From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932406AbdDJQwF (ORCPT ); Mon, 10 Apr 2017 12:52:05 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36330 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755553AbdDJQwC (ORCPT ); Mon, 10 Apr 2017 12:52:02 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Rui Wang , Huacai Chen , John Crispin , "Steven J . Hill" , Fuxin Zhang , Zhangjin Wu , linux-mips@linux-mips.org, Ralf Baechle Subject: [PATCH 4.10 059/110] MIPS: Flush wrong invalid FTLB entry for huge page Date: Mon, 10 Apr 2017 18:42:50 +0200 Message-Id: <20170410164204.525779052@linuxfoundation.org> X-Mailer: git-send-email 2.12.2 In-Reply-To: <20170410164201.247583164@linuxfoundation.org> References: <20170410164201.247583164@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Huacai Chen commit 0115f6cbf26663c86496bc56eeea293f85b77897 upstream. On VTLB+FTLB platforms (such as Loongson-3A R2), FTLB's pagesize is usually configured the same as PAGE_SIZE. In such a case, Huge page entry is not suitable to write in FTLB. Unfortunately, when a huge page is created, its page table entries haven't created immediately. Then the TLB refill handler will fetch an invalid page table entry which has no "HUGE" bit, and this entry may be written to FTLB. Since it is invalid, TLB load/store handler will then use tlbwi to write the valid entry at the same place. However, the valid entry is a huge page entry which isn't suitable for FTLB. Our solution is to modify build_huge_handler_tail. Flush the invalid old entry (whether it is in FTLB or VTLB, this is in order to reduce branches) and use tlbwr to write the valid new entry. Signed-off-by: Rui Wang Signed-off-by: Huacai Chen Cc: John Crispin Cc: Steven J . Hill Cc: Fuxin Zhang Cc: Zhangjin Wu Cc: Huacai Chen Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15754/ Signed-off-by: Ralf Baechle Signed-off-by: Greg Kroah-Hartman --- arch/mips/mm/tlbex.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) --- a/arch/mips/mm/tlbex.c +++ b/arch/mips/mm/tlbex.c @@ -762,7 +762,8 @@ static void build_huge_update_entries(u3 static void build_huge_handler_tail(u32 **p, struct uasm_reloc **r, struct uasm_label **l, unsigned int pte, - unsigned int ptr) + unsigned int ptr, + unsigned int flush) { #ifdef CONFIG_SMP UASM_i_SC(p, pte, 0, ptr); @@ -771,6 +772,22 @@ static void build_huge_handler_tail(u32 #else UASM_i_SW(p, pte, 0, ptr); #endif + if (cpu_has_ftlb && flush) { + BUG_ON(!cpu_has_tlbinv); + + UASM_i_MFC0(p, ptr, C0_ENTRYHI); + uasm_i_ori(p, ptr, ptr, MIPS_ENTRYHI_EHINV); + UASM_i_MTC0(p, ptr, C0_ENTRYHI); + build_tlb_write_entry(p, l, r, tlb_indexed); + + uasm_i_xori(p, ptr, ptr, MIPS_ENTRYHI_EHINV); + UASM_i_MTC0(p, ptr, C0_ENTRYHI); + build_huge_update_entries(p, pte, ptr); + build_huge_tlb_write_entry(p, l, r, pte, tlb_random, 0); + + return; + } + build_huge_update_entries(p, pte, ptr); build_huge_tlb_write_entry(p, l, r, pte, tlb_indexed, 0); } @@ -2197,7 +2214,7 @@ static void build_r4000_tlb_load_handler uasm_l_tlbl_goaround2(&l, p); } uasm_i_ori(&p, wr.r1, wr.r1, (_PAGE_ACCESSED | _PAGE_VALID)); - build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2); + build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 1); #endif uasm_l_nopage_tlbl(&l, p); @@ -2252,7 +2269,7 @@ static void build_r4000_tlb_store_handle build_tlb_probe_entry(&p); uasm_i_ori(&p, wr.r1, wr.r1, _PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY); - build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2); + build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 1); #endif uasm_l_nopage_tlbs(&l, p); @@ -2308,7 +2325,7 @@ static void build_r4000_tlb_modify_handl build_tlb_probe_entry(&p); uasm_i_ori(&p, wr.r1, wr.r1, _PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY); - build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2); + build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 0); #endif uasm_l_nopage_tlbm(&l, p);