On Tue, Jul 14, 2020 at 4:32 AM Palmer Dabbelt <palmer@xxxxxxxxxxx> wrote: > > On Sat, 27 Jun 2020 09:19:52 PDT (-0700), Anup Patel wrote: > > The current RISC-V timer driver is convoluted and implements two > > distinct timers: > > 1. S-mode timer: This is for Linux RISC-V S-mode with MMU. The > > clocksource is implemented using TIME CSR and clockevent device > > is implemented using SBI Timer calls. > > 2. M-mode timer: This is for Linux RISC-V M-mode without MMU. The > > clocksource is implemented using CLINT MMIO time register and > > clockevent device is implemented using CLINT MMIO timecmp registers. > > > > This patchset removes clint related code from RISC-V timer driver and > > arch/riscv directory. Instead, the series adds a dedicated MMIO based > > CLINT driver under drivers/clocksource directory which can be used by > > Linux RISC-V M-mode (i.e NoMMU Linux RISC-V). > > > > The patchset is based up Linux-5.8-rc2 and can be found at riscv_clint_v2 > > branch of: https://github.com/avpatel/linux.git > > > > This series is tested on: > > 1. QEMU RV64 virt machine using Linux RISC-V S-mode > > 2. QEMU RV32 virt machine using Linux RISC-V S-mode > > 3. QEMU RV64 virt machine using Linux RISC-V M-mode (i.e. NoMMU) > > > > Changes since v1: > > - Rebased series on Linux-5.8-rc2 > > - Added pr_warn() for case where ipi_ops not available in PATCH1 > > - Updated ipi_inject() prototype to use "struct cpumask *" in PATCH1 > > - Updated CLINT_TIMER kconfig option to depend on RISCV_M_MODE in PATCH4 > > - Added riscv,clint0 compatible string in DT bindings document > > > > Anup Patel (5): > > RISC-V: Add mechanism to provide custom IPI operations > > RISC-V: Remove CLINT related code > > clocksource/drivers/timer-riscv: Remove MMIO related stuff > > clocksource/drivers: Add CLINT timer driver > > dt-bindings: timer: Add CLINT bindings > > This all generally LGTM, though I haven't been through the code line-by-line > yet. It touches a bunch of trees, so I'd prefer to have some Acks before > merging -- I'll dig through the RISC-V specific stuff, but the new CLINT driver > probhably deserves a look from one of the clocksource folks. > > I think the only issue is that the port will be broken between patch 2 and 4, > as at that point we won't have an M-mode timer driver. I think it shouldn't be > too much to just reorder these, LMK if you want to do it or you want me to. Okay, I will try your suggestion to reorder patches. There is another minor build issue reported by test bots which I will fix as well. I will send v3 in a couple of days before end-of-week. Regards, Anup > > Thanks! > > > > > .../bindings/timer/sifive,clint.txt | 34 +++ > > arch/riscv/Kconfig | 2 +- > > arch/riscv/include/asm/clint.h | 39 --- > > arch/riscv/include/asm/smp.h | 11 + > > arch/riscv/include/asm/timex.h | 28 +-- > > arch/riscv/kernel/Makefile | 2 +- > > arch/riscv/kernel/clint.c | 44 ---- > > arch/riscv/kernel/sbi.c | 14 ++ > > arch/riscv/kernel/setup.c | 2 - > > arch/riscv/kernel/smp.c | 44 ++-- > > arch/riscv/kernel/smpboot.c | 4 +- > > drivers/clocksource/Kconfig | 12 +- > > drivers/clocksource/Makefile | 1 + > > drivers/clocksource/timer-clint.c | 229 ++++++++++++++++++ > > drivers/clocksource/timer-riscv.c | 17 +- > > include/linux/cpuhotplug.h | 1 + > > 16 files changed, 337 insertions(+), 147 deletions(-) > > create mode 100644 Documentation/devicetree/bindings/timer/sifive,clint.txt > > delete mode 100644 arch/riscv/include/asm/clint.h > > delete mode 100644 arch/riscv/kernel/clint.c > > create mode 100644 drivers/clocksource/timer-clint.c
