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2018-02-16arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tablesWill Deacon1-1/+1
In many cases, page tables can be accessed concurrently by either another CPU (due to things like fast gup) or by the hardware page table walker itself, which may set access/dirty bits. In such cases, it is important to use READ_ONCE/WRITE_ONCE when accessing page table entries so that entries cannot be torn, merged or subject to apparent loss of coherence due to compiler transformations. Whilst there are some scenarios where this cannot happen (e.g. pinned kernel mappings for the linear region), the overhead of using READ_ONCE /WRITE_ONCE everywhere is minimal and makes the code an awful lot easier to reason about. This patch consistently uses these macros in the arch code, as well as explicitly namespacing pointers to page table entries from the entries themselves by using adopting a 'p' suffix for the former (as is sometimes used elsewhere in the kernel source). Tested-by: Yury Norov <ynorov@caviumnetworks.com> Tested-by: Richard Ruigrok <rruigrok@codeaurora.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-03arm64/efi: Ignore EFI_MEMORY_XP attribute if RP and/or WP are setArd Biesheuvel1-1/+3
The UEFI memory map is a bit vague about how to interpret the EFI_MEMORY_XP attribute when it is combined with EFI_MEMORY_RP and/or EFI_MEMORY_WP, which have retroactively been redefined as cacheability attributes rather than permission attributes. So let's ignore EFI_MEMORY_XP if _RP and/or _WP are also set. In this case, it is likely that they are being used to describe the capability of the region (i.e., whether it has the controls to reconfigure it as non-executable) rather than the nature of the contents of the region (i.e., whether it contains data that we will never attempt to execute) Reported-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arvind Yadav <arvind.yadav.cs@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tyler Baicar <tbaicar@codeaurora.org> Cc: Vasyl Gomonovych <gomonovych@gmail.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180102181042.19074-3-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-05efi/arm: Enable DMI/SMBIOSArd Biesheuvel1-15/+0
Wire up the existing arm64 support for SMBIOS tables (aka DMI) for ARM as well, by moving the arm64 init code to drivers/firmware/efi/arm-runtime.c (which is shared between ARM and arm64), and adding a asm/dmi.h header to ARM that defines the mapping routines for the firmware tables. This allows userspace to access these tables to discover system information exposed by the firmware. It also sets the hardware name used in crash dumps, e.g.: Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = ed3c0000 [00000000] *pgd=bf1f3835 Internal error: Oops: 817 [#1] SMP THUMB2 Modules linked in: CPU: 0 PID: 759 Comm: bash Not tainted 4.10.0-09601-g0e8f38792120-dirty #112 Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 ^^^ NOTE: This does *NOT* enable or encourage the use of DMI quirks, i.e., the the practice of identifying the platform via DMI to decide whether certain workarounds for buggy hardware and/or firmware need to be enabled. This would require the DMI subsystem to be enabled much earlier than we do on ARM, which is non-trivial. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20170602135207.21708-14-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-07arm64: mm: replace 'block_mappings_allowed' with 'page_mappings_only'Ard Biesheuvel1-4/+4
In preparation of adding support for contiguous PTE and PMD mappings, let's replace 'block_mappings_allowed' with 'page_mappings_only', which will be a more accurate description of the nature of the setting once we add such contiguous mappings into the mix. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-07-01arm64: efi: avoid block mappings for unaligned UEFI memory regionsArd Biesheuvel1-0/+14
When running the OS with a page size > 4 KB, we need to round up mappings for regions that are not aligned to the OS's page size. We already avoid block mappings for EfiRuntimeServicesCode/Data regions for other reasons, but in the unlikely event that other unaliged regions exists that have the EFI_MEMORY_RUNTIME attribute set, ensure that unaligned regions are always mapped down to pages. This way, the overlapping page is guaranteed not to be covered by a block mapping that needs to be split. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-07-01arm64: efi: always map runtime services code and data regions down to pagesArd Biesheuvel1-1/+35
