From patchwork Thu Oct 3 21:17:58 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Santosh Shilimkar X-Patchwork-Id: 2986101 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id B32BB9F288 for ; Thu, 3 Oct 2013 21:25:41 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 86F1A203A8 for ; Thu, 3 Oct 2013 21:25:40 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3E8FB20395 for ; Thu, 3 Oct 2013 21:25:39 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VRqNf-00081n-LI; Thu, 03 Oct 2013 21:24:20 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VRqIl-0000wo-Cw; Thu, 03 Oct 2013 21:19:15 +0000 Received: from arroyo.ext.ti.com ([192.94.94.40]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VRqIY-0000sh-IV for linux-arm-kernel@lists.infradead.org; Thu, 03 Oct 2013 21:19:04 +0000 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by arroyo.ext.ti.com (8.13.7/8.13.7) with ESMTP id r93LIaRC026308; Thu, 3 Oct 2013 16:18:36 -0500 Received: from DFLE72.ent.ti.com (dfle72.ent.ti.com [128.247.5.109]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id r93LIaGo008743; Thu, 3 Oct 2013 16:18:36 -0500 Received: from dflp33.itg.ti.com (10.64.6.16) by DFLE72.ent.ti.com (128.247.5.109) with Microsoft SMTP Server id 14.2.342.3; Thu, 3 Oct 2013 16:18:36 -0500 Received: from ula0393909.am.dhcp.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp33.itg.ti.com (8.14.3/8.13.8) with ESMTP id r93LI3Bm024025; Thu, 3 Oct 2013 16:18:36 -0500 From: Santosh Shilimkar To: Subject: [PATCH v3 4/6] ARM: mm: Correct virt_to_phys patching for 64 bit physical addresses Date: Thu, 3 Oct 2013 17:17:58 -0400 Message-ID: <1380835081-12129-5-git-send-email-santosh.shilimkar@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1380835081-12129-1-git-send-email-santosh.shilimkar@ti.com> References: <1380835081-12129-1-git-send-email-santosh.shilimkar@ti.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131003_171902_902231_A5EC4A72 X-CRM114-Status: GOOD ( 15.04 ) X-Spam-Score: -7.6 (-------) Cc: nicolas.pitre@linaro.org, linux@arm.linux.org.uk, Nicolas Pitre , Sricharan R , arm@kernel.org, Santosh Shilimkar X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Sricharan R The current phys_to_virt patching mechanism works only for 32 bit physical addresses and this patch extends the idea for 64bit physical addresses. The 64bit v2p patching mechanism patches the higher 8 bits of physical address with a constant using 'mov' instruction and lower 32bits are patched using 'add'. While this is correct, in those platforms where the lowmem addressable physical memory spawns across 4GB boundary, a carry bit can be produced as a result of addition of lower 32bits. This has to be taken in to account and added in to the upper. The patched __pv_offset and va are added in lower 32bits, where __pv_offset can be in two's complement form when PA_START < VA_START and that can result in a false carry bit. e.g 1) PA = 0x80000000; VA = 0xC0000000 __pv_offset = PA - VA = 0xC0000000 (2's complement) 2) PA = 0x2 80000000; VA = 0xC000000 __pv_offset = PA - VA = 0x1 C0000000 So adding __pv_offset + VA should never result in a true overflow for (1). So in order to differentiate between a true carry, a __pv_offset is extended to 64bit and the upper 32bits will have 0xffffffff