From nobody Thu Oct 13 14:09:57 2022 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4MpBHB1F4fz4g2jn; Thu, 13 Oct 2022 14:09:58 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4MpBHB0kSvz3KXn; Thu, 13 Oct 2022 14:09:58 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1665670198; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=44aSE7Fu6Hd284GKFlDGaAlkKdlu9J0TjsN87x8frrI=; b=yE1AkgFeuMf8m5eF/pywI0G90KBCbLeATdVywRKltTFNVUxlSYZpA7VGGWW3vD8F27k9H9 GKc2/hinQWNAAfZhKJFtfTlv5AXBejSmz9O8WovpyqlqqopCr7nyUo3rNp5q37SyjK6t3r YE0nvJQ+8QpY38bGWPuAbTXqoZ/+D49t4I74b03txT0GS5LRZRAiVHrX3j/+TGTxhEP0ht Rj2KWpQjioxUyGCheHG4uh+w4eYypAbE+mjxKLUns62Acmz0NFDMtibI2aYy8w36Su2I27 ADjx+xsXuFHryN/mqcJiwXOp3azFt5m8Zg56b8Cg2CcJtJLuAmTfyN69pUTkCQ== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4MpBH96y6wzRMl; Thu, 13 Oct 2022 14:09:57 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 29DE9va4099380; Thu, 13 Oct 2022 14:09:57 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 29DE9vCl099379; Thu, 13 Oct 2022 14:09:57 GMT (envelope-from git) Date: Thu, 13 Oct 2022 14:09:57 GMT Message-Id: <202210131409.29DE9vCl099379@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Mitchell Horne Subject: git: ce82d6846bda - stable/13 - riscv: handle kernel PTE edge-case in pmap_enter_l2() List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-all@freebsd.org X-BeenThere: dev-commits-src-all@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: mhorne X-Git-Repository: src X-Git-Refname: refs/heads/stable/13 X-Git-Reftype: branch X-Git-Commit: ce82d6846bda5378d91aa94c442f9b8c416ffce9 Auto-Submitted: auto-generated ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1665670198; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=44aSE7Fu6Hd284GKFlDGaAlkKdlu9J0TjsN87x8frrI=; b=jpAsgP/kxrFDySvj7lDU6MuHBaZmT4TkV76Jl8/PCe3uz1MwJ6/YO1KRSGO2/74hhSNRkI RzSFpH+iINQv6pNyFKVzz1Z9K0KPPz5YvskPhaRH8va/2BXTa0W06TQ/aoaj0j79zy4ay+ re1inDzL0J0p6gR+WSYu47sFvc6zo/3jbNHsnWSq+eiHuSod/YvOtLpdns1TDKJjNz6krV o7915h2p+rDBKhmsof1Z+ihStDH1nBA8RQajqvja6eYspjFXRKnUJ6Y4gO5/ZyemzV+ps8 /AcDiCxTj5CgQWxj+/dAmB7LxFs8GoIfp1e9x8XTrHrrcM0jATl91wL0pXgo7A== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1665670198; a=rsa-sha256; cv=none; b=pa0fvOIRo1JVuf/wnm0poAGHvyxkzTTUjhajYwPD3QQQLAS+I7yWx/0IoH2ODWCBLr+ci7 MUP5FuLH926GL4kKARZHnOy9+o4huKPP8W7rnk78XGa/IcEi2gxZvpM0DTBmnmNrxXvg2a M4oaEdzzlfeDYH8IXRmcZrPr3KQUa+e/9vyp7G4ab5qQ8r0oRYu0H0vYn8ObuFX/rUiSFG KTf7fUmXm8eCy9f8IvXUMi4M+xk9Nujtm1HUy7+8Ivp1SS1prgv2CQTxHibBsE+MAPck6o 8+8/lss3AaDJ/jVKAhOnOb1szinZuXnH5QiWz6tWXCR+vv0e7C6/LQS7ciqiWg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-ThisMailContainsUnwantedMimeParts: N The branch stable/13 has been updated by mhorne: URL: https://cgit.FreeBSD.org/src/commit/?id=ce82d6846bda5378d91aa94c442f9b8c416ffce9 commit ce82d6846bda5378d91aa94c442f9b8c416ffce9 Author: Mitchell Horne AuthorDate: 2022-10-05 16:14:36 +0000 Commit: Mitchell Horne CommitDate: 2022-10-13 14:05:21 +0000 riscv: handle kernel PTE edge-case in pmap_enter_l2() Page table pages are never freed from the kernel pmap, instead they are zeroed when a range is unmapped. This allows future mappings to be constructed more quickly. Detect this scenario in pmap_enter_l2(), so we don't fail to create a superpage mapping when the 2MB range is actually available. Reviewed by: markj MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D36885 (cherry picked from commit 1f9cc5ffc50523498545b6f7d50406feb18903be) --- sys/riscv/riscv/pmap.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/sys/riscv/riscv/pmap.c b/sys/riscv/riscv/pmap.c index a3a26a8a883d..df473acef0e7 100644 --- a/sys/riscv/riscv/pmap.c +++ b/sys/riscv/riscv/pmap.c @@ -3146,6 +3146,24 @@ pmap_enter_2mpage(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot, PMAP_ENTER_NOREPLACE | PMAP_ENTER_NORECLAIM, NULL, lockp)); } +/* + * Returns true if every page table entry in the specified page table is + * zero. + */ +static bool +pmap_every_pte_zero(vm_paddr_t pa) +{ + pt_entry_t *pt_end, *pte; + + KASSERT((pa & PAGE_MASK) == 0, ("pa is misaligned")); + pte = (pt_entry_t *)PHYS_TO_DMAP(pa); + for (pt_end = pte + Ln_ENTRIES; pte < pt_end; pte++) { + if (*pte != 0) + return (false); + } + return (true); +} + /* * Tries to create the specified 2MB page mapping. Returns KERN_SUCCESS if * the mapping was created, and one of KERN_FAILURE, KERN_NO_SPACE, or @@ -3190,7 +3208,8 @@ pmap_enter_l2(pmap_t pmap, vm_offset_t va, pd_entry_t new_l2, u_int flags, "pmap_enter_l2: no space for va %#lx" " in pmap %p", va, pmap); return (KERN_NO_SPACE); - } else { + } else if (va < VM_MAXUSER_ADDRESS || + !pmap_every_pte_zero(L2PTE_TO_PHYS(oldl2))) { l2pg->ref_count--; CTR2(KTR_PMAP, "pmap_enter_l2:" " failed to replace existing mapping"