To avoid triggering diagnostics in the MMU code that are finicky about splitting block mappings into more granular mappings, ensure that regions that are likely to appear in the Memory Attributes table as well as the UEFI memory map are always mapped down to pages. This way, we can use apply_to_page_range() instead of create_pgd_mapping() for the second pass, which cannot split or merge block entries, and operates strictly on PTEs. Note that this aligns the arm64 Memory Attributes table handling code with the ARM code, which already uses apply_to_page_range() to set the strict permissions. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-07-01arm64: mm: add param to force create_pgd_mapping() to use page mappingsArd Biesheuvel1-1/+1
Add a bool parameter 'allow_block_mappings' to create_pgd_mapping() and the various helper functions that it descends into, to give the caller control over whether block entries may be used to create the mapping. The UEFI runtime mapping routines will use this to avoid creating block entries that would need to split up into page entries when applying the permissions listed in the Memory Attributes firmware table. This also replaces the block_mappings_allowed() helper function that was added for DEBUG_PAGEALLOC functionality, but the resulting code is functionally equivalent (given that debug_page_alloc does not operate on EFI page table entries anyway) Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-04-28arm64/efi/libstub: Make screen_info accessible to the UEFI stubArd Biesheuvel1-0/+3
Unlike on 32-bit ARM, where we need to pass the stub's version of struct screen_info to the kernel proper via a configuration table, on 64-bit ARM it simply involves making the core kernel's copy of struct screen_info visible to the stub by exposing an __efistub_ alias for it. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Borislav Petkov <bp@alien8.de> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1461614832-17633-21-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28arm64/efi: Apply strict permissions to UEFI Runtime Services regionsArd Biesheuvel1-14/+40
Recent UEFI versions expose permission attributes for runtime services memory regions, either in the UEFI memory map or in the separate memory attributes table. This allows the kernel to map these regions with stricter permissions, rather than the RWX permissions that are used by default. So wire this up in our mapping routine. Note that in the absence of permission attributes, we still only map regions of type EFI_RUNTIME_SERVICE_CODE with the executable bit set. Also, we base the mapping attributes of EFI_MEMORY_MAPPED_IO on the type directly rather than on the absence of the EFI_MEMORY_WB attribute. This is more correct, but is also required for compatibility with the upcoming support for the Memory Attributes Table, which only carries permission attributes, not memory type attributes. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1461614832-17633-12-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-09arm64/efi: refactor EFI init and runtime code for reuse by 32-bit ARMArd Biesheuvel1-0/+23
This refactors the EFI init and runtime code that will be shared between arm64 and ARM so that it can be built for both archs. Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-09arm64/efi: split off EFI init and runtime code for reuse by 32-bit ARMArd Biesheuvel1-325/+1
This splits off the early EFI init and runtime code that - discovers the EFI params and the memory map from the FDT, and installs the memblocks and config tables. - prepares and installs the EFI page tables so that UEFI Runtime Services can be invoked at the virtual address installed by the stub. This will allow it to be reused for 32-bit ARM. Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-09arm64/efi: mark UEFI reserved regions as MEMBLOCK_NOMAPArd Biesheuvel1-3/+4
Change the EFI memory reservation logic to use memblock_mark_nomap() rather than memblock_reserve() to mark UEFI reserved regions as occupied. In addition to reserving them against allocations done by memblock, this will also prevent them from being covered by the linear mapping. Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-11-26arm64: efi: fix initcall return valuesArd Biesheuvel1-5/+5
Even though initcall return values are typically ignored, the prototype is to return 0 on success or a negative errno value on error. So fix the arm_enable_runtime_services() implementation to return 0 on conditions that are not in fact errors, and return a meaningful error code otherwise. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-26arm64: efi: deal with NULL return value of early_memremap()Ard Biesheuvel1-1/+13
Add NULL return value checks to two invocations of early_memremap() in the UEFI init code. For the UEFI configuration tables, we just warn since we have a better chance of being able to report the issue in a way that can actually be noticed by a human operator if we don't abort right away. For the UEFI memory map, however, all we can do is panic() since we cannot proceed without a description of memory. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-25arm64: efi: correctly map runtime regionsMark Rutland1-7/+2
