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[35.245.167.64]) by smtp.gmail.com with ESMTPSA id 3f1490d57ef6-e842ac5c538sm3942684276.33.2025.06.25.16.18.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Jun 2025 16:18:49 -0700 (PDT) From: Pasha Tatashin To: pratyush@kernel.org, jasonmiu@google.com, graf@amazon.com, changyuanl@google.com, pasha.tatashin@soleen.com, rppt@kernel.org, dmatlack@google.com, rientjes@google.com, corbet@lwn.net, rdunlap@infradead.org, ilpo.jarvinen@linux.intel.com, kanie@linux.alibaba.com, ojeda@kernel.org, aliceryhl@google.com, masahiroy@kernel.org, akpm@linux-foundation.org, tj@kernel.org, yoann.congal@smile.fr, mmaurer@google.com, roman.gushchin@linux.dev, chenridong@huawei.com, axboe@kernel.dk, mark.rutland@arm.com, jannh@google.com, vincent.guittot@linaro.org, hannes@cmpxchg.org, dan.j.williams@intel.com, david@redhat.com, joel.granados@kernel.org, rostedt@goodmis.org, anna.schumaker@oracle.com, song@kernel.org, zhangguopeng@kylinos.cn, linux@weissschuh.net, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, gregkh@linuxfoundation.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, rafael@kernel.org, dakr@kernel.org, bartosz.golaszewski@linaro.org, cw00.choi@samsung.com, myungjoo.ham@samsung.com, yesanishhere@gmail.com, Jonathan.Cameron@huawei.com, quic_zijuhu@quicinc.com, aleksander.lobakin@intel.com, ira.weiny@intel.com, andriy.shevchenko@linux.intel.com, leon@kernel.org, lukas@wunner.de, bhelgaas@google.com, wagi@kernel.org, djeffery@redhat.com, stuart.w.hayes@gmail.com, ptyadav@amazon.de, lennart@poettering.net, brauner@kernel.org, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v1 04/32] kho: allow to drive kho from within kernel Date: Wed, 25 Jun 2025 23:17:51 +0000 Message-ID: <20250625231838.1897085-5-pasha.tatashin@soleen.com> X-Mailer: git-send-email 2.50.0.727.gbf7dc18ff4-goog In-Reply-To: <20250625231838.1897085-1-pasha.tatashin@soleen.com> References: <20250625231838.1897085-1-pasha.tatashin@soleen.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Allow to do finalize and abort from kernel modules, so LUO could drive the KHO sequence via its own state machine. Signed-off-by: Pasha Tatashin --- include/linux/kexec_handover.h | 15 +++++++++ kernel/kexec_handover.c | 58 ++++++++++++++++++++++++++++++++-- 2 files changed, 71 insertions(+), 2 deletions(-) diff --git a/include/linux/kexec_handover.h b/include/linux/kexec_handover.h index 348844cffb13..f98565def593 100644 --- a/include/linux/kexec_handover.h +++ b/include/linux/kexec_handover.h @@ -54,6 +54,10 @@ void kho_memory_init(void); =20 void kho_populate(phys_addr_t fdt_phys, u64 fdt_len, phys_addr_t scratch_p= hys, u64 scratch_len); + +int kho_finalize(void); +int kho_abort(void); + #else static inline bool kho_is_enabled(void) { @@ -104,6 +108,17 @@ static inline void kho_populate(phys_addr_t fdt_phys, = u64 fdt_len, phys_addr_t scratch_phys, u64 scratch_len) { } + +static inline int kho_finalize(void) +{ + return -EOPNOTSUPP; +} + +static inline int kho_abort(void) +{ + return -EOPNOTSUPP; +} + #endif /* CONFIG_KEXEC_HANDOVER */ =20 #endif /* LINUX_KEXEC_HANDOVER_H */ diff --git a/kernel/kexec_handover.c b/kernel/kexec_handover.c index 069d5890841c..af6a11f48213 100644 --- a/kernel/kexec_handover.c +++ b/kernel/kexec_handover.c @@ -757,7 +757,7 @@ static int kho_out_update_debugfs_fdt(void) return err; } =20 -static int kho_abort(void) +static int __kho_abort(void) { int err; unsigned long order; @@ -790,7 +790,34 @@ static int kho_abort(void) return err; } =20 -static int kho_finalize(void) +int kho_abort(void) +{ + int ret =3D 0; + + if (!kho_enable) + return -EOPNOTSUPP; + + mutex_lock(&kho_out.lock); + + if (!kho_out.finalized) { + ret =3D -ENOENT; + goto unlock; + } + + ret =3D __kho_abort(); + if (ret) + goto unlock; + + kho_out.finalized =3D false; + ret =3D kho_out_update_debugfs_fdt(); + +unlock: + mutex_unlock(&kho_out.lock); + return ret; +} +EXPORT_SYMBOL_GPL(kho_abort); + +static int __kho_finalize(void) { int err =3D 0; u64 *preserved_mem_map; @@ -839,6 +866,33 @@ static int kho_finalize(void) return err; } =20 +int kho_finalize(void) +{ + int ret =3D 0; + + if (!kho_enable) + return -EOPNOTSUPP; + + mutex_lock(&kho_out.lock); + + if (kho_out.finalized) { + ret =3D -EEXIST; + goto unlock; + } + + ret =3D __kho_finalize(); + if (ret) + goto unlock; + + kho_out.finalized =3D true; + ret =3D kho_out_update_debugfs_fdt(); + +unlock: + mutex_unlock(&kho_out.lock); + return ret; +} +EXPORT_SYMBOL_GPL(kho_finalize); + static int kho_out_finalize_get(void *data, u64 *val) { mutex_lock(&kho_out.lock); --=20 2.50.0.727.gbf7dc18ff4-goog