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2019-08-14arm64: memory: rename VA_START to PAGE_ENDMark Rutland6-19/+19
Prior to commit: 14c127c957c1c607 ("arm64: mm: Flip kernel VA space") ... VA_START described the start of the TTBR1 address space for a given VA size described by VA_BITS, where all kernel mappings began. Since that commit, VA_START described a portion midway through the address space, where the linear map ends and other kernel mappings begin. To avoid confusion, let's rename VA_START to PAGE_END, making it clear that it's not the start of the TTBR1 address space and implying that it's related to PAGE_OFFSET. Comments and other mnemonics are updated accordingly, along with a typo fix in the decription of VMEMMAP_SIZE. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: fix flipped VA space falloutMark Rutland2-2/+2
VA_START used to be the start of the TTBR1 address space, but now it's a point midway though. In a couple of places we still use VA_START to get the start of the TTBR1 address space, so let's fix these up to use PAGE_OFFSET instead. Fixes: 14c127c957c1c607 ("arm64: mm: Flip kernel VA space") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: Cosmetic cleanupsWill Deacon1-12/+11
Cleanup memory.h so that the indentation is consistent, remove pointless line-wrapping and use consistent parameter names for different versions of the same macro. Reviewed-by: Steve Capper <steve.capper@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: Add comments to end of non-trivial #ifdef blocksWill Deacon1-6/+8
Commenting the #endif of a multi-statement #ifdef block with the condition which guards it is useful and can save having to scroll back through the file to figure out which set of Kconfig options apply to a particular piece of code. Reviewed-by: Steve Capper <steve.capper@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: Implement __tag_set() as common functionWill Deacon1-7/+7
There's no need for __tag_set() to be a complicated macro when CONFIG_KASAN_SW_TAGS=y and a simple static inline otherwise. Rewrite the thing as a common static inline function. Tested-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: Simplify _VA_START and _PAGE_OFFSET definitionsWill Deacon1-4/+2
Rather than subtracting from -1 and then adding 1, we can simply subtract from 0. Tested-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: Simplify virt_to_page() implementationWill Deacon1-1/+1
Build virt_to_page() on top of virt_to_pfn() so we can avoid the need for explicit shifting. Tested-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: Rewrite default page_to_virt()/virt_to_page()Will Deacon1-11/+10
The default implementations of page_to_virt() and virt_to_page() are fairly confusing to read and the former evaluates its 'page' parameter twice in the macro Rewrite them so that the computation is expressed as 'base + index' in both cases and the parameter is always evaluated exactly once. Tested-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: Ensure address tag is masked in conversion macrosWill Deacon1-2/+3
When converting a linear virtual address to a physical address, pfn or struct page *, we must make sure that the tag bits are masked before the calculation otherwise we end up with corrupt pointers when running with CONFIG_KASAN_SW_TAGS=y: | Unable to handle kernel paging request at virtual address 0037fe0007580d08 | [0037fe0007580d08] address between user and kernel address ranges Mask out the tag in __virt_to_phys_nodebug() and virt_to_page(). Reported-by: Qian Cai <cai@lca.pw> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Fixes: 9cb1c5ddd2c4 ("arm64: mm: Remove bit-masking optimisations for PAGE_OFFSET and VMEMMAP_START") Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: Fix virt_addr_valid() using __is_lm_address()Will Deacon1-8/+8
virt_addr_valid() is intended to test whether or not the passed address is a valid linear map address. Unfortunately, it relies on _virt_addr_is_linear() which is broken because it assumes the linear map is at the top of the address space, which it no longer is. Reimplement virt_addr_valid() using __is_lm_address() and remove _virt_addr_is_linear() entirely. At the same time, ensure we evaluate the macro parameter only once and move it within the __ASSEMBLY__ block. Reported-by: Qian Cai <cai@lca.pw> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Fixes: 14c127c957c1 ("arm64: mm: Flip kernel VA space") Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14Merge tag 'common/for-v5.4-rc1/cpu-topology' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux into for-next/cpu-topologyWill Deacon12-486/+514