The kernel may use a page granularity of 4K, 16K, or 64K depending on configuration. When mapping EFI runtime regions, we use memrange_efi_to_native to round the physical base address of a region down to a kernel page boundary, and round the size up to a kernel page boundary, adding the residue left over from rounding down the physical base address. We do not round down the virtual base address. In __create_mapping we account for the offset of the virtual base from a granule boundary, adding the residue to the size before rounding the base down to said granule boundary. Thus we account for the residue twice, and when the residue is non-zero will cause __create_mapping to map an additional page at the end of the region. Depending on the memory map, this page may be in a region we are not intended/permitted to map, or may clash with a different region that we wish to map. In typical cases, mapping the next item in the memory map will overwrite the erroneously created entry, as we sort the memory map in the stub. As __create_mapping can cope with base addresses which are not page aligned, we can instead rely on it to map the region appropriately, and simplify efi_virtmap_init by removing the unnecessary code. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-18arm64: use non-global mappings for UEFI runtime regionsArd Biesheuvel1-9/+5
As pointed out by Russell King in response to the proposed ARM version of this code, the sequence to switch between the UEFI runtime mapping and current's actual userland mapping (and vice versa) is potentially unsafe, since it leaves a time window between the switch to the new page tables and the TLB flush where speculative accesses may hit on stale global TLB entries. So instead, use non-global mappings, and perform the switch via the ordinary ASID-aware context switch routines. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-04Merge tag 'arm64-upstream' of ↵Linus Torvalds1-3/+2
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: - "genirq: Introduce generic irq migration for cpu hotunplugged" patch merged from tip/irq/for-arm to allow the arm64-specific part to be upstreamed via the arm64 tree - CPU feature detection reworked to cope with heterogeneous systems where CPUs may not have exactly the same features. The features reported by the kernel via internal data structures or ELF_HWCAP are delayed until all the CPUs are up (and before user space starts) - Support for 16KB pages, with the additional bonus of a 36-bit VA space, though the latter only depending on EXPERT - Implement native {relaxed, acquire, release} atomics for arm64 - New ASID allocation algorithm which avoids IPI on roll-over, together with TLB invalidation optimisations (using local vs global where feasible) - KASan support for arm64 - EFI_STUB clean-up and isolation for the kernel proper (required by KASan) - copy_{to,from,in}_user optimisations (sharing the memcpy template) - perf: moving arm64 to the arm32/64 shared PMU framework - L1_CACHE_BYTES increased to 128 to accommodate Cavium hardware - Support for the contiguous PTE hint on kernel mapping (16 consecutive entries may be able to use a single TLB entry) - Generic CONFIG_HZ now used on arm64 - defconfig updates * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (91 commits) arm64/efi: fix libstub build under CONFIG_MODVERSIONS ARM64: Enable multi-core scheduler support by default arm64/efi: move arm64 specific stub C code to libstub arm64: page-align sections for DEBUG_RODATA arm64: Fix build with CONFIG_ZONE_DMA=n arm64: Fix compat register mappings arm64: Increase the max granular size arm64: remove bogus TASK_SIZE_64 check arm64: make Timer Interrupt Frequency selectable arm64/mm: use PAGE_ALIGNED instead of IS_ALIGNED arm64: cachetype: fix definitions of ICACHEF_* flags arm64: cpufeature: declare enable_cpu_capabilities as static genirq: Make the cpuhotplug migration code less noisy arm64: Constify hwcap name string arrays arm64/kvm: Make use of the system wide safe values arm64/debug: Make use of the system wide safe value arm64: Move FP/ASIMD hwcap handling to common code arm64/HWCAP: Use system wide safe values arm64/capabilities: Make use of system wide safe value arm64: Delay cpu feature capability checks ...
2015-10-28efi: Use correct type for struct efi_memory_map::phys_mapArd Biesheuvel1-2/+2
We have been getting away with using a void* for the physical address of the UEFI memory map, since, even on 32-bit platforms with 64-bit physical addresses, no truncation takes place if the memory map has been allocated by the firmware (which only uses 1:1 virtually addressable memory), which is usually the case. However, commit: 0f96a99dab36 ("efi: Add "efi_fake_mem" boot option") adds code that clones and modifies the UEFI memory map, and the clone may live above 4 GB on 32-bit platforms. This means our use of void* for struct efi_memory_map::phys_map has graduated from 'incorrect but working' to 'incorrect and broken', and we need to fix it. So redefine struct efi_memory_map::phys_map as phys_addr_t, and get rid of a bunch of casts that are now unneeded. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: izumi.taku@jp.fujitsu.com Cc: kamezawa.hiroyu@jp.fujitsu.com Cc: linux-efi@vger.kernel.org Cc: matt.fleming@intel.com Link: http://lkml.kernel.org/r/1445593697-1342-1-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-14Merge tag 'efi-next' of ↵Ingo Molnar1-14/+5
