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author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-12-13 20:13:05 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-12-13 20:13:05 -0800 |
commit | 4e746cf4f721d6397bace501f5feadb46eec1314 (patch) | |
tree | cdae0fd17a74cae07c5fb55c7112d8aa038b7837 | |
parent | d39a01eff9af1045f6e30ff9db40310517c4b45f (diff) | |
parent | 27b0174525325bf18919597016483a709f3372f8 (diff) | |
download | op-kernel-dev-4e746cf4f721d6397bace501f5feadb46eec1314.zip op-kernel-dev-4e746cf4f721d6397bace501f5feadb46eec1314.tar.gz |
Merge tag 'riscv-for-linus-4.15-rc4-riscv_fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux
Pull RISC-V fixes from Palmer Dabbelt:
"This contains three small fixes:
- A fix to a typo in sys_riscv_flush_icache. This only effects error
handling, but I think it's a small and obvious enough change that
it's sane outside the merge window.
- The addition of smp_mb__after_spinlock(), which was recently
removed due to an incorrect comment. This is largly a comment
change (as there's a big one now), and while it's necessary for
complience with the RISC-V memory model the lack of this fence
shouldn't manifest as a bug on current implementations.
Nonetheless, it still seems saner to have the fence in 4.15.
- The removal of some of the HVC_RISCV_SBI driver that snuck into the
arch port. This is compile-time dead code in 4.15 (as the driver
isn't in yet), and during the review process we found a better way
to implement early printk on RISC-V. While this change doesn't do
anything, it will make staging our HVC driver easier: without this
change the HVC driver we hope to upstream won't build on 4.15
(because the 4.15 arch code would reference a function that no
longer exists).
I don't think this is the last patch set we'll want for 4.15: I think
I'll want to remove some of the first-level irqchip driver that snuck
in as well, which will look a lot like the HVC patch here. This is
pending some asm-generic cleanup I'm doing that I haven't quite gotten
clean enough to send out yet, though, but hopefully it'll be ready by
next week (and still OK for that late)"
* tag 'riscv-for-linus-4.15-rc4-riscv_fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux:
RISC-V: Remove unused CONFIG_HVC_RISCV_SBI code
RISC-V: Resurrect smp_mb__after_spinlock()
RISC-V: Logical vs Bitwise typo
-rw-r--r-- | arch/riscv/include/asm/barrier.h | 19 | ||||
-rw-r--r-- | arch/riscv/kernel/setup.c | 11 | ||||
-rw-r--r-- | arch/riscv/kernel/sys_riscv.c | 2 |
3 files changed, 20 insertions, 12 deletions
diff --git a/arch/riscv/include/asm/barrier.h b/arch/riscv/include/asm/barrier.h index 773c4e0..c0319cb 100644 --- a/arch/riscv/include/asm/barrier.h +++ b/arch/riscv/include/asm/barrier.h @@ -38,6 +38,25 @@ #define smp_rmb() RISCV_FENCE(r,r) #define smp_wmb() RISCV_FENCE(w,w) +/* + * This is a very specific barrier: it's currently only used in two places in + * the kernel, both in the scheduler. See include/linux/spinlock.h for the two + * orderings it guarantees, but the "critical section is RCsc" guarantee + * mandates a barrier on RISC-V. The sequence looks like: + * + * lr.aq lock + * sc lock <= LOCKED + * smp_mb__after_spinlock() + * // critical section + * lr lock + * sc.rl lock <= UNLOCKED + * + * The AQ/RL pair provides a RCpc critical section, but there's not really any + * way we can take advantage of that here because the ordering is only enforced + * on that one lock. Thus, we're just doing a full fence. + */ +#define smp_mb__after_spinlock() RISCV_FENCE(rw,rw) + #include <asm-generic/barrier.h> #endif /* __ASSEMBLY__ */ diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c index 8fbb674..cb7b0c6 100644 --- a/arch/riscv/kernel/setup.c +++ b/arch/riscv/kernel/setup.c @@ -38,10 +38,6 @@ #include <asm/tlbflush.h> #include <asm/thread_info.h> -#ifdef CONFIG_HVC_RISCV_SBI -#include <asm/hvc_riscv_sbi.h> -#endif - #ifdef CONFIG_DUMMY_CONSOLE struct screen_info screen_info = { .orig_video_lines = 30, @@ -212,13 +208,6 @@ static void __init setup_bootmem(void) void __init setup_arch(char **cmdline_p) { -#if defined(CONFIG_HVC_RISCV_SBI) - if (likely(early_console == NULL)) { - early_console = &riscv_sbi_early_console_dev; - register_console(early_console); - } -#endif - #ifdef CONFIG_CMDLINE_BOOL #ifdef CONFIG_CMDLINE_OVERRIDE strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE); diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c index a2ae936..79c7866 100644 --- a/arch/riscv/kernel/sys_riscv.c +++ b/arch/riscv/kernel/sys_riscv.c @@ -70,7 +70,7 @@ SYSCALL_DEFINE3(riscv_flush_icache, uintptr_t, start, uintptr_t, end, bool local = (flags & SYS_RISCV_FLUSH_ICACHE_LOCAL) != 0; /* Check the reserved flags. */ - if (unlikely(flags & !SYS_RISCV_FLUSH_ICACHE_ALL)) + if (unlikely(flags & ~SYS_RISCV_FLUSH_ICACHE_ALL)) return -EINVAL; flush_icache_mm(mm, local); |