Pull in generic CPU topology changes from Paul Walmsley (RISC-V). * tag 'common/for-v5.4-rc1/cpu-topology' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: MAINTAINERS: Add an entry for generic architecture topology base: arch_topology: update Kconfig help description RISC-V: Parse cpu topology during boot. arm: Use common cpu_topology structure and functions. cpu-topology: Move cpu topology code to common code. dt-binding: cpu-topology: Move cpu-map to a common binding. Documentation: DT: arm: add support for sockets defining package boundaries
2019-08-13arm64: constify sys64_hook instancesMark Rutland1-5/+5
All instances of struct sys64_hook contain compile-time constant data, and are never inentionally modified, so let's make them all const. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-13arm64: constify aarch64_insn_encoding_class[]Mark Rutland1-1/+1
The aarch64_insn_encoding_class[] array contains compile-time constant data, and is never intentionally modified, so let's mark it as const. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-13arm64: constify icache_policy_str[]Mark Rutland1-1/+1
The icache_policy_str[] array contains compile-time constant data, and is never intentionally modified, so let's mark it as const. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-13arm64: prefer __section from compiler_attributes.hNick Desaulniers2-2/+2
GCC unescapes escaped string section names while Clang does not. Because __section uses the `#` stringification operator for the section name, it doesn't need to be escaped. This antipattern was found with: $ grep -e __section\(\" -e __section__\(\" -r Reported-by: Sedat Dilek <sedat.dilek@gmail.com> Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-12arm64: topology: Use PPTT to determine if PE is a threadJeremy Linton1-4/+15
ACPI 6.3 adds a thread flag to represent if a CPU/PE is actually a thread. Given that the MPIDR_MT bit may not represent this information consistently on homogeneous machines we should prefer the PPTT flag if its available. Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Robert Richter <rrichter@marvell.com> [will: made acpi_cpu_is_threaded() return 'bool'] Signed-off-by: Will Deacon <will@kernel.org>
2019-08-12ACPI/PPTT: Add support for ACPI 6.3 thread flagJeremy Linton2-1/+57
ACPI 6.3 adds a flag to the CPU node to indicate whether the given PE is a thread. Add a function to return that information for a given linux logical CPU. Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Robert Richter <rrichter@marvell.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09PSCI: cpuidle: Refactor CPU suspend power_state parameter handlingLorenzo Pieralisi5-160/+154
Current PSCI code handles idle state entry through the psci_cpu_suspend_enter() API, that takes an idle state index as a parameter and convert the index into a previously initialized power_state parameter before calling the PSCI.CPU_SUSPEND() with it. This is unwieldly, since it forces the PSCI firmware layer to keep track of power_state parameter for every idle state so that the index->power_state conversion can be made in the PSCI firmware layer instead of the CPUidle driver implementations. Move the power_state handling out of drivers/firmware/psci into the respective ACPI/DT PSCI CPUidle backends and convert the psci_cpu_suspend_enter() API to get the power_state parameter as input, which makes it closer to its firmware interface PSCI.CPU_SUSPEND() API. A notable side effect is that the PSCI ACPI/DT CPUidle backends now can directly handle (and if needed update) power_state parameters before handing them over to the PSCI firmware interface to trigger PSCI.CPU_SUSPEND() calls. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09ARM: psci: cpuidle: Enable PSCI CPUidle driverLorenzo Pieralisi4-18/+5
Allow selection of the PSCI CPUidle in the kernel by updating the respective Kconfig entry. Remove PSCI callbacks from ARM/ARM64 generic CPU ops to prevent the PSCI idle driver from clashing with the generic ARM CPUidle driver initialization, that relies on CPU ops to initialize and enter idle states. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Cc: Will Deacon <will@kernel.org> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09ARM: psci: cpuidle: Introduce PSCI CPUidle driverLorenzo Pieralisi4-0/+170
PSCI firmware is the standard power management control for all ARM64 based platforms and it is also deployed on some ARM 32 bit platforms to date. Idle state entry in PSCI is currently achieved by calling arm_cpuidle_init() and arm_cpuidle_suspend() in a generic idle driver, which in turn relies on ARM/ARM64 CPUidle back-end to relay the call into PSCI firmware if PSCI is the boot method. Given that PSCI is the standard idle entry method on ARM64 systems (which means that no other CPUidle driver are expected on ARM64 platforms - so PSCI is already a generic idle driver), in order to simplify idle entry and code maintenance, it makes sense to have a PSCI specific idle driver so that idle code that it is currently living in drivers/firmware directory can be hoisted out of it and moved where it belongs, into a full-fledged PSCI driver, leaving PSCI code in drivers/firmware as a pure firmware interface, as it should be. Implement a PSCI CPUidle driver. By default it is a silent Kconfig entry which is left unselected, since it selection would clash with the generic ARM CPUidle driver that provides a PSCI based idle driver through the arm/arm64 arches back-ends CPU operations. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09drivers: firmware: psci: Decouple checker from generic ARM CPUidleLorenzo Pieralisi1-9/+7
