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2019-11-28Merge tag 'ioremap-5.5' of git://git.infradead.org/users/hch/ioremapLinus Torvalds2-14/+7
Pull generic ioremap support from Christoph Hellwig: "This adds the remaining bits for an entirely generic ioremap and iounmap to lib/ioremap.c. To facilitate that, it cleans up the giant mess of weird ioremap variants we had with no users outside the arch code. For now just the three newest ports use the code, but there is more than a handful others that can be converted without too much work. Summary: - clean up various obsolete ioremap and iounmap variants - add a new generic ioremap implementation and switch csky, nds32 and riscv over to it" * tag 'ioremap-5.5' of git://git.infradead.org/users/hch/ioremap: (21 commits) nds32: use generic ioremap csky: use generic ioremap csky: remove ioremap_cache riscv: use the generic ioremap code lib: provide a simple generic ioremap implementation sh: remove __iounmap nios2: remove __iounmap hexagon: remove __iounmap m68k: rename __iounmap and mark it static arch: rely on asm-generic/io.h for default ioremap_* definitions asm-generic: don't provide ioremap for CONFIG_MMU asm-generic: ioremap_uc should behave the same with and without MMU xtensa: clean up ioremap x86: Clean up ioremap() parisc: remove __ioremap nios2: remove __ioremap alpha: remove the unused __ioremap wrapper hexagon: clean up ioremap ia64: rename ioremap_nocache to ioremap_uc unicore32: remove ioremap_cached ...
2019-11-22Merge branch 'next/nommu' into for-nextPaul Walmsley20-226/+417
Conflicts: arch/riscv/boot/Makefile arch/riscv/include/asm/sbi.h
2019-11-22Merge branch 'next/misc' into for-nextPaul Walmsley15-33/+40
2019-11-17riscv: add nommu supportChristoph Hellwig12-49/+102
The kernel runs in M-mode without using page tables, and thus can't run bare metal without help from additional firmware. Most of the patch is just stubbing out code not needed without page tables, but there is an interesting detail in the signals implementation: - The normal RISC-V syscall ABI only implements rt_sigreturn as VDSO entry point, but the ELF VDSO is not supported for nommu Linux. We instead copy the code to call the syscall onto the stack. In addition to enabling the nommu code a new defconfig for a small kernel image that can run in nommu mode on qemu is also provided, to run a kernel in qemu you can use the following command line: qemu-system-riscv64 -smp 2 -m 64 -machine virt -nographic \ -kernel arch/riscv/boot/loader \ -drive file=rootfs.ext2,format=raw,id=hd0 \ -device virtio-blk-device,drive=hd0 Contains contributions from Damien Le Moal <Damien.LeMoal@wdc.com>. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anup Patel <anup@brainfault.org> [paul.walmsley@sifive.com: updated to apply; add CONFIG_MMU guards around PCI_IOBASE definition to fix build issues; fixed checkpatch issues; move the PCI_IO_* and VMEMMAP address space macros along with the others; resolve sparse warning] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-11-17riscv: clear the instruction cache and all registers when bootingChristoph Hellwig1-0/+1
When we get booted we want a clear slate without any leaks from previous supervisors or the firmware. Flush the instruction cache and then clear all registers to known good values. This is really important for the upcoming nommu support that runs on M-mode, but can't really harm when running in S-mode either. Vaguely based on the concepts from opensbi. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-11-17riscv: read the hart ID from mhartid on bootDamien Le Moal1-0/+1
When in M-Mode, we can use the mhartid CSR to get the ID of the running HART. Doing so, direct M-Mode boot without firmware is possible. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-11-17riscv: provide native clint access for M-modeChristoph Hellwig2-0/+41
RISC-V has the concept of a cpu level interrupt controller. The interface for it is split between a standardized part that is exposed as bits in the mstatus/sstatus register and the mie/mip/sie/sip CRS. But the bit to actually trigger IPIs is not standardized and just mentioned as implementable using MMIO. Add support for IPIs using MMIO using the SiFive clint layout (which is also shared by Ariane, Kendryte and the Qemu virt platform). Additionally the MMIO block also supports the time value and timer compare registers, so they are also set up using the same OF node. Support for other layouts should also be relatively easy to add in the future. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anup Patel <anup@brainfault.org> [paul.walmsley@sifive.com: update include guard format; fix checkpatch issues; minor commit message cleanup] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-11-13riscv: add support for MMIO access to the timer registersChristoph Hellwig2-3/+19
When running in M-mode we can't use the SBI to set the timer, and don't have access to the time CSR as that usually is emulated by M-mode. Instead provide code that directly accesses the MMIO for the timer. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anup Patel <anup@brainfault.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> # for drivers/clocksource [paul.walmsley@sifive.com: updated to apply; fixed checkpatch issue; timex.h now includes asm/mmio.h to resolve header file problems] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-11-13riscv: implement remote sfence.i using IPIsChristoph Hellwig1-0/+3
