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author | 2016-09-13 20:21:55 +0200 | |
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committer | 2016-09-13 20:21:55 +0200 | |
commit | 5465fe0fc3316f7cdda66732a7986f4ebe76d949 (patch) | |
tree | 077a65dba2192e8efc3ccdec89f96ad6ba697ba2 /arch/x86/platform/efi/quirks.c | |
parent | Merge tag 'efi-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into efi/urgent (diff) | |
parent | x86/efi: Allow invocation of arbitrary boot services (diff) | |
download | linux-dev-5465fe0fc3316f7cdda66732a7986f4ebe76d949.tar.xz linux-dev-5465fe0fc3316f7cdda66732a7986f4ebe76d949.zip |
Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into efi/core
Pull EFI updates from Matt Fleming:
"* Refactor the EFI memory map code into architecture neutral files
and allow drivers to permanently reserve EFI boot services regions
on x86, as well as ARM/arm64 - Matt Fleming
* Add ARM support for the EFI esrt driver - Ard Biesheuvel
* Make the EFI runtime services and efivar API interruptible by
swapping spinlocks for semaphores - Sylvain Chouleur
* Provide the EFI identity mapping for kexec which allows kexec to
work on SGI/UV platforms with requiring the "noefi" kernel command
line parameter - Alex Thorlton
* Add debugfs node to dump EFI page tables on arm64 - Ard Biesheuvel
* Merge the EFI test driver being carried out of tree until now in
the FWTS project - Ivan Hu
* Expand the list of flags for classifying EFI regions as "RAM" on
arm64 so we align with the UEFI spec - Ard Biesheuvel
* Optimise out the EFI mixed mode if it's unsupported (CONFIG_X86_32)
or disabled (CONFIG_EFI_MIXED=n) and switch the early EFI boot
services function table for direct calls, alleviating us from
having to maintain the custom function table - Lukas Wunner
* Miscellaneous cleanups and fixes"
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/platform/efi/quirks.c')
-rw-r--r-- | arch/x86/platform/efi/quirks.c | 123 |
1 files changed, 110 insertions, 13 deletions
diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c index 89d1146f5a6f..f14b7a9da24b 100644 --- a/arch/x86/platform/efi/quirks.c +++ b/arch/x86/platform/efi/quirks.c @@ -164,6 +164,71 @@ efi_status_t efi_query_variable_store(u32 attributes, unsigned long size, EXPORT_SYMBOL_GPL(efi_query_variable_store); /* + * The UEFI specification makes it clear that the operating system is + * free to do whatever it wants with boot services code after + * ExitBootServices() has been called. Ignoring this recommendation a + * significant bunch of EFI implementations continue calling into boot + * services code (SetVirtualAddressMap). In order to work around such + * buggy implementations we reserve boot services region during EFI + * init and make sure it stays executable. Then, after + * SetVirtualAddressMap(), it is discarded. + * + * However, some boot services regions contain data that is required + * by drivers, so we need to track which memory ranges can never be + * freed. This is done by tagging those regions with the + * EFI_MEMORY_RUNTIME attribute. + * + * Any driver that wants to mark a region as reserved must use + * efi_mem_reserve() which will insert a new EFI memory descriptor + * into efi.memmap (splitting existing regions if necessary) and tag + * it with EFI_MEMORY_RUNTIME. + */ +void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size) +{ + phys_addr_t new_phys, new_size; + struct efi_mem_range mr; + efi_memory_desc_t md; + int num_entries; + void *new; + + if (efi_mem_desc_lookup(addr, &md)) { + pr_err("Failed to lookup EFI memory descriptor for %pa\n", &addr); + return; + } + + if (addr + size > md.phys_addr + (md.num_pages << EFI_PAGE_SHIFT)) { + pr_err("Region spans EFI memory descriptors, %pa\n", &addr); + return; + } + + mr.range.start = addr; + mr.range.end = addr + size; + mr.attribute = md.attribute | EFI_MEMORY_RUNTIME; + + num_entries = efi_memmap_split_count(&md, &mr.range); + num_entries += efi.memmap.nr_map; + + new_size = efi.memmap.desc_size * num_entries; + + new_phys = memblock_alloc(new_size, 0); + if (!new_phys) { + pr_err("Could not allocate boot services memmap\n"); + return; + } + + new = early_memremap(new_phys, new_size); + if (!new) { + pr_err("Failed to map new boot services memmap\n"); + return; + } + + efi_memmap_insert(&efi.memmap, new, &mr); + early_memunmap(new, new_size); + + efi_memmap_install(new_phys, num_entries); +} + +/* * Helper function for efi_reserve_boot_services() to figure out if we * can free regions in efi_free_boot_services(). * @@ -184,15 +249,6 @@ static bool can_free_region(u64 start, u64 size) return true; } -/* - * The UEFI specification makes it clear that the operating system is free to do - * whatever it wants with boot services code after ExitBootServices() has been - * called. Ignoring this recommendation a significant bunch of EFI implementations - * continue calling into boot services code (SetVirtualAddressMap). In order to - * work around such buggy implementations we reserve boot services region during - * EFI init and make sure it stays executable. Then, after SetVirtualAddressMap(), it -* is discarded. -*/ void __init efi_reserve_boot_services(void) { efi_memory_desc_t *md; @@ -249,7 +305,10 @@ void __init efi_reserve_boot_services(void) void __init efi_free_boot_services(void) { + phys_addr_t new_phys, new_size; efi_memory_desc_t *md; + int num_entries = 0; + void *new, *new_md; for_each_efi_memory_desc(md) { unsigned long long start = md->phys_addr; @@ -257,12 +316,16 @@ void __init efi_free_boot_services(void) size_t rm_size; if (md->type != EFI_BOOT_SERVICES_CODE && - md->type != EFI_BOOT_SERVICES_DATA) + md->type != EFI_BOOT_SERVICES_DATA) { + num_entries++; continue; + } /* Do not free, someone else owns it: */ - if (md->attribute & EFI_MEMORY_RUNTIME) + if (md->attribute & EFI_MEMORY_RUNTIME) { + num_entries++; continue; + } /* * Nasty quirk: if all sub-1MB memory is used for boot @@ -287,7 +350,41 @@ void __init efi_free_boot_services(void) free_bootmem_late(start, size); } - efi_unmap_memmap(); + new_size = efi.memmap.desc_size * num_entries; + new_phys = memblock_alloc(new_size, 0); + if (!new_phys) { + pr_err("Failed to allocate new EFI memmap\n"); + return; + } + + new = memremap(new_phys, new_size, MEMREMAP_WB); + if (!new) { + pr_err("Failed to map new EFI memmap\n"); + return; + } + + /* + * Build a new EFI memmap that excludes any boot services + * regions that are not tagged EFI_MEMORY_RUNTIME, since those + * regions have now been freed. + */ + new_md = new; + for_each_efi_memory_desc(md) { + if (!(md->attribute & EFI_MEMORY_RUNTIME) && + (md->type == EFI_BOOT_SERVICES_CODE || + md->type == EFI_BOOT_SERVICES_DATA)) + continue; + + memcpy(new_md, md, efi.memmap.desc_size); + new_md += efi.memmap.desc_size; + } + + memunmap(new); + + if (efi_memmap_install(new_phys, num_entries)) { + pr_err("Could not install new EFI memmap\n"); + return; + } } /* @@ -365,7 +462,7 @@ void __init efi_apply_memmap_quirks(void) */ if (!efi_runtime_supported()) { pr_info("Setup done, disabling due to 32/64-bit mismatch\n"); - efi_unmap_memmap(); + efi_memmap_unmap(); } /* UV2+ BIOS has a fix for this issue. UV1 still needs the quirk. */ |