From patchwork Fri Mar 20 16:49:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Gunthorpe X-Patchwork-Id: 11450831 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F2F09159A for ; Sat, 21 Mar 2020 10:44:53 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CFB6B206F9 for ; Sat, 21 Mar 2020 10:44:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="o7rS5S0A" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CFB6B206F9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7ACBA6E2FF; Sat, 21 Mar 2020 10:44:43 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mail-io1-xd41.google.com (mail-io1-xd41.google.com [IPv6:2607:f8b0:4864:20::d41]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2F7DA6E1A3 for ; Fri, 20 Mar 2020 16:59:22 +0000 (UTC) Received: by mail-io1-xd41.google.com with SMTP id q9so6687522iod.4 for ; Fri, 20 Mar 2020 09:59:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=BDvip0TEDdRy6Qebq3Jjm9q8IZushhhH41Cv5CSPsYg=; b=o7rS5S0AsnboKmeY0i8V6l4XrqKbMaIDN+dRT8M7ae7SN5uO0Y9cf5ue5fxCfIsNeK 7iTs5hK3BaB1JxF52ajkDDYSXgSFTdwuf6/PJzrPkUaNZxdW7j8GIbNnfDfPpx1JJ8QR iY9Bk8KNLT8H/jvnvDRYe8hfY4b8PFCjJv7Vojrcmd7ScA1lwNOpAK6ov2UvK4BihL52 DimyOsT04Yb3PYKXwsmVS/zgNQ1PtTiqXJ5fUO09wpABkfc6R/kKXb5kLhMWR0NNU65q 5pNmHCVQek+18grxw250tHfu3iPlEwtGlaO69s+IBK7W2mA6w+hcVKc1j0uQBi9jwJ37 RInQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=BDvip0TEDdRy6Qebq3Jjm9q8IZushhhH41Cv5CSPsYg=; b=E85etcDxuzYnldCyENFsrFx0EeGj5o1wi6qI0w/JLkuS6g1YmxH50gtgMIdBOeNclF pFQrSHE/dqBudWG+C4OadOCifSd1MRI2tRS16pRkqXX5tWAoFrwsBkBIxOFkO8zV2gpP S1pQLPghIL9iizSHNmM8LTpvLyiCmLin4uTcvqsA0UXRFVVtdDVP+eR8QMIWLX23j6+P o0g7I/q974Atx8cr2zitkhOdlOvaliwjaXYGqLy6XUS/e0WEqnRiQTs5ttPwvk3JJUGJ IHwmQroTnBh/uTV0UTEt+RztEAEQTOaxkRlKRBMgkzURcwrBm0Zcbo7+Sfy7O0eSC9PW m0fw== X-Gm-Message-State: ANhLgQ29LlcN00QXPBiHkLgzdtRODuNAvV7ao8jGMobT8lqA7Iy1+Qeb wXzqIYcCLdC3WZwZW/X9b6VZ3KuSCXpiNw== X-Google-Smtp-Source: ADFU+vs0SluEmhvLyLkrqPiv0NLdzSfR4fL3A9Pz7jSUSruFagO/rzdeFOruZ31ExN9mYVZmWbzX6Q== X-Received: by 2002:a37:9b51:: with SMTP id d78mr9261623qke.65.1584723024806; Fri, 20 Mar 2020 09:50:24 -0700 (PDT) Received: from ziepe.ca (hlfxns017vw-142-68-57-212.dhcp-dynamic.fibreop.ns.bellaliant.net. [142.68.57.212]) by smtp.gmail.com with ESMTPSA id g3sm4393051qke.89.2020.03.20.09.50.23 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 20 Mar 2020 09:50:23 -0700 (PDT) Received: from jgg by mlx.ziepe.ca with local (Exim 4.90_1) (envelope-from ) id 1jFKql-0005k6-8B; Fri, 20 Mar 2020 13:50:23 -0300 From: Jason Gunthorpe To: Jerome Glisse , Ralph Campbell , Felix.Kuehling@amd.com Subject: [PATCH hmm 2/6] mm/hmm: return the fault type from hmm_pte_need_fault() Date: Fri, 20 Mar 2020 13:49:01 -0300 Message-Id: <20200320164905.21722-3-jgg@ziepe.ca> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200320164905.21722-1-jgg@ziepe.ca> References: <20200320164905.21722-1-jgg@ziepe.ca> MIME-Version: 1.0 X-Mailman-Approved-At: Sat, 21 Mar 2020 10:44:31 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Philip Yang , John Hubbard , amd-gfx@lists.freedesktop.org, linux-mm@kvack.org, Jason Gunthorpe , dri-devel@lists.freedesktop.org, Christoph Hellwig Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Jason Gunthorpe Using two bools instead of flags return is not necessary and leads to bugs. Returning a value is easier for the compiler to check and easier to pass around the code flow. Convert the two bools into flags and push the change to all callers. Signed-off-by: Jason Gunthorpe --- mm/hmm.c | 153 ++++++++++++++++++++++++------------------------------- 1 file changed, 67 insertions(+), 86 deletions(-) diff --git a/mm/hmm.c b/mm/hmm.c index 3a2610e0713329..b4f662eadb7a7c 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -32,6 +32,11 @@ struct hmm_vma_walk { unsigned int flags; }; +enum { + NEED_FAULT = 1 << 0, + NEED_WRITE_FAULT = 1 << 1, +}; + static int hmm_pfns_fill(unsigned long addr, unsigned long end, struct hmm_range *range, enum hmm_pfn_value_e value) { @@ -49,8 +54,7 @@ static int hmm_pfns_fill(unsigned long addr, unsigned long end, * hmm_vma_fault() - fault in a range lacking valid pmd or pte(s) * @addr: range virtual start address (inclusive) * @end: range virtual end address (exclusive) - * @fault: should we fault or not ? - * @write_fault: write fault ? + * @required_fault: NEED_FAULT_* flags * @walk: mm_walk structure * Return: -EBUSY after page fault, or page fault error * @@ -58,8 +62,7 @@ static int hmm_pfns_fill(unsigned long addr, unsigned long end, * or whenever there is no page directory covering the virtual address range. */ static int hmm_vma_fault(unsigned long addr, unsigned long end, - bool fault, bool write_fault, - struct mm_walk *walk) + unsigned int required_fault, struct mm_walk *walk) { struct hmm_vma_walk *hmm_vma_walk = walk->private; struct hmm_range *range = hmm_vma_walk->range; @@ -68,13 +71,13 @@ static int hmm_vma_fault(unsigned long addr, unsigned long end, unsigned long i = (addr - range->start) >> PAGE_SHIFT; unsigned int fault_flags = FAULT_FLAG_REMOTE; - WARN_ON_ONCE(!fault && !write_fault); + WARN_ON_ONCE(!required_fault); hmm_vma_walk->last = addr; if (!vma) goto out_error; - if (write_fault) { + if (required_fault & NEED_WRITE_FAULT) { if (!(vma->vm_flags & VM_WRITE)) return -EPERM; fault_flags |= FAULT_FLAG_WRITE; @@ -91,14 +94,13 @@ static int hmm_vma_fault(unsigned long addr, unsigned long end, return -EFAULT; } -static inline void hmm_pte_need_fault(const struct hmm_vma_walk *hmm_vma_walk, - uint64_t pfns, uint64_t cpu_flags, - bool *fault, bool *write_fault) +static unsigned int hmm_pte_need_fault(const struct hmm_vma_walk *hmm_vma_walk, + uint64_t pfns, uint64_t cpu_flags) { struct hmm_range *range = hmm_vma_walk->range; if (hmm_vma_walk->flags & HMM_FAULT_SNAPSHOT) - return; + return 0; /* * So we not only consider the individual per page request we also @@ -114,37 +116,37 @@ static inline void hmm_pte_need_fault(const struct hmm_vma_walk *hmm_vma_walk, /* We aren't ask to do anything ... */ if (!(pfns & range->flags[HMM_PFN_VALID])) - return; + return 0; - /* If CPU page table is not valid then we need to fault */ - *fault = !(cpu_flags & range->flags[HMM_PFN_VALID]); /* Need to write fault ? */ if ((pfns & range->flags[HMM_PFN_WRITE]) && - !(cpu_flags & range->flags[HMM_PFN_WRITE])) { - *write_fault = true; - *fault = true; - } + !(cpu_flags & range->flags[HMM_PFN_WRITE])) + return NEED_FAULT | NEED_WRITE_FAULT; + + /* If CPU page table is not valid then we need to fault */ + if (!(cpu_flags & range->flags[HMM_PFN_VALID])) + return NEED_FAULT; + return 0; } -static void hmm_range_need_fault(const struct hmm_vma_walk *hmm_vma_walk, - const uint64_t *pfns, unsigned long npages, - uint64_t cpu_flags, bool *fault, - bool *write_fault) +static unsigned int +hmm_range_need_fault(const struct hmm_vma_walk *hmm_vma_walk, + const uint64_t *pfns, unsigned long npages, + uint64_t cpu_flags) { + unsigned int required_fault = 0; unsigned long i; - if (hmm_vma_walk->flags & HMM_FAULT_SNAPSHOT) { - *fault = *write_fault = false; - return; - } + if (hmm_vma_walk->flags & HMM_FAULT_SNAPSHOT) + return 0; - *fault = *write_fault = false; for (i = 0; i < npages; ++i) { - hmm_pte_need_fault(hmm_vma_walk, pfns[i], cpu_flags, - fault, write_fault); - if ((*write_fault)) - return; + required_fault |= + hmm_pte_need_fault(hmm_vma_walk, pfns[i], cpu_flags); + if (required_fault == (NEED_FAULT | NEED_WRITE_FAULT)) + return required_fault; } + return