The RISC-V ISA only supports flushing the instruction cache for the local CPU core. Currently we always offload the remote TLB flushing to the SBI, which then issues an IPI under the hoods. But with M-mode we do not have an SBI so we have to do it ourselves. IPI to the other nodes using the existing kernel helpers instead if we have native clint support and thus can IPI directly from the kernel. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anup Patel <anup@brainfault.org> [paul.walmsley@sifive.com: cleaned up code comment] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-11-13riscv: poison SBI calls for M-modeChristoph Hellwig1-2/+3
There is no SBI when we run in M-mode, so fail the compile for any code trying to use SBI calls. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-11-12riscv: clean up the macro format in each header fileZong Li15-33/+40
There are many different formats in each header now, such as _ASM_XXX_H, __ASM_XXX_H, _ASM_RISCV_XXX_H, RISCV_XXX_H, etc., This patch tries to unify the format by using _ASM_RISCV_XXX_H, because the most header use it now. This patch also adds the conditional to the headers if they lost it. Signed-off-by: Zong Li <zong.li@sifive.com> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-11-11riscv: use the generic ioremap codeChristoph Hellwig2-3/+6
Use the generic ioremap code instead of providing a local version. Note that this relies on the asm-generic no-op definition of pgprot_noncached. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Paul Walmsley <paul.walmsley@sifive.com> Tested-by: Paul Walmsley <paul.walmsley@sifive.com> # rv32, rv64 boot Acked-by: Paul Walmsley <paul.walmsley@sifive.com> # arch/riscv
2019-11-11arch: rely on asm-generic/io.h for default ioremap_* definitionsChristoph Hellwig1-10/+0
Various architectures that use asm-generic/io.h still defined their own default versions of ioremap_nocache, ioremap_wt and ioremap_wc that point back to plain ioremap directly or indirectly. Remove these definitions and rely on asm-generic/io.h instead. For this to work the backup ioremap_* defintions needs to be changed to purely cpp macros instea of inlines to cover for architectures like openrisc that only define ioremap after including <asm-generic/io.h>. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Palmer Dabbelt <palmer@dabbelt.com>
2019-11-05riscv: abstract out CSR names for supervisor vs machine modeChristoph Hellwig5-30/+82
Many of the privileged CSRs exist in a supervisor and machine version that are used very similarly. Provide versions of the CSR names and fields that map to either the S-mode or M-mode variant depending on a new CONFIG_RISCV_M_MODE kconfig symbol. Contains contributions from Damien Le Moal <Damien.LeMoal@wdc.com> and Paul Walmsley <paul.walmsley@sifive.com>. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> # for drivers/clocksource, drivers/irqchip [paul.walmsley@sifive.com: updated to apply] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-11-05riscv: separate MMIO functions into their own header filePaul Walmsley2-144/+167
Separate the low-level MMIO static inline functions and macros, such as {read,write}{b,w,l,q}(), into their own header file under arch/riscv/include: asm/mmio.h. This is done to break a header dependency chain that arises when both asm/pgtable.h and asm/io.h are included by asm/timex.h. Since the problem is related to the legacy I/O port support in asm/io.h, this allows files under arch/riscv that encounter those issues to simply include asm/mmio.h instead, and bypass the legacy I/O port functions. Existing users of asm/io.h don't need to change anything, since asm/mmio.h is included by asm/io.h. While here, clean up some checkpatch.pl-related issues with the original code. Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-10-29riscv: add support for SECCOMP and SECCOMP_FILTERDavid Abdurachmanov2-1/+14
This patch was extensively tested on Fedora/RISCV (applied by default on top of 5.2-rc7 kernel for <2 months). The patch was also tested with 5.3-rc on QEMU and SiFive Unleashed board. libseccomp (userspace) was rebased: https://github.com/seccomp/libseccomp/pull/134 Fully passes libseccomp regression testing (simulation and live). There is one failing kernel selftest: global.user_notification_signal v1 -> v2: - return immediately if secure_computing(NULL) returns -1 - fixed whitespace issues - add missing seccomp.h - remove patch #2 (solved now) - add riscv to seccomp kernel selftest Signed-off-by: David Abdurachmanov <david.abdurachmanov@sifive.com> Cc: keescook@chromium.org Cc: me@carlosedp.com Tested-by: Carlos de Paula <me@carlosedp.com> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/linux-riscv/CAEn-LTp=ss0Dfv6J00=rCAy+N78U2AmhqJNjfqjr2FDpPYjxEQ@mail.gmail.com/ Link: https://lore.kernel.org/linux-riscv/CAJr-aD=UnCN9E_mdVJ2H5nt=6juRSWikZnA5HxDLQxXLbsRz-w@mail.gmail.com/ [paul.walmsley@sifive.com: cleaned up Cc: lines; fixed spelling and checkpatch issues; updated to apply] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-10-28RISC-V: Add PCIe I/O BAR memory mappingYash Shah2-1/+13
