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Fri, 30 May 2025 02:30:28 -0700 (PDT) From: Bo Li To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, luto@kernel.org, kees@kernel.org, akpm@linux-foundation.org, david@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, peterz@infradead.org Cc: dietmar.eggemann@arm.com, hpa@zytor.com, acme@kernel.org, namhyung@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, irogers@google.com, adrian.hunter@intel.com, kan.liang@linux.intel.com, viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, mhocko@suse.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, jannh@google.com, pfalcato@suse.de, riel@surriel.com, harry.yoo@oracle.com, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, duanxiongchun@bytedance.com, yinhongbo@bytedance.com, dengliang.1214@bytedance.com, xieyongji@bytedance.com, chaiwen.cc@bytedance.com, songmuchun@bytedance.com, yuanzhu@bytedance.com, chengguozhu@bytedance.com, sunjiadong.lff@bytedance.com, Bo Li Subject: [RFC v2 08/35] RPAL: enable sender/receiver registration Date: Fri, 30 May 2025 17:27:36 +0800 Message-Id: X-Mailer: git-send-email 2.39.5 (Apple Git-154) In-Reply-To: References: 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" In RPAL, there are two roles: the sender (caller) and the receiver ( callee). This patch provides an interface for threads to register as a sender or a receiver with the kernel. Each sender and receiver has its own data structure, along with a block of memory shared between the user space and the kernel space, which is allocated through rpal_mmap(). Signed-off-by: Bo Li --- arch/x86/rpal/Makefile | 2 +- arch/x86/rpal/internal.h | 7 ++ arch/x86/rpal/proc.c | 12 +++ arch/x86/rpal/service.c | 6 ++ arch/x86/rpal/thread.c | 165 +++++++++++++++++++++++++++++++++++++++ include/linux/rpal.h | 79 +++++++++++++++++++ include/linux/sched.h | 15 ++++ init/init_task.c | 2 + kernel/fork.c | 2 + 9 files changed, 289 insertions(+), 1 deletion(-) create mode 100644 arch/x86/rpal/thread.c diff --git a/arch/x86/rpal/Makefile b/arch/x86/rpal/Makefile index a5926fc19334..89f745382c51 100644 --- a/arch/x86/rpal/Makefile +++ b/arch/x86/rpal/Makefile @@ -2,4 +2,4 @@ =20 obj-$(CONFIG_RPAL) +=3D rpal.o =20 -rpal-y :=3D service.o core.o mm.o proc.o +rpal-y :=3D service.o core.o mm.o proc.o thread.o diff --git a/arch/x86/rpal/internal.h b/arch/x86/rpal/internal.h index 65fd14a26f0e..3559c9c6e868 100644 --- a/arch/x86/rpal/internal.h +++ b/arch/x86/rpal/internal.h @@ -34,3 +34,10 @@ static inline void rpal_put_shared_page(struct rpal_shar= ed_page *rsp) int rpal_mmap(struct file *filp, struct vm_area_struct *vma); struct rpal_shared_page *rpal_find_shared_page(struct rpal_service *rs, unsigned long addr); + +/* thread.c */ +int rpal_register_sender(unsigned long addr); +int rpal_unregister_sender(void); +int rpal_register_receiver(unsigned long addr); +int rpal_unregister_receiver(void); +void exit_rpal_thread(void); diff --git a/arch/x86/rpal/proc.c b/arch/x86/rpal/proc.c index 86947dc233d0..8a1e4a8a2271 100644 --- a/arch/x86/rpal/proc.c +++ b/arch/x86/rpal/proc.c @@ -51,6 +51,18 @@ static long rpal_ioctl(struct file *file, unsigned int c= md, unsigned long arg) case