int flags)
-{
- ASSERT(IS_ALIGNED(s, PAGE_SIZE));
- ASSERT(IS_ALIGNED(e, PAGE_SIZE));
- ASSERT(s <= e);
- return xen_pt_update(s, INVALID_MFN, (e - s) >> PAGE_SHIFT, flags);
-}
-
/* Release all __init and __initdata ranges to be reused */
void free_init_memory(void)
{
diff --git a/xen/arch/arm/mmu/Makefile b/xen/arch/arm/mmu/Makefile
new file mode 100644
index 0000000000..bdfc2e077d
--- /dev/null
+++ b/xen/arch/arm/mmu/Makefile
@@ -0,0 +1 @@
+obj-y += pt.o
diff --git a/xen/arch/arm/mmu/pt.c b/xen/arch/arm/mmu/pt.c
new file mode 100644
index 0000000000..e6fc5ed45a
--- /dev/null
+++ b/xen/arch/arm/mmu/pt.c
@@ -0,0 +1,736 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * xen/arch/arm/mmu/pt.c
+ *
+ * MMU system page table related functions.
+ */
+
+#include <xen/domain_page.h>
+#include <xen/init.h>
+#include <xen/pfn.h>
+#include <xen/sizes.h>
+#include <xen/vmap.h>
+
+#include <asm/fixmap.h>
+
+#ifdef NDEBUG
+static inline void
+__attribute__ ((__format__ (__printf__, 1, 2)))
+mm_printk(const char *fmt, ...) {}
+#else
+#define mm_printk(fmt, args...) \
+ do \
+ { \
+ dprintk(XENLOG_ERR, fmt, ## args); \
+ WARN(); \
+ } while (0)
+#endif
+
+#ifdef CONFIG_ARM_64
+#define HYP_PT_ROOT_LEVEL 0
+#else
+#define HYP_PT_ROOT_LEVEL 1
+#endif
+
+static lpae_t *xen_map_table(mfn_t mfn)
+{
+ /*
+ * During early boot, map_domain_page() may be unusable. Use the
+ * PMAP to map temporarily a page-table.
+ */
+ if ( system_state == SYS_STATE_early_boot )
+ return pmap_map(mfn);
+
+ return map_domain_page(mfn);
+}
+
+static void xen_unmap_table(const lpae_t *table)
+{
+ /*
+ * During early boot, xen_map_table() will not use map_domain_page()
+ * but the PMAP.
+ */
+ if ( system_state == SYS_STATE_early_boot )
+ pmap_unmap(table);
+ else
+ unmap_domain_page(table);
+}
+
+void dump_pt_walk(paddr_t ttbr, paddr_t addr,
+ unsigned int root_level,
+ unsigned int nr_root_tables)
+{
+ static const char *level_strs[4] = { "0TH", "1ST", "2ND", "3RD" };
+ const mfn_t root_mfn = maddr_to_mfn(ttbr);
+ DECLARE_OFFSETS(offsets, addr);
+ lpae_t pte, *mapping;
+ unsigned int level, root_table;
+
+#ifdef CONFIG_ARM_32
+ BUG_ON(root_level < 1);
+#endif
+ BUG_ON(root_level > 3);
+
+ if ( nr_root_tables > 1 )
+ {
+ /*
+ * Concatenated root-level tables. The table number will be
+ * the offset at the previous level. It is not possible to
+ * concatenate a level-0 root.