For legacy I/O BARs (non-MMIO BARs) to work correctly on RISC-V Linux, we need to establish a reserved memory region for them, so that drivers that wish to use the legacy I/O BARs can issue reads and writes against a memory region that is mapped to the host PCIe controller's I/O BAR mapping. Signed-off-by: Yash Shah <yash.shah@sifive.com> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-10-28riscv: add missing header file includesPaul Walmsley2-0/+4
sparse identifies several missing prototypes caused by missing preprocessor include directives: arch/riscv/kernel/cpufeature.c:16:6: warning: symbol 'has_fpu' was not declared. Should it be static? arch/riscv/kernel/process.c:26:6: warning: symbol 'arch_cpu_idle' was not declared. Should it be static? arch/riscv/kernel/reset.c:15:6: warning: symbol 'pm_power_off' was not declared. Should it be static? arch/riscv/kernel/syscall_table.c:15:6: warning: symbol 'sys_call_table' was not declared. Should it be static? arch/riscv/kernel/traps.c:149:13: warning: symbol 'trap_init' was not declared. Should it be static? arch/riscv/kernel/vdso.c:54:5: warning: symbol 'arch_setup_additional_pages' was not declared. Should it be static? arch/riscv/kernel/smp.c:64:6: warning: symbol 'arch_match_cpu_phys_id' was not declared. Should it be static? arch/riscv/kernel/module-sections.c:89:5: warning: symbol 'module_frob_arch_sections' was not declared. Should it be static? arch/riscv/mm/context.c:42:6: warning: symbol 'switch_mm' was not declared. Should it be static? Fix by including the appropriate header files in the appropriate source files. This patch should have no functional impact. Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2019-10-23riscv: cleanup <asm/bug.h>Christoph Hellwig1-13/+3
Remove various not required ifdefs and externs. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-10-23riscv: Fix implicit declaration of 'page_to_section'Kefeng Wang1-4/+1
With CONFIG_SPARSEMEM and !CONFIG_SPARSEMEM_VMEMMAP, arch/riscv/include/asm/pgtable.h: In function ‘mk_pte’: include/asm-generic/memory_model.h:64:14: error: implicit declaration of function ‘page_to_section’; did you mean ‘present_section’? [-Werror=implicit-function-declaration] int __sec = page_to_section(__pg); \ ^~~~~~~~~~~~~~~ Fixed by changing mk_pte() from inline function to macro. Cc: Logan Gunthorpe <logang@deltatee.com> Fixes: d95f1a542c3d ("RISC-V: Implement sparsemem") Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> [paul.walmsley@sifive.com: fixed checkpatch errors] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-10-23riscv: fix fs/proc/kcore.c compilation with sparsemem enabledDavid Abdurachmanov1-2/+0
Failed to compile Fedora/RISCV kernel (5.4-rc3+) with sparsemem enabled: fs/proc/kcore.c: In function 'read_kcore': fs/proc/kcore.c:510:8: error: implicit declaration of function 'kern_addr_valid'; did you mean 'virt_addr_valid'? [-Werror=implicit-function-declaration] 510 | if (kern_addr_valid(start)) { | ^~~~~~~~~~~~~~~ | virt_addr_valid Looking at other architectures I don't see kern_addr_valid being guarded by CONFIG_FLATMEM. Fixes: d95f1a542c3d ("RISC-V: Implement sparsemem") Signed-off-by: David Abdurachmanov <david.abdurachmanov@sifive.com> Tested-by: David Abdurachmanov <david.abdurachmanov@sifive.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-10-15RISC-V: fix virtual address overlapped in FIXADDR_START and VMEMMAP_STARTGreentime Hu1-8/+8
This patch fixes the virtual address layout in pgtable.h. The virtual address of FIXADDR_START and VMEMMAP_START should not be overlapped. Fixes: d95f1a542c3d ("RISC-V: Implement sparsemem") Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> [paul.walmsley@sifive.com: fixed patch description] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-10-14riscv: tlbflush: remove confusing comment on local_flush_tlb_all()Paul Walmsley1-4/+0
Remove a confusing comment on our local_flush_tlb_all() implementation. Per an internal discussion with Andrew, while it's true that the fence.i is not necessary, it's not the case that an sfence.vma implies a fence.i. We also drop the section about "flush[ing] the entire local TLB" to better align with the language in section 4.2.1 "Supervisor Memory-Management Fence Instruction" of the RISC-V Privileged Specification v20190608. Fixes: c901e45a999a1 ("RISC-V: `sfence.vma` orderes the instruction cache") Reported-by: Alan Kao <alankao@andestech.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Andrew Waterman <andrew@sifive.com> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-10-01RISC-V: Clear load reservations while restoring hart contextsPalmer Dabbelt1-0/+1
This is almost entirely a comment. The bug is unlikely to manifest on existing hardware because there is a timeout on load reservations, but manifests on QEMU because there is no timeout. Signed-off-by: Palmer Dabbelt <palmer@sifive.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-09-27Merge tag 'riscv/for-v5.4-rc1-b' of ↵Linus Torvalds1-12/+12
