From: Dave.Martin@arm.com (Dave Martin)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH v2 10/41] arm64/sve: Boot-time feature enablement
Date: Wed, 22 Mar 2017 14:50:40 +0000 [thread overview]
Message-ID: <1490194274-30569-11-git-send-email-Dave.Martin@arm.com> (raw)
In-Reply-To: <1490194274-30569-1-git-send-email-Dave.Martin@arm.com>
This patch enables Scalable Vector Extension access for the kernel
on boot.
If entered at EL2 without VHE support, ZCR_EL2 is also configured
to allow the maximum available vector length for EL1 initially, so
that the vector length can be correctly probed in advance of KVM
being initialised.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
---
arch/arm64/include/asm/kvm_arm.h | 1 +
arch/arm64/include/asm/sysreg.h | 10 ++++++++++
arch/arm64/kernel/head.S | 15 ++++++++++++++-
arch/arm64/mm/proc.S | 14 ++++++++++++--
4 files changed, 37 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 6e99978..6f536ef 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -185,6 +185,7 @@
#define CPTR_EL2_TCPAC (1 << 31)
#define CPTR_EL2_TTA (1 << 20)
#define CPTR_EL2_TFP (1 << CPTR_EL2_TFP_SHIFT)
+#define CPTR_EL2_TZ (1 << 8)
#define CPTR_EL2_DEFAULT 0x000033ff
/* Hyp Debug Configuration Register bits */
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 8f1a43e..9c4a2cc 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -118,6 +118,9 @@
#define SYS_ID_AA64MMFR1_EL1 sys_reg(3, 0, 0, 7, 1)
#define SYS_ID_AA64MMFR2_EL1 sys_reg(3, 0, 0, 7, 2)
+#define SYS_ZCR_EL1 sys_reg(3, 0, 1, 2, 0)
+#define SYS_ZCR_EL2 sys_reg(3, 4, 1, 2, 0)
+
#define SYS_CNTFRQ_EL0 sys_reg(3, 3, 14, 0, 0)
#define SYS_CTR_EL0 sys_reg(3, 3, 0, 0, 1)
#define SYS_DCZID_EL0 sys_reg(3, 3, 0, 0, 7)
@@ -267,6 +270,13 @@
#endif
+#define ZCR_EL1_LEN_MASK 0x1ff
+
+#define CPACR_EL1_ZEN_EL1EN (1 << 16)
+#define CPACR_EL1_ZEN_EL0EN (1 << 17)
+#define CPACR_EL1_ZEN (CPACR_EL1_ZEN_EL1EN | CPACR_EL1_ZEN_EL0EN)
+
+
/* Safe value for MPIDR_EL1: Bit31:RES1, Bit30:U:0, Bit24:MT:0 */
#define SYS_MPIDR_SAFE_VAL (1UL << 31)
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 4fb6ccd..344a0dd 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -629,9 +629,22 @@ CPU_LE( movk x0, #0x30d0, lsl #16 ) // Clear EE and E0E on LE systems
/* Coprocessor traps. */
mov x0, #0x33ff
+
+ /* SVE register access */
+ mrs x1, id_aa64pfr0_el1
+ ubfx x1, x1, #ID_AA64PFR0_SVE_SHIFT, #4
+ cbz x1, 4f
+
+ bic x0, x0, #CPTR_EL2_TZ // Disable SVE traps to EL2
msr cptr_el2, x0 // Disable copro. traps to EL2
-1:
+ isb
+
+ mov x1, #ZCR_EL1_LEN_MASK // SVE: Enable full vector
+ msr_s SYS_ZCR_EL1, x1 // length for EL1.
