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From: Dave Martin <Dave.Martin@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: "Catalin Marinas" <catalin.marinas@arm.com>,
	"Will Deacon" <will.deacon@arm.com>,
	"Ard Biesheuvel" <ard.biesheuvel@linaro.org>,
	"Alex Bennée" <alex.bennee@linaro.org>,
	"Szabolcs Nagy" <szabolcs.nagy@arm.com>,
	"Richard Sandiford" <richard.sandiford@arm.com>,
	kvmarm@lists.cs.columbia.edu, libc-alpha@sourceware.org,
	linux-arch@vger.kernel.org
Subject: [PATCH v2 10/28] arm64/sve: Low-level CPU setup
Date: Thu, 31 Aug 2017 18:00:42 +0100	[thread overview]
Message-ID: <1504198860-12951-11-git-send-email-Dave.Martin@arm.com> (raw)
In-Reply-To: <1504198860-12951-1-git-send-email-Dave.Martin@arm.com>

To enable the kernel to use SVE, all SVE traps from EL1 must be
disabled.  To take maximum advantage of the hardware, the full
available vector length also needs to be enabled for EL1 by
programming ZCR_EL2.LEN.  (The kernel will program ZCR_EL1.LEN as
required, but this cannot override the limit set by ZCR_EL2.)

In advance of full SVE support being implemented for userspace, it
also necessary to ensure that SVE traps from EL0 are enabled.

This patch makes the appropriate changes to the primary and
secondary CPU initialisation code.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
---
 arch/arm64/kernel/head.S | 13 ++++++++++++-
 arch/arm64/mm/proc.S     | 14 ++++++++++++--
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 7434ec0..f411f71 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -516,8 +516,19 @@ CPU_LE(	movk	x0, #0x30d0, lsl #16	)	// Clear EE and E0E on LE systems
 	mov	x0, #0x33ff
 	msr	cptr_el2, x0			// Disable copro. traps to EL2
 
+	/* SVE register access */
+	mrs	x1, id_aa64pfr0_el1
+	ubfx	x1, x1, #ID_AA64PFR0_SVE_SHIFT, #4
+	cbz	x1, 7f
+
+	bic	x0, x0, #CPTR_EL2_TZ		// Also disable SVE traps
+	msr	cptr_el2, x0			// Disable copro. traps to EL2
+	isb
+	mov	x1, #ZCR_ELx_LEN_MASK		// SVE: Enable full vector
+	msr_s	SYS_ZCR_EL2, x1			// length for EL1.
+
 	/* Hypervisor stub */
-	adr_l	x0, __hyp_stub_vectors
+7:	adr_l	x0, __hyp_stub_vectors
 	msr	vbar_el2, x0
 
 	/* spsr */
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
index 877d42f..dd22ef2 100644
--- a/arch/arm64/mm/proc.S
+++ b/arch/arm64/mm/proc.S
@@ -27,6 +27,7 @@
 #include <asm/pgtable-hwdef.h>
 #include <asm/cpufeature.h>
 #include <asm/alternative.h>
+#include <asm/sysreg.h>
 
 #ifdef CONFIG_ARM64_64K_PAGES
 #define TCR_TG_FLAGS	TCR_TG0_64K | TCR_TG1_64K
@@ -186,8 +187,17 @@ ENTRY(__cpu_setup)
 	tlbi	vmalle1				// Invalidate local TLB
 	dsb	nsh
 
-	mov	x0, #3 << 20
-	msr	cpacr_el1, x0			// Enable FP/ASIMD
+	mov	x0, #3 << 20			// FEN
+
+	/* SVE */
+	mrs	x5, id_aa64pfr0_el1
+	ubfx	x5, x5, #ID_AA64PFR0_SVE_SHIFT, #4
+	cbz	x5, 1f
+
+	bic	x0, x0, #CPACR_EL1_ZEN
+	orr	x0, x0, #CPACR_EL1_ZEN_EL1EN	// SVE: trap for EL0, not EL1
+1:	msr	cpacr_el1, x0			// Enable FP/ASIMD
+
 	mov	x0, #1 << 12			// Reset mdscr_el1 and disable
 	msr	mdscr_el1, x0			// access to the DCC from EL0
 	isb					// Unmask debug exceptions now,
-- 
2.1.4