The PSCI checker currently relies on the generic ARM CPUidle infrastructure to enter an idle state, which in turn creates a dependency that is not really needed. The PSCI checker code to test PSCI CPU suspend is built on top of the CPUidle framework and can easily reuse the struct cpuidle_state.enter() function (previously initialized by an idle driver, with a PSCI back-end) to trigger an entry into an idle state, decoupling the PSCI checker from the generic ARM CPUidle infrastructure and simplyfing the code in the process. Convert the PSCI checker suspend entry function to use the struct cpuidle_state.enter() function callback. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09ARM: cpuidle: Remove overzealous error loggingLorenzo Pieralisi1-3/+9
CPUidle back-end operations are not implemented in some platforms but this should not be considered an error serious enough to be logged. Check the arm_cpuidle_init() return value to detect whether the failure must be reported or not in the kernel log and do not log it if the platform does not support CPUidle operations. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09ARM: cpuidle: Remove useless header includeLorenzo Pieralisi1-1/+0
The generic ARM CPUidle driver includes <linux/topology.h> by mistake. Remove the topology header include. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09arm64: mm: Really fix sparse warning in untagged_addr()Will Deacon1-1/+1
untagged_addr() can be called with a '__user' pointer parameter and must therefore use '__force' casts both when passing this parameter through to sign_extend64() as a 'u64', but also when casting the 's64' return value back to the '__user' pointer type. Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09arm64: mm: Simplify definition of virt_addr_valid()Will Deacon1-4/+2
_virt_addr_valid() is defined as the same value in two places and rolls its own version of virt_to_pfn() in both cases. Consolidate these definitions by inlining a simplified version directly into virt_addr_valid(). Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09docs: arm64: Add layout and 52-bit info to memory documentSteve Capper1-28/+95
As the kernel no longer prints out the memory layout on boot, this patch adds this information back to the memory document. Also, as the 52-bit support introduces some subtle changes to the arm64 memory, the rationale behind these changes are also added to the memory document. Signed-off-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09arm64: mm: Remove vabits_userSteve Capper7-16/+5
Previous patches have enabled 52-bit kernel + user VAs and there is no longer any scenario where user VA != kernel VA size. This patch removes the, now redundant, vabits_user variable and replaces usage with vabits_actual where appropriate. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09arm64: mm: Introduce 52-bit Kernel VAsSteve Capper8-22/+39
Most of the machinery is now in place to enable 52-bit kernel VAs that are detectable at boot time. This patch adds a Kconfig option for 52-bit user and kernel addresses and plumbs in the requisite CONFIG_ macros as well as sets TCR.T1SZ, physvirt_offset and vmemmap at early boot. To simplify things this patch also removes the 52-bit user/48-bit kernel kconfig option. Signed-off-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09arm64: mm: Modify calculation of VMEMMAP_SIZESteve Capper1-1/+8
In a later patch we will need to have a slightly larger VMEMMAP region to accommodate boot time selection between 48/52-bit kernel VAs. This patch modifies the formula for computing VMEMMAP_SIZE to depend explicitly on the PAGE_OFFSET and start of kernel addressable memory. (This allows for a slightly larger direct linear map in future). Signed-off-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09arm64: mm: Separate out vmemmapSteve Capper2-2/+7
vmemmap is a preprocessor definition that depends on a variable, memstart_addr. In a later patch we will need to expand the size of the VMEMMAP region and optionally modify vmemmap depending upon whether or not hardware support is available for 52-bit virtual addresses. This patch changes vmemmap to be a variable. As the old definition depended on a variable load, this should not affect performance noticeably. Signed-off-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09arm64: mm: Logic to make offset_ttbr1 conditionalSteve Capper4-10/+18
