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path: root/arch/riscv/kernel/cpufeature.c
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2019-03-04RISC-V: Assign hwcap as per comman capabilities.Atish Patra
Currently, we set hwcap based on first valid hart from DT. This may not be correct always as that hart might not be current booting cpu or may have a different capability. Set hwcap as the capabilities supported by all possible harts with "okay" status. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Johan Hovold <johan@kernel.org> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-02-11riscv: use for_each_of_cpu_node iteratorJohan Hovold
Use the new for_each_of_cpu_node() helper to iterate over cpu nodes instead of open coding. Note that this will allow matching also on the node name instead of the (for FDT) deprecated device_type property. Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-02-11riscv: add missing newlines to printk messagesJohan Hovold
Add missing newline characters to printk messages. Also replace two pr_warning with the shorter pr_warn, and fix up the tense of one error message while at it. Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-12-21RISC-V: Fix of_node_* refcountAtish Patra
Fix of_node* refcount at various places by using of_node_put. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-31RISC-V: properly determine hardware capsAndreas Schwab
On the Hifive-U platform, cpu 0 is a masked cpu with less capabilities than the other cpus. Ignore it for the purpose of determining the hardware capabilities of the system. Signed-off-by: Andreas Schwab <schwab@suse.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22riscv: Add support to no-FPU systemsPalmer Dabbelt
This patchset adds an option, CONFIG_FPU, to enable/disable floating- point support within the kernel. The kernel's new behavior will be as follows: * with CONFIG_FPU=y All FPU codes are reserved. If no FPU is found during booting, a global flag will be set, and those functions will be bypassed with condition check to that flag. * with CONFIG_FPU=n No floating-point instructions in kernel and all related settings are excluded. Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22RISC-V: Mask out the F extension on systems without DPalmer Dabbelt
The RISC-V Linux port doesn't support systems that have the F extension but don't have the D extension -- we actually don't support systems without D either, but Alan's patch set is rectifying that soon. For now I think we can leave this in a semi-broken state and just wait for Alan's patch set to get merged for proper non-FPU support -- the patch set is starting to look good, so doing something in-between doesn't seem like it's worth the work. I don't think it's worth fretting about support for systems with F but not D for now: our glibc ABIs are IMAC and IMAFDC so they probably won't end up being popular. We can always extend this in the future. CC: Alan Kao <alankao@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22Auto-detect whether a FPU existsAlan Kao
We expect that a kernel with CONFIG_FPU=y can still support no-FPU machines. To do so, the kernel should first examine the existence of a FPU, then do nothing if a FPU does exist; otherwise, it should disable/bypass all FPU-related functions. In this patch, a new global variable, has_fpu, is created and determined when parsing the hardware capability from device tree during booting. This variable is used in those FPU-related functions. Signed-off-by: Alan Kao <alankao@andestech.com> Cc: Greentime Hu <greentime@andestech.com> Cc: Vincent Chen <vincentc@andestech.com> Cc: Zong Li <zong@andestech.com> Cc: Nick Hu <nickhu@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-09-26RISC-V: User-facing APIPalmer Dabbelt
This patch contains code that is in some way visible to the user: including via system calls, the VDSO, module loading and signal handling. It also contains some generic code that is ABI visible. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>