Linus Torvalds b293fca43b RISC-V Port for Linux 4.15 v9 ... This tag contains the core RISC-V Linux port, which has been through nine rounds of review on various mailing lists. The port is not complete: there's some cleanup patches moving through the review process, a whole bunch of drivers that need some work, and a lot of feature additions that will be needed. The patches contained in this tag have been through nine rounds of review on the various mailing lists. I have some outstanding cleanup patches, but since there's been so much review on these patches I thought it would be best to submit them as-is and then submit explicit cleanup patches so everyone can review them. This first patch set is big enough that it's a bit of a pain to constantly rewrite, and it's caused a few headaches with various contributors. The port is definately a work in progress. While what's there builds and boots with 4.14, it's a bit hard to actually see anything happen because there are no device drivers yet. I maintain a staging branch that contains all the device drivers and cleanup that actually works, but those patches won't all be ready for a while. I'd like to get what we currently have into your tree so everyone can start working from a single base -- of particular importance is allowing the glibc upstreaming process to proceed so we can sort out any possibly lingering user-visible ABI problems we might have. Copied below is the ChangeLog that contains the history of this patch set: (v9) As per suggestions on our v8 patch set, I've split the core architecture code out from our drivers and would like to submit this patch set to be included into linux-next, with the goal being to be merged in during the next merge window. This patch set is based on 4.14-rc2, but if it's better to have it based on something else then I can change it around. This patch set contains just the core arch code for RISC-V, so while it builds an nominally boots, you can't print or take an interrupt so it's not that useful. If you're looking to actually boot a system it would probably be better to use the full patch set listed below. We've collected a handful of tags from reviewers, and the remainder of the patch set only got minimal feedback last time. Here's what changed: * We now use the device tree to initialize the timer driver so it's less tighly coupled with the arch port. * I cleaned up the defconfigs -- there's actually now just one, and it's empty. For now I think we're OK with what the kernel sets as defaults, but I anticipate we'll begin to expand this as people start to use the port more. * The VDSO symbols version is sane. * We WFI while spinning in the boot loop. * A handful of comments have been added. While there are still a handful of FIXMEs in this patch set, we've started to get enough interest from various users and contributors that maintaining an out of tree patch set is starting to become a big burden. Hopefully the patches are good enough to merge now, which will at least get everyone working in a more reasonable manner as we clean up the remaining issues. This patch set is also availiable on github https://github.com/riscv/riscv-linux/tree/riscv-for-submission-v9-arch as is the entire patch set necessary to get a more functional RISC-V system up and running, including a handful of patches that aren't ready for upstream yet. https://github.com/riscv/riscv-linux/tree/riscv-for-submission-v9 Hopefully I've managed to get everyone's feedback Here's the change highlights from the whole patch set: (v8) I know it may not be the ideal time to submit a patch set right now, as it's the middle of the merge window, but things have calmed down quite a bit in the last month so I thought it would be good to get everyone on the same page. There's been a handful of changes since the last patch set, but most of them are fairly minor: * We changed PAGE_OFFSET to allowing mapping more physical memory on 64-bit systems. This is user configurable, as it triggers a different code model that generates slightly less efficient code. * The device tree binding documentation is back, I'd managed to lose it at some point. * We now pass the atomic64 test suite. The SBI timer driver has been * refactored. (v7) It's been a while since my last patch set, but the changes han been fairly minimal: * The PCI cleanup patches have been dropped, we'll do them as a separate patch set later. * We've the Kconfig entries from CONFIG_ISA_* to CONFIG_RISCV_ISA_*, to make grep easier. * There have been a handful of memory model related tweaks in I/O land, particularly relating the PCI and the upcoming platform specification. There are significant comments in the relevant files. This is still a WIP, but I think we're close to getting as good as we're going