When running with a 52-bit userspace VA and a 48-bit kernel VA we offset ttbr1_el1 to allow the kernel pagetables with a 52-bit PTRS_PER_PGD to be used for both userspace and kernel. Moving on to a 52-bit kernel VA we no longer require this offset to ttbr1_el1 should we be running on a system with HW support for 52-bit VAs. This patch introduces conditional logic to offset_ttbr1 to query SYS_ID_AA64MMFR2_EL1 whenever 52-bit VAs are selected. If there is HW support for 52-bit VAs then the ttbr1 offset is skipped. We choose to read a system register rather than vabits_actual because offset_ttbr1 can be called in places where the kernel data is not actually mapped. Calls to offset_ttbr1 appear to be made from rarely called code paths so this extra logic is not expected to adversely affect performance. Signed-off-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09arm64: mm: Introduce vabits_actualSteve Capper8-17/+31
In order to support 52-bit kernel addresses detectable at boot time, one needs to know the actual VA_BITS detected. A new variable vabits_actual is introduced in this commit and employed for the KVM hypervisor layout, KASAN, fault handling and phys-to/from-virt translation where there would normally be compile time constants. In order to maintain performance in phys_to_virt, another variable physvirt_offset is introduced. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09arm64: mm: Introduce VA_BITS_MINSteve Capper6-9/+17
In order to support 52-bit kernel addresses detectable at boot time, the kernel needs to know the most conservative VA_BITS possible should it need to fall back to this quantity due to lack of hardware support. A new compile time constant VA_BITS_MIN is introduced in this patch and it is employed in the KASAN end address, KASLR, and EFI stub. For Arm, if 52-bit VA support is unavailable the fallback is to 48-bits. In other words: VA_BITS_MIN = min (48, VA_BITS) Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09arm64: dump: De-constify VA_START and KASAN_SHADOW_STARTSteve Capper1-3/+16
The kernel page table dumper assumes that the placement of VA regions is constant and determined at compile time. As we are about to introduce variable VA logic, we need to be able to determine certain regions at boot time. Specifically the VA_START and KASAN_SHADOW_START will depend on whether or not the system is booted with 52-bit kernel VAs. This patch adds logic to the kernel page table dumper s.t. these regions can be computed at boot time. Signed-off-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09arm64: kasan: Switch to using KASAN_SHADOW_OFFSETSteve Capper5-18/+51
KASAN_SHADOW_OFFSET is a constant that is supplied to gcc as a command line argument and affects the codegen of the inline address sanetiser. Essentially, for an example memory access: *ptr1 = val; The compiler will insert logic similar to the below: shadowValue = *(ptr1 >> KASAN_SHADOW_SCALE_SHIFT + KASAN_SHADOW_OFFSET) if (somethingWrong(shadowValue)) flagAnError(); This code sequence is inserted into many places, thus KASAN_SHADOW_OFFSET is essentially baked into many places in the kernel text. If we want to run a single kernel binary with multiple address spaces, then we need to do this with KASAN_SHADOW_OFFSET fixed. Thankfully, due to the way the KASAN_SHADOW_OFFSET is used to provide shadow addresses we know that the end of the shadow region is constant w.r.t. VA space size: KASAN_SHADOW_END = ~0 >> KASAN_SHADOW_SCALE_SHIFT + KASAN_SHADOW_OFFSET This means that if we increase the size of the VA space, the start of the KASAN region expands into lower addresses whilst the end of the KASAN region is fixed. Currently the arm64 code computes KASAN_SHADOW_OFFSET at build time via build scripts with the VA size used as a parameter. (There are build time checks in the C code too to ensure that expected values are being derived). It is sufficient, and indeed is a simplification, to remove the build scripts (and build time checks) entirely and instead provide KASAN_SHADOW_OFFSET values. This patch removes the logic to compute the KASAN_SHADOW_OFFSET in the arm64 Makefile, and instead we adopt the approach used by x86 to supply offset values in kConfig. To help debug/develop future VA space changes, the Makefile logic has been preserved in a script file in the arm64 Documentation folder. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09arm64: mm: Flip kernel VA spaceSteve Capper8-22/+16