+ */
+ BUG_ON(root_level == 0);
+ root_table = offsets[root_level - 1];
+ printk("Using concatenated root table %u\n", root_table);
+ if ( root_table >= nr_root_tables )
+ {
+ printk("Invalid root table offset\n");
+ return;
+ }
+ }
+ else
+ root_table = 0;
+
+ mapping = xen_map_table(mfn_add(root_mfn, root_table));
+
+ for ( level = root_level; ; level++ )
+ {
+ if ( offsets[level] > XEN_PT_LPAE_ENTRIES )
+ break;
+
+ pte = mapping[offsets[level]];
+
+ printk("%s[0x%03x] = 0x%"PRIx64"\n",
+ level_strs[level], offsets[level], pte.bits);
+
+ if ( level == 3 || !pte.walk.valid || !pte.walk.table )
+ break;
+
+ /* For next iteration */
+ xen_unmap_table(mapping);
+ mapping = xen_map_table(lpae_get_mfn(pte));
+ }
+
+ xen_unmap_table(mapping);
+}
+
+void dump_hyp_walk(vaddr_t addr)
+{
+ uint64_t ttbr = READ_SYSREG64(TTBR0_EL2);
+
+ printk("Walking Hypervisor VA 0x%"PRIvaddr" "
+ "on CPU%d via TTBR 0x%016"PRIx64"\n",
+ addr, smp_processor_id(), ttbr);
+
+ dump_pt_walk(ttbr, addr, HYP_PT_ROOT_LEVEL, 1);
+}
+
+lpae_t mfn_to_xen_entry(mfn_t mfn, unsigned int attr)
+{
+ lpae_t e = (lpae_t) {
+ .pt = {
+ .valid = 1, /* Mappings are present */
+ .table = 0, /* Set to 1 for links and 4k maps */
+ .ai = attr,
+ .ns = 1, /* Hyp mode is in the non-secure world */
+ .up = 1, /* See below */
+ .ro = 0, /* Assume read-write */
+ .af = 1, /* No need for access tracking */
+ .ng = 1, /* Makes TLB flushes easier */
+ .contig = 0, /* Assume non-contiguous */
+ .xn = 1, /* No need to execute outside .text */
+ .avail = 0, /* Reference count for domheap mapping */
+ }};
+ /*
+ * For EL2 stage-1 page table, up (aka AP[1]) is RES1 as the translation
+ * regime applies to only one exception level (see D4.4.4 and G4.6.1
+ * in ARM DDI 0487B.a). If this changes, remember to update the
+ * hard-coded values in head.S too.
+ */
+
+ switch ( attr )
+ {
+ case MT_NORMAL_NC:
+ /*
+ * ARM ARM: Overlaying the shareability attribute (DDI
+ * 0406C.b B3-1376 to 1377)
+ *
+ * A memory region with a resultant memory type attribute of Normal,
+ * and a resultant cacheability attribute of Inner Non-cacheable,
+ * Outer Non-cacheable, must have a resultant shareability attribute
+ * of Outer Shareable, otherwise shareability is UNPREDICTABLE.
+ *
+ * On ARMv8 sharability is ignored and explicitly treated as Outer
+ * Shareable for Normal Inner Non_cacheable, Outer Non-cacheable.
+ */
+ e.pt.sh = LPAE_SH_OUTER;
+ break;
+ case MT_DEVICE_nGnRnE:
+ case MT_DEVICE_nGnRE:
+ /*
+ * Shareability is ignored for non-Normal memory, Outer is as
+ * good as anything.
+ *
+ * On ARMv8 sharability is ignored and explicitly treated as Outer
+ * Shareable for any device memory type.
+ */
+ e.pt.sh = LPAE_SH_OUTER;
+ break;
+ default:
+ e.pt.sh = LPAE_SH_INNER; /* Xen mappings are SMP coherent */
+ break;
+ }
+
+ ASSERT(!(mfn_to_maddr(mfn) & ~PADDR_MASK));
+
+ lpae_set_mfn(e, mfn);
+
+ return e;
+}
+
+/* Map a 4k page in a fixmap entry */
+void set_fixmap(unsigned int map, mfn_t mfn, unsigned int flags)
+{
+ int res;
+
+ res = map_pages_to_xen(FIXMAP_ADDR(map), mfn, 1, flags);
+ BUG_ON(res != 0);
+}
+
+/* Remove a mapping from a fixmap entry */
+void clear_fixmap(unsigned int map)
+{
+ int res;
+
+ res = destroy_xen_mappings(FIXMAP_ADDR(map), FIXMAP_ADDR(map) + PAGE_SIZE);
+ BUG_ON(res != 0);
+}
+
+/*
+ * This function should only be used to remap device address ranges
+ * TODO: add a check to verify this assumption
+ */
+void *ioremap_attr(paddr_t start, size_t len, unsigned int attributes)
+{
+ mfn_t mfn = _mfn(PFN_DOWN(start));
+ unsigned int offs = start & (PAGE_SIZE - 1);
+ unsigned int nr = PFN_UP(offs + len);
+ void *ptr = __vmap(&mfn, nr, 1, 1, attributes, VMAP_DEFAULT);
+
+ if ( ptr == NULL )
+ return NULL;
+
+ return ptr + offs;
+}
+
+void *ioremap(paddr_t pa, size_t len)
+{
+ return ioremap_attr(pa, len, PAGE_HYPERVISOR_NOCACHE);
+}
+
+static int create_xen_table(lpae_t *entry)
+{
+ mfn_t mfn;
+ void *p;
+ lpae_t pte;
+
+ if ( system_state != SYS_STATE_early_boot )
+ {
+ struct page_info *pg = alloc_domheap_page(NULL, 0);
+
+ if ( pg == NULL )
+ return -ENOMEM;
+
+ mfn = page_to_mfn(pg);
+ }
+ else
+ mfn = alloc_boot_pages(1, 1);
+
+ p = xen_map_table(mfn);
+ clear_page(p);
+ xen_unmap_table(p);
+
+ pte = mfn_to_xen_entry(mfn, MT_NORMAL);
+ pte.pt.table = 1;
+ write_pte(entry, pte);
+ /*
+ * No ISB here. It is deferred to xen_pt_update() as the new table
+ * will not be used for hardware translation table access as part of
+ * the mapping update.
