From: Peter Zijlstra <peterz@infradead.org>
To: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org, ada.coupriediaz@arm.com,
ardb@kernel.org, catalin.marinas@arm.com, hca@linux.ibm.com,
linux-kernel@vger.kernel.org, maz@kernel.org,
ruanjinjie@huawei.com, vladimir.murzin@arm.com, will@kernel.org,
yang@os.amperecomputing.com
Subject: Re: [RFC PATCH 06/13] arm64: percpu: Add infrastructure for preemptible this_cpu_*() ops
Date: Tue, 28 Jul 2026 18:46:31 +0200 [thread overview]
Message-ID: <20260728164631.GJ651302@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <amjQkPyNAsFRJF9I@J2N7QTR9R3>
On Tue, Jul 28, 2026 at 04:53:52PM +0100, Mark Rutland wrote:
> I was being lazy here relative to what we do for asm-extable.h. How
> about I match the pattern there, and have:
>
> | #define PCPU_GPR_PCP_SHIFT 0
> | #define PCPU_GPR_PCP GENMASK(4, 0)
> | #define PCPU_GPR_OFF_SHIFT 5
> | #define PCPU_GPR_OFF GENMASK(9, 5)
> | #define PCPU_GPR_ADDR_SHIFT 10
> | #define PCPU_GPR_ADDR GENMASK(14, 10)
> |
> | #define __VAL_PCPU_GPRS(pcp, off, addr) \
> | "(" \
> | "(.L__gpr_num_" pcp " << " __stringify(PCPU_GPR_PCP_SHIFT) ") | " \
> | "(.L__gpr_num_" off " << " __stringify(PCPU_GPR_OFF_SHIFT) ") | " \
> | "(.L__gpr_num_" addr " << " __stringify(PCPU_GPR_ADDR_SHIFT) ")" \
> | ")"
>
> ... if that's any better?
#define PCPU_GPR_BITS 5
#define __PCPU_GPR_MASK(_shift) GENMASK((_shift+PCPU_GPR_BITS-1), _shift)
#define PCPU_GPR_PCP_SHIFT (0*PCPU_GPR_BITS)
#define PCPU_GPR_OFF_SHIFT (1*PCPU_GPR_BITS)
#define PCPU_GPR_ADDR_SHIFT (2*PCPU_GPR_BITS)
#define PCPU_GPR_PCP __PCPU_GPR_MASK(PCPU_GPR_PCP_SHIFT)
#define PCPU_GPR_OFF __PCPU_GPR_MASK(PCPU_GPR_OFF_SHIFT)
#define PCPU_GPR_ADDR __PCPU_GPR_MASK(PCPU_GPR_ADDR_SHIFT)
?
next prev parent reply other threads:[~2026-07-28 16:46 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-28 12:38 [RFC PATCH 00/13] arm64: Preemptible this_cpu_*() operations Mark Rutland
2026-07-28 12:38 ` [RFC PATCH 01/13] arm64: preempt: Simplify and optimize __preempt_count_dec_and_test() Mark Rutland
2026-07-28 12:38 ` [RFC PATCH 02/13] arm64: preempt: Treat should_resched() as unlikely Mark Rutland
2026-07-28 12:38 ` [RFC PATCH 03/13] arm64: ptrace: Always inline pt_regs_[read,write}_reg() Mark Rutland
2026-07-28 12:38 ` [RFC PATCH 04/13] arm64: percpu: Factor out percpu offset asm Mark Rutland
2026-07-28 12:38 ` [RFC PATCH 05/13] arm64: gpr-num: Add wxN aliases for wN registers Mark Rutland
2026-07-28 12:38 ` [RFC PATCH 06/13] arm64: percpu: Add infrastructure for preemptible this_cpu_*() ops Mark Rutland
2026-07-28 14:19 ` Peter Zijlstra
2026-07-28 14:30 ` Peter Zijlstra
2026-07-28 16:03 ` Mark Rutland
2026-07-28 16:49 ` Peter Zijlstra
2026-07-28 15:53 ` Mark Rutland
2026-07-28 16:46 ` Peter Zijlstra [this message]
2026-07-28 16:49 ` Peter Zijlstra
2026-07-28 16:51 ` Heiko Carstens
2026-07-28 12:38 ` [RFC PATCH 07/13] arm64: percpu: Implement preemptible read/write ops Mark Rutland
2026-07-28 21:47 ` David Laight
2026-07-28 22:05 ` David Laight
2026-07-28 12:38 ` [RFC PATCH 08/13] arm64: percpu: Implement preemptible void RMW ops Mark Rutland
2026-07-28 12:38 ` [RFC PATCH 09/13] arm64: percpu: Implement preemptible return " Mark Rutland
2026-07-28 12:38 ` [RFC PATCH 10/13] arm64: percpu: Implement preemptible XCHG ops Mark Rutland
2026-07-28 12:38 ` [RFC PATCH 11/13] arm64: percpu: Implement preemptible CMPXCHG ops Mark Rutland
2026-07-28 12:38 ` [RFC PATCH 12/13] arm64: percpu: Implement preemptible CMPXCHG128 ops Mark Rutland
2026-07-28 12:38 ` [RFC PATCH 13/13] arm64: percpu: Remove _pcp_protect*() wrappers Mark Rutland
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