git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into core/efi Pull v4.4 EFI updates from Matt Fleming: - Make the EFI System Resource Table (ESRT) driver explicitly non-modular by ripping out the module_* code since Kconfig doesn't allow it to be built as a module anyway. (Paul Gortmaker) - Make the x86 efi=debug kernel parameter, which enables EFI debug code and output, generic and usable by arm64. (Leif Lindholm) - Add support to the x86 EFI boot stub for 64-bit Graphics Output Protocol frame buffer addresses. (Matt Fleming) - Detect when the UEFI v2.5 EFI_PROPERTIES_TABLE feature is enabled in the firmware and set an efi.flags bit so the kernel knows when it can apply more strict runtime mapping attributes - Ard Biesheuvel - Auto-load the efi-pstore module on EFI systems, just like we currently do for the efivars module. (Ben Hutchings) - Add "efi_fake_mem" kernel parameter which allows the system's EFI memory map to be updated with additional attributes for specific memory ranges. This is useful for testing the kernel code that handles the EFI_MEMORY_MORE_RELIABLE memmap bit even if your firmware doesn't include support. (Taku Izumi) Note: there is a semantic conflict between the following two commits: 8a53554e12e9 ("x86/efi: Fix multiple GOP device support") ae2ee627dc87 ("efifb: Add support for 64-bit frame buffer addresses") I fixed up the interaction in the merge commit, changing the type of current_fb_base from u32 to u64. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-12efi/arm64: Clean up efi_get_fdt_params() interfaceLeif Lindholm1-1/+1
As we now have a common debug infrastructure between core and arm64 efi, drop the bit of the interface passing verbose output flags around. Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Mark Salter <msalter@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-10-12arm64: Use core efi=debug instead of uefi_debug command line parameterLeif Lindholm1-14/+5
Now that we have an efi=debug command line option in the core code, use this instead of the arm64-specific uefi_debug option. Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Mark Salter <msalter@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2015-10-07arm64: mm: rewrite ASID allocator and MM context-switching codeWill Deacon1-1/+0
Our current switch_mm implementation suffers from a number of problems: (1) The ASID allocator relies on IPIs to synchronise the CPUs on a rollover event (2) Because of (1), we cannot allocate ASIDs with interrupts disabled and therefore make use of a TIF_SWITCH_MM flag to postpone the actual switch to finish_arch_post_lock_switch (3) We run context switch with a reserved (invalid) TTBR0 value, even though the ASID and pgd are updated atomically (4) We take a global spinlock (cpu_asid_lock) during context-switch (5) We use h/w broadcast TLB operations when they are not required (e.g. in flush_context) This patch addresses these problems by rewriting the ASID algorithm to match the bitmap-based arch/arm/ implementation more closely. This in turn allows us to remove much of the complications surrounding switch_mm, including the ugly thread flag. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-07arm64: flush: use local TLB and I-cache invalidationWill Deacon1-2/+2
There are a number of places where a single CPU is running with a private page-table and we need to perform maintenance on the TLB and I-cache in order to ensure correctness, but do not require the operation to be broadcast to other CPUs. This patch adds local variants of tlb_flush_all and __flush_icache_all to support these use-cases and updates the callers respectively. __local_flush_icache_all also implies an isb, since it is intended to be used synchronously. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: David Daney <david.daney@cavium.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-01arm64/efi: Fix boot crash by not padding between EFI_MEMORY_RUNTIME regionsArd Biesheuvel1-1/+2