In order to allow for a KASAN shadow that changes size at boot time, one must fix the KASAN_SHADOW_END for both 48 & 52-bit VAs and "grow" the start address. Also, it is highly desirable to maintain the same function addresses in the kernel .text between VA sizes. Both of these requirements necessitate us to flip the kernel address space halves s.t. the direct linear map occupies the lower addresses. This patch puts the direct linear map in the lower addresses of the kernel VA range and everything else in the higher ranges. We need to adjust: *) KASAN shadow region placement logic, *) KASAN_SHADOW_OFFSET computation logic, *) virt_to_phys, phys_to_virt checks, *) page table dumper. These are all small changes, that need to take place atomically, so they are bundled into this commit. As part of the re-arrangement, a guard region of 2MB (to preserve alignment for fixed map) is added after the vmemmap. Otherwise the vmemmap could intersect with IS_ERR pointers. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09arm64: mm: Remove bit-masking optimisations for PAGE_OFFSET and VMEMMAP_STARTSteve Capper1-6/+5
Currently there are assumptions about the alignment of VMEMMAP_START and PAGE_OFFSET that won't be valid after this series is applied. These assumptions are in the form of bitwise operators being used instead of addition and subtraction when calculating addresses. This patch replaces these bitwise operators with addition/subtraction. Signed-off-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-07arm64/ptrace: Fix typoes in sve_set() commentJulien Grall1-1/+1
The ptrace trace SVE flags are prefixed with SVE_PT_*. Update the comment accordingly. Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-07arm64: mm: print hexadecimal EC value in mem_abort_decode()Miles Chen1-2/+2
This change prints the hexadecimal EC value in mem_abort_decode(), which makes it easier to lookup the corresponding EC in the ARM Architecture Reference Manual. The commit 1f9b8936f36f ("arm64: Decode information from ESR upon mem faults") prints useful information when memory abort occurs. It would be easier to lookup "0x25" instead of "DABT" in the document. Then we can check the corresponding ISS. For example: Current info Document EC Exception class "CP15 MCR/MRC" 0x3 "MCR or MRC access to CP15a..." "ASIMD" 0x7 "Access to SIMD or floating-point..." "DABT (current EL)" 0x25 "Data Abort taken without..." ... Before: Unable to handle kernel paging request at virtual address 000000000000c000 Mem abort info: ESR = 0x96000046 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000046 CM = 0, WnR = 1 After: Unable to handle kernel paging request at virtual address 000000000000c000 Mem abort info: ESR = 0x96000046 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000046 CM = 0, WnR = 1 Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: James Morse <james.morse@arm.com> Acked-by: Mark Rutland <Mark.rutland@arm.com> Signed-off-by: Miles Chen <miles.chen@mediatek.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-07arm64/prefetch: fix a -Wtype-limits warningQian Cai2-11/+12
The commit d5370f754875 ("arm64: prefetch: add alternative pattern for CPUs without a prefetcher") introduced MIDR_IS_CPU_MODEL_RANGE() to be used in has_no_hw_prefetch() with rv_min=0 which generates a compilation warning from GCC, In file included from ./arch/arm64/include/asm/cache.h:8, from ./include/linux/cache.h:6, from ./include/linux/printk.h:9, from ./include/linux/kernel.h:15, from ./include/linux/cpumask.h:10, from arch/arm64/kernel/cpufeature.c:11: arch/arm64/kernel/cpufeature.c: In function 'has_no_hw_prefetch': ./arch/arm64/include/asm/cputype.h:59:26: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits] _model == (model) && rv >= (rv_min) && rv <= (rv_max); \ ^~ arch/arm64/kernel/cpufeature.c:889:9: note: in expansion of macro 'MIDR_IS_CPU_MODEL_RANGE' return MIDR_IS_CPU_MODEL_RANGE(midr, MIDR_THUNDERX, ^~~~~~~~~~~~~~~~~~~~~~~ Fix it by converting MIDR_IS_CPU_MODEL_RANGE to a static inline function. Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-07init/Kconfig: Fix infinite Kconfig recursion on PPCWill Deacon1-1/+1
Commit 5cf896fb6be3 ("arm64: Add support for relocating the kernel with RELR relocations") introduced CONFIG_TOOLS_SUPPORT_RELR, which checks for RELR support in the toolchain as part of the kernel configuration. During this procedure, "$(NM)" is invoked to see if it supports the new relocation format, however PowerPC conditionally overrides this variable in the architecture Makefile in order to pass '--synthetic' when targetting PPC64. This conditional override causes Kconfig to recurse forever, since CONFIG_TOOLS_SUPPORT_RELR cannot be determined without $(NM) being defined, but that in turn depends on CONFIG_PPC64: $ make ARCH=powerpc CROSS_COMPILE=powerpc-linux-gnu- scripts/kconfig/conf --syncconfig Kconfig scripts/kconfig/conf --syncconfig Kconfig scripts/kconfig/conf --syncconfig Kconfig [...] In this particular case, it looks like PowerPC may be able to pass '--synthetic' unconditionally to nm or even drop it altogether. While that is being resolved, let's just bodge the RELR check by picking up $(NM) directly from the environment in whatever state it happens to be in. Cc: Peter Collingbourne <pcc@google.com> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-07arm64: Add support for function error injectionLeo Yan4-0/+26
