[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen master] xen/arm: mm: Move domain_{,un}map_* helpers in a separate file
commit 68b01ef0b3c182d207bff01dd3e20d287668c855 Author: Julien Grall <jgrall@xxxxxxxxxx> AuthorDate: Fri Jul 29 22:59:01 2022 +0100 Commit: Julien Grall <julien@xxxxxxx> CommitDate: Fri Jul 29 23:03:22 2022 +0100 xen/arm: mm: Move domain_{,un}map_* helpers in a separate file The file xen/arch/mm.c has been growing quite a lot. It now contains various independent part of the MM subsytem. One of them is the helpers to map/unmap a page which is only used by arm32 and protected by CONFIG_ARCH_MAP_DOMAIN_PAGE. Move them in a new file xen/arch/arm/domain_page.c. Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx> Reviewed-by: Bertrand Marquis <bertrand.marquis@xxxxxxx> --- xen/arch/arm/Makefile | 1 + xen/arch/arm/domain_page.c | 193 +++++++++++++++++++++++++++++++++++ xen/arch/arm/include/asm/arm32/mm.h | 6 ++ xen/arch/arm/include/asm/lpae.h | 17 ++++ xen/arch/arm/mm.c | 198 +----------------------------------- 5 files changed, 219 insertions(+), 196 deletions(-) diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile index bb7a6151c1..4d076b278b 100644 --- a/xen/arch/arm/Makefile +++ b/xen/arch/arm/Makefile @@ -17,6 +17,7 @@ obj-y += device.o obj-$(CONFIG_IOREQ_SERVER) += dm.o obj-y += domain.o obj-y += domain_build.init.o +obj-$(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 new file mode 100644 index 0000000000..71182575f9 --- /dev/null +++ b/xen/arch/arm/domain_page.c @@ -0,0 +1,193 @@ +#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 *va) +{ + vunmap(va); +} + +/* 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 *va) +{ + unsigned long flags; + lpae_t *map = this_cpu(xen_dommap); + int slot = ((unsigned long) va - DOMHEAP_VIRT_START) >> SECOND_SHIFT; + + if ( !va ) + 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/include/asm/arm32/mm.h b/xen/arch/arm/include/asm/arm32/mm.h index 575373aeb9..8bfc906e71 100644 --- a/xen/arch/arm/include/asm/arm32/mm.h +++ b/xen/arch/arm/include/asm/arm32/mm.h @@ -1,6 +1,12 @@ #ifndef __ARM_ARM32_MM_H__ #define __ARM_ARM32_MM_H__ +#include <xen/percpu.h> + +#include <asm/lpae.h> + +DECLARE_PER_CPU(lpae_t *, xen_pgtable); + /* * Only a limited amount of RAM, called xenheap, is always mapped on ARM32. * For convenience always return false. diff --git a/xen/arch/arm/include/asm/lpae.h b/xen/arch/arm/include/asm/lpae.h index fc19cbd847..3fdd5d0de2 100644 --- a/xen/arch/arm/include/asm/lpae.h +++ b/xen/arch/arm/include/asm/lpae.h @@ -261,6 +261,23 @@ lpae_t mfn_to_xen_entry(mfn_t mfn, unsigned int attr); #define third_table_offset(va) TABLE_OFFSET(third_linear_offset(va)) #define zeroeth_table_offset(va) TABLE_OFFSET(zeroeth_linear_offset(va)) +/* + * Macros to define page-tables: + * - DEFINE_BOOT_PAGE_TABLE is used to define page-table that are used + * in assembly code before BSS is zeroed. + * - DEFINE_PAGE_TABLE{,S} are used to define one or multiple + * page-tables to be used after BSS is zeroed (typically they are only used + * in C). + */ +#define DEFINE_BOOT_PAGE_TABLE(name) \ +lpae_t __aligned(PAGE_SIZE) __section(".data.page_aligned") \ + name[XEN_PT_LPAE_ENTRIES] + +#define DEFINE_PAGE_TABLES(name, nr) \ +lpae_t __aligned(PAGE_SIZE) name[XEN_PT_LPAE_ENTRIES * (nr)] + +#define DEFINE_PAGE_TABLE(name) DEFINE_PAGE_TABLES(name, 1) + #endif /* __ARM_LPAE_H__ */ /* diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c index 1423bdd700..77bec199e7 100644 --- a/xen/arch/arm/mm.c +++ b/xen/arch/arm/mm.c @@ -57,23 +57,6 @@ mm_printk(const char *fmt, ...) {} } while (0) #endif -/* - * Macros to define page-tables: - * - DEFINE_BOOT_PAGE_TABLE is used to define page-table that are used - * in assembly code before BSS is zeroed. - * - DEFINE_PAGE_TABLE{,S} are used to define one or multiple - * page-tables to be used after BSS is zeroed (typically they are only used - * in C). - */ -#define DEFINE_BOOT_PAGE_TABLE(name) \ -lpae_t __aligned(PAGE_SIZE) __section(".data.page_aligned") \ - name[XEN_PT_LPAE_ENTRIES] - -#define DEFINE_PAGE_TABLES(name, nr) \ -lpae_t __aligned(PAGE_SIZE) name[XEN_PT_LPAE_ENTRIES * (nr)] - -#define DEFINE_PAGE_TABLE(name) DEFINE_PAGE_TABLES(name, 1) - /* 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. @@ -110,7 +93,7 @@ DEFINE_BOOT_PAGE_TABLE(boot_third); /* Main runtime page tables */ /* - * For arm32 xen_pgtable and xen_dommap are per-PCPU and are allocated before + * For arm32 xen_pgtable are per-PCPU and are allocated before * bringing up each CPU. For arm64 xen_pgtable is common to all PCPUs. * * xen_second, xen_fixmap and xen_xenmap are always shared between all @@ -126,18 +109,10 @@ static DEFINE_PAGE_TABLE(xen_first); #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) */ -static DEFINE_PER_CPU(lpae_t *, xen_pgtable); +DEFINE_PER_CPU(lpae_t *, xen_pgtable); #define THIS_CPU_PGTABLE this_cpu(xen_pgtable) -/* - * 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); /* Root of the trie for cpu0, other CPU's PTs are dynamically allocated */ static DEFINE_PAGE_TABLE(cpu0_pgtable); -/* cpu0's domheap page tables */ -static DEFINE_PAGE_TABLES(cpu0_dommap, DOMHEAP_SECOND_PAGES); #endif /* Common pagetable leaves */ @@ -371,175 +346,6 @@ void clear_fixmap(unsigned int map) BUG_ON(res != 0); } -#ifdef CONFIG_ARCH_MAP_DOMAIN_PAGE -/* - * 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 *va) -{ - vunmap(va); -} - -/* 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 *va) -{ - unsigned long flags; - lpae_t *map = this_cpu(xen_dommap); - int slot = ((unsigned long) va - DOMHEAP_VIRT_START) >> SECOND_SHIFT; - - if ( !va ) - 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); -} -#endif - void flush_page_to_ram(unsigned long mfn, bool sync_icache) { void *v = map_domain_page(_mfn(mfn)); -- generated by git-patchbot for /home/xen/git/xen.git#master
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