From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 781CACAC5B0 for ; Fri, 3 Oct 2025 13:39:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:Cc:To:From: Subject:Message-ID:References:Mime-Version:In-Reply-To:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=cusWrm7Pe7Vzh2zNqiDKt7LKbdzyFf6LREbhhod2FBw=; b=buuz6uZXUNWv0zyggqIxjDJLEr DSPH5H7FcAPF0wXAGfkM5xwSVDrtpHR9CxHubK9o60Ne2HJBPFc3rJQhP2EdlYzTydQ+6d0LFmEF/ WTWMr6fb3tVARUv1wVmuufkooNbYIBH5wkw8f1Jpedd278WUl7M4B/t2ewk0n+GbVChdl2tRotmEU 4I6cL2D4CxtiwVCc2LvCYvlvI4OcHXyZZC1rVySrFtKX3EY1jfqATxaLLmCddGqVkfEVn7p2Wza0U bYZDwSRV1giyQZgyje6jKl7KGcmrg93KJVyWrc2IWmoKcKKgEyhPmsqVLddy/IuFyjMDT0QdvfAPs s/yGv3uw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1v4g0V-0000000CQot-0GXp; Fri, 03 Oct 2025 13:39:35 +0000 Received: from mail-wr1-x449.google.com ([2a00:1450:4864:20::449]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1v4g0B-0000000CQIc-3Ptv for linux-arm-kernel@lists.infradead.org; Fri, 03 Oct 2025 13:39:18 +0000 Received: by mail-wr1-x449.google.com with SMTP id ffacd0b85a97d-3f44000639fso1382779f8f.0 for ; Fri, 03 Oct 2025 06:39:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1759498753; x=1760103553; darn=lists.infradead.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=cusWrm7Pe7Vzh2zNqiDKt7LKbdzyFf6LREbhhod2FBw=; b=WUG8aTA47Z+nv0aCm3zTXTKrOlfc2Q+aD3S/0eYmLbk0S2RhpKjWIYwb0eXKEnBZDM XBbdIwxoLWQdg6okFNEJ1ZPH4uPpNzz+pSsCtQ0wo76a71xhqTpM7SFB3O9KURPW50TO WyzH73PwlVxL4EjkQeU4x/IWp8pRCJQwd4HwSdSfFY5qyDN/HCAI4aqmcLUSX3Kko5Wx 1iFVh6cVS5fWBva44mt4eBWiO3+UJ2Rk+86w207YXaeuc9tehX9cItagp/ey7jXmFhwd P4RuRoZSxrahT2yqwB70htz4T8r8DccqNj+WQ/ztuYiwUJ67yJxS6zwVKXPksaKRmWl8 iGCw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1759498753; x=1760103553; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=cusWrm7Pe7Vzh2zNqiDKt7LKbdzyFf6LREbhhod2FBw=; b=INokJwY6NzzWN+qR5STcq4uj6t27YoPXef0T1ZziE2Xjs+3LkCznZXRBevZP3bLfth BF9KPDNHRQ14WA2OX4k1HZegNUApw2W4Mi6QLWaWJKLv3MPchl2e5br3afJx8kAHGKby aoT/bSt1Z4T0dHOYkDrU2FVf7qOhKQyBNSAQEraXg8M/cyS4XGQ04T+C8BwlM4PAnlpU 2rI57DHPhepZPap4AqBwU4IJrkkh1b+TUfYsG41/9Zr17Xe5G7+TiuYTzRwlf2OOJHow pmK6OYdrTUmsDEhtHuju7pL/MBkkmfIwMFnDMYZ/5oY5bW0L5cnnehmysEyz5i7kt79Z JJhw== X-Forwarded-Encrypted: i=1; AJvYcCVaB09V+m7lxxuHCH/y6BYMij5sE5PZKEHSDvD0igh6lNUL4ufKkW8/xBAgTxrgjcvfzWEmpKbN/BZYneAbqy1s@lists.infradead.org X-Gm-Message-State: AOJu0Yze4CNiiANS/nvbob0icJgleV/u4vprF61cDB8SDKSHrRS5iIdv dlgp8XUX80cwQ3LGS2qstsaIYdr5WFwZgXflMYbQKR13xIba42CeU58I+0+exsmimAbW9/Uo905 kwN4pyu1jzyL8uD5QgdF5MA== X-Google-Smtp-Source: AGHT+IF6GiKCqwKfjKEeuxZgNsXAZSGVRxvCwcB1YwHTIPjTMo5AijDWEtVQrQi9EZhBvqgSIyLZKQ4QheeyH+xU X-Received: from wmby13.prod.google.com ([2002:a05:600c:c04d:b0:46e:3771:b9c9]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6000:18a9:b0:404:ac77:6598 with SMTP id ffacd0b85a97d-4256713ac9dmr2185339f8f.11.1759498753278; Fri, 03 Oct 2025 06:39:13 -0700 (PDT) Date: Fri, 3 Oct 2025 14:38:14 +0100 In-Reply-To: <20251003133825.2068970-1-vdonnefort@google.com> Mime-Version: 1.0 References: <20251003133825.2068970-1-vdonnefort@google.com> X-Mailer: git-send-email 2.51.0.618.g983fd99d29-goog Message-ID: <20251003133825.2068970-18-vdonnefort@google.com> Subject: [PATCH v7 17/28] tracing: load/unload page callbacks for simple_ring_buffer From: Vincent Donnefort To: rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, linux-trace-kernel@vger.kernel.org, maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, jstultz@google.com, qperret@google.com, will@kernel.org, aneesh.kumar@kernel.org, kernel-team@android.com, linux-kernel@vger.kernel.org, Vincent Donnefort Content-Type: text/plain; charset="UTF-8" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251003_063916_016611_E70F33C1 X-CRM114-Status: GOOD ( 16.18 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Add load/unload callback used for each admitted page in the ring-buffer. This will be later useful for the pKVM hypervisor which uses a different VA space and need to dynamically map/unmap the ring-buffer pages. Signed-off-by: Vincent Donnefort diff --git a/include/linux/simple_ring_buffer.h b/include/linux/simple_ring_buffer.h index f324df2f875b..ecd0e988c699 100644 --- a/include/linux/simple_ring_buffer.h +++ b/include/linux/simple_ring_buffer.h @@ -110,4 +110,11 @@ int simple_ring_buffer_reset(struct simple_rb_per_cpu *cpu_buffer); */ int simple_ring_buffer_swap_reader_page(struct simple_rb_per_cpu *cpu_buffer); +int __simple_ring_buffer_init(struct simple_rb_per_cpu *cpu_buffer, + struct simple_buffer_page *bpages, + const struct ring_buffer_desc *desc, + void *(*load_page)(unsigned long va), + void (*unload_page)(void *va)); +void __simple_ring_buffer_unload(struct simple_rb_per_cpu *cpu_buffer, + void (*unload_page)(void *)); #endif diff --git a/kernel/trace/simple_ring_buffer.c b/kernel/trace/simple_ring_buffer.c index 20e3cd6071a2..c2ec6017c37c 100644 --- a/kernel/trace/simple_ring_buffer.c +++ b/kernel/trace/simple_ring_buffer.c @@ -71,7 +71,7 @@ static void simple_bpage_reset(struct simple_buffer_page *bpage) local_set(&bpage->page->commit, 0); } -static void simple_bpage_init(struct simple_buffer_page *bpage, unsigned long page) +static void simple_bpage_init(struct simple_buffer_page *bpage, void *page) { INIT_LIST_HEAD(&bpage->link); bpage->page = (struct buffer_data_page *)page; @@ -338,10 +338,15 @@ int simple_ring_buffer_reset(struct simple_rb_per_cpu *cpu_buffer) return 0; } -int simple_ring_buffer_init(struct simple_rb_per_cpu *cpu_buffer, struct simple_buffer_page *bpages, - const struct ring_buffer_desc *desc) +int __simple_ring_buffer_init(struct simple_rb_per_cpu *cpu_buffer, + struct simple_buffer_page *bpages, + const struct ring_buffer_desc *desc, + void *(*load_page)(unsigned long va), + void (*unload_page)(void *va)) { struct simple_buffer_page *bpage = bpages; + int ret = 0; + void *page; int i; /* At least 