if __pv_offset is 2's complement. So 'mvn #0' is inserted instead of 'mov' while patching for the same reason. Since mov, add, sub instruction are to patched with different constants inside the same stub, the rotation field of the opcode is using to differentiate between them. So the above examples for v2p translation becomes for VA=0xC0000000, 1) PA[63:32] = 0xffffffff PA[31:0] = VA + 0xC0000000 --> results in a carry PA[63:32] = PA[63:32] + carry PA[63:0] = 0x0 80000000 2) PA[63:32] = 0x1 PA[31:0] = VA + 0xC0000000 --> results in a carry PA[63:32] = PA[63:32] + carry PA[63:0] = 0x2 80000000 The above ideas were suggested by Nicolas Pitre as part of the review of first and second versions of the subject patch. There is no corresponding change on the phys_to_virt() side, because computations on the upper 32-bits would be discarded anyway. Cc: Nicolas Pitre Cc: Russell King Signed-off-by: Sricharan R Signed-off-by: Santosh Shilimkar Reviewed-by: Nicolas Pitre --- arch/arm/include/asm/memory.h | 35 +++++++++++++++++++++--- arch/arm/kernel/armksyms.c | 1 + arch/arm/kernel/head.S | 60 ++++++++++++++++++++++++++--------------- arch/arm/kernel/patch.c | 3 +++ 4 files changed, 75 insertions(+), 24 deletions(-) diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index d9b96c65..942ad84 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -172,9 +172,12 @@ * so that all we need to do is modify the 8-bit constant field. */ #define __PV_BITS_31_24 0x81000000 +#define __PV_BITS_7_0 0x81 extern phys_addr_t (*arch_virt_to_idmap) (unsigned long x); -extern unsigned long __pv_phys_offset; +extern u64 __pv_phys_offset; +extern u64 __pv_offset; + #define PHYS_OFFSET __pv_phys_offset #define __pv_stub(from,to,instr,type) \ @@ -186,10 +189,36 @@ extern unsigned long __pv_phys_offset; : "=r" (to) \ : "r" (from), "I" (type)) +#define __pv_stub_mov_hi(t) \ + __asm__ volatile("@ __pv_stub_mov\n" \ + "1: mov %R0, %1\n" \ + " .pushsection .pv_table,\"a\"\n" \ + " .long 1b\n" \ + " .popsection\n" \ + : "=r" (t) \ + : "I" (__PV_BITS_7_0)) + +#define __pv_add_carry_stub(x, y) \ + __asm__ volatile("@ __pv_add_carry_stub\n" \ + "1: adds %Q0, %1, %2\n" \ + " adc %R0, %R0, #0\n" \ + " .pushsection .pv_table,\"a\"\n" \ + " .long 1b\n" \ + " .popsection\n" \ + : "+r" (y) \ + : "r" (x), "I" (__PV_BITS_31_24) \ + : "cc") + static inline phys_addr_t __virt_to_phys(unsigned long x) { - unsigned long t; - __pv_stub(x, t, "add", __PV_BITS_31_24); + phys_addr_t t; + + if (sizeof(phys_addr_t) == 4) { + __pv_stub(x, t, "add", __PV_BITS_31_24); + } else { + __pv_stub_mov_hi(t); + __pv_add_carry_stub(x, t); + } return t; } diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c index 60d3b73..1f031dd 100644 --- a/arch/arm/kernel/armksyms.c +++ b/arch/arm/kernel/armksyms.c @@ -155,4 +155,5 @@ EXPORT_SYMBOL(__gnu_mcount_nc); #ifdef CONFIG_ARM_PATCH_PHYS_VIRT EXPORT_SYMBOL(__pv_phys_offset); +EXPORT_SYMBOL(__pv_offset); #endif diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 2c7cc1e..90d04d7 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -536,6 +536,14 @@ ENTRY(fixup_smp) ldmfd sp!, {r4 - r6, pc} ENDPROC(fixup_smp) +#ifdef __ARMEB_ +#define LOW_OFFSET 0x4 +#define HIGH_OFFSET 0x0 +#else +#define LOW_OFFSET 0x0 +#define HIGH_OFFSET 0x4 +#endif + #ifdef