From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:49230 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730004AbgLHP2J (ORCPT ); Tue, 8 Dec 2020 10:28:09 -0500 Date: Tue, 8 Dec 2020 16:27:09 +0100 From: Heiko Carstens Subject: Re: [PATCH 3/3] s390/mm: Define arch_get_mappable_range() Message-ID: <20201208152709.GA26979@osiris> References: <1607400978-31595-1-git-send-email-anshuman.khandual@arm.com> <1607400978-31595-4-git-send-email-anshuman.khandual@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1607400978-31595-4-git-send-email-anshuman.khandual@arm.com> List-ID: To: Anshuman Khandual Cc: linux-mm@kvack.org, akpm@linux-foundation.org, david@redhat.com, catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, Vasily Gorbik , Will Deacon , Ard Biesheuvel , Mark Rutland On Tue, Dec 08, 2020 at 09:46:18AM +0530, Anshuman Khandual wrote: > This overrides arch_get_mappabble_range() on s390 platform which will be > used with recently added generic framework. It drops a redundant similar > check in vmem_add_mapping() while compensating __segment_load() with a new > address range check to preserve the existing functionality. It also adds a > VM_BUG_ON() check that would ensure that memhp_range_allowed() has already > been called on the hotplug path. > > Cc: Heiko Carstens > Cc: Vasily Gorbik > Cc: David Hildenbrand > Cc: linux-s390@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Anshuman Khandual > --- > arch/s390/mm/extmem.c | 5 +++++ > arch/s390/mm/init.c | 10 ++++++++++ > arch/s390/mm/vmem.c | 4 ---- > 3 files changed, 15 insertions(+), 4 deletions(-) > > diff --git a/arch/s390/mm/extmem.c b/arch/s390/mm/extmem.c > index 5060956b8e7d..cc055a78f7b6 100644 > --- a/arch/s390/mm/extmem.c > +++ b/arch/s390/mm/extmem.c > @@ -337,6 +337,11 @@ __segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long > goto out_free_resource; > } > > + if (seg->end + 1 > VMEM_MAX_PHYS || seg->end + 1 < seg->start_addr) { > + rc = -ERANGE; > + goto out_resource; > + } > + > rc = vmem_add_mapping(seg->start_addr, seg->end - seg->start_addr + 1); > if (rc) > goto out_resource; > diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c > index 77767850d0d0..64937baabf93 100644 > --- a/arch/s390/mm/init.c > +++ b/arch/s390/mm/init.c > @@ -278,6 +278,15 @@ device_initcall(s390_cma_mem_init); > > #endif /* CONFIG_CMA */ > > +struct range arch_get_mappable_range(void) > +{ > + struct range memhp_range; > + > + memhp_range.start = 0; > + memhp_range.end = VMEM_MAX_PHYS; > + return memhp_range; > +} > + > int arch_add_memory(int nid, u64 start, u64 size, > struct mhp_params *params) > { > @@ -291,6 +300,7 @@ int arch_add_memory(int nid, u64 start, u64 size, > if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot)) > return -EINVAL; > > + VM_BUG_ON(!memhp_range_allowed(start, size, 1)); > rc = vmem_add_mapping(start, size); > if (rc) > return rc; > diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c > index b239f2ba93b0..749eab43aa93 100644 > --- a/arch/s390/mm/vmem.c > +++ b/arch/s390/mm/vmem.c > @@ -536,10 +536,6 @@ int vmem_add_mapping(unsigned long start, unsigned long size) > { > int ret; > > - if (start + size > VMEM_MAX_PHYS || > - start + size < start) > - return -ERANGE; > - Is there a reason why you added the memhp_range_allowed() check call to arch_add_memory() instead of vmem_add_mapping()? If you would do that, then the extra code in __segment_load() wouldn't be required. Even though the error message from memhp_range_allowed() might be highly confusing.