+ b 1f
+4: msr cptr_el2, x0 // Disable copro. traps to EL2
+1:
#ifdef CONFIG_COMPAT
msr hstr_el2, xzr // Disable CP15 traps to EL2
#endif
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
next prev parent reply other threads:[~2017-03-22 14:50 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-22 14:50 [RFC PATCH v2 00/41] Scalable Vector Extension (SVE) core support Dave Martin
2017-03-22 14:50 ` Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 01/41] arm64: signal: Refactor sigcontext parsing in rt_sigreturn Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 02/41] arm64: signal: factor frame layout and population into separate passes Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 03/41] arm64: signal: factor out signal frame record allocation Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 04/41] arm64: signal: Allocate extra sigcontext space as needed Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 05/41] arm64: signal: Parse extra_context during sigreturn Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 06/41] arm64: efi: Add missing Kconfig dependency on KERNEL_MODE_NEON Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 07/41] arm64/sve: Allow kernel-mode NEON to be disabled in Kconfig Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 08/41] arm64/sve: Low-level save/restore code Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 09/41] arm64/sve: Boot-time feature detection and reporting Dave Martin
2017-03-22 14:50 ` Dave Martin [this message]
2017-03-22 14:50 ` [RFC PATCH v2 11/41] arm64/sve: Expand task_struct for Scalable Vector Extension state Dave Martin
2017-03-22 16:20 ` Mark Rutland
2017-03-23 10:49 ` Dave Martin
2017-03-23 11:26 ` Mark Rutland
2017-03-22 14:50 ` [RFC PATCH v2 12/41] arm64/sve: Save/restore SVE state on context switch paths Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 13/41] arm64/sve: [BROKEN] Basic support for KERNEL_MODE_NEON Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 14/41] Revert "arm64/sve: Allow kernel-mode NEON to be disabled in Kconfig" Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 15/41] arm64/sve: Restore working FPSIMD save/restore around signals Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 16/41] arm64/sve: signal: Add SVE state record to sigcontext Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 17/41] arm64/sve: signal: Dump Scalable Vector Extension registers to user stack Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 18/41] arm64/sve: signal: Restore FPSIMD/SVE state in rt_sigreturn Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 19/41] arm64/sve: Avoid corruption when replacing the SVE state Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 20/41] arm64/sve: traps: Add descriptive string for SVE exceptions Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 21/41] arm64/sve: Enable SVE on demand for userspace Dave Martin
2017-03-22 16:48 ` Mark Rutland
2017-03-23 11:24 ` Dave Martin
2017-03-23 11:30 ` Suzuki K Poulose
2017-03-23 11:52 ` Mark Rutland
2017-03-23 12:07 ` Dave Martin
2017-03-23 13:40 ` Mark Rutland
2017-03-23 13:45 ` Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 22/41] arm64/sve: Implement FPSIMD-only context for tasks not using SVE Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 23/41] arm64/sve: Move ZEN handling to the common task_fpsimd_load() path Dave Martin
2017-03-22 16:55 ` Mark Rutland
2017-03-23 11:52 ` Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 24/41] arm64/sve: Discard SVE state on system call Dave Martin
2017-03-22 17:03 ` Mark Rutland
2017-03-23 11:59 ` Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 25/41] arm64/sve: Avoid preempt_disable() during sigreturn Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 26/41] arm64/sve: Avoid stale user register state after SVE access exception Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 27/41] arm64/sve: ptrace support Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 28/41] arm64: KVM: Treat SVE use by guests as undefined instruction execution Dave Martin
2017-03-22 17:06 ` Mark Rutland
2017-03-23 12:10 ` Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 29/41] prctl: Add skeleton for PR_SVE_{SET,GET}_VL controls Dave Martin
2017-03-22 14:50 ` [RFC PATCH v2 29/41] prctl: Add skeleton for PR_SVE_{SET, GET}_VL controls Dave Martin
2017-03-22 14:51 ` [RFC PATCH v2 30/41] arm64/sve: Track vector length for each task Dave Martin
2017-03-22 14:51 ` [RFC PATCH v2 31/41] arm64/sve: Set CPU vector length to match current task Dave Martin
2017-03-22 14:51 ` [RFC PATCH v2 32/41] arm64/sve: Factor out clearing of tasks' SVE regs Dave Martin
2017-03-22 14:51 ` [RFC PATCH v2 33/41] arm64/sve: Wire up vector length control prctl() calls Dave Martin
2017-03-22 14:51 ` Dave Martin
2017-03-22 14:51 ` [RFC PATCH v2 34/41] arm64/sve: Disallow VL setting for individual threads by default Dave Martin
2017-03-22 14:51 ` [RFC PATCH v2 35/41] arm64/sve: Add vector length inheritance control Dave Martin
2017-03-22 14:51 ` [RFC PATCH v2 36/41] arm64/sve: ptrace: Wire up vector length control and reporting Dave Martin
2017-03-22 14:51 ` [RFC PATCH v2 37/41] arm64/sve: Enable default vector length control via procfs Dave Martin
2017-03-22 14:51 ` [RFC PATCH v2 38/41] arm64/sve: Detect SVE via the cpufeature framework Dave Martin
2017-03-23 14:11 ` Suzuki K Poulose
2017-03-23 14:37 ` Dave Martin
2017-03-23 14:43 ` Dave Martin
2017-03-22 14:51 ` [RFC PATCH v2 39/41] arm64/sve: Migrate to cpucap based detection for runtime SVE code Dave Martin
2017-03-22 14:51 ` [RFC PATCH v2 40/41] arm64/sve: Allocate task SVE context storage dynamically Dave Martin
2017-03-22 14:51 ` [RFC PATCH v2 41/41] arm64/sve: Documentation: Add overview of the SVE userspace ABI Dave Martin
2017-03-22 14:51 ` Dave Martin
2017-03-31 15:28 ` [RFC PATCH v2 00/41] Scalable Vector Extension (SVE) core support Ard Biesheuvel
2017-03-31 15:28 ` Ard Biesheuvel
2017-04-03 9:45 ` Dave Martin
2017-04-03 9:45 ` Dave Martin
2017-04-03 10:01 ` Ard Biesheuvel
2017-04-03 10:01 ` Ard Biesheuvel
2017-04-03 10:51 ` Dave Martin
2017-04-03 10:51 ` Dave Martin
2017-04-03 10:55 ` Ard Biesheuvel
2017-04-03 10:55 ` Ard Biesheuvel
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