CONFIG_ARM_PATCH_PHYS_VIRT /* __fixup_pv_table - patch the stub instructions with the delta between @@ -546,17 +554,20 @@ ENDPROC(fixup_smp) __HEAD __fixup_pv_table: adr r0, 1f - ldmia r0, {r3-r5, r7} - sub r3, r0, r3 @ PHYS_OFFSET - PAGE_OFFSET + ldmia r0, {r3-r7} + mvn ip, #0 + subs r3, r0, r3 @ PHYS_OFFSET - PAGE_OFFSET add r4, r4, r3 @ adjust table start address add r5, r5, r3 @ adjust table end address - add r7, r7, r3 @ adjust __pv_phys_offset address - str r8, [r7] @ save computed PHYS_OFFSET to __pv_phys_offset + add r6, r6, r3 @ adjust __pv_phys_offset address + add r7, r7, r3 @ adjust __pv_offset address + str r8, [r6, #LOW_OFFSET] @ save computed PHYS_OFFSET to __pv_phys_offset + strcc ip, [r7, #HIGH_OFFSET] @ save to __pv_offset high bits mov r6, r3, lsr #24 @ constant for add/sub instructions teq r3, r6, lsl #24 @ must be 16MiB aligned THUMB( it ne @ cross section branch ) bne __error - str r6, [r7, #4] @ save to __pv_offset + str r3, [r7, #LOW_OFFSET] @ save to __pv_offset low bits b __fixup_a_pv_table ENDPROC(__fixup_pv_table) @@ -565,9 +576,18 @@ ENDPROC(__fixup_pv_table) .long __pv_table_begin .long __pv_table_end 2: .long __pv_phys_offset + .long __pv_offset .text __fixup_a_pv_table: + adr r0, 3f + ldr r6, [r0] + add r6, r6, r3 + ldr r0, [r6, #HIGH_OFFSET] @ pv_offset high word + ldr r6, [r6, #LOW_OFFSET] @ pv_offset low word + mov r6, r6, lsr #24 + cmn r0, #1 + moveq r0, #0x400000 @ set bit 22, mov to mvn instruction #ifdef CONFIG_THUMB2_KERNEL lsls r6, #24 beq 2f @@ -582,9 +602,15 @@ __fixup_a_pv_table: b 2f 1: add r7, r3 ldrh ip, [r7, #2] - and ip, 0x8f00 - orr ip, r6 @ mask in offset bits 31-24 + tst ip, #0x4000 + and ip, #0x8f00 + orrne ip, r6 @ mask in offset bits 31-24 + orreq ip, r0 @ mask in offset bits 7-0 strh ip, [r7, #2] + ldrheq ip, [r7] + biceq ip, #0x20 + orreq ip, ip, r0, lsr #16 + strheq ip, [r7] 2: cmp r4, r5 ldrcc r7, [r4], #4 @ use branch for delay slot bcc 1b @@ -593,7 +619,10 @@ __fixup_a_pv_table: b 2f 1: ldr ip, [r7, r3] bic ip, ip, #0x000000ff - orr ip, ip, r6 @ mask in offset bits 31-24 + tst ip, #0xf00 @ check the rotation field + orrne ip, ip, r6 @ mask in offset bits 31-24 + biceq ip, ip, #0x400000 @ clear bit 22 + orreq ip, ip, r0 @ mask in offset bits 7-0 str ip, [r7, r3] 2: cmp r4, r5 ldrcc r7, [r4], #4 @ use branch for delay slot @@ -602,28 +631,17 @@ __fixup_a_pv_table: #endif ENDPROC(__fixup_a_pv_table) +3: .long __pv_offset + ENTRY(fixup_pv_table) stmfd sp!, {r4 - r7, lr} - ldr r2, 2f @ get address of __pv_phys_offset mov r3, #0 @ no offset mov r4, r0 @ r0 = table start add r5, r0, r1 @ r1 = table size - ldr r6, [r2, #4] @ get __pv_offset bl __fixup_a_pv_table ldmfd sp!, {r4 - r7, pc} ENDPROC(fixup_pv_table) - .align -2: .long __pv_phys_offset - - .data - .globl __pv_phys_offset - .type __pv_phys_offset, %object -__pv_phys_offset: - .long 0 - .size __pv_phys_offset, . - __pv_phys_offset -__pv_offset: - .long 0 #endif #include "head-common.S" diff --git a/arch/arm/kernel/patch.c b/arch/arm/kernel/patch.c index 07314af..8356312 100644 --- a/arch/arm/kernel/patch.c +++ b/arch/arm/kernel/patch.c @@ -8,6 +8,9 @@ #include "patch.h" +u64 __pv_phys_offset __attribute__((section(".data"))); +u64 __pv_offset __attribute__((section(".data"))); + struct patch { void *addr; unsigned int insn;