The new Properties Table feature introduced in UEFIv2.5 may split memory regions that cover PE/COFF memory images into separate code and data regions. Since these regions only differ in the type (runtime code vs runtime data) and the permission bits, but not in the memory type attributes (UC/WC/WT/WB), the spec does not require them to be aligned to 64 KB. Since the relative offset of PE/COFF .text and .data segments cannot be changed on the fly, this means that we can no longer pad out those regions to be mappable using 64 KB pages. Unfortunately, there is no annotation in the UEFI memory map that identifies data regions that were split off from a code region, so we must apply this logic to all adjacent runtime regions whose attributes only differ in the permission bits. So instead of rounding each memory region to 64 KB alignment at both ends, only round down regions that are not directly preceded by another runtime region with the same type attributes. Since the UEFI spec does not mandate that the memory map be sorted, this means we also need to sort it first. Note that this change will result in all EFI_MEMORY_RUNTIME regions whose start addresses are not aligned to the OS page size to be mapped with executable permissions (i.e., on kernels compiled with 64 KB pages). However, since these mappings are only active during the time that UEFI Runtime Services are being invoked, the window for abuse is rather small. Tested-by: Mark Salter <msalter@redhat.com> Tested-by: Mark Rutland <mark.rutland@arm.com> [UEFI 2.4 only] Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Reviewed-by: Mark Salter <msalter@redhat.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Cc: <stable@vger.kernel.org> # v4.0+ Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1443218539-7610-3-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-27arm64/efi: map the entire UEFI vendor string before reading itArd Biesheuvel1-2/+2
At boot, the UTF-16 UEFI vendor string is copied from the system table into a char array with a size of 100 bytes. However, this size of 100 bytes is also used for memremapping() the source, which may not be sufficient if the vendor string exceeds 50 UTF-16 characters, and the placement of the vendor string inside a 4 KB page happens to leave the end unmapped. So use the correct '100 * sizeof(efi_char16_t)' for the size of the mapping. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Fixes: f84d02755f5a ("arm64: add EFI runtime services") Cc: <stable@vger.kernel.org> # 3.16+ Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-05-27e820, efi: add ACPI 6.0 persistent memory typesDan Williams1-0/+1
ACPI 6.0 formalizes e820-type-7 and efi-type-14 as persistent memory. Mark it "reserved" and allow it to be claimed by a persistent memory device driver. This definition is in addition to the Linux kernel's existing type-12 definition that was recently added in support of shipping platforms with NVDIMM support that predate ACPI 6.0 (which now classifies type-12 as OEM reserved). Note, /proc/iomem can be consulted for differentiating legacy "Persistent Memory (legacy)" E820_PRAM vs standard "Persistent Memory" E820_PMEM. Cc: Boaz Harrosh <boaz@plexistor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jens Axboe <axboe@fb.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jeff Moyer <jmoyer@redhat.com> Acked-by: Andy Lutomirski <luto@amacapital.net> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by: Christoph Hellwig <hch@lst.de> Tested-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-03-20arm64: efi: don't restore TTBR0 if active_mm points at init_mmWill Deacon1-1/+5
init_mm isn't a normal mm: it has swapper_pg_dir as its pgd (which contains kernel mappings) and is used as the active_mm for the idle thread. When restoring the pgd after an EFI call, we write current->active_mm into TTBR0. If the current task is actually the idle thread (e.g. when initialising the EFI RTC before entering userspace), then the TLB can erroneously populate itself with junk global entries as a result of speculative table walks. When we do eventually return to userspace, the task can end up hitting these junk mappings leading to lockups, corruption or crashes. This patch fixes the problem in the same way as the CPU suspend code by ensuring that we never switch to the init_mm in efi_set_pgd and instead point TTBR0 at the zero page. A check is also added to cpu_switch_mm to BUG if we get passed swapper_pg_dir. Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Fixes: f3cdfd239da5 ("arm64/efi: move SetVirtualAddressMap() to UEFI stub") Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-03-14efi/arm64: use UEFI for system reset and poweroffArd Biesheuvel1-0/+9
If UEFI Runtime Services are available, they are preferred over direct PSCI calls or other methods to reset the system. For the reset case, we need to hook into machine_restart(), as the arm_pm_restart function pointer may be overwritten by modules. Tested-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-22arm64/efi: move virtmap init to early initcallArd Biesheuvel1-58/+53