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull more RISC-V updates from Paul Walmsley: "Some additional RISC-V updates. This includes one significant fix: - Prevent interrupts from being unconditionally re-enabled during exception handling if they were disabled in the context in which the exception occurred Also a few other fixes: - Fix a build error when sparse memory support is manually enabled - Prevent CPUs beyond CONFIG_NR_CPUS from being enabled in early boot And a few minor improvements: - DT improvements: in the FU540 SoC DT files, improve U-Boot compatibility by adding an "ethernet0" alias, drop an unnecessary property from the DT files, and add support for the PWM device - KVM preparation: add a KVM-related macro for future RISC-V KVM support, and export some symbols required to build KVM support as modules - defconfig additions: build more drivers by default for QEMU configurations" * tag 'riscv/for-v5.4-rc1-b' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: Avoid interrupts being erroneously enabled in handle_exception() riscv: dts: sifive: Drop "clock-frequency" property of cpu nodes riscv: dts: sifive: Add ethernet0 to the aliases node RISC-V: Export kernel symbols for kvm KVM: RISC-V: Add KVM_REG_RISCV for ONE_REG interface arch/riscv: disable excess harts before picking main boot hart RISC-V: Enable VIRTIO drivers in RV64 and RV32 defconfig RISC-V: Fix building error when CONFIG_SPARSEMEM_MANUAL=y riscv: dts: Add DT support for SiFive FU540 PWM driver
2019-09-26mm: treewide: clarify pgtable_page_{ctor,dtor}() namingMark Rutland1-1/+1
The naming of pgtable_page_{ctor,dtor}() seems to have confused a few people, and until recently arm64 used these erroneously/pointlessly for other levels of page table. To make it incredibly clear that these only apply to the PTE level, and to align with the naming of pgtable_pmd_page_{ctor,dtor}(), let's rename them to pgtable_pte_page_{ctor,dtor}(). These changes were generated with the following shell script: ---- git grep -lw 'pgtable_page_.tor' | while read FILE; do sed -i '{s/pgtable_page_ctor/pgtable_pte_page_ctor/}' $FILE; sed -i '{s/pgtable_page_dtor/pgtable_pte_page_dtor/}' $FILE; done ---- ... with the documentation re-flowed to remain under 80 columns, and whitespace fixed up in macros to keep backslashes aligned. There should be no functional change as a result of this patch. Link: http://lkml.kernel.org/r/20190722141133.3116-1-mark.rutland@arm.com Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: consolidate pgtable_cache_init() and pgd_cache_init()Mike Rapoport1-5/+0
Both pgtable_cache_init() and pgd_cache_init() are used to initialize kmem cache for page table allocations on several architectures that do not use PAGE_SIZE tables for one or more levels of the page table hierarchy. Most architectures do not implement these functions and use __weak default NOP implementation of pgd_cache_init(). Since there is no such default for pgtable_cache_init(), its empty stub is duplicated among most architectures. Rename the definitions of pgd_cache_init() to pgtable_cache_init() and drop empty stubs of pgtable_cache_init(). Link: http://lkml.kernel.org/r/1566457046-22637-1-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Will Deacon <will@kernel.org> [arm64] Acked-by: Thomas Gleixner <tglx@linutronix.de> [x86] Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: remove quicklist page table cachesNicholas Piggin1-4/+0
Patch series "mm: remove quicklist page table caches". A while ago Nicholas proposed to remove quicklist page table caches [1]. I've rebased his patch on the curren upstream and switched ia64 and sh to use generic versions of PTE allocation. [1] https://lore.kernel.org/linux-mm/20190711030339.20892-1-npiggin@gmail.com This patch (of 3): Remove page table allocator "quicklists". These have been around for a long time, but have not got much traction in the last decade and are only used on ia64 and sh architectures. The numbers in the initial commit look interesting but probably don't apply anymore. If anybody wants to resurrect this it's in the git history, but it's unhelpful to have this code and divergent allocator behaviour for minor archs. Also it might be better to instead make more general improvements to page allocator if this is still so slow. Link: http://lkml.kernel.org/r/1565250728-21721-2-git-send-email-rppt@linux.ibm.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-19RISC-V: Fix building error when CONFIG_SPARSEMEM_MANUAL=yGreentime Hu1-12/+12
Fix a build break by adjusting where VMALLOC_* and FIXADDR_* are defined. This fixes the definition of the MEMMAP_* macros. CC init/main.o In file included from ./include/linux/mm.h:99, from ./include/linux/ring_buffer.h:5, from ./include/linux/trace_events.h:6, from ./include/trace/syscall.h:7, from ./include/linux/syscalls.h:85, from init/main.c:21: ./arch/riscv/include/asm/pgtable.h: In function ‘pmd_page’: ./arch/riscv/include/asm/pgtable.h:95:24: error: ‘VMALLOC_START’ undeclared (first use in this function); did you mean ‘VMEMMAP_START’? #define VMEMMAP_START (VMALLOC_START - VMEMMAP_SIZE) ^~~~~~~~~~~~~ Fixes: d95f1a542c3d ("RISC-V: Implement sparsemem") Signed-off-by: Greentime Hu <greentime.hu@sifive.com> [paul.walmsley@sifive.com: minor patch description fix] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-09-16Merge tag 'riscv/for-v5.4-rc1' of ↵Linus Torvalds7-60/+96