WARNING: multiple messages have this Message-ID (diff)
From: Dave.Martin@arm.com (Dave Martin)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 10/28] arm64/sve: Low-level CPU setup
Date: Thu, 31 Aug 2017 18:00:42 +0100	[thread overview]
Message-ID: <1504198860-12951-11-git-send-email-Dave.Martin@arm.com> (raw)
In-Reply-To: <1504198860-12951-1-git-send-email-Dave.Martin@arm.com>

To enable the kernel to use SVE, all SVE traps from EL1 must be
disabled.  To take maximum advantage of the hardware, the full
available vector length also needs to be enabled for EL1 by
programming ZCR_EL2.LEN.  (The kernel will program ZCR_EL1.LEN as
required, but this cannot override the limit set by ZCR_EL2.)

In advance of full SVE support being implemented for userspace, it
also necessary to ensure that SVE traps from EL0 are enabled.

This patch makes the appropriate changes to the primary and
secondary CPU initialisation code.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Alex Benn?e <alex.bennee@linaro.org>
---
 arch/arm64/kernel/head.S | 13 ++++++++++++-
 arch/arm64/mm/proc.S     | 14 ++++++++++++--
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 7434ec0..f411f71 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -516,8 +516,19 @@ CPU_LE(	movk	x0, #0x30d0, lsl #16	)	// Clear EE and E0E on LE systems
 	mov	x0, #0x33ff
 	msr	cptr_el2, x0			// Disable copro. traps to EL2
 
+	/* SVE register access */
+	mrs	x1, id_aa64pfr0_el1
+	ubfx	x1, x1, #ID_AA64PFR0_SVE_SHIFT, #4
+	cbz	x1, 7f
+
+	bic	x0, x0, #CPTR_EL2_TZ		// Also disable SVE traps
+	msr	cptr_el2, x0			// Disable copro. traps to EL2
+	isb
+	mov	x1, #ZCR_ELx_LEN_MASK		// SVE: Enable full vector
+	msr_s	SYS_ZCR_EL2, x1			// length for EL1.
+
 	/* Hypervisor stub */
-	adr_l	x0, __hyp_stub_vectors
+7:	adr_l	x0, __hyp_stub_vectors
 	msr	vbar_el2, x0
 
 	/* spsr */
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
index 877d42f..dd22ef2 100644
--- a/arch/arm64/mm/proc.S
+++ b/arch/arm64/mm/proc.S
@@ -27,6 +27,7 @@
 #include <asm/pgtable-hwdef.h>
 #include <asm/cpufeature.h>
 #include <asm/alternative.h>
+#include <asm/sysreg.h>
 
 #ifdef CONFIG_ARM64_64K_PAGES
 #define TCR_TG_FLAGS	TCR_TG0_64K | TCR_TG1_64K
@@ -186,8 +187,17 @@ ENTRY(__cpu_setup)
 	tlbi	vmalle1				// Invalidate local TLB
 	dsb	nsh
 
-	mov	x0, #3 << 20
-	msr	cpacr_el1, x0			// Enable FP/ASIMD
+	mov	x0, #3 << 20			// FEN
+
+	/* SVE */
+	mrs	x5, id_aa64pfr0_el1
+	ubfx	x5, x5, #ID_AA64PFR0_SVE_SHIFT, #4
+	cbz	x5, 1f
+
+	bic	x0, x0, #CPACR_EL1_ZEN
+	orr	x0, x0, #CPACR_EL1_ZEN_EL1EN	// SVE: trap for EL0, not EL1
+1:	msr	cpacr_el1, x0			// Enable FP/ASIMD
+
 	mov	x0, #1 << 12			// Reset mdscr_el1 and disable
 	msr	mdscr_el1, x0			// access to the DCC from EL0
 	isb					// Unmask debug exceptions now,
-- 
2.1.4

  parent reply	other threads:[~2017-08-31 17:01 UTC|newest]