required_fault; } static int hmm_vma_walk_hole(unsigned long addr, unsigned long end, @@ -152,17 +154,16 @@ static int hmm_vma_walk_hole(unsigned long addr, unsigned long end, { struct hmm_vma_walk *hmm_vma_walk = walk->private; struct hmm_range *range = hmm_vma_walk->range; - bool fault, write_fault; + unsigned int required_fault; unsigned long i, npages; uint64_t *pfns; i = (addr - range->start) >> PAGE_SHIFT; npages = (end - addr) >> PAGE_SHIFT; pfns = &range->pfns[i]; - hmm_range_need_fault(hmm_vma_walk, pfns, npages, - 0, &fault, &write_fault); - if (fault || write_fault) - return hmm_vma_fault(addr, end, fault, write_fault, walk); + required_fault = hmm_range_need_fault(hmm_vma_walk, pfns, npages, 0); + if (required_fault) + return hmm_vma_fault(addr, end, required_fault, walk); hmm_vma_walk->last = addr; return hmm_pfns_fill(addr, end, range, HMM_PFN_NONE); } @@ -183,16 +184,15 @@ static int hmm_vma_handle_pmd(struct mm_walk *walk, unsigned long addr, struct hmm_vma_walk *hmm_vma_walk = walk->private; struct hmm_range *range = hmm_vma_walk->range; unsigned long pfn, npages, i; - bool fault, write_fault; + unsigned int required_fault; uint64_t cpu_flags; npages = (end - addr) >> PAGE_SHIFT; cpu_flags = pmd_to_hmm_pfn_flags(range, pmd); - hmm_range_need_fault(hmm_vma_walk, pfns, npages, cpu_flags, - &fault, &write_fault); - - if (fault || write_fault) - return hmm_vma_fault(addr, end, fault, write_fault, walk); + required_fault = + hmm_range_need_fault(hmm_vma_walk, pfns, npages, cpu_flags); + if (required_fault) + return hmm_vma_fault(addr, end, required_fault, walk); pfn = pmd_pfn(pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); for (i = 0; addr < end; addr += PAGE_SIZE, i++, pfn++) @@ -229,18 +229,15 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, { struct hmm_vma_walk *hmm_vma_walk = walk->private; struct hmm_range *range = hmm_vma_walk->range; - bool fault, write_fault; + unsigned int required_fault; uint64_t cpu_flags; pte_t pte = *ptep; uint64_t orig_pfn = *pfn; *pfn = range->values[HMM_PFN_NONE]; - fault = write_fault = false; - if (pte_none(pte)) { - hmm_pte_need_fault(hmm_vma_walk, orig_pfn, 0, - &fault, &write_fault); - if (fault || write_fault) + required_fault = hmm_pte_need_fault(hmm_vma_walk, orig_pfn, 0); + if (required_fault) goto fault; return 0; } @@ -261,9 +258,8 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, return 0; } - hmm_pte_need_fault(hmm_vma_walk, orig_pfn, 0, &fault, - &write_fault); - if (!fault && !write_fault) + required_fault = hmm_pte_need_fault(hmm_vma_walk, orig_pfn, 0); + if (!required_fault) return 0; if (!non_swap_entry(entry)) @@ -283,9 +279,8 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, } cpu_flags = pte_to_hmm_pfn_flags(range, pte); - hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags, &fault, - &write_fault); - if (fault || write_fault) + required_fault = hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags); + if (required_fault) goto fault; /* @@ -293,9 +288,7 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, * fall through and treat it like a normal page. */ if (pte_special(pte) && !is_zero_pfn(pte_pfn(pte))) { - hmm_pte_need_fault(hmm_vma_walk, orig_pfn, 0, &fault, - &write_fault); - if (fault || write_fault) { + if (hmm_pte_need_fault(hmm_vma_walk, orig_pfn, 0)) { pte_unmap(ptep); return -EFAULT; } @@ -309,7 +302,7 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, fault: pte_unmap(ptep); /* Fault any virtual address we were asked to fault */ - return hmm_vma_fault(addr, end, fault, write_fault, walk); + return hmm_vma_fault(addr, end, required_fault, walk); } static int hmm_vma_walk_pmd(pmd_t *pmdp, @@ -322,7 +315,6 @@ static int hmm_vma_walk_pmd(pmd_t *pmdp, uint64_t *pfns = &range->pfns[(start - range->start) >> PAGE_SHIFT]; unsigned long npages = (end - start) >> PAGE_SHIFT; unsigned long addr = start; - bool fault, write_fault; pte_t *ptep; pmd_t pmd; @@ -332,9 +324,7 @@ static int hmm_vma_walk_pmd(pmd_t *pmdp, return hmm_vma_walk_hole(start, end, -1, walk); if (thp_migration_supported() && is_pmd_migration_entry(pmd)) { - hmm_range_need_fault(hmm_vma_walk, pfns, npages, - 0, &fault, &write_fault); - if (fault || write_fault) { + if (hmm_range_need_fault(hmm_vma_walk, pfns, npages, 0)) { hmm_vma_walk->last = addr; pmd_migration_entry_wait(walk->mm, pmdp); return -EBUSY; @@ -343,9 +333,7 @@ static int hmm_vma_walk_pmd(pmd_t *pmdp, } if (!pmd_present(pmd)) { - hmm_range_need_fault(hmm_vma_walk, pfns, npages, 0, &fault, - &write_fault); - if (fault || write_fault) + if (hmm_range_need_fault(hmm_vma_walk, pfns, npages, 0)) return -EFAULT; return hmm_pfns_fill(start, end, range, HMM_PFN_ERROR); } @@ -375,9 +363,7 @@ static int hmm_vma_walk_pmd(pmd_t *pmdp, * recover. */ if (pmd_bad(pmd)) { - hmm_range_need_fault(hmm_vma_walk, pfns, npages, 0, &fault, - &write_fault); - if (fault || write_fault) + if (hmm_range_need_fault(hmm_vma_walk, pfns, npages, 0)) return -EFAULT; return hmm_pfns_fill(start, end, range, HMM_PFN_ERROR); } @@ -434,8 +420,8 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end, if (pud_huge(pud) && pud_devmap(pud)) { unsigned long i, npages, pfn; + unsigned int required_fault; uint64_t *pfns, cpu_flags; - bool fault, write_fault; if (!pud_present(pud)) { spin_unlock(ptl); @@ -447,12 +433,11 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end, pfns = &range->pfns[i]; cpu_flags = pud_to_hmm_pfn_flags(range, pud); - hmm_range_need_fault(hmm_vma_walk, pfns, npages, - cpu_flags, &fault, &write_fault); - if (fault || write_fault) { + required_fault = hmm_range_need_fault(hmm_vma_walk, pfns, + npages, cpu_flags); + if (required_fault) { spin_unlock(ptl); - return hmm_vma_fault(addr, end, fault, write_fault, - walk); + return hmm_vma_fault(addr, end, required_fault, walk); } pfn = pud_pfn(pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT); @@ -484,7 +469,7 @@ static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask, struct hmm_range *range = hmm_vma_walk->range; struct vm_area_struct *vma = walk->vma; uint64_t orig_pfn, cpu_flags; - bool fault, write_fault; + unsigned int required_fault; spinlock_t *ptl; pte_t entry; @@ -495,12 +480,10 @@ static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask, orig_pfn = range->pfns[i]; range->pfns[i] = range->values[HMM_PFN_NONE]; cpu_flags = pte_to_hmm_pfn_flags(range, entry); - fault = write_fault = false; - hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags, - &fault, &write_fault); - if (fault || write_fault) { + required_fault = hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags); + if (required_fault) { spin_unlock(ptl); - return hmm_vma_fault(addr, end, fault, write_fault, walk); + return hmm_vma_fault(addr, end, required_fault, walk); } pfn = pte_pfn(entry) + ((start & ~hmask) >> PAGE_SHIFT); @@ -532,17 +515,15 @@ static int hmm_vma_walk_test(unsigned long start, unsigned long end, */ if ((vma->vm_flags & (VM_IO | VM_PFNMAP | VM_MIXEDMAP)) || !(vma->vm_flags & VM_READ)) { - bool fault, write_fault; - /* * Check to see if a fault is requested for any page in the * range. */ - hmm_range_need_fault(hmm_vma_walk, range->pfns + - ((start - range->start) >> PAGE_SHIFT), - (end - start) >> PAGE_SHIFT, - 0, &fault, &write_fault); - if (fault || write_fault) + if (hmm_range_need_fault(hmm_vma_walk, + range->pfns + + ((start - range->start) >> + PAGE_SHIFT), + (end - start) >> PAGE_SHIFT, 0)) return -EFAULT; hmm_pfns_fill(start, end, range, HMM_PFN_ERROR);