RPAL_IOCTL_GET_SERVICE_ID: ret =3D put_user(cur->id, (int __user *)arg); break; + case RPAL_IOCTL_REGISTER_SENDER: + ret =3D rpal_register_sender(arg); + break; + case RPAL_IOCTL_UNREGISTER_SENDER: + ret =3D rpal_unregister_sender(); + break; + case RPAL_IOCTL_REGISTER_RECEIVER: + ret =3D rpal_register_receiver(arg); + break; + case RPAL_IOCTL_UNREGISTER_RECEIVER: + ret =3D rpal_unregister_receiver(); + break; default: return -EINVAL; } diff --git a/arch/x86/rpal/service.c b/arch/x86/rpal/service.c index f29a046fc22f..42fb719dbb2a 100644 --- a/arch/x86/rpal/service.c +++ b/arch/x86/rpal/service.c @@ -176,6 +176,7 @@ struct rpal_service *rpal_register_service(void) mutex_init(&rs->mutex); rs->nr_shared_pages =3D 0; INIT_LIST_HEAD(&rs->shared_pages); + atomic_set(&rs->thread_cnt, 0); =20 rs->bad_service =3D false; rs->base =3D calculate_base_address(rs->id); @@ -216,6 +217,9 @@ void rpal_unregister_service(struct rpal_service *rs) if (!rs) return; =20 + while (atomic_read(&rs->thread_cnt) !=3D 0) + schedule(); + delete_service(rs); =20 pr_debug("rpal: unregister service, id: %d, tgid: %d\n", rs->id, @@ -238,6 +242,8 @@ void exit_rpal(bool group_dead) if (!rs) return; =20 + exit_rpal_thread(); + current->rpal_rs =3D NULL; rpal_put_service(rs); =20 diff --git a/arch/x86/rpal/thread.c b/arch/x86/rpal/thread.c new file mode 100644 index 000000000000..7550ad94b63f --- /dev/null +++ b/arch/x86/rpal/thread.c @@ -0,0 +1,165 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * RPAL service level operations + * Copyright (c) 2025, ByteDance. All rights reserved. + * + * Author: Jiadong Sun + */ + +#include + +#include "internal.h" + +static void rpal_common_data_init(struct rpal_common_data *rcd) +{ + rcd->bp_task =3D current; + rcd->service_id =3D rpal_current_service()->id; +} + +int rpal_register_sender(unsigned long addr) +{ + struct rpal_service *cur =3D rpal_current_service(); + struct rpal_shared_page *rsp; + struct rpal_sender_data *rsd; + long ret =3D 0; + + if (rpal_test_current_thread_flag(RPAL_SENDER_BIT)) { + ret =3D -EINVAL; + goto out; + } + + rsp =3D rpal_find_shared_page(cur, addr); + if (!rsp) { + ret =3D -EINVAL; + goto out; + } + + if (addr + sizeof(struct rpal_sender_call_context) > + rsp->user_start + rsp->npage * PAGE_SIZE) { + ret =3D -EINVAL; + goto put_shared_page; + } + + rsd =3D kzalloc(sizeof(*rsd), GFP_KERNEL); + if (rsd =3D=3D NULL) { + ret =3D -ENOMEM; + goto put_shared_page; + } + + rpal_common_data_init(&rsd->rcd); + rsd->rsp =3D rsp; + rsd->scc =3D (struct rpal_sender_call_context *)(addr - rsp->user_start + + rsp->kernel_start); + + current->rpal_sd =3D rsd; + rpal_set_current_thread_flag(RPAL_SENDER_BIT); + + atomic_inc(&cur->thread_cnt); + + return 0; + +put_shared_page: + rpal_put_shared_page(rsp); +out: + return ret; +} + +int rpal_unregister_sender(void) +{ + struct rpal_service *cur =3D rpal_current_service(); + struct rpal_sender_data *rsd =3D current->rpal_sd; + long ret =3D 0; + + if (!rpal_test_current_thread_flag(RPAL_SENDER_BIT)) { + ret =3D -EINVAL; + goto out; + } + + rpal_put_shared_page(rsd->rsp); + rpal_clear_current_thread_flag(RPAL_SENDER_BIT); + kfree(rsd); + + atomic_dec(&cur->thread_cnt); + +out: + return ret; +} + +int rpal_register_receiver(unsigned