[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen staging] xen: arm: Move domain_page.c to MMU specific
commit 576459a06ad55fd1c4cea912fc0bc26b9f901f1e Author: Ayan Kumar Halder <ayan.kumar.halder@xxxxxxx> AuthorDate: Wed Aug 21 13:25:01 2024 +0100 Commit: Julien Grall <jgrall@xxxxxxxxxx> CommitDate: Thu Aug 22 11:06:33 2024 +0100 xen: arm: Move domain_page.c to MMU specific domain_page.c is moved to mmu/domain_page.c. The reason being this file implements MMU specific logic for mapping, unmapping, etc domain page. Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@xxxxxxx> Reviewed-by: Michal Orzel <michal.orzel@xxxxxxx> --- xen/arch/arm/Makefile | 1 - xen/arch/arm/domain_page.c | 194 ----------------------------------------- xen/arch/arm/mmu/Makefile | 1 + xen/arch/arm/mmu/domain_page.c | 194 +++++++++++++++++++++++++++++++++++++++++ 4 files changed, 195 insertions(+), 195 deletions(-) diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile index da9c979dc4..7792bff597 100644 --- a/xen/arch/arm/Makefile +++ b/xen/arch/arm/Makefile @@ -18,7 +18,6 @@ obj-$(CONFIG_IOREQ_SERVER) += dm.o obj-$(CONFIG_DOM0LESS_BOOT) += dom0less-build.init.o obj-y += domain.o obj-y += domain_build.init.o -obj-$(CONFIG_ARCH_MAP_DOMAIN_PAGE) += domain_page.o obj-y += domctl.o obj-$(CONFIG_EARLY_PRINTK) += early_printk.o obj-y += efi/ diff --git a/xen/arch/arm/domain_page.c b/xen/arch/arm/domain_page.c deleted file mode 100644 index 3a43601623..0000000000 --- a/xen/arch/arm/domain_page.c +++ /dev/null @@ -1,194 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -#include <xen/mm.h> -#include <xen/pmap.h> -#include <xen/vmap.h> - -/* Override macros from asm/page.h to make them work with mfn_t */ -#undef virt_to_mfn -#define virt_to_mfn(va) _mfn(__virt_to_mfn(va)) - -/* cpu0's domheap page tables */ -static DEFINE_PAGE_TABLES(cpu0_dommap, DOMHEAP_SECOND_PAGES); - -/* - * xen_dommap == pages used by map_domain_page, these pages contain - * the second level pagetables which map the domheap region - * starting at DOMHEAP_VIRT_START in 2MB chunks. - */ -static DEFINE_PER_CPU(lpae_t *, xen_dommap); - -/* - * Prepare the area that will be used to map domheap pages. They are - * mapped in 2MB chunks, so we need to allocate the page-tables up to - * the 2nd level. - * - * The caller should make sure the root page-table for @cpu has been - * allocated. - */ -bool init_domheap_mappings(unsigned int cpu) -{ - unsigned int order = get_order_from_pages(DOMHEAP_SECOND_PAGES); - lpae_t *root = per_cpu(xen_pgtable, cpu); - unsigned int i, first_idx; - lpae_t *domheap; - mfn_t mfn; - - ASSERT(root); - ASSERT(!per_cpu(xen_dommap, cpu)); - - /* - * The domheap for cpu0 is initialized before the heap is initialized. - * So we need to use pre-allocated pages. - */ - if ( !cpu ) - domheap = cpu0_dommap; - else - domheap = alloc_xenheap_pages(order, 0); - - if ( !domheap ) - return false; - - /* Ensure the domheap has no stray mappings */ - memset(domheap, 0, DOMHEAP_SECOND_PAGES * PAGE_SIZE); - - /* - * Update the first level mapping to reference the local CPUs - * domheap mapping pages. - */ - mfn = virt_to_mfn(domheap); - first_idx = first_table_offset(DOMHEAP_VIRT_START); - for ( i = 0; i < DOMHEAP_SECOND_PAGES; i++ ) - { - lpae_t pte = mfn_to_xen_entry(mfn_add(mfn, i), MT_NORMAL); - pte.pt.table = 1; - write_pte(&root[first_idx + i], pte); - } - - per_cpu(xen_dommap, cpu) = domheap; - - return true; -} - -void *map_domain_page_global(mfn_t mfn) -{ - return vmap(&mfn, 1); -} - -void unmap_domain_page_global(const void *ptr) -{ - vunmap(ptr); -} - -/* Map a page of domheap memory */ -void *map_domain_page(mfn_t mfn) -{ - unsigned long flags; - lpae_t *map = this_cpu(xen_dommap); - unsigned long slot_mfn = mfn_x(mfn) & ~XEN_PT_LPAE_ENTRY_MASK; - vaddr_t va; - lpae_t pte; - int i, slot; - - local_irq_save(flags); - - /* The map is laid out as an open-addressed hash table where each - * entry is a 2MB superpage