+ */
+
+ return 0;
+}
+
+#define XEN_TABLE_MAP_FAILED 0
+#define XEN_TABLE_SUPER_PAGE 1
+#define XEN_TABLE_NORMAL_PAGE 2
+
+/*
+ * Take the currently mapped table, find the corresponding entry,
+ * and map the next table, if available.
+ *
+ * The read_only parameters indicates whether intermediate tables should
+ * be allocated when not present.
+ *
+ * Return values:
+ * XEN_TABLE_MAP_FAILED: Either read_only was set and the entry
+ * was empty, or allocating a new page failed.
+ * XEN_TABLE_NORMAL_PAGE: next level mapped normally
+ * XEN_TABLE_SUPER_PAGE: The next entry points to a superpage.
+ */
+static int xen_pt_next_level(bool read_only, unsigned int level,
+ lpae_t **table, unsigned int offset)
+{
+ lpae_t *entry;
+ int ret;
+ mfn_t mfn;
+
+ entry = *table + offset;
+
+ if ( !lpae_is_valid(*entry) )
+ {
+ if ( read_only )
+ return XEN_TABLE_MAP_FAILED;
+
+ ret = create_xen_table(entry);
+ if ( ret )
+ return XEN_TABLE_MAP_FAILED;
+ }
+
+ /* The function xen_pt_next_level is never called at the 3rd level */
+ if ( lpae_is_mapping(*entry, level) )
+ return XEN_TABLE_SUPER_PAGE;
+
+ mfn = lpae_get_mfn(*entry);
+
+ xen_unmap_table(*table);
+ *table = xen_map_table(mfn);
+
+ return XEN_TABLE_NORMAL_PAGE;
+}
+
+/* Sanity check of the entry */
+static bool xen_pt_check_entry(lpae_t entry, mfn_t mfn, unsigned int level,
+ unsigned int flags)
+{
+ /* Sanity check when modifying an entry. */
+ if ( (flags & _PAGE_PRESENT) && mfn_eq(mfn, INVALID_MFN) )
+ {
+ /* We don't allow modifying an invalid entry. */
+ if ( !lpae_is_valid(entry) )
+ {
+ mm_printk("Modifying invalid entry is not allowed.\n");
+ return false;
+ }
+
+ /* We don't allow modifying a table entry */
+ if ( !lpae_is_mapping(entry, level) )
+ {
+ mm_printk("Modifying a table entry is not allowed.\n");
+ return false;
+ }
+
+ /* We don't allow changing memory attributes. */
+ if ( entry.pt.ai != PAGE_AI_MASK(flags) )
+ {
+ mm_printk("Modifying memory attributes is not allowed (0x%x -> 0x%x).\n",
+ entry.pt.ai, PAGE_AI_MASK(flags));
+ return false;
+ }
+
+ /* We don't allow modifying entry with contiguous bit set. */
+ if ( entry.pt.contig )
+ {
+ mm_printk("Modifying entry with contiguous bit set is not allowed.\n");
+ return false;
+ }
+ }
+ /* Sanity check when inserting a mapping */
+ else if ( flags & _PAGE_PRESENT )
+ {
+ /* We should be here with a valid MFN. */
+ ASSERT(!mfn_eq(mfn, INVALID_MFN));
+
+ /*
+ * We don't allow replacing any valid entry.
+ *
+ * Note that the function xen_pt_update() relies on this
+ * assumption and will skip the TLB flush. The function will need
+ * to be updated if the check is relaxed.
