From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:45298 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727366AbhAMJmX (ORCPT ); Wed, 13 Jan 2021 04:42:23 -0500 From: Janosch Frank Subject: [PATCH 03/14] s390/mm: Take locking out of gmap_protect_pte Date: Wed, 13 Jan 2021 09:41:02 +0000 Message-Id: <20210113094113.133668-4-frankja@linux.ibm.com> In-Reply-To: <20210113094113.133668-1-frankja@linux.ibm.com> References: <20210113094113.133668-1-frankja@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit List-ID: To: kvm@vger.kernel.org Cc: borntraeger@de.ibm.com, david@redhat.com, linux-s390@vger.kernel.org, imbrenda@linux.ibm.com Locking outside of the function gives us the freedom of ordering locks, which will be important to not get locking issues for gmap_protect_rmap. Signed-off-by: Janosch Frank --- arch/s390/mm/gmap.c | 30 ++++++++++++++---------------- 1 file changed, 14 insertions(+), 16 deletions(-) diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index 650c51749f4d..c38f49dedf35 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -1017,25 +1017,15 @@ static int gmap_protect_pmd(struct gmap *gmap, unsigned long gaddr, * Expected to be called with sg->mm->mmap_lock in read */ static int gmap_protect_pte(struct gmap *gmap, unsigned long gaddr, - pmd_t *pmdp, int prot, unsigned long bits) + pte_t *ptep, int prot, unsigned long bits) { int rc; - pte_t *ptep; - spinlock_t *ptl = NULL; unsigned long pbits = 0; - if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID) - return -EAGAIN; - - ptep = pte_alloc_map_lock(gmap->mm, pmdp, gaddr, &ptl); - if (!ptep) - return -ENOMEM; - pbits |= (bits & GMAP_NOTIFY_MPROT) ? PGSTE_IN_BIT : 0; pbits |= (bits & GMAP_NOTIFY_SHADOW) ? PGSTE_VSIE_BIT : 0; /* Protect and unlock. */ rc = ptep_force_prot(gmap->mm, gaddr, ptep, prot, pbits); - gmap_pte_op_end(ptl); return rc; } @@ -1056,18 +1046,26 @@ static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr, unsigned long len, int prot, unsigned long bits) { unsigned long vmaddr, dist; - spinlock_t *ptl = NULL; + spinlock_t *ptl_pmd = NULL, *ptl_pte = NULL; pmd_t *pmdp; + pte_t *ptep; int rc; BUG_ON(gmap_is_shadow(gmap)); while (len) { rc = -EAGAIN; - pmdp = gmap_pmd_op_walk(gmap, gaddr, &ptl); + pmdp = gmap_pmd_op_walk(gmap, gaddr, &ptl_pmd); if (pmdp) { if (!pmd_large(*pmdp)) { - rc = gmap_protect_pte(gmap, gaddr, pmdp, prot, - bits); + ptl_pte = NULL; + ptep = pte_alloc_map_lock(gmap->mm, pmdp, gaddr, + &ptl_pte); + if (ptep) + rc = gmap_protect_pte(gmap, gaddr, + ptep, prot, bits); + else + rc = -ENOMEM; + gmap_pte_op_end(ptl_pte); if (!rc) { len -= PAGE_SIZE; gaddr += PAGE_SIZE; @@ -1081,7 +1079,7 @@ static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr, gaddr = (gaddr & HPAGE_MASK) + HPAGE_SIZE; } } - gmap_pmd_op_end(ptl); + gmap_pmd_op_end(ptl_pmd); } if (rc) { if (rc == -EINVAL) -- 2.27.0