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To: Shrikanth Hegde , Mukesh Kumar Chaurasiya , maddy@linux.ibm.com, mpe@ellerman.id.au, npiggin@gmail.com, christophe.leroy@csgroup.eu Cc: oleg@redhat.com, kees@kernel.org, luto@amacapital.net, wad@chromium.org, deller@gmx.de, ldv@strace.io, macro@orcam.me.uk, charlie@rivosinc.com, akpm@linux-foundation.org, bigeasy@linutronix.de, ankur.a.arora@oracle.com, naveen@kernel.org, thomas.weissschuh@linutronix.de, Jason@zx2c4.com, peterz@infradead.org, tglx@linutronix.de, namcao@linutronix.de, kan.liang@linux.intel.com, mingo@kernel.org, oliver.upton@linux.dev, mark.barnett@arm.com, atrajeev@linux.vnet.ibm.com, rppt@kernel.org, coltonlewis@google.com, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org References: <20250908210235.137300-2-mchauras@linux.ibm.com> <20250908210235.137300-10-mchauras@linux.ibm.com> <589f259e-1db9-4ec2-accc-b27966d09a3e@linux.ibm.com> Content-Language: en-US, en-IN, en-GB From: Mukesh Kumar Chaurasiya In-Reply-To: <589f259e-1db9-4ec2-accc-b27966d09a3e@linux.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Authority-Analysis: v=2.4 cv=Qf5mvtbv c=1 sm=1 tr=0 ts=68cbad0b cx=c_pps a=bLidbwmWQ0KltjZqbj+ezA==:117 a=bLidbwmWQ0KltjZqbj+ezA==:17 a=IkcTkHD0fZMA:10 a=yJojWOMRYYMA:10 a=VnNF1IyMAAAA:8 a=q5CvZCToSJJqjgns3BoA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 X-Proofpoint-ORIG-GUID: IUAX_AP3EfalgYdLro8ulS_vbTnlZPn5 X-Proofpoint-GUID: 2Okb0Q0M4TVWHetba6bcmpHlWN1t0k3g X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwOTE2MDIwNCBTYWx0ZWRfXw1g9te6O2pOb rUM9pLlvWVxarW8Kehn6rEjCE98eFiQWC/Mg3Vome2eofKa2DNEX3xl+RXdBkxV/eO6Q4/nfSky bNHePQZHKxL/BtVKXhLUi5d7tFQUwqW3RM9kcwQKPb9ggqOjMG2qqfjyWLDku0TWQucfkIx23WI jwMjgSfVGKiB3C3loyQgGvhJSQ5Rj2ciHnnNMpc3KDzJXOAyCdO72sCIl0s0ViZRK8ro0Nyhm80 /vq5Ju3iNzD/FRc/jv1ETdat/B82Jw1ZlJ6Agt5/+AGoowuBgaMHq7iIXcp+D91DVjQ7y8GgFAq qgBg8CJQsImg7vSi8NRt4Kue11lkH6xSR2XMs/I4JRZncQGIeEU+FGEmadjcoUoVlVUAP3Ok2qf EK9YCzrc X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1117,Hydra:6.1.9,FMLib:17.12.80.40 definitions=2025-09-17_01,2025-09-18_01,2025-03-28_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 clxscore=1015 phishscore=0 suspectscore=0 adultscore=0 priorityscore=1501 malwarescore=0 bulkscore=0 impostorscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2507300000 definitions=main-2509160204 On 9/16/25 9:46 AM, Shrikanth Hegde wrote: > > > On 9/9/25 2:32 AM, Mukesh Kumar Chaurasiya wrote: >> Enable generic entry/exit path for ppc irq. >> >> Signed-off-by: Mukesh Kumar Chaurasiya >> --- >>   arch/powerpc/Kconfig                    |   1 + >>   arch/powerpc/include/asm/entry-common.h |  93 ++--- >>   arch/powerpc/include/asm/interrupt.h    | 492 +++--------------------- >>   arch/powerpc/kernel/interrupt.c         |   9 +- >>   arch/powerpc/kernel/interrupt_64.S      |   2 - >>   5 files changed, 92 insertions(+), 505 deletions(-) >> >                                 \ >> diff --git a/arch/powerpc/kernel/interrupt.c >> b/arch/powerpc/kernel/interrupt.c >> index f53d432f60870..7bb8a31b24ea7 100644 >> --- a/arch/powerpc/kernel/interrupt.c >> +++ b/arch/powerpc/kernel/interrupt.c >> @@ -297,13 +297,8 @@ notrace unsigned long >> interrupt_exit_kernel_prepare(struct pt_regs *regs) >>           /* Returning to a kernel context with local irqs enabled. */ >>           WARN_ON_ONCE(!(regs->msr & MSR_EE)); >>   again: >> -        if (need_irq_preemption()) { >> -            /* Return to preemptible kernel context */ >> -            if (unlikely(read_thread_flags() & _TIF_NEED_RESCHED)) { >> -                if (preempt_count() == 0) >> -                    preempt_schedule_irq(); >> -            } >> -        } >> +        if (need_irq_preemption()) >> +            irqentry_exit_cond_resched(); > > irqentry_exit_cond_resched is also called in irqentry_exit. It would > be better if we can find ways to avoid calling it again. > > I see a loop here. But comment says it is not enabling irq again. so > the loop is bounded. So might be okay to remove cond_resched here. do run > preemptirq, irq tracers to ensure that is case. > Sure. > Also, what is this "soft_interrupts"? You mean soft masked interrupts? It's a mechanism to buffer interrupts without disabling the ee bit so that we can replay those interrupts later. >>             check_return_regs_valid(regs); >>   diff --git a/arch/powerpc/kernel/interrupt_64.S >> b/arch/powerpc/kernel/interrupt_64.S >> index 1ad059a9e2fef..6aa88fe91fb6a 100644 >> --- a/arch/powerpc/kernel/interrupt_64.S >> +++ b/arch/powerpc/kernel/interrupt_64.S >> @@ -418,8 +418,6 @@ _ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\()) >>       beq    interrupt_return_\srr\()_kernel >>   interrupt_return_\srr\()_user: /* make backtraces match the _kernel >> variant */ >>   _ASM_NOKPROBE_SYMBOL(interrupt_return_\srr\()_user) >> -    addi    r3,r1,STACK_INT_FRAME_REGS >> -    bl    CFUNC(interrupt_exit_user_prepare) >>   #ifndef CONFIG_INTERRUPT_SANITIZE_REGISTERS >>       cmpdi    r3,0 >>       bne-    .Lrestore_nvgprs_\srr >