From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B84A5233733; Mon, 2 Jun 2025 14:56:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748876189; cv=none; b=F2to0ErwZAhPmLfQ9NphAT6A3t9x0jM7lv07Pa4fFe7PMyF9/3R4HR808SOmYl62lPJ5SRiJ7p6c7pegDQSVmUCrbqWncCM0pRZDK+yif3bj6EbUyW0jDWML5PqIFL9UCC72KEMglvrclNWzQkptYA1tHZjpSGsrc85InUzb0lk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748876189; c=relaxed/simple; bh=V7Cvn6C8IwvPK1uEvfO9Y+3VAk083o5DkVDawD1xjZ0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PqPLULWXQhdydDNkOvBTlbTvPnQ85cl8vfyZffCqDv0C7ADhR0asyi5CLH5oIELtfzfEDlsy4hMLbJ2Rop1pe6u3mIoUdyddWNFRaw+Vx4tB8YbLuAaL+yFxuZnySeTAl2i4FdGklSKBcFELIThJt9PIKkx7hkXXkND0fzUUId4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nKGp2eoh; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nKGp2eoh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AB0F6C4CEEE; Mon, 2 Jun 2025 14:56:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1748876189; bh=V7Cvn6C8IwvPK1uEvfO9Y+3VAk083o5DkVDawD1xjZ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nKGp2eohM/kw4DNUe2TjLhNTng9RAOEO0p+BB4OP4UVEeIy1ZhmrrxOc/YKiXnvPd JFSzbDIOJ4IfBZZMI1hK7v6u2meJZSgN15gJxIX/8rhN40ID5/htJ8p+i5OGrurvrv HrSakA2CglHBqtKWKSM+fnnLz97qmv+vtW1uHN6s= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Paul Burton , Dragan Mladjenovic , Aleksandar Rikalo , Serge Semin , Gregory CLEMENT , Thomas Bogendoerfer , Sasha Levin Subject: [PATCH 5.15 100/207] MIPS: pm-cps: Use per-CPU variables as per-CPU, not per-core Date: Mon, 2 Jun 2025 15:47:52 +0200 Message-ID: <20250602134302.656890656@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250602134258.769974467@linuxfoundation.org> References: <20250602134258.769974467@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paul Burton [ Upstream commit 00a134fc2bb4a5f8fada58cf7ff4259149691d64 ] The pm-cps code has up until now used per-CPU variables indexed by core, rather than CPU number, in order to share data amongst sibling CPUs (ie. VPs/threads in a core). This works fine for single cluster systems, but with multi-cluster systems a core number is no longer unique in the system, leading to sharing between CPUs that are not actually siblings. Avoid this issue by using per-CPU variables as they are more generally used - ie. access them using CPU numbers rather than core numbers. Sharing between siblings is then accomplished by: - Assigning the same pointer to entries for each sibling CPU for the nc_asm_enter & ready_count variables, which allow this by virtue of being per-CPU pointers. - Indexing by the first CPU set in a CPUs cpu_sibling_map in the case of pm_barrier, for which we can't use the previous approach because the per-CPU variable is not a pointer. Signed-off-by: Paul Burton Signed-off-by: Dragan Mladjenovic Signed-off-by: Aleksandar Rikalo Tested-by: Serge Semin Tested-by: Gregory CLEMENT Signed-off-by: Thomas Bogendoerfer Signed-off-by: Sasha Levin --- arch/mips/kernel/pm-cps.c | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-) diff --git a/arch/mips/kernel/pm-cps.c b/arch/mips/kernel/pm-cps.c index 9bf60d7d44d36..a7bcf2b814c86 100644 --- a/arch/mips/kernel/pm-cps.c +++ b/arch/mips/kernel/pm-cps.c @@ -56,10 +56,7 @@ static DEFINE_PER_CPU_ALIGNED(u32*, ready_count); /* Indicates online CPUs coupled with the current CPU */ static DEFINE_PER_CPU_ALIGNED(cpumask_t, online_coupled); -/* - * Used to synchronize entry to deep idle states. Actually per-core rather - * than per-CPU. - */ +/* Used to synchronize entry to deep idle states */ static DEFINE_PER_CPU_ALIGNED(atomic_t, pm_barrier); /* Saved CPU state across the CPS_PM_POWER_GATED state */ @@ -118,9 +115,10 @@ int cps_pm_enter_state(enum cps_pm_state state) cps_nc_entry_fn entry; struct core_boot_config *core_cfg; struct vpe_boot_config *vpe_cfg; + atomic_t *barrier; /* Check that there is an entry function for this state */ - entry = per_cpu(nc_asm_enter, core)[state]; + entry = per_cpu(nc_asm_enter, cpu)[state]; if (!entry) return -EINVAL; @@ -156,7 +154,7 @@ int cps_pm_enter_state(enum cps_pm_state state) smp_mb__after_atomic(); /* Create a non-coherent mapping of the core ready_count */ - core_ready_count = per_cpu(ready_count, core); + core_ready_count = per_cpu(ready_count, cpu); nc_addr = kmap_noncoherent(virt_to_page(core_ready_count), (unsigned long)core_ready_count); nc_addr += ((unsigned long)core_ready_count & ~PAGE_MASK); @@ -164,7 +162,8 @@ int cps_pm_enter_state(enum cps_pm_state state) /* Ensure ready_count is zero-initialised before the assembly runs */ WRITE_ONCE(*nc_core_ready_count, 0); - coupled_barrier(&per_cpu(pm_barrier, core), online); + barrier = &per_cpu(pm_barrier, cpumask_first(&cpu_sibling_map[cpu])); + coupled_barrier(barrier, online); /* Run the generated entry code */ left = entry(online, nc_core_ready_count); @@ -635,12 +634,14 @@ static void *cps_gen_entry_code(unsigned cpu, enum cps_pm_state state) static int cps_pm_online_cpu(unsigned int cpu) { - enum cps_pm_state state; - unsigned core = cpu_core(&cpu_data[cpu]); + unsigned int sibling, core; void *entry_fn, *core_rc; + enum cps_pm_state state; + + core = cpu_core(&cpu_data[cpu]); for (state = CPS_PM_NC_WAIT; state < CPS_PM_STATE_COUNT; state++) { - if (per_cpu(nc_asm_enter, core)[state]) + if (per_cpu(nc_asm_enter, cpu)[state]) continue; if (!test_bit(state, state_support)) continue; @@ -652,16 +653,19 @@ static int cps_pm_online_cpu(unsigned int cpu) clear_bit(state, state_support); } - per_cpu(nc_asm_enter, core)[state] = entry_fn; + for_each_cpu(sibling, &cpu_sibling_map[cpu]) + per_cpu(nc_asm_enter, sibling)[state] = entry_fn; } - if (!per_cpu(ready_count, core)) { + if (!per_cpu(ready_count, cpu)) { core_rc = kmalloc(sizeof(u32), GFP_KERNEL); if (!core_rc) { pr_err("Failed allocate core %u ready_count\n", core); return -ENOMEM; } - per_cpu(ready_count, core) = core_rc; + + for_each_cpu(sibling, &cpu_sibling_map[cpu]) + per_cpu(ready_count, sibling) = core_rc; } return 0; -- 2.39.5