linux-kernel - [PATCH v2 07/23 fix] mips: update_mmu_cache() can replace __update

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Message-ID: <6852be98-64e6-6092-d1c-13124b97bc75@google.com>
Date:   Fri, 9 Jun 2023 01:08:52 -0700 (PDT)
From:   Hugh Dickins <hughd@...gle.com>
To:     Andrew Morton <akpm@...ux-foundation.org>
cc:     Mike Kravetz <mike.kravetz@...cle.com>,
        Mike Rapoport <rppt@...nel.org>,
        "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
        Matthew Wilcox <willy@...radead.org>,
        David Hildenbrand <david@...hat.com>,
        Suren Baghdasaryan <surenb@...gle.com>,
        Qi Zheng <zhengqi.arch@...edance.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Russell King <linux@...linux.org.uk>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        Geert Uytterhoeven <geert@...ux-m68k.org>,
        Greg Ungerer <gerg@...ux-m68k.org>,
        Michal Simek <monstr@...str.eu>,
        Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
        Helge Deller <deller@....de>,
        John David Anglin <dave.anglin@...l.net>,
        "Aneesh Kumar K.V" <aneesh.kumar@...ux.ibm.com>,
        Michael Ellerman <mpe@...erman.id.au>,
        Alexandre Ghiti <alexghiti@...osinc.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        Heiko Carstens <hca@...ux.ibm.com>,
        Christian Borntraeger <borntraeger@...ux.ibm.com>,
        Claudio Imbrenda <imbrenda@...ux.ibm.com>,
        Alexander Gordeev <agordeev@...ux.ibm.com>,
        John Paul Adrian Glaubitz <glaubitz@...sik.fu-berlin.de>,
        "David S. Miller" <davem@...emloft.net>,
        Chris Zankel <chris@...kel.net>,
        Max Filippov <jcmvbkbc@...il.com>, x86@...nel.org,
        linux-arm-kernel@...ts.infradead.org, linux-ia64@...r.kernel.org,
        linux-m68k@...ts.linux-m68k.org, linux-mips@...r.kernel.org,
        linux-parisc@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
        linux-riscv@...ts.infradead.org, linux-s390@...r.kernel.org,
        linux-sh@...r.kernel.org, sparclinux@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: [PATCH v2 07/23 fix] mips: update_mmu_cache() can replace __update_tlb():
 fix

I expect this to fix the
arch/mips/mm/tlb-r4k.c:300:16: warning: variable 'pmdp' set but not used
reported by the kernel test robot; but I am uncomfortable rearranging
lines in this tlb_probe_hazard() area, and would be glad for review and
testing by someone familiar with mips - thanks in advance!

Reported-by: kernel test robot <lkp@...el.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202306091304.cNVIspK0-lkp@intel.com/
Signed-off-by: Hugh Dickins <hughd@...gle.com>
---
 arch/mips/mm/tlb-r4k.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c
index c96725d17cab..80fc90d8d2f1 100644
--- a/arch/mips/mm/tlb-r4k.c
+++ b/arch/mips/mm/tlb-r4k.c
@@ -293,11 +293,13 @@ void local_flush_tlb_one(unsigned long page)
 void update_mmu_cache(struct vm_area_struct *vma,
 		      unsigned long address, pte_t *ptep)
 {
-	unsigned long flags;
+#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
 	pgd_t *pgdp;
 	p4d_t *p4dp;
 	pud_t *pudp;
 	pmd_t *pmdp;
+#endif
+	unsigned long flags;
 	int idx, pid;
 
 	/*
@@ -316,15 +318,15 @@ void update_mmu_cache(struct vm_area_struct *vma,
 		pid = read_c0_entryhi() & cpu_asid_mask(&current_cpu_data);
 		write_c0_entryhi(address | pid);
 	}
-	pgdp = pgd_offset(vma->vm_mm, address);
 	mtc0_tlbw_hazard();
 	tlb_probe();
 	tlb_probe_hazard();
+	idx = read_c0_index();
+#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
+	pgdp = pgd_offset(vma->vm_mm, address);
 	p4dp = p4d_offset(pgdp, address);
 	pudp = pud_offset(p4dp, address);
 	pmdp = pmd_offset(pudp, address);
-	idx = read_c0_index();
-#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
 	/* this could be a huge page  */
 	if (ptep == (pte_t *)pmdp) {
 		unsigned long lo;
-- 
2.35.3