to get until we end up with some more specifications. (v6) As it's been only a day since the v5 patch set, the changes are pretty minimal: * The patch set is now based on linux-next/master, which I believe is a better base now that we're getting closer to upstream. * EARLY_PRINTK is no longer an option. Since the SBI console is reasonable, there's no penalty to enabling it (and thus no benefit to disabling it). * The mmap syscalls were refactored a bit. (v5) Things have really started to calm down, so this is fairly similar to the v4 patch set. The most interesting changes include: * We've moved back to a single patch set. * SMP support has been fixed, I was accidentally running on a non-SMP configuration. There were various mistakes all over the tree as a result of this. * The cmpxchg syscalls have been removed, as they were deemed a bad idea. As a result, RISC-V Linux systems mandate the A extension. The corresponding Kconfig entry to enable builds on non-A systems has been removed. * A few more atomic fixes: mostly fence changes, but those resulted in a handful of additional macros that were no longer necessary. * riscv_early_sie has been removed. (v4) There have only been a few changes since the v3 patch set: * The cmpxchg64 syscall is no longer enabled on 32-bit systems. It's not possible to provide this on SMP systems, and it's not necessary as glibc knows not to call it. * We provide a ELF_HWCAP so users can determine the ISA of the machine the kernel is running on. * The multi-line comments are in a better form. * There were a handful of headers that could be replaced with the asm-generic versions, and a few unnecessary definitions. * We no longer use printk, but instead use pr_*. * A few Kconfig and defconfig entries have been cleaned up. (v3) A highlight of the changes since the v2 patch set includes: * We've split out all our drivers into separate patch sets, which I've already sent out to the relevant maintainers. I haven't included those patches in this patch set, but some of them are necessary to build our port. A git tree that contains all our patch sets merged together lives at <https://github.com/riscv/riscv-linux/tree/riscv-for-submission-v3>. * The patch set is now split up differently: rather than being split per directory it is split per topic. Hopefully this will make it easier to review the port on the mailing list. The split is a bit rough, so you probably still want to look at the patch set as a whole. * atomic.h has been completely rewritten and is hopefully now correct. I've attempted to sanitize the various other memory model related code as well, and I think it should all be sane now aside from a handful of FIXMEs commented in the code. * We've changed the cmpexchg syscall to always exist and to not be multiplexed. There is also a VDSO entry for compare and exchange, which allows kernels with the A extension to execute user code without the A extension reasonably fast. * Our user-visible register state now contains enough space for the Q extension for 128-bit floating point, as well as a few words to allow extensibility to future ISA extensions like the eventual V extension for vectors. * A handful of driver cleanups, but these have been split into separate patch sets now so I won't duplicate them here. (v2) A highlight of the changes since the v1 patch set includes: * We've split out our drivers into the right places, which means now there's a lot more patches. I'll be submitting these patches to various subsystem maintainers and including them in any future RISC-V patch sets until they've been merged. * The SBI console driver has been completely rewritten to use the HVC helpers and is now significantly smaller. * We've begun to use weaker barriers as opposed to just the big "fence". There's still some work to do here, specifically: - We need fences in the relaxed MMIO functions. - The non-relaxed MMIO functions are missing R/W bits on their fences. - Many AMOs need the aq and rl bits set. * We now have thread_info in task_struct. As a result, sscratch now contains TP instead of SP. This was necessary because thread_info is no longer on the stack. * A few shared routines have been added that we use instead of creating another arch copy. -----BEGIN PGP SIGNATURE----- iQJHBAABCAAxFiEEAM520YNJYN/OiG3470yhUCzLq0EFAloLD8sTHHBhbG1lckBk YWJiZWx0LmNvbQAKCRDvTKFQLMurQbCZEAC2IgWFOAhYDIv4s39jC/iuGcofuuwC atTVgKSM8tUES5wBomoVxRH1yjDvmyb2jeq3gsp6gWPcchUpLMdfwf2MwW3NV3Mw ESCZPwYiuFhORh1Jt5RSespjK+V9qMvCW0iU6cPE/9kAlPfMGGDv2vEttOFgOGEm yVb1i0gHBcdzbw5H0xszBionUAQVXOFqkfO8AW8VPtFMdzZB6t9OBXRgHJLdWgmK 2Zr5pFN75uivNh4RI1KXHpUeD1kLRVICzG7Ak/aQCfKxWsJutFI1dnLFZmFOIoTf 2wgW4KsDsZakcA9rILtfo3SFH+mSD5PWzvv5G44yf9sEkGG9bSgxl29GeJYL7NzG 3Da9FVMvzjIhmxamPGHfFOFTxTud9+6GU6Lj0iBLpHzpcttjhNgE2NXzcY8r1uMD