long addr) +{ + struct rpal_service *cur =3D rpal_current_service(); + struct rpal_receiver_data *rrd; + struct rpal_shared_page *rsp; + long ret =3D 0; + + if (rpal_test_current_thread_flag(RPAL_RECEIVER_BIT)) { + ret =3D -EINVAL; + goto out; + } + + rsp =3D rpal_find_shared_page(cur, addr); + if (!rsp) { + ret =3D -EINVAL; + goto out; + } + + if (addr + sizeof(struct rpal_receiver_call_context) > + rsp->user_start + rsp->npage * PAGE_SIZE) { + ret =3D -EINVAL; + goto put_shared_page; + } + + rrd =3D kzalloc(sizeof(*rrd), GFP_KERNEL); + if (rrd =3D=3D NULL) { + ret =3D -ENOMEM; + goto put_shared_page; + } + + rpal_common_data_init(&rrd->rcd); + rrd->rsp =3D rsp; + rrd->rcc =3D + (struct rpal_receiver_call_context *)(addr - rsp->user_start + + rsp->kernel_start); + + current->rpal_rd =3D rrd; + rpal_set_current_thread_flag(RPAL_RECEIVER_BIT); + + atomic_inc(&cur->thread_cnt); + + return 0; + +put_shared_page: + rpal_put_shared_page(rsp); +out: + return ret; +} + +int rpal_unregister_receiver(void) +{ + struct rpal_service *cur =3D rpal_current_service(); + struct rpal_receiver_data *rrd =3D current->rpal_rd; + long ret =3D 0; + + if (!rpal_test_current_thread_flag(RPAL_RECEIVER_BIT)) { + ret =3D -EINVAL; + goto out; + } + + rpal_put_shared_page(rrd->rsp); + rpal_clear_current_thread_flag(RPAL_RECEIVER_BIT); + kfree(rrd); + + atomic_dec(&cur->thread_cnt); + +out: + return ret; +} + +void exit_rpal_thread(void) +{ + if (rpal_test_current_thread_flag(RPAL_SENDER_BIT)) + rpal_unregister_sender(); + + if (rpal_test_current_thread_flag(RPAL_RECEIVER_BIT)) + rpal_unregister_receiver(); +} diff --git a/include/linux/rpal.h b/include/linux/rpal.h index 986dfbd16fc9..c33425e896af 100644 --- a/include/linux/rpal.h +++ b/include/linux/rpal.h @@ -79,6 +79,11 @@ =20 extern unsigned long rpal_cap; =20 +enum rpal_task_flag_bits { + RPAL_SENDER_BIT, + RPAL_RECEIVER_BIT, +}; + /* * Each RPAL process (a.k.a RPAL service) should have a pointer to * struct rpal_service in all its tasks' task_struct. @@ -117,6 +122,9 @@ struct rpal_service { int nr_shared_pages; struct list_head shared_pages; =20 + /* sender/receiver thread count */ + atomic_t thread_cnt; + /* delayed service put work */ struct delayed_work delayed_put_work; =20 @@ -149,10 +157,55 @@ struct rpal_shared_page { struct list_head list; }; =20 +struct rpal_common_data { + /* back pointer to task_struct */ + struct task_struct *bp_task; + /* service id of rpal_service */ + int service_id; +}; + +/* User registers state */ +struct rpal_task_context { + u64 r15; + u64 r14; + u64 r13; + u64 r12; + u64 rbx; + u64 rbp; + u64 rip; + u64 rsp; +}; + +struct rpal_receiver_call_context { + struct rpal_task_context rtc; + int receiver_id; +}; + +struct rpal_receiver_data { + struct rpal_common_data rcd; + struct rpal_shared_page *rsp; + struct rpal_receiver_call_context *rcc; +}; + +struct rpal_sender_call_context { + struct rpal_task_context rtc; + int sender_id; +}; + +struct rpal_sender_data { + struct rpal_common_data rcd; + struct rpal_shared_page *rsp; + struct rpal_sender_call_context *scc; +}; + enum rpal_command_type { RPAL_CMD_GET_API_VERSION_AND_CAP, RPAL_CMD_GET_SERVICE_KEY, RPAL_CMD_GET_SERVICE_ID, + RPAL_CMD_REGISTER_SENDER, + RPAL_CMD_UNREGISTER_SENDER, + RPAL_CMD_REGISTER_RECEIVER, + RPAL_CMD_UNREGISTER_RECEIVER, RPAL_NR_CMD, }; =20 @@ -165,6 +218,14 @@ enum rpal_command_type { _IOWR(RPAL_IOCTL_MAGIC, RPAL_CMD_GET_SERVICE_KEY, u64 *) #define RPAL_IOCTL_GET_SERVICE_ID \ _IOWR(RPAL_IOCTL_MAGIC, RPAL_CMD_GET_SERVICE_ID, int *) +#define RPAL_IOCTL_REGISTER_SENDER \ + _IOWR(RPAL_IOCTL_MAGIC, RPAL_CMD_REGISTER_SENDER, unsigned long) +#define RPAL_IOCTL_UNREGISTER_SENDER \ + _IO(RPAL_IOCTL_MAGIC, RPAL_CMD_UNREGISTER_SENDER) +#define RPAL_IOCTL_REGISTER_RECEIVER \ + _IOWR(RPAL_IOCTL_MAGIC, RPAL_CMD_REGISTER_RECEIVER, unsigned long) +#define RPAL_IOCTL_UNREGISTER_RECEIVER \ + _IO(RPAL_IOCTL_MAGIC, RPAL_CMD_UNREGISTER_RECEIVER) =20 /** * @brief get new reference to a rpal service, a corresponding @@ -200,8 +261,26 @@ static inline struct rpal_service *rpal_current_servic= e(void) { return current->rpal_rs; } + +static inline void rpal_set_current_thread_flag(unsigned long bit) +{ + set_bit(bit, ¤t->rpal_flag); +} + +static inline void rpal_clear_current_thread_flag(unsigned long bit) +{ + clear_bit(bit, ¤t->rpal_flag); +} + +static inline bool rpal_test_current_thread_flag(unsigned long bit) +{ + return test_bit(bit, ¤t->rpal_flag); +} #else static inline struct rpal_service *rpal_current_service(void) { return NUL= L; } +static inline void rpal_set_current_thread_flag(unsigned long bit) { } +static inline void rpal_clear_current_thread_flag(unsigned long bit) { } +static inline bool rpal_test_current_thread_flag(unsigned long bit) { retu= rn false; } #endif =20 void rpal_unregister_service(struct rpal_service *rs); diff --git a/include/linux/sched.h b/include/linux/sched.h index ad35b197543c..5f25cc09fb71 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -72,6 +72,9 @@ struct rcu_node; struct reclaim_state; struct robust_list_head; struct root_domain; +struct rpal_common_data; +struct rpal_receiver_data; +struct rpal_sender_data; struct rpal_service; struct rq; struct sched_attr; @@ -1648,6 +1651,18 @@ struct task_struct { =20 #ifdef CONFIG_RPAL struct rpal_service *rpal_rs; + unsigned long rpal_flag; + /* + * The first member of both rpal_sd and rpal_rd has a type + * of struct rpal_common_data. So if we do not care whether + * it is a struct rpal_sender_data or a struct rpal_receiver_data, + * use rpal_cd instead of rpal_sd or rpal_rd. + */ + union { + struct rpal_common_data *rpal_cd; + struct rpal_sender_data *rpal_sd; + struct rpal_receiver_data *rpal_rd; + }; #endif =20 /* CPU-specific state of this task: */ diff --git a/init/init_task.c b/init/init_task.c index 0c5b1927da41..2eb08b96e66b 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -222,6 +222,8 @@ struct task_struct init_task __aligned(L1_CACHE_BYTES) = =3D { #endif #ifdef CONFIG_RPAL .rpal_rs =3D NULL, + .rpal_flag =3D 0, + .rpal_cd =3D NULL, #endif }; EXPORT_SYMBOL(init_task); diff --git a/kernel/fork.c b/kernel/fork.c index 1d1c8484a8f2..01cd48eadf68 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1220,6 +1220,8 @@ static struct task_struct *dup_task_struct(struct tas= k_struct *orig, int node) =20 #ifdef CONFIG_RPAL tsk->rpal_rs =3D NULL; + tsk->rpal_flag =3D 0; + tsk->rpal_cd =3D NULL; #endif return tsk; =20 --=20 2.20.1