Now that the create_mapping() code in mm/mmu.c is able to support setting up kernel page tables at initcall time, we can move the whole virtmap creation to arm64_enable_runtime_services() instead of having a distinct stage during early boot. This also allows us to drop the arm64-specific EFI_VIRTMAP flag. Signed-off-by: Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-16arm64/efi: handle potential failure to remap memory mapArd Biesheuvel1-4/+6
When remapping the UEFI memory map using ioremap_cache(), we have to deal with potential failure. Note that, even if the common case is for ioremap_cache() to return the existing linear mapping of the memory map, we cannot rely on that to be always the case, e.g., in the presence of a mem= kernel parameter. At the same time, remove a stale comment and move the memmap code together. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Mark Salter <msalter@redhat.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-12arm64/efi: remove idmap manipulations from UEFI codeArd Biesheuvel1-31/+1
Now that we have moved the call to SetVirtualAddressMap() to the stub, UEFI has no use for the ID map, so we can drop the code that installs ID mappings for UEFI memory regions. Acked-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Tested-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2015-01-12arm64/efi: remove free_boot_services() and friendsArd Biesheuvel1-122/+1
Now that we are calling SetVirtualAddressMap() from the stub, there is no need to reserve boot-only memory regions, which implies that there is also no reason to free them again later. Acked-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Tested-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2015-01-12arm64/efi: move SetVirtualAddressMap() to UEFI stubArd Biesheuvel1-103/+127
In order to support kexec, the kernel needs to be able to deal with the state of the UEFI firmware after SetVirtualAddressMap() has been called. To avoid having separate code paths for non-kexec and kexec, let's move the call to SetVirtualAddressMap() to the stub: this will guarantee us that it will only be called once (since the stub is not executed during kexec), and ensures that the UEFI state is identical between kexec and normal boot. This implies that the layout of the virtual mapping needs to be created by the stub as well. All regions are rounded up to a naturally aligned multiple of 64 KB (for compatibility with 64k pages kernels) and recorded in the UEFI memory map. The kernel proper reads those values and installs the mappings in a dedicated set of page tables that are swapped in during UEFI Runtime Services calls. Acked-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Matt Fleming <matt.fleming@intel.com> Tested-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2015-01-08arm64/efi: add missing call to early_ioremap_reset()Ard Biesheuvel1-1/+1
The early ioremap support introduced by patch bf4b558eba92 ("arm64: add early_ioremap support") failed to add a call to early_ioremap_reset() at an appropriate time. Without this call, invocations of early_ioremap etc. that are done too late will go unnoticed and may cause corruption. This is exactly what happened when the first user of this feature was added in patch f84d02755f5a ("arm64: add EFI runtime services"). The early mapping of the EFI memory map is unmapped during an early initcall, at which time the early ioremap support is long gone. Fix by adding the missing call to early_ioremap_reset() to setup_arch(), and move the offending early_memunmap() to right after the point where the early mapping of the EFI memory map is last used. Fixes: f84d02755f5a ("arm64: add EFI runtime services") Cc: <stable@vger.kernel.org> Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-11-05arm64: dmi: set DMI string as dump stack arch descriptionArd Biesheuvel1-0/+2
This sets the DMI string, containing system type, serial number, firmware version etc. as dump stack arch description, so that oopses and other kernel stack dumps automatically have this information included, if available. Tested-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2014-11-05arm64: dmi: Add SMBIOS/DMI supportYi Li1-0/+13
SMBIOS is important for server hardware vendors. It implements a spec for providing descriptive information about the platform. Things like serial numbers, physical layout of the ports, build configuration data, and the like. Signed-off-by: Yi Li <yi.li@linaro.org> Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Tested-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2014-11-05arm64/efi: drop redundant set_bit(EFI_CONFIG_TABLES)Ard Biesheuvel1-2/+0
The EFI_CONFIG_TABLES bit already gets set by efi_config_init(), so there is no reason to set it again after this function returns successfully. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2014-11-05arm64/efi: invert UEFI memory region reservation logicArd Biesheuvel1-10/+10