1 reader page and two pages in the ring-buffer */ @@ -350,15 +355,22 @@ int simple_ring_buffer_init(struct simple_rb_per_cpu *cpu_buffer, struct simple_ memset(cpu_buffer, 0, sizeof(*cpu_buffer)); - cpu_buffer->bpages = bpages; + cpu_buffer->meta = load_page(desc->meta_va); + if (!cpu_buffer->meta) + return -EINVAL; - cpu_buffer->meta = (void *)desc->meta_va; memset(cpu_buffer->meta, 0, sizeof(*cpu_buffer->meta)); cpu_buffer->meta->meta_page_size = PAGE_SIZE; cpu_buffer->meta->nr_subbufs = cpu_buffer->nr_pages; /* The reader page is not part of the ring initially */ - simple_bpage_init(bpage, desc->page_va[0]); + page = load_page(desc->page_va[0]); + if (!page) { + unload_page(cpu_buffer->meta); + return -EINVAL; + } + + simple_bpage_init(bpage, page); bpage->id = 0; cpu_buffer->nr_pages = 1; @@ -368,7 +380,13 @@ int simple_ring_buffer_init(struct simple_rb_per_cpu *cpu_buffer, struct simple_ cpu_buffer->head_page = bpage + 1; for (i = 1; i < desc->nr_page_va; i++) { - simple_bpage_init(++bpage, desc->page_va[i]); + page = load_page(desc->page_va[i]); + if (!page) { + ret = -EINVAL; + break; + } + + simple_bpage_init(++bpage, page); bpage->link.next = &(bpage + 1)->link; bpage->link.prev = &(bpage - 1)->link; @@ -377,6 +395,14 @@ int simple_ring_buffer_init(struct simple_rb_per_cpu *cpu_buffer, struct simple_ cpu_buffer->nr_pages = i + 1; } + if (ret) { + for (i--; i >= 0; i--) + unload_page((void *)desc->page_va[i]); + unload_page(cpu_buffer->meta); + + return ret; + } + /* Close the ring */ bpage->link.next = &cpu_buffer->tail_page->link; cpu_buffer->tail_page->link.prev = &bpage->link; @@ -384,19 +410,46 @@ int simple_ring_buffer_init(struct simple_rb_per_cpu *cpu_buffer, struct simple_ /* The last init'ed page points to the head page */ simple_bpage_set_head_link(bpage); + cpu_buffer->bpages = bpages; + return 0; } -void simple_ring_buffer_unload(struct simple_rb_per_cpu *cpu_buffer) +static void *__load_page(unsigned long page) { + return (void *)page; +} + +static void __unload_page(void *page) { } + +int simple_ring_buffer_init(struct simple_rb_per_cpu *cpu_buffer, struct simple_buffer_page *bpages, + const struct ring_buffer_desc *desc) +{ + return __simple_ring_buffer_init(cpu_buffer, bpages, desc, __load_page, __unload_page); +} + +void __simple_ring_buffer_unload(struct simple_rb_per_cpu *cpu_buffer, + void (*unload_page)(void *)) +{ + int p; + if (!simple_rb_loaded(cpu_buffer)) return; simple_rb_enable_tracing(cpu_buffer, false); + unload_page(cpu_buffer->meta); + for (p = 0; p < cpu_buffer->nr_pages; p++) + unload_page(cpu_buffer->bpages[p].page); + cpu_buffer->bpages = NULL; } +void simple_ring_buffer_unload(struct simple_rb_per_cpu *cpu_buffer) +{ + return __simple_ring_buffer_unload(cpu_buffer, __unload_page); +} + int simple_ring_buffer_enable_tracing(struct simple_rb_per_cpu *cpu_buffer, bool enable) { if (!simple_rb_loaded(cpu_buffer)) -- 2.51.0.618.g983fd99d29-goog