pte. We use the available bits of each - * PTE as a reference count; when the refcount is zero the slot can - * be reused. */ - for ( slot = (slot_mfn >> XEN_PT_LPAE_SHIFT) % DOMHEAP_ENTRIES, i = 0; - i < DOMHEAP_ENTRIES; - slot = (slot + 1) % DOMHEAP_ENTRIES, i++ ) - { - if ( map[slot].pt.avail < 0xf && - map[slot].pt.base == slot_mfn && - map[slot].pt.valid ) - { - /* This slot already points to the right place; reuse it */ - map[slot].pt.avail++; - break; - } - else if ( map[slot].pt.avail == 0 ) - { - /* Commandeer this 2MB slot */ - pte = mfn_to_xen_entry(_mfn(slot_mfn), MT_NORMAL); - pte.pt.avail = 1; - write_pte(map + slot, pte); - break; - } - - } - /* If the map fills up, the callers have misbehaved. */ - BUG_ON(i == DOMHEAP_ENTRIES); - -#ifndef NDEBUG - /* Searching the hash could get slow if the map starts filling up. - * Cross that bridge when we come to it */ - { - static int max_tries = 32; - if ( i >= max_tries ) - { - dprintk(XENLOG_WARNING, "Domheap map is filling: %i tries\n", i); - max_tries *= 2; - } - } -#endif - - local_irq_restore(flags); - - va = (DOMHEAP_VIRT_START - + (slot << SECOND_SHIFT) - + ((mfn_x(mfn) & XEN_PT_LPAE_ENTRY_MASK) << THIRD_SHIFT)); - - /* - * We may not have flushed this specific subpage at map time, - * since we only flush the 4k page not the superpage - */ - flush_xen_tlb_range_va_local(va, PAGE_SIZE); - - return (void *)va; -} - -/* Release a mapping taken with map_domain_page() */ -void unmap_domain_page(const void *ptr) -{ - unsigned long flags; - lpae_t *map = this_cpu(xen_dommap); - int slot = ((unsigned long)ptr - DOMHEAP_VIRT_START) >> SECOND_SHIFT; - - if ( !ptr ) - return; - - local_irq_save(flags); - - ASSERT(slot >= 0 && slot < DOMHEAP_ENTRIES); - ASSERT(map[slot].pt.avail != 0); - - map[slot].pt.avail--; - - local_irq_restore(flags); -} - -mfn_t domain_page_map_to_mfn(const void *ptr) -{ - unsigned long va = (unsigned long)ptr; - lpae_t *map = this_cpu(xen_dommap); - int slot = (va - DOMHEAP_VIRT_START) >> SECOND_SHIFT; - unsigned long offset = (va>>THIRD_SHIFT) & XEN_PT_LPAE_ENTRY_MASK; - - if ( (va >= VMAP_VIRT_START) && ((va - VMAP_VIRT_START) < VMAP_VIRT_SIZE) ) - return virt_to_mfn(va); - - ASSERT(slot >= 0 && slot < DOMHEAP_ENTRIES); - ASSERT(map[slot].pt.avail != 0); - - return mfn_add(lpae_get_mfn(map[slot]), offset); -} - -/* - * Local variables: - * mode: C - * c-file-style: "BSD" - * c-basic-offset: 4 - * indent-tabs-mode: nil - * End: - */ diff --git a/xen/arch/arm/mmu/Makefile b/xen/arch/arm/mmu/Makefile index 67475fcd80..2cb44b857d 100644 --- a/xen/arch/arm/mmu/Makefile +++ b/xen/arch/arm/mmu/Makefile @@ -2,3 +2,4 @@ obj-y += p2m.o obj-y += pt.o obj-y += setup.o obj-y += smpboot.o +obj-$(CONFIG_ARCH_MAP_DOMAIN_PAGE) += domain_page.o diff --git a/xen/arch/arm/mmu/domain_page.c b/xen/arch/arm/mmu/domain_page.c new file mode 100644 index 0000000000..3a43601623 --- /dev/null +++ b/xen/arch/arm/mmu/domain_page.c @@ -0,0 +1,194 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#include <xen/mm.h> +#include <xen/pmap.h> +#include <xen/vmap.h> + +/* Override macros from asm/page.h to make them work with mfn_t */ +#undef virt_to_mfn +#define virt_to_mfn(va) _mfn(__virt_to_mfn(va)) + +/* cpu0's domheap page tables */ +static DEFINE_PAGE_TABLES(cpu0_dommap, DOMHEAP_SECOND_PAGES); + +/* + * xen_dommap == pages used by map_domain_page, these pages contain + * the second level pagetables which map the domheap region + * starting at DOMHEAP_VIRT_START in 2MB chunks. + */ +static DEFINE_PER_CPU(lpae_t *, xen_dommap); + +/* + * Prepare the area that will be used to map domheap pages. They are + * mapped in 2MB chunks, so we need to allocate the page-tables up to + * the 2nd level. + * + * The caller should make sure the root page-table for @cpu has been + * allocated. + */ +bool init_domheap_mappings(unsigned int cpu) +{ + unsigned int order = get_order_from_pages(DOMHEAP_SECOND_PAGES); + lpae_t *root = per_cpu(xen_pgtable, cpu); + unsigned