Thread overview: 224+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-31 17:00 [PATCH v2 00/28] ARM Scalable Vector Extension (SVE) Dave Martin
2017-08-31 17:00 ` Dave Martin
2017-08-31 17:00 ` [PATCH v2 01/28] regset: Add support for dynamically sized regsets Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-08-31 17:00 ` [PATCH v2 02/28] arm64: KVM: Hide unsupported AArch64 CPU features from guests Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-09-13 14:37   ` Alex Bennée
2017-09-13 14:37     ` Alex Bennée
2017-09-13 14:37     ` Alex Bennée
2017-09-15  0:04     ` Dave Martin
2017-09-15  0:04       ` Dave Martin
2017-08-31 17:00 ` [PATCH v2 03/28] arm64: efi: Add missing Kconfig dependency on KERNEL_MODE_NEON Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-08-31 17:00 ` [PATCH v2 04/28] arm64: Port deprecated instruction emulation to new sysctl interface Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-08-31 17:00 ` [PATCH v2 05/28] arm64: fpsimd: Simplify uses of {set,clear}_ti_thread_flag() Dave Martin
2017-08-31 17:00   ` [PATCH v2 05/28] arm64: fpsimd: Simplify uses of {set, clear}_ti_thread_flag() Dave Martin
2017-08-31 17:00 ` [PATCH v2 06/28] arm64/sve: System register and exception syndrome definitions Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-09-13 14:48   ` Alex Bennée
2017-09-13 14:48     ` Alex Bennée
2017-09-13 14:48     ` Alex Bennée
2017-08-31 17:00 ` [PATCH v2 07/28] arm64/sve: Low-level SVE architectural state manipulation functions Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-09-13 15:39   ` Alex Bennée
2017-09-13 15:39     ` Alex Bennée
2017-09-13 15:39     ` Alex Bennée
2017-08-31 17:00 ` [PATCH v2 08/28] arm64/sve: Kconfig update and conditional compilation support Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-08-31 17:00 ` [PATCH v2 09/28] arm64/sve: Signal frame and context structure definition Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-09-13 13:36   ` Catalin Marinas
2017-09-13 13:36     ` Catalin Marinas
2017-09-13 21:33     ` Dave Martin
2017-09-13 21:33       ` Dave Martin
2017-08-31 17:00 ` Dave Martin [this message]
2017-08-31 17:00   ` [PATCH v2 10/28] arm64/sve: Low-level CPU setup Dave Martin
2017-09-13 13:32   ` Catalin Marinas
2017-09-13 13:32     ` Catalin Marinas
2017-09-13 19:21     ` Dave Martin
2017-09-13 19:21       ` Dave Martin
2017-09-13 19:21       ` Dave Martin
2017-10-05 10:47       ` Dave Martin
2017-10-05 10:47         ` Dave Martin
2017-10-05 11:04         ` Suzuki K Poulose
2017-10-05 11:04           ` Suzuki K Poulose
2017-10-05 11:22           ` Dave Martin
2017-10-05 11:22             ` Dave Martin
2017-08-31 17:00 ` [PATCH v2 11/28] arm64/sve: Core task context handling Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-09-13 14:33   ` Catalin Marinas
2017-09-13 14:33     ` Catalin Marinas
2017-09-14 19:55     ` Dave Martin
2017-09-14 19:55       ` Dave Martin
2017-09-20 13:58       ` Catalin Marinas
2017-09-20 13:58         ` Catalin Marinas
2017-10-03 11:11         ` Dave Martin
2017-10-03 11:11           ` Dave Martin
2017-10-04 17:29           ` Catalin Marinas
2017-10-04 17:29             ` Catalin Marinas
2017-10-03 11:33     ` Dave Martin
2017-10-03 11:33       ` Dave Martin
2017-10-05 11:28       ` Catalin Marinas
2017-10-05 11:28         ` Catalin Marinas
2017-10-06 13:10         ` Dave Martin
2017-10-06 13:10           ` Dave Martin
2017-10-06 13:36           ` Catalin Marinas
2017-10-06 13:36             ` Catalin Marinas