Inspired by the commit 7cd01b08d35f ("powerpc: Add support for function error injection"), this patch supports function error injection for Arm64. This patch mainly support two functions: one is regs_set_return_value() which is used to overwrite the return value; the another function is override_function_with_return() which is to override the probed function returning and jump to its caller. Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Leo Yan <leo.yan@linaro.org> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-07error-injection: Consolidate override function definitionLeo Yan4-29/+9
The function override_function_with_return() is defined separately for each architecture and every architecture's definition is almost same with each other. E.g. x86 and powerpc both define function in its own asm/error-injection.h header and override_function_with_return() has the same definition, the only difference is that x86 defines an extra function just_return_func() but it is specific for x86 and is only used by x86's override_function_with_return(), so don't need to export this function. This patch consolidates override_function_with_return() definition into asm-generic/error-injection.h header, thus all architectures can use the common definition. As result, the architecture specific headers are removed; the include/linux/error-injection.h header also changes to include asm-generic/error-injection.h header rather than architecture header, furthermore, it includes linux/compiler.h for successful compilation. Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Leo Yan <leo.yan@linaro.org> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-06selftests, arm64: add a selftest for passing tagged pointers to kernelAndrey Konovalov4-0/+53
This patch is a part of a series that extends kernel ABI to allow to pass tagged user pointers (with the top byte set to something else other than 0x00) as syscall arguments. This patch adds a simple test, that calls the uname syscall with a tagged user pointer as an argument. Without the kernel accepting tagged user pointers the test fails with EFAULT. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-06arm64: Introduce prctl() options to control the tagged user addresses ABICatalin Marinas7-1/+111
It is not desirable to relax the ABI to allow tagged user addresses into the kernel indiscriminately. This patch introduces a prctl() interface for enabling or disabling the tagged ABI with a global sysctl control for preventing applications from enabling the relaxed ABI (meant for testing user-space prctl() return error checking without reconfiguring the kernel). The ABI properties are inherited by threads of the same application and fork()'ed children but cleared on execve(). A Kconfig option allows the overall disabling of the relaxed ABI. The PR_SET_TAGGED_ADDR_CTRL will be expanded in the future to handle MTE-specific settings like imprecise vs precise exceptions. Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-06arm64: untag user pointers in access_ok and __uaccess_mask_ptrAndrey Konovalov2-4/+8
This patch is a part of a series that extends kernel ABI to allow to pass tagged user pointers (with the top byte set to something else other than 0x00) as syscall arguments. copy_from_user (and a few other similar functions) are used to copy data from user memory into the kernel memory or vice versa. Since a user can provided a tagged pointer to one of the syscalls that use copy_from_user, we need to correctly handle such pointers. Do this by untagging user pointers in access_ok and in __uaccess_mask_ptr, before performing access validity checks. Note, that this patch only temporarily untags the pointers to perform the checks, but then passes them as is into the kernel internals. Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> [will: Add __force to casting in untagged_addr() to kill sparse warning] Signed-off-by: Will Deacon <will@kernel.org>
2019-08-05arm64: Add support for relocating the kernel with RELR relocationsPeter Collingbourne7-6/+137
RELR is a relocation packing format for relative relocations. The format is described in a generic-abi proposal: https://groups.google.com/d/topic/generic-abi/bX460iggiKg/discussion The LLD linker can be instructed to pack relocations in the RELR format by passing the flag --pack-dyn-relocs=relr. This patch adds a new config option, CONFIG_RELR. Enabling this option instructs the linker to pack vmlinux's relative relocations in the RELR format, and causes the kernel to apply the relocations at startup along with the RELA relocations. RELA relocations still need to be applied because the linker will emit RELA relative relocations if they are unrepresentable in the RELR format (i.e. address not a multiple of 2). Enabling CONFIG_RELR reduces the size of a defconfig kernel image with CONFIG_RANDOMIZE_BASE by 3.5MB/16% uncompressed, or 550KB/5% compressed (lz4). Signed-off-by: Peter Collingbourne <pcc@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-05arm64: Move TIF_* documentation to individual definitionsGeert Uytterhoeven1-18/+7