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Paul Walmsley: "Add the following new features: - Generic CPU topology description support for DT-based platforms, including ARM64, ARM and RISC-V. - Sparsemem support - Perf callchain support - SiFive PLIC irqchip modifications, in preparation for M-mode Linux and clean up the code base: - Clean up chip-specific register (CSR) manipulation code, IPIs, TLB flushing, and the RISC-V CPU-local timer code - Kbuild cleanup from one of the Kbuild maintainers" [ The CPU topology parts came in through the arm64 tree with a shared branch - Linus ] * tag 'riscv/for-v5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: irqchip/sifive-plic: set max threshold for ignored handlers riscv: move the TLB flush logic out of line riscv: don't use the rdtime(h) pseudo-instructions riscv: cleanup riscv_cpuid_to_hartid_mask riscv: optimize send_ipi_single riscv: cleanup send_ipi_mask riscv: refactor the IPI code riscv: Add support for libdw riscv: Add support for perf registers sampling riscv: Add perf callchain support riscv: add arch/riscv/Kbuild RISC-V: Implement sparsemem riscv: Using CSR numbers to access CSRs
2019-09-13riscv: modify the Image header to improve compatibility with the ARM64 headerPaul Walmsley1-6/+6
Part of the intention during the definition of the RISC-V kernel image header was to lay the groundwork for a future merge with the ARM64 image header. One error during my original review was not noticing that the RISC-V header's "magic" field was at a different size and position than the ARM64's "magic" field. If the existing ARM64 Image header parsing code were to attempt to parse an existing RISC-V kernel image header format, it would see a magic number 0. This is undesirable, since it's our intention to align as closely as possible with the ARM64 header format. Another problem was that the original "res3" field was not being initialized correctly to zero. Address these issues by creating a 32-bit "magic2" field in the RISC-V header which matches the ARM64 "magic" field. RISC-V binaries will store "RSC\x05" in this field. The intention is that the use of the existing 64-bit "magic" field in the RISC-V header will be deprecated over time. Increment the minor version number of the file format to indicate this change, and update the documentation accordingly. Fix the assembler directives in head.S to ensure that reserved fields are properly zero-initialized. Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com> Reported-by: Palmer Dabbelt <palmer@sifive.com> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Cc: Atish Patra <atish.patra@wdc.com> Cc: Karsten Merker <merker@debian.org> Link: https://lore.kernel.org/linux-riscv/194c2f10c9806720623430dbf0cc59a965e50448.camel@wdc.com/T/#u Link: https://lore.kernel.org/linux-riscv/mhng-755b14c4-8f35-4079-a7ff-e421fd1b02bc@palmer-si-x1e/T/#t
2019-09-05riscv: move the TLB flush logic out of lineChristoph Hellwig1-30/+7
The TLB flush logic is going to become more complex. Start moving it out of line. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Atish Patra <atish.patra@wdc.com> [paul.walmsley@sifive.com: fixed checkpatch whitespace warnings] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-09-05riscv: don't use the rdtime(h) pseudo-instructionsChristoph Hellwig1-23/+21
If we just use the CSRs that these map to directly the code is simpler and doesn't require extra inline assembly code. Also fix up the top-level comment in timer-riscv.c to not talk about the cycle count or mention details of the clocksource interface, of which this file is just a consumer. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-09-05riscv: cleanup riscv_cpuid_to_hartid_maskChristoph Hellwig2-7/+0
Move the initial clearing of the mask from the callers to riscv_cpuid_to_hartid_mask, and remove the unused !CONFIG_SMP stub. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-09-05riscv: Add support for perf registers samplingMao Han1-0/+42
This patch implements the perf registers sampling and validation API for the riscv arch. The valid registers and their register ID are defined in perf_regs.h. Perf tool can backtrace in userspace with unwind library and the registers/user stack dump support. Signed-off-by: Mao Han <han_mao@c-sky.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Greentime Hu <green.hu@gmail.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: linux-riscv <linux-riscv@lists.infradead.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Guo Ren <guoren@kernel.org> Tested-by: Greentime Hu <greentime.hu@sifive.com> [paul.walmsley@sifive.com: minor patch description fix] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-08-30RISC-V: Implement sparsememLogan Gunthorpe3-0/+26
Implement sparsemem support for Risc-v which helps pave the way for memory hotplug and eventually P2P support. Introduce Kconfig options for virtual and physical address bits which are used to calculate the size of the vmemmap and set the MAX_PHYSMEM_BITS. The vmemmap is located directly before the VMALLOC region and sized such that we can allocate enough pages to populate all the virtual address space in the system (similar to the way it's done in arm64). During initialization, call memblocks_present() and sparse_init(), and provide a stub for vmemmap_populate() (all of which is similar to arm64). [greentime.hu@sifive.com: fixed pfn_valid, FIXADDR_TOP and fixed a bug rebasing onto v5.3] Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Andrew Waterman <andrew@sifive.com> Cc: Olof Johansson <olof@lixom.net> Cc: Michael Clark <michaeljclark@mac.com> Cc: Rob Herring <robh@kernel.org> Cc: Zong Li <zong@andestech.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> [paul.walmsley@sifive.com: updated to apply; minor commit message reformat] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-08-28RISC-V: Fix FIXMAP area corruption on RV32 systemsAnup Patel2-6/+10
