From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from na01-bn1-obe.outbound.protection.outlook.com (mail-bn1bn0106.outbound.protection.outlook.com [157.56.110.106]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 246161A00F8 for ; Wed, 7 Oct 2015 14:48:58 +1100 (AEDT) From: Scott Wood To: CC: Tiejun Chen , Michael Ellerman , , Tiejun Chen , Scott Wood Subject: [PATCH v2 14/18] powerpc/book3e-64/kexec: create an identity TLB mapping Date: Tue, 6 Oct 2015 22:48:18 -0500 Message-ID: <1444189702-17241-15-git-send-email-scottwood@freescale.com> In-Reply-To: <1444189702-17241-1-git-send-email-scottwood@freescale.com> References: <1444189702-17241-1-git-send-email-scottwood@freescale.com> MIME-Version: 1.0 Content-Type: text/plain List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Tiejun Chen book3e has no real MMU mode so we have to create an identity TLB mapping to make sure we can access the real physical address. Signed-off-by: Tiejun Chen [scottwood: cleanup, and split off some changes] Signed-off-by: Scott Wood --- arch/powerpc/kernel/misc_64.S | 52 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 51 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S index 6e4168c..246ad8c 100644 --- a/arch/powerpc/kernel/misc_64.S +++ b/arch/powerpc/kernel/misc_64.S @@ -26,6 +26,7 @@ #include #include #include +#include .text @@ -496,6 +497,51 @@ kexec_flag: #ifdef CONFIG_KEXEC +#ifdef CONFIG_PPC_BOOK3E +/* + * BOOK3E has no real MMU mode, so we have to setup the initial TLB + * for a core to identity map v:0 to p:0. This current implementation + * assumes that 1G is enough for kexec. + */ +kexec_create_tlb: + /* + * Invalidate all non-IPROT TLB entries to avoid any TLB conflict. + * IPROT TLB entries should be >= PAGE_OFFSET and thus not conflict. + */ + PPC_TLBILX_ALL(0,R0) + sync + isync + + mfspr r10,SPRN_TLB1CFG + andi. r10,r10,TLBnCFG_N_ENTRY /* Extract # entries */ + subi r10,r10,1 /* Last entry: no conflict with kernel text */ + lis r9,MAS0_TLBSEL(1)@h + rlwimi r9,r10,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r9) */ + +/* Set up a temp identity mapping v:0 to p:0 and return to it. */ +#if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC) +#define M_IF_NEEDED MAS2_M +#else +#define M_IF_NEEDED 0 +#endif + mtspr SPRN_MAS0,r9 + + lis r9,(MAS1_VALID|MAS1_IPROT)@h + ori r9,r9,(MAS1_TSIZE(BOOK3E_PAGESZ_1GB))@l + mtspr SPRN_MAS1,r9 + + LOAD_REG_IMMEDIATE(r9, 0x0 | M_IF_NEEDED) + mtspr SPRN_MAS2,r9 + + LOAD_REG_IMMEDIATE(r9, 0x0 | MAS3_SR | MAS3_SW | MAS3_SX) + mtspr SPRN_MAS3,r9 + li r9,0 + mtspr SPRN_MAS7,r9 + + tlbwe + isync + blr +#endif /* kexec_smp_wait(void) * @@ -525,6 +571,10 @@ _GLOBAL(kexec_smp_wait) * don't overwrite r3 here, it is live for kexec_wait above. */ real_mode: /* assume normal blr return */ +#ifdef CONFIG_PPC_BOOK3E + /* Create an identity mapping. */ + b kexec_create_tlb +#else 1: li r9,MSR_RI li r10,MSR_DR|MSR_IR mflr r11 /* return address to SRR0 */ @@ -536,7 +586,7 @@ real_mode: /* assume normal blr return */ mtspr SPRN_SRR1,r10 mtspr SPRN_SRR0,r11 rfid - +#endif /* * kexec_sequence(newstack, start, image, control, clear_all()) -- 2.1.4