Some TIF_* flags are documented in the comment block at the top, some next to their definitions, some in both places. Move all documentation to the individual definitions for consistency, and for easy lookup. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-05arm64: mm: free the initrd reserved memblock in a aligned mannerJunhua Huang1-1/+5
We should free the initrd reserved memblock in an aligned manner, because the initrd reserves the memblock in an aligned manner in arm64_memblock_init(). Otherwise there are some fragments in memblock_reserved regions after free_initrd_mem(). e.g.: /sys/kernel/debug/memblock # cat reserved 0: 0x0000000080080000..0x00000000817fafff 1: 0x0000000083400000..0x0000000083ffffff 2: 0x0000000090000000..0x000000009000407f 3: 0x00000000b0000000..0x00000000b000003f 4: 0x00000000b26184ea..0x00000000b2618fff The fragments like the ranges from b0000000 to b000003f and from b26184ea to b2618fff should be freed. And we can do free_reserved_area() after memblock_free(), as free_reserved_area() calls __free_pages(), once we've done that it could be allocated somewhere else, but memblock and iomem still say this is reserved memory. Fixes: 05c58752f9dc ("arm64: To remove initrd reserved area entry from memblock") Signed-off-by: Junhua Huang <huang.junhua@zte.com.cn> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-05arm64: io: Relax implicit barriers in default I/O accessorsWill Deacon1-2/+2
The arm64 implementation of the default I/O accessors requires barrier instructions to satisfy the memory ordering requirements documented in memory-barriers.txt [1], which are largely derived from the behaviour of I/O accesses on x86. Of particular interest are the requirements that a write to a device must be ordered against prior writes to memory, and a read from a device must be ordered against subsequent reads from memory. We satisfy these requirements using various flavours of DSB: the most expensive barrier we have, since it implies completion of prior accesses. This was deemed necessary when we first implemented the accessors, since accesses to different endpoints could propagate independently and therefore the only way to enforce order is to rely on completion guarantees [2]. Since then, the Armv8 memory model has been retrospectively strengthened to require "other-multi-copy atomicity", a property that requires memory accesses from an observer to become visible to all other observers simultaneously [3]. In other words, propagation of accesses is limited to transitioning from locally observed to globally observed. It recently became apparent that this change also has a subtle impact on our I/O accessors for shared peripherals, allowing us to use the cheaper DMB instruction instead. As a concrete example, consider the following: memcpy(dma_buffer, data, bufsz); writel(DMA_START, dev->ctrl_reg); A DMB ST instruction between the final write to the DMA buffer and the write to the control register will ensure that the writes to the DMA buffer are observed before the write to the control register by all observers. Put another way, if an observer can see the write to the control register, it can also see the writes to memory. This has always been the case and is not sufficient to provide the ordering required by Linux, since there is no guarantee that the master interface of the DMA-capable device has observed either of the accesses. However, in an other-multi-copy atomic world, we can infer two things: 1. A write arriving at an endpoint shared between multiple CPUs is visible to all CPUs 2. A write that is visible to all CPUs is also visible to all other observers in the shareability domain Pieced together, this allows us to use DMB OSHST for our default I/O write accessors and DMB OSHLD for our default I/O read accessors (the outer-shareability is for handling non-cacheable mappings) for shared devices. Memory-mapped, DMA-capable peripherals that are private to a CPU (i.e. inaccessible to other CPUs) still require the DSB, however these are few and far between and typically require special treatment anyway which is outside of the scope of the portable driver API (e.g. GIC, page-table walker, SPE profiler). Note that our mandatory barriers remain as DSBs, since there are cases where they are used to flush the store buffer of the CPU, e.g. when publishing page table updates to the SMMU. [1] https://git.kernel.org/linus/4614bbdee357 [2] https://www.youtube.com/watch?v=i6DayghhA8Q [3] https://www.cl.cam.ac.uk/~pes20/armv8-mca/ Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>