Currently, various virtual memory areas of Linux RISC-V are organized in increasing order of their virtual addresses is as follows: 1. User space area (This is lowest area and starts at 0x0) 2. FIXMAP area 3. VMALLOC area 4. Kernel area (This is highest area and starts at PAGE_OFFSET) The maximum size of user space aread is represented by TASK_SIZE. On RV32 systems, TASK_SIZE is defined as VMALLOC_START which causes the user space area to overlap the FIXMAP area. This allows user space apps to potentially corrupt the FIXMAP area and kernel OF APIs will crash whenever they access corrupted FDT in the FIXMAP area. On RV64 systems, TASK_SIZE is set to fixed 256GB and no other areas happen to overlap so we don't see any FIXMAP area corruptions. This patch fixes FIXMAP area corruption on RV32 systems by setting TASK_SIZE to FIXADDR_START. We also move FIXADDR_TOP, FIXADDR_SIZE, and FIXADDR_START defines to asm/pgtable.h so that we can avoid cyclic header includes. Signed-off-by: Anup Patel <anup.patel@wdc.com> Tested-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-08-14riscv: Make __fstate_clean() work correctly.Vincent Chen1-1/+1
Make the __fstate_clean() function correctly set the state of sstatus.FS in pt_regs to SR_FS_CLEAN. Fixes: 7db91e57a0acd ("RISC-V: Task implementation") Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Christoph Hellwig <hch@lst.de> [paul.walmsley@sifive.com: expanded "Fixes" commit ID] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-08-14riscv: Correct the initialized flow of FP registerVincent Chen1-0/+6
The following two reasons cause FP registers are sometimes not initialized before starting the user program. 1. Currently, the FP context is initialized in flush_thread() function and we expect these initial values to be restored to FP register when doing FP context switch. However, the FP context switch only occurs in switch_to function. Hence, if this process does not be scheduled out and scheduled in before entering the user space, the FP registers have no chance to initialize. 2. In flush_thread(), the state of reg->sstatus.FS inherits from the parent. Hence, the state of reg->sstatus.FS may be dirty. If this process is scheduled out during flush_thread() and initializing the FP register, the fstate_save() in switch_to will corrupt the FP context which has been initialized until flush_thread(). To solve the 1st case, the initialization of the FP register will be completed in start_thread(). It makes sure all FP registers are initialized before starting the user program. For the 2nd case, the state of reg->sstatus.FS in start_thread will be set to SR_FS_OFF to prevent this process from corrupting FP context in doing context save. The FP state is set to SR_FS_INITIAL in start_trhead(). Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Fixes: 7db91e57a0acd ("RISC-V: Task implementation") Cc: stable@vger.kernel.org [paul.walmsley@sifive.com: fixed brace alignment issue reported by checkpatch] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-08-13riscv: fix flush_tlb_range() end address for flush_tlb_page()Paul Walmsley1-2/+9
The RISC-V kernel implementation of flush_tlb_page() when CONFIG_SMP is set is wrong. It passes zero to flush_tlb_range() as the final address to flush, but it should be at least 'addr'. Some other Linux architecture ports use the beginning address to flush, plus PAGE_SIZE, as the final address to flush. This might flush slightly more than what's needed, but it seems unlikely that being more clever would improve anything. So let's just take that implementation for now. While here, convert the macro into a static inline function, primarily to avoid unintentional multiple evaluations of 'addr'. This second version of the patch fixes a coding style issue found by Christoph Hellwig <hch@lst.de>. Reported-by: Andreas Schwab <schwab@suse.de> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2019-07-28Merge tag 'spdx-5.3-rc2' of ↵Linus Torvalds7-7/+7
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx Pull SPDX fixes from Greg KH: "Here are some small SPDX fixes for 5.3-rc2 for things that came in during the 5.3-rc1 merge window that we previously missed. Only three small patches here: - two uapi patches to resolve some SPDX tags that were not correct - fix an invalid SPDX tag in the iomap Makefile file All have been properly reviewed on the public mailing lists" * tag 'spdx-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx: iomap: fix Invalid License ID treewide: remove SPDX "WITH Linux-syscall-note" from kernel-space headers again treewide: add "WITH Linux-syscall-note" to SPDX tag of uapi headers
2019-07-25treewide: add "WITH Linux-syscall-note" to SPDX tag of uapi headersMasahiro Yamada7-7/+7
