linux-kernel - [PATCH v1 01/11] x86/mm/pat: factor out setting cachemode into pgprot_set

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Message-ID: <20250425081715.1341199-2-david@redhat.com>
Date: Fri, 25 Apr 2025 10:17:05 +0200
From: David Hildenbrand <david@...hat.com>
To: linux-kernel@...r.kernel.org
Cc: linux-mm@...ck.org,
	x86@...nel.org,
	intel-gfx@...ts.freedesktop.org,
	dri-devel@...ts.freedesktop.org,
	linux-trace-kernel@...r.kernel.org,
	David Hildenbrand <david@...hat.com>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	Andy Lutomirski <luto@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	Borislav Petkov <bp@...en8.de>,
	"H. Peter Anvin" <hpa@...or.com>,
	Jani Nikula <jani.nikula@...ux.intel.com>,
	Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
	Rodrigo Vivi <rodrigo.vivi@...el.com>,
	Tvrtko Ursulin <tursulin@...ulin.net>,
	David Airlie <airlied@...il.com>,
	Simona Vetter <simona@...ll.ch>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	Masami Hiramatsu <mhiramat@...nel.org>,
	Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
	"Liam R. Howlett" <Liam.Howlett@...cle.com>,
	Lorenzo Stoakes <lorenzo.stoakes@...cle.com>,
	Vlastimil Babka <vbabka@...e.cz>,
	Jann Horn <jannh@...gle.com>,
	Pedro Falcato <pfalcato@...e.de>,
	Peter Xu <peterx@...hat.com>
Subject: [PATCH v1 01/11] x86/mm/pat: factor out setting cachemode into pgprot_set_cachemode()

Let's factor it out to make the code easier to grasp.

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.

Signed-off-by: David Hildenbrand <david@...hat.com>
---
 arch/x86/mm/pat/memtype.c | 33 +++++++++++++++------------------
 1 file changed, 15 insertions(+), 18 deletions(-)

diff --git a/arch/x86/mm/pat/memtype.c b/arch/x86/mm/pat/memtype.c
index 72d8cbc611583..edec5859651d6 100644
--- a/arch/x86/mm/pat/memtype.c
+++ b/arch/x86/mm/pat/memtype.c
@@ -800,6 +800,12 @@ static inline int range_is_allowed(unsigned long pfn, unsigned long size)
 }
 #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 file *file, unsigned long pfn,
 	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 size, pgprot_t *vma_prot,
 				(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, unsigned long size, pgprot_t *vma_prot,
 		 * 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_struct *vma, pgprot_t *prot,
 			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_struct *vma, pgprot_t *prot, pfn_t pfn)
 	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_struct *vma)
 
 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);
 
-- 
2.49.0