From bd1474cd4c96110f6b070b4fa6cdc3af95b74929 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 30 Jun 2021 13:24:32 +0100 Subject: [PATCH] ANDROID: BACKPORT: mm/vmalloc: Add arch-specific callbacks to track io{remap,unmap} physical pages Add a pair of hooks (ioremap_phys_range_hook/iounmap_phys_range_hook) that can be implemented by an architecture. Contrary to the existing arch_sync_kernel_mappings(), this one tracks things at the physical address level. This is specially useful in these virtualised environments where the guest has to tell the host whether (and how) it intends to use a MMIO device. Signed-off-by: Marc Zyngier [willdeacon@: Hook ioremap_page_range() in mm/ioremap.c] Bug: 209580772 Change-Id: I970c2e632cb2b01060d5e66e4194fa9248188f43 Signed-off-by: Will Deacon --- include/linux/io.h | 2 ++ mm/Kconfig | 5 +++++ mm/ioremap.c | 4 ++++ mm/vmalloc.c | 6 +++++- 4 files changed, 16 insertions(+), 1 deletion(-) diff --git a/include/linux/io.h b/include/linux/io.h index 8394c56babc2..416b936b19bc 100644 --- a/include/linux/io.h +++ b/include/linux/io.h @@ -21,6 +21,8 @@ void __ioread32_copy(void *to, const void __iomem *from, size_t count); void __iowrite64_copy(void __iomem *to, const void *from, size_t count); #ifdef CONFIG_MMU +void ioremap_phys_range_hook(phys_addr_t phys_addr, size_t size, pgprot_t prot); +void iounmap_phys_range_hook(phys_addr_t phys_addr, size_t size); int ioremap_page_range(unsigned long addr, unsigned long end, phys_addr_t phys_addr, pgprot_t prot); #else diff --git a/mm/Kconfig b/mm/Kconfig index 884ba3860ec8..4fa83145139a 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -888,4 +888,9 @@ config ARCH_HAS_HUGEPD config MAPPING_DIRTY_HELPERS bool +# Some architectures want callbacks for all IO mappings in order to +# track the physical addresses that get used as devices. +config ARCH_HAS_IOREMAP_PHYS_HOOKS + bool + endmenu diff --git a/mm/ioremap.c b/mm/ioremap.c index 5fa1ab41d152..17b1d49f79c5 100644 --- a/mm/ioremap.c +++ b/mm/ioremap.c @@ -225,6 +225,7 @@ int ioremap_page_range(unsigned long addr, pgd_t *pgd; unsigned long start; unsigned long next; + phys_addr_t phys_start = phys_addr; int err; pgtbl_mod_mask mask = 0; @@ -246,6 +247,9 @@ int ioremap_page_range(unsigned long addr, if (mask & ARCH_PAGE_TABLE_SYNC_MASK) arch_sync_kernel_mappings(start, end); + if (IS_ENABLED(CONFIG_ARCH_HAS_IOREMAP_PHYS_HOOKS) && !err) + ioremap_phys_range_hook(phys_start, end - start, prot); + return err; } diff --git a/mm/vmalloc.c b/mm/vmalloc.c index d5615977e7f3..775dd8476686 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -37,6 +37,7 @@ #include #include +#include #include #include @@ -69,7 +70,6 @@ static void free_work(struct work_struct *w) } /*** Page table manipulation functions ***/ - static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, pgtbl_mod_mask *mask) { @@ -2263,6 +2263,10 @@ static void __vunmap(const void *addr, int deallocate_pages) kasan_poison_vmalloc(area->addr, get_vm_area_size(area)); + if (IS_ENABLED(CONFIG_ARCH_HAS_IOREMAP_PHYS_HOOKS) && + area->flags & VM_IOREMAP) + iounmap_phys_range_hook(area->phys_addr, get_vm_area_size(area)); + vm_remove_mappings(area, deallocate_pages); if (deallocate_pages) {