UAPI headers licensed under GPL are supposed to have exception "WITH Linux-syscall-note" so that they can be included into non-GPL user space application code. The exception note is missing in some UAPI headers. Some of them slipped in by the treewide conversion commit b24413180f56 ("License cleanup: add SPDX GPL-2.0 license identifier to files with no license"). Just run: $ git show --oneline b24413180f56 -- arch/x86/include/uapi/asm/ I believe they are not intentional, and should be fixed too. This patch was generated by the following script: git grep -l --not -e Linux-syscall-note --and -e SPDX-License-Identifier \ -- :arch/*/include/uapi/asm/*.h :include/uapi/ :^*/Kbuild | while read file do sed -i -e '/[[:space:]]OR[[:space:]]/s/\(GPL-[^[:space:]]*\)/(\1 WITH Linux-syscall-note)/g' \ -e '/[[:space:]]or[[:space:]]/s/\(GPL-[^[:space:]]*\)/(\1 WITH Linux-syscall-note)/g' \ -e '/[[:space:]]OR[[:space:]]/!{/[[:space:]]or[[:space:]]/!s/\(GPL-[^[:space:]]*\)/\1 WITH Linux-syscall-note/g}' $file done After this patch is applied, there are 5 UAPI headers that do not contain "WITH Linux-syscall-note". They are kept untouched since this exception applies only to GPL variants. $ git grep --not -e Linux-syscall-note --and -e SPDX-License-Identifier \ -- :arch/*/include/uapi/asm/*.h :include/uapi/ :^*/Kbuild include/uapi/drm/panfrost_drm.h:/* SPDX-License-Identifier: MIT */ include/uapi/linux/batman_adv.h:/* SPDX-License-Identifier: MIT */ include/uapi/linux/qemu_fw_cfg.h:/* SPDX-License-Identifier: BSD-3-Clause */ include/uapi/linux/vbox_err.h:/* SPDX-License-Identifier: MIT */ include/uapi/linux/virtio_iommu.h:/* SPDX-License-Identifier: BSD-3-Clause */ Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-22riscv: include generic support for MSI irqdomainsWesley Terpstra1-0/+1
Some RISC-V systems include PCIe host controllers that support PCIe message-signaled interrupts. For this to work on Linux, we need to enable PCI_MSI_IRQ_DOMAIN and define struct msi_alloc_info. Support for the latter is enabled by including the architecture-generic msi.h include. Signed-off-by: Wesley Terpstra <wesley@sifive.com> [paul.walmsley@sifive.com: split initial patch into one arch/riscv patch and one drivers/pci patch] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-07-18riscv: enable sys_clone3 syscall for rv64Paul Walmsley1-0/+1
Enable the sys_clone3 syscall for RV64. We simply include the generic version. Tested by running the program from https://lore.kernel.org/lkml/20190716130631.tohj4ub54md25dys@brauner.io/ and verifying that it completes successfully. Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com> Acked-by: Christian Brauner <christian@brauner.io> Cc: Christian Brauner <christian@brauner.io>
2019-07-18Merge tag 'riscv/for-v5.3-rc1' of ↵Linus Torvalds7-10/+176
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Paul Walmsley: - Hugepage support - "Image" header support for RISC-V kernel binaries, compatible with the current ARM64 "Image" header - Initial page table setup now split into two stages - CONFIG_SOC support (starting with SiFive SoCs) - Avoid reserving memory between RAM start and the kernel in setup_bootmem() - Enable high-res timers and dynamic tick in the RV64 defconfig - Remove long-deprecated gate area stubs - MAINTAINERS updates to switch to the newly-created shared RISC-V git tree, and to fix a get_maintainers.pl issue for patches involving SiFive E-mail addresses Also, one integration fix to resolve a build problem introduced during in the v5.3-rc1 merge window: - Fix build break after macro-to-function conversion in asm-generic/cacheflush.h * tag 'riscv/for-v5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: fix build break after macro-to-function conversion in generic cacheflush.h RISC-V: Add an Image header that boot loader can parse. RISC-V: Setup initial page tables in two stages riscv: remove free_initrd_mem riscv: ccache: Remove unused variable riscv: Introduce huge page support for 32/64bit kernel x86, arm64: Move ARCH_WANT_HUGE_PMD_SHARE config in arch/Kconfig RISC-V: Fix memory reservation in setup_bootmem() riscv: defconfig: enable SOC_SIFIVE riscv: select SiFive platform drivers with SOC_SIFIVE arch: riscv: add config option for building SiFive's SoC resource riscv: Remove gate area stubs MAINTAINERS: change the arch/riscv git tree to the new shared tree MAINTAINERS: don't automatically patches involving SiFive to the linux-riscv list RISC-V: defconfig: Enable NO_HZ_IDLE and HIGH_RES_TIMERS
2019-07-18riscv: fix build break after macro-to-function conversion in generic ↵Paul Walmsley1-4/+59
cacheflush.h Commit c296d4dc13ae ("asm-generic: fix a compilation warning") converted the various flush_*cache_* macros in asm-generic/cacheflush.h to static inline functions. This breaks RISC-V builds, since RISC-V's cacheflush.h includes the generic cacheflush.h and then undefines the macros to be overridden. Fix by copying the subset of the no-op functions that are reused from the generic cacheflush.h into the RISC-V cacheflush.h, and dropping the include of the generic cacheflush.h. Fixes: c296d4dc13ae ("asm-generic: fix a compilation warning") Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com> Cc: Qian Cai <cai@lca.pw> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-12riscv: switch to generic version of pte allocationMike Rapoport1-27/+2