int i, first_idx; + lpae_t *domheap; + mfn_t mfn; + + ASSERT(root); + ASSERT(!per_cpu(xen_dommap, cpu)); + + /* + * The domheap for cpu0 is initialized before the heap is initialized. + * So we need to use pre-allocated pages. + */ + if ( !cpu ) + domheap = cpu0_dommap; + else + domheap = alloc_xenheap_pages(order, 0); + + if ( !domheap ) + return false; + + /* Ensure the domheap has no stray mappings */ + memset(domheap, 0, DOMHEAP_SECOND_PAGES * PAGE_SIZE); + + /* + * Update the first level mapping to reference the local CPUs + * domheap mapping pages. + */ + mfn = virt_to_mfn(domheap); + first_idx = first_table_offset(DOMHEAP_VIRT_START); + for ( i = 0; i < DOMHEAP_SECOND_PAGES; i++ ) + { + lpae_t pte = mfn_to_xen_entry(mfn_add(mfn, i), MT_NORMAL); + pte.pt.table = 1; + write_pte(&root[first_idx + i], pte); + } + + per_cpu(xen_dommap, cpu) = domheap; + + return true; +} + +void *map_domain_page_global(mfn_t mfn) +{ + return vmap(&mfn, 1); +} + +void unmap_domain_page_global(const void *ptr) +{ + vunmap(ptr); +} + +/* Map a page of domheap memory */ +void *map_domain_page(mfn_t mfn) +{ + unsigned long flags; + lpae_t *map = this_cpu(xen_dommap); + unsigned long slot_mfn = mfn_x(mfn) & ~XEN_PT_LPAE_ENTRY_MASK; + vaddr_t va; + lpae_t pte; + int i, slot; + + local_irq_save(flags); + + /* The map is laid out as an open-addressed hash table where each + * entry is a 2MB superpage pte. We use the available bits of each + * PTE as a reference count; when the refcount is zero the slot can + * be reused. */ + for ( slot = (slot_mfn >> XEN_PT_LPAE_SHIFT) % DOMHEAP_ENTRIES, i = 0; + i < DOMHEAP_ENTRIES; + slot = (slot + 1) % DOMHEAP_ENTRIES, i++ ) + { + if ( map[slot].pt.avail < 0xf && + map[slot].pt.base == slot_mfn && + map[slot].pt.valid ) + { + /* This slot already points to the right place; reuse it */ + map[slot].pt.avail++; + break; + } + else if ( map[slot].pt.avail == 0 ) + { + /* Commandeer this 2MB slot */ + pte = mfn_to_xen_entry(_mfn(slot_mfn), MT_NORMAL); + pte.pt.avail = 1; + write_pte(map + slot, pte); + break; + } + + } + /* If the map fills up, the callers have misbehaved. */ + BUG_ON(i == DOMHEAP_ENTRIES); + +#ifndef NDEBUG + /* Searching the hash could get slow if the map starts filling up. + * Cross that bridge when we come to it */ + { + static int max_tries = 32; + if ( i >= max_tries ) + { + dprintk(XENLOG_WARNING, "Domheap map is filling: %i tries\n", i); + max_tries *= 2; + } + } +#endif + + local_irq_restore(flags); + + va = (DOMHEAP_VIRT_START + + (slot << SECOND_SHIFT) + + ((mfn_x(mfn) & XEN_PT_LPAE_ENTRY_MASK) << THIRD_SHIFT)); + + /* + * We may not have flushed this specific subpage at map time, + * since we only flush the 4k page not the superpage + */ + flush_xen_tlb_range_va_local(va, PAGE_SIZE); + + return (void *)va; +} + +/* Release a mapping taken with map_domain_page() */ +void unmap_domain_page(const void *ptr) +{ + unsigned long flags; + lpae_t *map = this_cpu(xen_dommap); + int slot = ((unsigned long)ptr - DOMHEAP_VIRT_START) >> SECOND_SHIFT; + + if ( !ptr ) + return; + + local_irq_save(flags); + + ASSERT(slot >= 0 && slot < DOMHEAP_ENTRIES); + ASSERT(map[slot].pt.avail != 0); + + map[slot].pt.avail--; + + local_irq_restore(flags); +} + +mfn_t domain_page_map_to_mfn(const void *ptr) +{ + unsigned long va = (unsigned long)ptr; + lpae_t *map = this_cpu(xen_dommap); + int slot = (va - DOMHEAP_VIRT_START) >> SECOND_SHIFT; + unsigned long offset = (va>>THIRD_SHIFT) & XEN_PT_LPAE_ENTRY_MASK; + + if ( (va >= VMAP_VIRT_START) && ((va - VMAP_VIRT_START) < VMAP_VIRT_SIZE) ) + return virt_to_mfn(va); + + ASSERT(slot >= 0 && slot < DOMHEAP_ENTRIES); + ASSERT(map[slot].pt.avail != 0); + + return mfn_add(lpae_get_mfn(map[slot]), offset); +} + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * indent-tabs-mode: nil + * End: + */ -- generated by git-patchbot for /home/xen/git/xen.git#staging
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