From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ED91D1CEEB2 for ; Wed, 21 May 2025 16:57:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747846625; cv=none; b=Jtmyf3ikMxEtnAHcBBpwhrDrI5+xzrm5mgms4M/q52jOfcLAAUCKgqdnu+p7OQz+8q8Rif5mYLlL3169PkGrA/cONuBxa7J5xyPXz33/dKI6VLjgYX/gkafR/AZ54nQAHFCdv24ioo+/etf/vgq+wxFhKQmmFhMtZ27A1j17NQ4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747846625; c=relaxed/simple; bh=gqe3JAK1bBhFfoDw06i/+nOFdyytCLmyLPPQyc0pNiI=; h=Date:To:From:Subject:Message-Id; b=K8xmqT44AYcVV1CgahlJNMw6T8xajLhBvElGC0QBIL6Wy/J07+XKR6rOuiNOgGmrAbdElw6TMruGHsYWKZKrjSuS90zg2grm9dZRIuciMrITcLAFIO0YaFhzhqPYgU2CB89+nCq9/ACQwJ3QU3c4I8fFbjGIFBRrVfdy7hwrNrs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=0BY6TZf9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="0BY6TZf9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 40B05C4CEE4; Wed, 21 May 2025 16:57:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1747846624; bh=gqe3JAK1bBhFfoDw06i/+nOFdyytCLmyLPPQyc0pNiI=; h=Date:To:From:Subject:From; b=0BY6TZf97oWzbzDhNbqoMSv7V0P7zBx1Eby0BuGrNSjTjvNJD8mZ6UOPj9DTK1Eae c8PuXK7kHnXHmiudwsAvwOsJ+J2lT2ndRLFWsN6CULCpHJOeapPgU7UBZVqmfK6oii noK3Zx/G8PLr3szDGRuMRIh0hF6WPs7258qeUwOU= Date: Wed, 21 May 2025 09:57:03 -0700 To: mm-commits@vger.kernel.org,vbabka@suse.cz,tursulin@ursulin.net,tglx@linutronix.de,rostedt@goodmis.org,rodrigo.vivi@intel.com,peterz@infradead.org,peterx@redhat.com,mingo@kernel.org,mhiramat@kernel.org,mathieu.desnoyers@efficios.com,luto@kernel.org,lorenzo.stoakes@oracle.com,Liam.Howlett@oracle.com,joonas.lahtinen@linux.intel.com,jannh@google.com,jani.nikula@linux.intel.com,hpa@zytor.com,bp@alien8.de,airlied@gmail.com,david@redhat.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] x86-mm-pat-factor-out-setting-cachemode-into-pgprot_set_cachemode.patch removed from -mm tree Message-Id: <20250521165704.40B05C4CEE4@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: x86/mm/pat: factor out setting cachemode into pgprot_set_cachemode() has been removed from the -mm tree. Its filename was x86-mm-pat-factor-out-setting-cachemode-into-pgprot_set_cachemode.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: David Hildenbrand Subject: x86/mm/pat: factor out setting cachemode into pgprot_set_cachemode() Date: Mon, 12 May 2025 14:34:14 +0200 VM_PAT annoyed me too much and wasted too much of my time, let's clean PAT handling up and remove VM_PAT. This should sort out various issues with VM_PAT we discovered recently, and will hopefully make the whole code more stable and easier to maintain. In essence: we stop letting PAT mode mess with VMAs and instead lift what to track/untrack to the MM core. We remember per VMA which pfn range we tracked in a new struct we attach to a VMA (we have space without exceeding 192 bytes), use a kref to share it among VMAs during split/mremap/fork, and automatically untrack once the kref drops to 0. This implies that we'll keep tracking a full pfn range even after partially unmapping it, until fully unmapping it; but as that case was mostly broken before, this at least makes it work in a way that is least intrusive to VMA handling. Shrinking with mremap() used to work in a hacky way, now we'll similarly keep the original pfn range tacked even after this form of partial unmap. Does anybody care about that? Unlikely. If we run into issues, we could likely handled that (adjust the tracking) when our kref drops to 1 while freeing a VMA. But it adds more complexity, so avoid that for now. Briefly tested with the new pfnmap selftests [1]. This patch (of 11): Let's factor it out to make the code easier to grasp. Drop