+ */
+ if ( lpae_is_valid(entry) )
+ {
+ if ( lpae_is_mapping(entry, level) )
+ mm_printk("Changing MFN for a valid entry is not allowed (%#"PRI_mfn" -> %#"PRI_mfn").\n",
+ mfn_x(lpae_get_mfn(entry)), mfn_x(mfn));
+ else
+ mm_printk("Trying to replace a table with a mapping.\n");
+ return false;
+ }
+ }
+ /* Sanity check when removing a mapping. */
+ else if ( (flags & (_PAGE_PRESENT|_PAGE_POPULATE)) == 0 )
+ {
+ /* We should be here with an invalid MFN. */
+ ASSERT(mfn_eq(mfn, INVALID_MFN));
+
+ /* We don't allow removing a table */
+ if ( lpae_is_table(entry, level) )
+ {
+ mm_printk("Removing a table is not allowed.\n");
+ return false;
+ }
+
+ /* We don't allow removing a mapping with contiguous bit set. */
+ if ( entry.pt.contig )
+ {
+ mm_printk("Removing entry with contiguous bit set is not allowed.\n");
+ return false;
+ }
+ }
+ /* Sanity check when populating the page-table. No check so far. */
+ else
+ {
+ ASSERT(flags & _PAGE_POPULATE);
+ /* We should be here with an invalid MFN */
+ ASSERT(mfn_eq(mfn, INVALID_MFN));
+ }
+
+ return true;
+}
+
+/* Update an entry at the level @target. */
+static int xen_pt_update_entry(mfn_t root, unsigned long virt,
+ mfn_t mfn, unsigned int target,
+ unsigned int flags)
+{
+ int rc;
+ unsigned int level;
+ lpae_t *table;
+ /*
+ * The intermediate page tables are read-only when the MFN is not valid
+ * and we are not populating page table.
+ * This means we either modify permissions or remove an entry.
+ */
+ bool read_only = mfn_eq(mfn, INVALID_MFN) && !(flags & _PAGE_POPULATE);
+ lpae_t pte, *entry;
+
+ /* convenience aliases */
+ DECLARE_OFFSETS(offsets, (paddr_t)virt);
+
+ /* _PAGE_POPULATE and _PAGE_PRESENT should never be set together. */
+ ASSERT((flags & (_PAGE_POPULATE|_PAGE_PRESENT)) != (_PAGE_POPULATE|_PAGE_PRESENT));
+
+ table = xen_map_table(root);
+ for ( level = HYP_PT_ROOT_LEVEL; level < target; level++ )
+ {
+ rc = xen_pt_next_level(read_only, level, &table, offsets[level]);
+ if ( rc == XEN_TABLE_MAP_FAILED )
+ {
+ /*
+ * We are here because xen_pt_next_level has failed to map
+ * the intermediate page table (e.g the table does not exist
+ * and the pt is read-only). It is a valid case when
+ * removing a mapping as it may not exist in the page table.
+ * In this case, just ignore it.
+ */
+ if ( flags & (_PAGE_PRESENT|_PAGE_POPULATE) )
+ {
+ mm_printk("%s: Unable to map level %u\n", __func__, level);
+ rc = -ENOENT;
+ goto out;
+ }
+ else
+ {
+ rc = 0;
+ goto out;
+ }
+ }
+ else if ( rc != XEN_TABLE_NORMAL_PAGE )
+ break;
+ }
+
+ if ( level != target )
+ {
+ mm_printk("%s: Shattering superpage is not supported\n", __func__);
+ rc = -EOPNOTSUPP;
+ goto out;
+ }
+
+ entry = table + offsets[level];
+
+ rc = -EINVAL;
+ if ( !xen_pt_check_entry(*entry, mfn, level, flags) )
+ goto out;
+
+ /* If we are only populating page-table, then we are done. */
+ rc = 0;
+ if ( flags & _PAGE_POPULATE )
+ goto out;
+
+ /* We are removing the page */
+ if ( !(flags & _PAGE_PRESENT) )
+ memset(&pte, 0x00, sizeof(pte));
+ else
+ {
+ /* We are inserting a mapping => Create new pte. */
+ if ( !mfn_eq(mfn, INVALID_MFN) )
+ {
+ pte = mfn_to_xen_entry(mfn, PAGE_AI_MASK(flags));
+
+ /*
+ * First and second level pages set pte.pt.table = 0, but
+ * third level entries set pte.pt.table = 1.