2017-10-06 15:15             ` Dave Martin
2017-10-06 15:15               ` Dave Martin
2017-10-06 15:33               ` Catalin Marinas
2017-10-06 15:33                 ` Catalin Marinas
2017-09-13 17:26   ` Catalin Marinas
2017-09-13 17:26     ` Catalin Marinas
2017-09-13 19:17     ` Dave Martin
2017-09-13 19:17       ` Dave Martin
2017-09-13 22:21       ` Catalin Marinas
2017-09-13 22:21         ` Catalin Marinas
2017-09-14 19:40         ` Dave Martin
2017-09-14 19:40           ` Dave Martin
2017-09-19 17:13           ` Catalin Marinas
2017-09-19 17:13             ` Catalin Marinas
2017-08-31 17:00 ` [PATCH v2 12/28] arm64/sve: Support vector length resetting for new processes Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-09-14  8:47   ` Alex Bennée
2017-09-14  8:47     ` Alex Bennée
2017-09-14  8:47     ` Alex Bennée
2017-08-31 17:00 ` [PATCH v2 13/28] arm64/sve: Signal handling support Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-09-14  9:30   ` Alex Bennée
2017-09-14  9:30     ` Alex Bennée
2017-09-14  9:30     ` Alex Bennée
2017-08-31 17:00 ` [PATCH v2 14/28] arm64/sve: Backend logic for setting the vector length Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-09-13 17:29   ` Catalin Marinas
2017-09-13 17:29     ` Catalin Marinas
2017-09-13 19:06     ` Dave Martin
2017-09-13 19:06       ` Dave Martin
2017-09-13 22:11       ` Catalin Marinas
2017-09-13 22:11         ` Catalin Marinas
2017-10-05 16:42         ` Dave Martin
2017-10-05 16:42           ` Dave Martin
2017-10-05 16:53           ` Catalin Marinas
2017-10-05 16:53             ` Catalin Marinas
2017-10-05 17:04             ` Dave Martin
2017-10-05 17:04               ` Dave Martin
2017-09-20 10:57   ` Alan Hayward
2017-09-20 10:57     ` Alan Hayward
2017-09-20 10:59   ` Alan Hayward
2017-09-20 10:59     ` Alan Hayward
2017-09-20 11:09     ` Dave Martin
2017-09-20 11:09       ` Dave Martin
2017-09-20 18:08       ` Alan Hayward
2017-09-20 18:08         ` Alan Hayward
2017-09-21 11:19         ` Dave Martin
2017-09-21 11:19           ` Dave Martin
2017-09-21 11:57           ` Alan Hayward
2017-09-21 11:57             ` Alan Hayward
2017-08-31 17:00 ` [PATCH v2 15/28] arm64: cpufeature: Move sys_caps_initialised declarations Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-09-14  9:33   ` Alex Bennée
2017-09-14  9:33     ` Alex Bennée
2017-09-14  9:33     ` Alex Bennée
2017-09-14  9:35   ` Suzuki K Poulose
2017-09-14  9:35     ` Suzuki K Poulose
2017-08-31 17:00 ` [PATCH v2 16/28] arm64/sve: Probe SVE capabilities and usable vector lengths Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-09-14  9:45   ` Alex Bennée
2017-09-14  9:45     ` Alex Bennée
2017-09-14  9:45     ` Alex Bennée
2017-09-28 14:22     ` Dave Martin
2017-09-28 14:22       ` Dave Martin
2017-09-28 17:32       ` Alex Bennée
2017-09-28 17:32         ` Alex Bennée
2017-09-28 17:32         ` Alex Bennée
2017-08-31 17:00 ` [PATCH v2 17/28] arm64/sve: Preserve SVE registers around kernel-mode NEON use Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-09-14 10:52   ` Alex Bennée
2017-09-14 10:52     ` Alex Bennée
2017-09-14 10:52     ` Alex Bennée
2017-08-31 17:00 ` [PATCH v2 18/28] arm64/sve: Preserve SVE registers around EFI runtime service calls Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-09-14 11:01   ` Alex Bennée
2017-09-14 11:01     ` Alex Bennée
2017-09-14 11:01     ` Alex Bennée
2017-08-31 17:00 ` [PATCH v2 19/28] arm64/sve: ptrace and ELF coredump support Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-09-06 16:21   ` Okamoto, Takayuki