Instead of reserving the memory regions based on which types we know need to be reserved, consider only regions of the following types as free for general use by the OS: EFI_LOADER_CODE EFI_LOADER_DATA EFI_BOOT_SERVICES_CODE EFI_BOOT_SERVICES_DATA EFI_CONVENTIONAL_MEMORY Note that this also fixes a problem with the original code, which would misidentify a EFI_RUNTIME_SERVICES_DATA region as not reserved if it does not have the EFI_MEMORY_RUNTIME attribute set. However, it is perfectly legal for the firmware not to request a virtual mapping for EFI_RUNTIME_SERVICES_DATA regions that contain configuration tables, in which case the EFI_MEMORY_RUNTIME attribute would not be set. Acked-by: Roy Franz <roy.franz@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2014-10-03Merge branch 'next' into efi-next-mergeMatt Fleming1-26/+18
Conflicts: arch/x86/boot/compressed/eboot.c
2014-10-03arm64: efi: Format EFI memory type & attrs with efi_md_typeattr_format()Laszlo Ersek1-20/+6
An example log excerpt demonstrating the change: Before the patch: > Processing EFI memory map: > 0x000040000000-0x000040000fff [Loader Data] > 0x000040001000-0x00004007ffff [Conventional Memory] > 0x000040080000-0x00004072afff [Loader Data] > 0x00004072b000-0x00005fdfffff [Conventional Memory] > 0x00005fe00000-0x00005fe0ffff [Loader Data] > 0x00005fe10000-0x0000964e8fff [Conventional Memory] > 0x0000964e9000-0x0000964e9fff [Loader Data] > 0x0000964ea000-0x000096c52fff [Loader Code] > 0x000096c53000-0x00009709dfff [Boot Code]* > 0x00009709e000-0x0000970b3fff [Runtime Code]* > 0x0000970b4000-0x0000970f4fff [Runtime Data]* > 0x0000970f5000-0x000097117fff [Runtime Code]* > 0x000097118000-0x000097199fff [Runtime Data]* > 0x00009719a000-0x0000971dffff [Runtime Code]* > 0x0000971e0000-0x0000997f8fff [Conventional Memory] > 0x0000997f9000-0x0000998f1fff [Boot Data]* > 0x0000998f2000-0x0000999eafff [Conventional Memory] > 0x0000999eb000-0x00009af09fff [Boot Data]* > 0x00009af0a000-0x00009af21fff [Conventional Memory] > 0x00009af22000-0x00009af46fff [Boot Data]* > 0x00009af47000-0x00009af5bfff [Conventional Memory] > 0x00009af5c000-0x00009afe1fff [Boot Data]* > 0x00009afe2000-0x00009afe2fff [Conventional Memory] > 0x00009afe3000-0x00009c01ffff [Boot Data]* > 0x00009c020000-0x00009efbffff [Conventional Memory] > 0x00009efc0000-0x00009f14efff [Boot Code]* > 0x00009f14f000-0x00009f162fff [Runtime Code]* > 0x00009f163000-0x00009f194fff [Runtime Data]* > 0x00009f195000-0x00009f197fff [Boot Data]* > 0x00009f198000-0x00009f198fff [Runtime Data]* > 0x00009f199000-0x00009f1acfff [Conventional Memory] > 0x00009f1ad000-0x00009f1affff [Boot Data]* > 0x00009f1b0000-0x00009f1b0fff [Runtime Data]* > 0x00009f1b1000-0x00009fffffff [Boot Data]* > 0x000004000000-0x000007ffffff [Memory Mapped I/O] > 0x000009010000-0x000009010fff [Memory Mapped I/O] After the patch: > Processing EFI memory map: > 0x000040000000-0x000040000fff [Loader Data | | | | | |WB|WT|WC|UC] > 0x000040001000-0x00004007ffff [Conventional Memory| | | | | |WB|WT|WC|UC] > 0x000040080000-0x00004072afff [Loader Data | | | | | |WB|WT|WC|UC] > 0x00004072b000-0x00005fdfffff [Conventional Memory| | | | | |WB|WT|WC|UC] > 0x00005fe00000-0x00005fe0ffff [Loader Data | | | | | |WB|WT|WC|UC] > 0x00005fe10000-0x0000964e8fff [Conventional Memory| | | | | |WB|WT|WC|UC] > 0x0000964e9000-0x0000964e9fff [Loader Data | | | | | |WB|WT|WC|UC] > 0x0000964ea000-0x000096c52fff [Loader Code | | | | | |WB|WT|WC|UC] > 0x000096c53000-0x00009709dfff [Boot Code | | | | | |WB|WT|WC|UC]* > 0x00009709e000-0x0000970b3fff [Runtime Code |RUN| | | | |WB|WT|WC|UC]* > 0x0000970b4000-0x0000970f4fff [Runtime Data |RUN| | | | |WB|WT|WC|UC]* > 0x0000970f5000-0x000097117fff [Runtime Code |RUN| | | | |WB|WT|WC|UC]* > 0x000097118000-0x000097199fff [Runtime Data |RUN| | | | |WB|WT|WC|UC]* > 0x00009719a000-0x0000971dffff [Runtime Code |RUN| | | | |WB|WT|WC|UC]* > 0x0000971e0000-0x0000997f8fff [Conventional Memory| | | | | |WB|WT|WC|UC] > 0x0000997f9000-0x0000998f1fff [Boot Data | | | | | |WB|WT|WC|UC]* > 0x0000998f2000-0x0000999eafff [Conventional Memory| | | | | |WB|WT|WC|UC] > 0x0000999eb000-0x00009af09fff [Boot Data | | | | | |WB|WT|WC|UC]* > 0x00009af0a000-0x00009af21fff [Conventional Memory| | | | | |WB|WT|WC|UC] > 0x00009af22000-0x00009af46fff [Boot Data | | | | | |WB|WT|WC|UC]* > 0x00009af47000-0x00009af5bfff [Conventional Memory| | | | | |WB|WT|WC|UC] > 0x00009af5c000-0x00009afe1fff [Boot Data | | | | | |WB|WT|WC|UC]* > 0x00009afe2000-0x00009afe2fff [Conventional Memory| | | | | |WB|WT|WC|UC] > 0x00009afe3000-0x00009c01ffff [Boot Data | | | | | |WB|WT|WC|UC]* > 0x00009c020000-0x00009efbffff [Conventional Memory| | | | | |WB|WT|WC|UC] > 0x00009efc0000-0x00009f14efff [Boot Code | | | | | |WB|WT|WC|UC]* > 0x00009f14f000-0x00009f162fff [Runtime Code |RUN| | | | |WB|WT|WC|UC]* > 0x00009f163000-0x00009f194fff [Runtime Data |RUN| | | | |WB|WT|WC|UC]* > 0x00009f195000-0x00009f197fff [Boot Data | | | | | |WB|WT|WC|UC]* > 0x00009f198000-0x00009f198fff [Runtime Data |RUN| | | | |WB|WT|WC|UC]* > 0x00009f199000-0x00009f1acfff [Conventional Memory| | | | | |WB|WT|WC|UC] > 0x00009f1ad000-0x00009f1affff [Boot Data | | | | | |WB|WT|WC|UC]* > 0x00009f1b0000-0x00009f1b0fff [Runtime Data |RUN| | | | |WB|WT|WC|UC]* > 0x00009f1b1000-0x00009fffffff [Boot Data | | | | | |WB|WT|WC|UC]* > 0x000004000000-0x000007ffffff [Memory Mapped I/O |RUN| | | | | | | |UC] > 0x000009010000-0x000009010fff [Memory Mapped I/O |RUN| | | | | | | |UC] The attribute bitmap is now displayed, in decoded form. Signed-off-by: Laszlo Ersek <lersek@redhat.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-10-03arm64/efi: Do not enter virtual mode if booting with efi=noruntime or noefiDave Young1-3/+8