BcSwkK3duybjeiZLpwnxOywZidCQDv6pZYyc50WBtV/oUG1fncj8DT2ZTIqGv1V8 L6D/MXSr1jt9oJeWzfDCxHlaGaHL6grrmyJ8L1tQKPjMp+DbBPFbMLfvbn/dlsat mPqmfQZ4zydOVO53k6KiHozGQh6K+cuXMvNxrb9pCRy3etFV2wfTNxtbdeJSa7gj xarC6vSia8KFVyXp5nydSks5woHGJFQ1kQYSLEORUWiL5zWILbtI6POzOZeYHgej BvTzVq0AVIbxjA== =xDIk -----END PGP SIGNATURE----- Merge tag 'riscv-for-linus-4.15-arch-v9-premerge' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux Pull RISC-V architecture support from Palmer Dabbelt: "This contains the core RISC-V Linux port, which has been through nine rounds of review on various mailing lists. The port is not complete: there's some cleanup patches moving through the review process, a whole bunch of drivers that need some work, and a lot of feature additions that will be needed. The patches contained in this tag have been through nine rounds of review on the various mailing lists. I have some outstanding cleanup patches, but since there's been so much review on these patches I thought it would be best to submit them as-is and then submit explicit cleanup patches so everyone can review them. This first patch set is big enough that it's a bit of a pain to constantly rewrite, and it's caused a few headaches with various contributors. The port is definately a work in progress. While what's there builds and boots with 4.14, it's a bit hard to actually see anything happen because there are no device drivers yet. I maintain a staging branch that contains all the device drivers and cleanup that actually works, but those patches won't all be ready for a while. I'd like to get what we currently have into your tree so everyone can start working from a single base -- of particular importance is allowing the glibc upstreaming process to proceed so we can sort out any possibly lingering user-visible ABI problems we might have. Copied below is the ChangeLog that contains the history of this patch set: (v9) As per suggestions on our v8 patch set, I've split the core architecture code out from our drivers and would like to submit this patch set to be included into linux-next, with the goal being to be merged in during the next merge window. This patch set is based on 4.14-rc2, but if it's better to have it based on something else then I can change it around. This patch set contains just the core arch code for RISC-V, so while it builds an nominally boots, you can't print or take an interrupt so it's not that useful. If you're looking to actually boot a system it would probably be better to use the full patch set listed below. We've collected a handful of tags from reviewers, and the remainder of the patch set only got minimal feedback last time. Here's what changed: - We now use the device tree to initialize the timer driver so it's less tighly coupled with the arch port. - I cleaned up the defconfigs -- there's actually now just one, and it's empty. For now I think we're OK with what the kernel sets as defaults, but I anticipate we'll begin to expand this as people start to use the port more. - The VDSO symbols version is sane. - We WFI while spinning in the boot loop. - A handful of comments have been added. While there are still a handful of FIXMEs in this patch set, we've started to get enough interest from various users and contributors that maintaining an out of tree patch set is starting to become a big burden. Hopefully the patches are good enough to merge now, which will at least get everyone working in a more reasonable manner as we clean up the remaining issues. (v8) I know it may not be the ideal time to submit a patch set right now, as it's the middle of the merge window, but things have calmed down quite a bit in the last month so I thought it would be good to get everyone on the same page. There's been a handful of changes since the last patch set, but most of them are fairly minor: - We changed PAGE_OFFSET to allowing mapping more physical memory on 64-bit systems. This is user configurable, as it triggers a different code model that generates slightly less efficient code. - The device tree binding documentation is back, I'd managed to lose it at some point. - We now pass the atomic64 test suite - The SBI timer driver has been refactored. (v7) It's been a while since my last patch set, but the changes han been fairly minimal: - The PCI cleanup patches have been dropped, we'll do them as a separate patch set later. - We've the Kconfig entries from CONFIG_ISA_* to CONFIG_RISCV_ISA_*, to make grep easier. - There have been a handful of memory model related tweaks in I/O land, particularly relating the PCI and the upcoming platform specification. There are significant comments in the relevant files. This is still a WIP, but I think we're close to getting as good as we're going to get until we end