+ */
+ pte.pt.table = (level == 3);
+ }
+ else /* We are updating the permission => Copy the current pte. */
+ pte = *entry;
+
+ /* Set permission */
+ pte.pt.ro = PAGE_RO_MASK(flags);
+ pte.pt.xn = PAGE_XN_MASK(flags);
+ /* Set contiguous bit */
+ pte.pt.contig = !!(flags & _PAGE_CONTIG);
+ }
+
+ write_pte(entry, pte);
+ /*
+ * No ISB or TLB flush here. They are deferred to xen_pt_update()
+ * as the entry will not be used as part of the mapping update.
+ */
+
+ rc = 0;
+
+out:
+ xen_unmap_table(table);
+
+ return rc;
+}
+
+/* Return the level where mapping should be done */
+static int xen_pt_mapping_level(unsigned long vfn, mfn_t mfn, unsigned long nr,
+ unsigned int flags)
+{
+ unsigned int level;
+ unsigned long mask;
+
+ /*
+ * Don't take into account the MFN when removing mapping (i.e
+ * MFN_INVALID) to calculate the correct target order.
+ *
+ * Per the Arm Arm, `vfn` and `mfn` must be both superpage aligned.
+ * They are or-ed together and then checked against the size of
+ * each level.
+ *
+ * `left` is not included and checked separately to allow
+ * superpage mapping even if it is not properly aligned (the
+ * user may have asked to map 2MB + 4k).
+ */
+ mask = !mfn_eq(mfn, INVALID_MFN) ? mfn_x(mfn) : 0;
+ mask |= vfn;
+
+ /*
+ * Always use level 3 mapping unless the caller request block
+ * mapping.
+ */
+ if ( likely(!(flags & _PAGE_BLOCK)) )
+ level = 3;
+ else if ( !(mask & (BIT(FIRST_ORDER, UL) - 1)) &&
+ (nr >= BIT(FIRST_ORDER, UL)) )
+ level = 1;
+ else if ( !(mask & (BIT(SECOND_ORDER, UL) - 1)) &&
+ (nr >= BIT(SECOND_ORDER, UL)) )
+ level = 2;
+ else
+ level = 3;
+
+ return level;
+}
+
+#define XEN_PT_4K_NR_CONTIG 16
+
+/*
+ * Check whether the contiguous bit can be set. Return the number of
+ * contiguous entry allowed. If not allowed, return 1.
+ */
+static unsigned int xen_pt_check_contig(unsigned long vfn, mfn_t mfn,
+ unsigned int level, unsigned long left,
+ unsigned int flags)
+{
+ unsigned long nr_contig;
+
+ /*
+ * Allow the contiguous bit to set when the caller requests block
+ * mapping.
+ */
+ if ( !(flags & _PAGE_BLOCK) )
+ return 1;
+
+ /*
+ * We don't allow to remove mapping with the contiguous bit set.
+ * So shortcut the logic and directly return 1.
+ */
+ if ( mfn_eq(mfn, INVALID_MFN) )
+ return 1;
+
+ /*
+ * The number of contiguous entries varies depending on the page
+ * granularity used. The logic below assumes 4KB.
+ */
+ BUILD_BUG_ON(PAGE_SIZE != SZ_4K);
+
+ /*
+ * In order to enable the contiguous bit, we should have enough entries
+ * to map left and both the virtual and physical address should be
+ * aligned to the size of 16 translation tables entries.
+ */
+ nr_contig = BIT(XEN_PT_LEVEL_ORDER(level), UL) * XEN_PT_4K_NR_CONTIG;
+
+ if ( (left < nr_contig) || ((mfn_x(mfn) | vfn) & (nr_contig - 1)) )
+ return 1;
+
+ return XEN_PT_4K_NR_CONTIG;
+}
+
+static DEFINE_SPINLOCK(xen_pt_lock);
+
+static int xen_pt_update(unsigned long virt,
+ mfn_t mfn,
+ /* const on purpose as it is used for TLB flush */
+ const unsigned long nr_mfns,
+ unsigned int flags)
+{
+ int rc = 0;
+ unsigned long vfn = virt >> PAGE_SHIFT;
+ unsigned long left = nr_mfns;
+
+ /*
+ * For arm32, page-tables are different on each CPUs. Yet, they share
+ * some common mappings. It is assumed that only common mappings
+ * will be modified with this function.