one comment where it is now rather obvious what is happening. Use it also in pgprot_writecombine()/pgprot_writethrough() where clearing the old cachemode might not be required, but given that we are already doing a function call, no need to care about this micro-optimization. Link: https://lkml.kernel.org/r/20250512123424.637989-1-david@redhat.com Link: https://lkml.kernel.org/r/20250512123424.637989-2-david@redhat.com Link: https://lkml.kernel.org/r/20250509153033.952746-1-david@redhat.com [1] Signed-off-by: David Hildenbrand Reviewed-by: Lorenzo Stoakes Acked-by: Ingo Molnar [x86 bits] Reviewed-by: Liam R. Howlett Cc: Andy Lutomirski Cc: Borislav Betkov Cc: Dave Airlie Cc: David Hildenbrand Cc: "H. Peter Anvin" Cc: Jani Nikula Cc: Jann Horn Cc: Jonas Lahtinen Cc: "Masami Hiramatsu (Google)" Cc: Mathieu Desnoyers Cc: Peter Xu Cc: Peter Zijlstra Cc: Rodrigo Vivi Cc: Steven Rostedt Cc: Thomas Gleinxer Cc: Tvrtko Ursulin Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- arch/x86/mm/pat/memtype.c | 33 +++++++++++++++------------------ 1 file changed, 15 insertions(+), 18 deletions(-) --- a/arch/x86/mm/pat/memtype.c~x86-mm-pat-factor-out-setting-cachemode-into-pgprot_set_cachemode +++ a/arch/x86/mm/pat/memtype.c @@ -800,6 +800,12 @@ static inline int range_is_allowed(unsig } #endif /* CONFIG_STRICT_DEVMEM */ +static inline void pgprot_set_cachemode(pgprot_t *prot, enum page_cache_mode pcm) +{ + *prot = __pgprot((pgprot_val(*prot) & ~_PAGE_CACHE_MASK) | + cachemode2protval(pcm)); +} + int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, unsigned long size, pgprot_t *vma_prot) { @@ -811,8 +817,7 @@ int phys_mem_access_prot_allowed(struct if (file->f_flags & O_DSYNC) pcm = _PAGE_CACHE_MODE_UC_MINUS; - *vma_prot = __pgprot((pgprot_val(*vma_prot) & ~_PAGE_CACHE_MASK) | - cachemode2protval(pcm)); + pgprot_set_cachemode(vma_prot, pcm); return 1; } @@ -880,9 +885,7 @@ static int reserve_pfn_range(u64 paddr, (unsigned long long)paddr, (unsigned long long)(paddr + size - 1), cattr_name(pcm)); - *vma_prot = __pgprot((pgprot_val(*vma_prot) & - (~_PAGE_CACHE_MASK)) | - cachemode2protval(pcm)); + pgprot_set_cachemode(vma_prot, pcm); } return 0; } @@ -907,9 +910,7 @@ static int reserve_pfn_range(u64 paddr, * We allow returning different type than the one requested in * non strict case. */ - *vma_prot = __pgprot((pgprot_val(*vma_prot) & - (~_PAGE_CACHE_MASK)) | - cachemode2protval(pcm)); + pgprot_set_cachemode(vma_prot, pcm); } if (memtype_kernel_map_sync(paddr, size, pcm) < 0) { @@ -1060,9 +1061,7 @@ int track_pfn_remap(struct vm_area_struc return -EINVAL; } - *prot = __pgprot((pgprot_val(*prot) & (~_PAGE_CACHE_MASK)) | - cachemode2protval(pcm)); - + pgprot_set_cachemode(prot, pcm); return 0; } @@ -1073,10 +1072,8 @@ void track_pfn_insert(struct vm_area_str if (!pat_enabled()) return; - /* Set prot based on lookup */ pcm = lookup_memtype(pfn_t_to_phys(pfn)); - *prot = __pgprot((pgprot_val(*prot) & (~_PAGE_CACHE_MASK)) | - cachemode2protval(pcm)); + pgprot_set_cachemode(prot, pcm); } /* @@ -1115,15 +1112,15 @@ void untrack_pfn_clear(struct vm_area_st pgprot_t pgprot_writecombine(pgprot_t prot) { - return __pgprot(pgprot_val(prot) | - cachemode2protval(_PAGE_CACHE_MODE_WC)); + pgprot_set_cachemode(&prot, _PAGE_CACHE_MODE_WC); + return prot; } EXPORT_SYMBOL_GPL(pgprot_writecombine); pgprot_t pgprot_writethrough(pgprot_t prot) { - return __pgprot(pgprot_val(prot) | - cachemode2protval(_PAGE_CACHE_MODE_WT)); + pgprot_set_cachemode(&prot, _PAGE_CACHE_MODE_WT); + return prot; } EXPORT_SYMBOL_GPL(pgprot_writethrough); _ Patches currently in -mm which might be from david@redhat.com are