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[216.232.210.95]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2c7436af558sm60243105ad.14.2026.06.21.11.47.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 21 Jun 2026 11:47:14 -0700 (PDT) From: Kyle Hendry To: Thomas Bogendoerfer Cc: Kyle Hendry , linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] MIPS: mm: Add check for highmem before removing memory block Date: Sun, 21 Jun 2026 11:47:02 -0700 Message-ID: <20260621184702.17302-1-kylehendrydev@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit If a device has less physical memory than the highmem threshold bootmem_init() doesn't set highstart_pfn. This results in highmem_init() wrongly disabling the entire memory range if the cpu doesn't support highmem. Add a check that highstart_pfn is non zero before removing the highmem block. Signed-off-by: Kyle Hendry --- arch/mips/mm/init.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c index 1c07ca84ee21..352718e43f69 100644 --- a/arch/mips/mm/init.c +++ b/arch/mips/mm/init.c @@ -426,10 +426,11 @@ static inline void __init highmem_init(void) unsigned long tmp; /* - * If CPU cannot support HIGHMEM discard the memory above highstart_pfn + * If CPU cannot support HIGHMEM discard any memory above highstart_pfn */ if (cpu_has_dc_aliases) { - memblock_remove(PFN_PHYS(highstart_pfn), -1); + if (highstart_pfn) + memblock_remove(PFN_PHYS(highstart_pfn), -1); return; } -- 2.43.0