+ *
+ * XXX: Add a check.
+ */
+ const mfn_t root = maddr_to_mfn(READ_SYSREG64(TTBR0_EL2));
+
+ /*
+ * The hardware was configured to forbid mapping both writeable and
+ * executable.
+ * When modifying/creating mapping (i.e _PAGE_PRESENT is set),
+ * prevent any update if this happen.
+ */
+ if ( (flags & _PAGE_PRESENT) && !PAGE_RO_MASK(flags) &&
+ !PAGE_XN_MASK(flags) )
+ {
+ mm_printk("Mappings should not be both Writeable and Executable.\n");
+ return -EINVAL;
+ }
+
+ if ( flags & _PAGE_CONTIG )
+ {
+ mm_printk("_PAGE_CONTIG is an internal only flag.\n");
+ return -EINVAL;
+ }
+
+ if ( !IS_ALIGNED(virt, PAGE_SIZE) )
+ {
+ mm_printk("The virtual address is not aligned to the page-size.\n");
+ return -EINVAL;
+ }
+
+ spin_lock(&xen_pt_lock);
+
+ while ( left )
+ {
+ unsigned int order, level, nr_contig, new_flags;
+
+ level = xen_pt_mapping_level(vfn, mfn, left, flags);
+ order = XEN_PT_LEVEL_ORDER(level);
+
+ ASSERT(left >= BIT(order, UL));
+
+ /*
+ * Check if we can set the contiguous mapping and update the
+ * flags accordingly.
+ */
+ nr_contig = xen_pt_check_contig(vfn, mfn, level, left, flags);
+ new_flags = flags | ((nr_contig > 1) ? _PAGE_CONTIG : 0);
+
+ for ( ; nr_contig > 0; nr_contig-- )
+ {
+ rc = xen_pt_update_entry(root, vfn << PAGE_SHIFT, mfn, level,
+ new_flags);
+ if ( rc )
+ break;
+
+ vfn += 1U << order;
+ if ( !mfn_eq(mfn, INVALID_MFN) )
+ mfn = mfn_add(mfn, 1U << order);
+
+ left -= (1U << order);
+ }
+
+ if ( rc )
+ break;
+ }
+
+ /*
+ * The TLBs flush can be safely skipped when a mapping is inserted
+ * as we don't allow mapping replacement (see xen_pt_check_entry()).
+ * Although we still need an ISB to ensure any DSB in
+ * write_pte() will complete because the mapping may be used soon
+ * after.
+ *
+ * For all the other cases, the TLBs will be flushed unconditionally
+ * even if the mapping has failed. This is because we may have
+ * partially modified the PT. This will prevent any unexpected
+ * behavior afterwards.
+ */
+ if ( !((flags & _PAGE_PRESENT) && !mfn_eq(mfn, INVALID_MFN)) )
+ flush_xen_tlb_range_va(virt, PAGE_SIZE * nr_mfns);
+ else
+ isb();
+
+ spin_unlock(&xen_pt_lock);
+
+ return rc;
+}
+
+int map_pages_to_xen(unsigned long virt,
+ mfn_t mfn,
+ unsigned long nr_mfns,
+ unsigned int flags)
+{
+ return xen_pt_update(virt, mfn, nr_mfns, flags);
+}
+
+int __init populate_pt_range(unsigned long virt, unsigned long nr_mfns)
+{
+ return xen_pt_update(virt, INVALID_MFN, nr_mfns, _PAGE_POPULATE);
+}
+
+int destroy_xen_mappings(unsigned long s, unsigned long e)
+{
+ ASSERT(IS_ALIGNED(s, PAGE_SIZE));
+ ASSERT(IS_ALIGNED(e, PAGE_SIZE));
+ ASSERT(s <= e);
+ return xen_pt_update(s, INVALID_MFN, (e - s) >> PAGE_SHIFT, 0);
+}
+
+int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int flags)
+{
+ ASSERT(IS_ALIGNED(s, PAGE_SIZE));
+ ASSERT(IS_ALIGNED(e, PAGE_SIZE));
+ ASSERT(s <= e);
+ return xen_pt_update(s, INVALID_MFN, (e - s) >> PAGE_SHIFT, flags);
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
--
2.25.1© 2016 - 2024 Red Hat, Inc.