2017-09-06 16:21     ` Okamoto, Takayuki
2017-09-06 18:16     ` Dave Martin
2017-09-06 18:16       ` Dave Martin
2017-09-07  5:11       ` Okamoto, Takayuki
2017-09-07  5:11         ` Okamoto, Takayuki
2017-09-07  5:11         ` Okamoto, Takayuki
2017-09-08 13:11         ` Dave Martin
2017-09-08 13:11           ` Dave Martin
2017-09-14 12:57   ` Alex Bennée
2017-09-14 12:57     ` Alex Bennée
2017-09-14 12:57     ` Alex Bennée
2017-09-28 14:57     ` Dave Martin
2017-09-28 14:57       ` Dave Martin
2017-09-29 12:46     ` Dave Martin
2017-09-29 12:46       ` Dave Martin
2017-08-31 17:00 ` [PATCH v2 20/28] arm64/sve: Add prctl controls for userspace vector length management Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-09-14 13:02   ` Alex Bennée
2017-09-14 13:02     ` Alex Bennée
2017-09-14 13:02     ` Alex Bennée
2017-08-31 17:00 ` [PATCH v2 21/28] arm64/sve: Add sysctl to set the default vector length for new processes Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-09-14 13:05   ` Alex Bennée
2017-09-14 13:05     ` Alex Bennée
2017-09-14 13:05     ` Alex Bennée
2017-08-31 17:00 ` [PATCH v2 22/28] arm64/sve: KVM: Prevent guests from using SVE Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-09-14 13:28   ` Alex Bennée
2017-09-14 13:28     ` Alex Bennée
2017-09-14 13:28     ` Alex Bennée
2017-08-31 17:00 ` [PATCH v2 23/28] arm64/sve: KVM: Treat guest SVE use as undefined instruction execution Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-09-14 13:30   ` Alex Bennée
2017-09-14 13:30     ` Alex Bennée
2017-09-14 13:30     ` Alex Bennée
2017-09-14 13:31   ` Alex Bennée
2017-09-14 13:31     ` Alex Bennée
2017-09-14 13:31     ` Alex Bennée
2017-09-29 13:00     ` Dave Martin
2017-09-29 13:00       ` Dave Martin
2017-09-29 14:43       ` Alex Bennée
2017-09-29 14:43         ` Alex Bennée
2017-09-29 14:43         ` Alex Bennée
2017-08-31 17:00 ` [PATCH v2 24/28] arm64/sve: KVM: Hide SVE from CPU features exposed to guests Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-09-14 13:32   ` Alex Bennée
2017-09-14 13:32     ` Alex Bennée
2017-09-14 13:32     ` Alex Bennée
2017-08-31 17:00 ` [PATCH v2 25/28] arm64/sve: Detect SVE and activate runtime support Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-08-31 17:00 ` [PATCH v2 26/28] arm64/sve: Add documentation Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-10-05 16:39   ` Szabolcs Nagy
2017-10-05 16:39     ` Szabolcs Nagy
2017-10-05 17:02     ` Dave Martin
2017-10-05 17:02       ` Dave Martin
2017-10-06 15:43   ` Szabolcs Nagy
2017-10-06 15:43     ` Szabolcs Nagy
2017-10-06 17:37     ` Dave Martin
2017-10-06 17:37       ` Dave Martin
2017-10-09  9:34       ` Alex Bennée
2017-10-09  9:34         ` Alex Bennée
2017-10-09  9:34         ` Alex Bennée
2017-10-09  9:49         ` Dave Martin
2017-10-09  9:49           ` Dave Martin
2017-10-09 14:07           ` Alex Bennée
2017-10-09 14:07             ` Alex Bennée
2017-10-09 14:07             ` Alex Bennée
2017-10-09 16:20             ` Dave Martin
2017-10-09 16:20               ` Dave Martin
2017-08-31 17:00 ` [RFC PATCH v2 27/28] arm64: signal: Report signal frame size to userspace via auxv Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-08-31 17:00   ` Dave Martin
2017-08-31 17:01 ` [RFC PATCH v2 28/28] arm64/sve: signal: Include SVE when computing AT_MINSIGSTKSZ Dave Martin
2017-08-31 17:01   ` Dave Martin

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