The only difference between the generic and RISC-V implementation of PTE allocation is the usage of __GFP_RETRY_MAYFAIL for both kernel and user PTEs and the absence of __GFP_ACCOUNT for the user PTEs. The conversion to the generic version removes the __GFP_RETRY_MAYFAIL and ensures that GFP_ACCOUNT is used for the user PTE allocations. The pte_free() and pte_free_kernel() versions are identical to the generic ones and can be simply dropped. Link: http://lkml.kernel.org/r/1557296232-15361-13-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Guo Ren <ren_guo@c-sky.com> Cc: Helge Deller <deller@gmx.de> Cc: Ley Foon Tan <lftan@altera.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Sam Creasey <sammy@sammy.net> Cc: Vincent Chen <deanbo422@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-11RISC-V: Add an Image header that boot loader can parse.Atish Patra1-0/+65
Currently, the last stage boot loaders such as U-Boot can accept only uImage which is an unnecessary additional step in automating boot process. Add an image header that boot loader understands and boot Linux from flat Image directly. This header is based on ARM64 boot image header and provides an opportunity to combine both ARM64 & RISC-V image headers in future. Also make sure that PE/COFF header can co-exist in the same image so that EFI stub can be supported for RISC-V in future. EFI specification needs PE/COFF image header in the beginning of the kernel image in order to load it as an EFI application. In order to support EFI stub, code0 should be replaced with "MZ" magic string and res4(at offset 0x3c) should point to the rest of the PE/COFF header (which will be added during EFI support). Tested on both QEMU and HiFive Unleashed using OpenSBI + U-Boot + Linux. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Karsten Merker <merker@debian.org> Tested-by: Karsten Merker <merker@debian.org> (QEMU+OpenSBI+U-Boot) Tested-by: Kevin Hilman <khilman@baylibre.com> (OpenSBI + U-Boot + Linux) [paul.walmsley@sifive.com: fixed whitespace in boot-image-header.txt; converted structure comment to kernel-doc format and added some detail] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-07-10Merge branch 'for-next' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu Pull m68nommu updates from Greg Ungerer: "A series of cleanups for the FLAT format binary loader, binfmt_flat, from Christoph. The end goal is to support no-MMU on RISC-V, and the last patch enables that" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu: riscv: add binfmt_flat support binfmt_flat: don't offset the data start binfmt_flat: move the MAX_SHARED_LIBS definition to binfmt_flat.c binfmt_flat: remove the persistent argument from flat_get_addr_from_rp binfmt_flat: provide an asm-generic/flat.h binfmt_flat: make support for old format binaries optional binfmt_flat: add a ARCH_HAS_BINFMT_FLAT option binfmt_flat: add endianess annotations binfmt_flat: use fixed size type for the on-disk format binfmt_flat: consolidate two version of flat_v2_reloc_t binfmt_flat: remove the unused OLD_FLAT_FLAG_RAM definition binfmt_flat: remove the uapi <linux/flat.h> header binfmt_flat: replace flat_argvp_envp_on_stack with a Kconfig variable binfmt_flat: remove flat_old_ram_flag binfmt_flat: provide a default version of flat_get_relocate_addr binfmt_flat: remove flat_set_persistent binfmt_flat: remove flat_reloc_valid
2019-07-09RISC-V: Setup initial page tables in two stagesAnup Patel3-0/+18
Currently, the setup_vm() does initial page table setup in one-shot very early before enabling MMU. Due to this, the setup_vm() has to map all possible kernel virtual addresses since it does not know size and location of RAM. This means we have kernel mappings for non-existent RAM and any buggy driver (or kernel) code doing out-of-bound access to RAM will not fault and cause underterministic behaviour. Further, the setup_vm() creates PMD mappings (i.e. 2M mappings) for RV64 systems. This means for PAGE_OFFSET=0xffffffe000000000 (i.e. MAXPHYSMEM_128GB=y), the setup_vm() will require 129 pages (i.e. 516 KB) of memory for initial page tables which is never freed. The memory required for initial page tables will further increase if we chose a lower value of PAGE_OFFSET (e.g. 0xffffff0000000000) This patch implements two-staged initial page table setup, as follows: 1. Early (i.e. setup_vm()): This stage maps kernel image and DTB in a early page table (i.e. early_pg_dir). The early_pg_dir will be used only by boot HART so it can be freed as-part of init memory free-up. 2. Final (i.e. setup_vm_final()): This stage maps all possible RAM banks in the final page table (i.e. swapper_pg_dir). The boot HART will start using swapper_pg_dir at the end of setup_vm_final(). All non-boot HARTs directly use the swapper_pg_dir created by boot HART. We have following advantages with this new approach: 1. Kernel mappings for non-existent RAM don't exists anymore. 2. Memory consumed by initial page tables is now indpendent of the chosen PAGE_OFFSET. 3. Memory consumed by initial page tables on RV64 system is 2 pages (i.e. 8 KB) which has significantly reduced and these pages will be freed as-part of the init memory free-up. The patch also provides a foundation for implementing strict kernel mappings where we protect kernel text and rodata using PTE permissions. Suggested-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> [paul.walmsley@sifive.com: updated to apply; fixed a checkpatch warning] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
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