In case efi runtime disabled via noefi kernel cmdline arm64_enter_virtual_mode should error out. At the same time move early_memunmap(memmap.map, mapsize) to the beginning of the function or it will leak early mem. Signed-off-by: Dave Young <dyoung@redhat.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-10-03arm64/efi: uefi_init error handling fixDave Young1-3/+4
There's one early memmap leak in uefi_init error path, fix it and slightly tune the error handling code. Signed-off-by: Dave Young <dyoung@redhat.com> Acked-by: Mark Salter <msalter@redhat.com> Reported-by: Will Deacon <will.deacon@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-08-24Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "A couple of EFI fixes, plus misc fixes all around the map" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi/arm64: Store Runtime Services revision firmware: Do not use WARN_ON(!spin_is_locked()) x86_32, entry: Clean up sysenter_badsys declaration x86/doc: Fix the 'tlb_single_page_flush_ceiling' sysconfig path x86/mm: Fix sparse 'tlb_single_page_flush_ceiling' warning and make the variable read-mostly x86/mm: Fix RCU splat from new TLB tracepoints
2014-08-22efi/arm64: Store Runtime Services revisionSemen Protsenko1-0/+2
"efi" global data structure contains "runtime_version" field which must be assigned in order to use it later in Runtime Services virtual calls (virt_efi_* functions). Before this patch "runtime_version" was unassigned (0), so each Runtime Service virtual call that checks revision would fail. Signed-off-by: Semen Protsenko <semen.protsenko@linaro.org> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: <stable@vger.kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-08-19arm64: ignore DT memreserve entries when booting in UEFI modeLeif Lindholm1-0/+2
UEFI provides its own method for marking regions to reserve, via the memory map which is also used to initialise memblock. So when using the UEFI memory map, ignore any memreserve entries present in the DT. Reported-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-07-18efi/arm64: Handle missing virtual mapping for UEFI System TableArd Biesheuvel1-4/+24
If we cannot resolve the virtual address of the UEFI System Table, its physical offset must be missing from the virtual memory map, and there is really no point in proceeding with installing the virtual memory map and the runtime services dispatch table. So back out gracefully. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Mark Salter <msalter@redhat.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-07-07efi/arm64: Preserve FP/SIMD registers on UEFI runtime services callsArd Biesheuvel1-13/+1
According to the UEFI spec section 2.3.6.4, the use of FP/SIMD instructions is allowed, and should adhere to the AAPCS64 calling convention, which states that 'only the bottom 64 bits of each value stored in registers v8-v15 need to be preserved' (section 5.1.2). This applies equally to UEFI Runtime Services called by the kernel, so make sure the FP/SIMD register file is preserved in this case. We do this by enabling the wrappers for UEFI Runtime Services (CONFIG_EFI_RUNTIME_WRAPPERS) and inserting calls to kernel_neon_begin()and kernel_neon_end() into these wrappers. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-05-23arm64: efi: only attempt efi map setup if booting via EFILeif Lindholm1-0/+3
Booting a kernel with CONFIG_EFI enabled on a non-EFI system caused an oops with the current UEFI support code. Add the required test to prevent this. Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-04-30arm64: add EFI runtime servicesMark Salter1-0/+466
This patch adds EFI runtime support for arm64. This runtime support allows the kernel to access various EFI runtime services provided by EFI firmware. Things like reboot, real time clock, EFI boot variables, and others. This functionality is supported for little endian kernels only. The UEFI firmware standard specifies that the firmware be little endian. A future patch is expected to add support for big endian kernels running with little endian firmware. Signed-off-by: Mark Salter <msalter@redhat.com> [ Remove unnecessary cache/tlb maintenance. ] Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>