From patchwork Mon Oct 14 10:58:42 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ryan Roberts X-Patchwork-Id: 13834727 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6372C1A4F03; Mon, 14 Oct 2024 11:01:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728903679; cv=none; b=FGpslM2M1DCe35IYaL0Vy7N6ickhpF+40JZrB1Ic+ZOP3uPsyL4+vHW1kqgpkoM+/BjB/dVZdKmO90Jim/ohDHLYQ0YnXZDFB809QYxtL3iAoNE+CswfxHZgb0ybsG6vVVZRhIEka5OZ6I1lnq3Th+p705XHw+K47uDA/rlj/TE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728903679; c=relaxed/simple; bh=gGmDIIzyy9IHazPso2R/WKF0iZif8zx/sBJb7QmIGlg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=b65UB5V6zugMtMjyBtJbIXB+gI/wILq6RORvfof+QD0zt1MTP2YwYGJEIeBp2mfkaJGoCJw3CRdq0v8xcYr8FKp1cw20S+u0W+GohYP3nJZbwsHwiIa56QyIZe/8J2euZ5tL0xKG5IK/3il1TR8Pm6Ie6iZY7lmfR79dzJC0/wE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 997AD16F8; Mon, 14 Oct 2024 04:01:47 -0700 (PDT) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.27]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 769A53F51B; Mon, 14 Oct 2024 04:01:14 -0700 (PDT) From: Ryan Roberts To: "Michael S. Tsirkin" , Andrew Morton , Anshuman Khandual , Ard Biesheuvel , Catalin Marinas , David Hildenbrand , Dominique Martinet , Eric Van Hensbergen , Greg Marsden , Ivan Ivanov , Jason Wang , Jens Axboe , Kalesh Singh , Latchesar Ionkov , Marc Zyngier , Mark Rutland , Matthias Brugger , Miroslav Benes , Will Deacon Cc: Ryan Roberts , linux-arm-kernel@lists.infradead.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, v9fs@lists.linux.dev, virtualization@lists.linux.dev Subject: [RFC PATCH v1 35/57] virtio: Remove PAGE_SIZE compile-time constant assumption Date: Mon, 14 Oct 2024 11:58:42 +0100 Message-ID: <20241014105912.3207374-35-ryan.roberts@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241014105912.3207374-1-ryan.roberts@arm.com> References: <20241014105514.3206191-1-ryan.roberts@arm.com> <20241014105912.3207374-1-ryan.roberts@arm.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 To prepare for supporting boot-time page size selection, refactor code to remove assumptions about PAGE_SIZE being compile-time constant. Code intended to be equivalent when compile-time page size is active. Updated multiple BUILD_BUG_ON() instances to test against page size limits. Wrap global variables that are initialized with PAGE_SIZE derived values using DEFINE_GLOBAL_PAGE_SIZE_VAR() so their initialization can be deferred for boot-time page size builds. Signed-off-by: Ryan Roberts --- ***NOTE*** Any confused maintainers may want to read the cover note here for context: https://lore.kernel.org/all/20241014105514.3206191-1-ryan.roberts@arm.com/ drivers/block/virtio_blk.c | 2 +- drivers/virtio/virtio_balloon.c | 10 ++++++---- net/9p/trans_virtio.c | 4 ++-- 3 files changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 194417abc1053..8a8960b609bc9 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -899,7 +899,7 @@ static ssize_t serial_show(struct device *dev, int err; /* sysfs gives us a PAGE_SIZE buffer */ - BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES); + BUILD_BUG_ON(PAGE_SIZE_MIN < VIRTIO_BLK_ID_BYTES); buf[VIRTIO_BLK_ID_BYTES] = '\0'; err = virtblk_get_id(disk, buf); diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 54469277ca303..3818d894bd212 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -25,6 +25,7 @@ * page units. */ #define VIRTIO_BALLOON_PAGES_PER_PAGE (unsigned int)(PAGE_SIZE >> VIRTIO_BALLOON_PFN_SHIFT) +#define VIRTIO_BALLOON_PAGES_PER_PAGE_MAX (unsigned int)(PAGE_SIZE_MAX >> VIRTIO_BALLOON_PFN_SHIFT) #define VIRTIO_BALLOON_ARRAY_PFNS_MAX 256 /* Maximum number of (4k) pages to deflate on OOM notifications. */ #define VIRTIO_BALLOON_OOM_NR_PAGES 256 @@ -138,7 +139,7 @@ static u32 page_to_balloon_pfn(struct page *page) { unsigned long pfn = page_to_pfn(page); - BUILD_BUG_ON(PAGE_SHIFT < VIRTIO_BALLOON_PFN_SHIFT); + BUILD_BUG_ON(PAGE_SHIFT_MIN < VIRTIO_BALLOON_PFN_SHIFT); /* Convert pfn from Linux page size to balloon page size. */ return pfn * VIRTIO_BALLOON_PAGES_PER_PAGE; } @@ -228,7 +229,7 @@ static void set_page_pfns(struct virtio_balloon *vb, { unsigned int i; - BUILD_BUG_ON(VIRTIO_BALLOON_PAGES_PER_PAGE > VIRTIO_BALLOON_ARRAY_PFNS_MAX); + BUILD_BUG_ON(VIRTIO_BALLOON_PAGES_PER_PAGE_MAX > VIRTIO_BALLOON_ARRAY_PFNS_MAX); /* * Set balloon pfns pointing at this page. @@ -1042,8 +1043,9 @@ static int virtballoon_probe(struct virtio_device *vdev) * host's base page size. However, it needs more work to report * that value. The hard-coded order would be fine currently. */ -#if defined(CONFIG_ARM64) && defined(CONFIG_ARM64_64K_PAGES) - vb->pr_dev_info.order = 5; +#if defined(CONFIG_ARM64) + if (PAGE_SIZE == SZ_64K) + vb->pr_dev_info.order = 5; #endif err = page_reporting_register(&vb->pr_dev_info); diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index 0b8086f58ad55..25b8253011cec 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -786,7 +786,7 @@ static struct virtio_driver p9_virtio_drv = { .remove = p9_virtio_remove, }; -static struct p9_trans_module p9_virtio_trans = { +static DEFINE_GLOBAL_PAGE_SIZE_VAR(struct p9_trans_module, p9_virtio_trans, { .name = "virtio", .create = p9_virtio_create, .close = p9_virtio_close, @@ -804,7 +804,7 @@ static struct p9_trans_module p9_virtio_trans = { .pooled_rbuffers = false, .def = 1, .owner = THIS_MODULE, -}; +}); /* The standard init function */ static int __init p9_virtio_init(void)