up with some more specifications. (v6) As it's been only a day since the v5 patch set, the changes are pretty minimal: - The patch set is now based on linux-next/master, which I believe is a better base now that we're getting closer to upstream. - EARLY_PRINTK is no longer an option. Since the SBI console is reasonable, there's no penalty to enabling it (and thus no benefit to disabling it). - The mmap syscalls were refactored a bit. (v5) Things have really started to calm down, so this is fairly similar to the v4 patch set. The most interesting changes include: - We've moved back to a single patch set. - SMP support has been fixed, I was accidentally running on a non-SMP configuration. There were various mistakes all over the tree as a result of this. - The cmpxchg syscalls have been removed, as they were deemed a bad idea. As a result, RISC-V Linux systems mandate the A extension. The corresponding Kconfig entry to enable builds on non-A systems has been removed. - A few more atomic fixes: mostly fence changes, but those resulted in a handful of additional macros that were no longer necessary. - riscv_early_sie has been removed. (v4) There have only been a few changes since the v3 patch set: - The cmpxchg64 syscall is no longer enabled on 32-bit systems. It's not possible to provide this on SMP systems, and it's not necessary as glibc knows not to call it. - We provide a ELF_HWCAP so users can determine the ISA of the machine the kernel is running on. - The multi-line comments are in a better form. - There were a handful of headers that could be replaced with the asm-generic versions, and a few unnecessary definitions. - We no longer use printk, but instead use pr_*. - A few Kconfig and defconfig entries have been cleaned up. (v3) A highlight of the changes since the v2 patch set includes: - We've split out all our drivers into separate patch sets, which I've already sent out to the relevant maintainers. I haven't included those patches in this patch set, but some of them are necessary to build our port. - The patch set is now split up differently: rather than being split per directory it is split per topic. Hopefully this will make it easier to review the port on the mailing list. The split is a bit rough, so you probably still want to look at the patch set as a whole. - atomic.h has been completely rewritten and is hopefully now correct. I've attempted to sanitize the various other memory model related code as well, and I think it should all be sane now aside from a handful of FIXMEs commented in the code. - We've changed the cmpexchg syscall to always exist and to not be multiplexed. There is also a VDSO entry for compare and exchange, which allows kernels with the A extension to execute user code without the A extension reasonably fast. - Our user-visible register state now contains enough space for the Q extension for 128-bit floating point, as well as a few words to allow extensibility to future ISA extensions like the eventual V extension for vectors. - A handful of driver cleanups, but these have been split into separate patch sets now so I won't duplicate them here. (v2) A highlight of the changes since the v1 patch set includes: - We've split out our drivers into the right places, which means now there's a lot more patches. I'll be submitting these patches to various subsystem maintainers and including them in any future RISC-V patch sets until they've been merged. - The SBI console driver has been completely rewritten to use the HVC helpers and is now significantly smaller. - We've begun to use weaker barriers as opposed to just the big "fence". There's still some work to do here, specifically: - We need fences in the relaxed MMIO functions. - The non-relaxed MMIO functions are missing R/W bits on their fences. - Many AMOs need the aq and rl bits set. - We now have thread_info in task_struct. As a result, sscratch now contains TP instead of SP. This was necessary because thread_info is no longer on the stack. - A few shared routines have been added that we use instead of creating another arch copy" Reviewed-by: Arnd Bergmann <arnd@arndb.de> * tag 'riscv-for-linus-4.15-arch-v9-premerge' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux: RISC-V: Build Infrastructure RISC-V: User-facing API RISC-V: Paging and MMU RISC-V: Device, timer, IRQs, and the SBI RISC-V: Task implementation RISC-V: ELF and module implementation RISC-V: Generic library routines and assembly RISC-V: Atomic and Locking Code RISC-V: Init and Halt Code dt-bindings: RISC-V CPU Bindings lib: Add shared copies of some GCC library routines MAINTAINERS: Add RISC-V		2017-11-15 10:49:15 -08:00
..
asm	RISC-V Port for Linux 4.15 v9	2017-11-15 10:49:15 -08:00
uapi/asm	RISC-V: User-facing API	2017-09-26 15:26:48 -07:00