Add support for FEAT_MTPMU for Armv8.6

If FEAT_PMUv3 is implemented and PMEVTYPER<n>(_EL0).MT bit is implemented
as well, it is possible to control whether PMU counters take into account
events happening on other threads.

If FEAT_MTPMU is implemented, EL3 (or EL2) can override the MT bit
leaving it to effective state of 0 regardless of any write to it.

This patch introduces the DISABLE_MTPMU flag, which allows to diable
multithread event count from EL3 (or EL2). The flag is disabled
by default so the behavior is consistent with those architectures
that do not implement FEAT_MTPMU.
Signed-off-by: Javier Almansa Sobrino <javier.almansasobrino@arm.com>
Change-Id: Iee3a8470ae8ba13316af1bd40c8d4aa86e0cb85e

Makefile

@@ -867,6 +867,7 @@ $(eval $(call assert_booleans,\
         CTX_INCLUDE_EL2_REGS \
         CTX_INCLUDE_NEVE_REGS \
         DEBUG \
+        DISABLE_MTPMU \
         DYN_DISABLE_AUTH \
         EL3_EXCEPTION_HANDLING \
         ENABLE_AMU \
@@ -956,6 +957,7 @@ $(eval $(call add_defines,\
         CTX_INCLUDE_EL2_REGS \
         CTX_INCLUDE_NEVE_REGS \
         DECRYPTION_SUPPORT_${DECRYPTION_SUPPORT} \
+        DISABLE_MTPMU \
         ENABLE_AMU \
         ENABLE_ASSERTIONS \
         ENABLE_BTI \

bl1/bl1.mk

 #
-# Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -16,6 +16,10 @@ BL1_SOURCES		+=	bl1/bl1_main.c				\
 				plat/common/${ARCH}/platform_up_stack.S \
 				${MBEDTLS_SOURCES}
 
+ifeq (${DISABLE_MTPMU},1)
+BL1_SOURCES		+=	lib/extensions/mtpmu/${ARCH}/mtpmu.S
+endif
+
 ifeq (${ARCH},aarch64)
 BL1_SOURCES		+=	lib/cpus/aarch64/dsu_helpers.S		\
 				lib/el3_runtime/aarch64/context.S

bl2/bl2.mk

 #
-# Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -25,6 +25,10 @@ BL2_SOURCES		+=	bl2/${ARCH}/bl2_el3_entrypoint.S	\
 				lib/cpus/${ARCH}/cpu_helpers.S		\
 				lib/cpus/errata_report.c
 
+ifeq (${DISABLE_MTPMU},1)
+BL2_SOURCES		+=	lib/extensions/mtpmu/${ARCH}/mtpmu.S
+endif
+
 ifeq (${ARCH},aarch64)
 BL2_SOURCES		+=	lib/cpus/aarch64/dsu_helpers.S
 endif

bl31/bl31.mk

 #
-# Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -40,6 +40,9 @@ BL31_SOURCES		+=	bl31/bl31_main.c				\
 				${SPMD_SOURCES}					\
 				${SPM_SOURCES}
 
+ifeq (${DISABLE_MTPMU},1)
+BL31_SOURCES		+=	lib/extensions/mtpmu/aarch64/mtpmu.S
+endif
 
 ifeq (${ENABLE_PMF}, 1)
 BL31_SOURCES		+=	lib/pmf/pmf_main.c

bl32/sp_min/sp_min.mk

 #
-# Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2016-2020, ARM Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -19,6 +19,10 @@ BL32_SOURCES		+=	bl32/sp_min/sp_min_main.c		\
 				services/std_svc/std_svc_setup.c	\
 				${PSCI_LIB_SOURCES}
 
+ifeq (${DISABLE_MTPMU},1)
+BL32_SOURCES		+=	lib/extensions/mtpmu/aarch32/mtpmu.S
+endif
+
 ifeq (${ENABLE_PMF}, 1)
 BL32_SOURCES		+=	lib/pmf/pmf_main.c
 endif

docs/getting_started/build-options.rst

@@ -185,6 +185,11 @@ Common build options
    of the binary image. If set to 1, then only the ELF image is built.
    0 is the default.
 
+-  ``DISABLE_MTPMU``: Boolean option to disable FEAT_MTPMU if implemented
+   (Armv8.6 onwards). Its default value is 0 to keep consistency with platforms
+   that do not implement FEAT_MTPMU. For more information on FEAT_MTPMU,
+   check the latest Arm ARM.
+
 -  ``DYN_DISABLE_AUTH``: Provides the capability to dynamically disable Trusted
    Board Boot authentication at runtime. This option is meant to be enabled only
    for development platforms. ``TRUSTED_BOARD_BOOT`` flag must be set if this

include/arch/aarch32/arch.h

@@ -102,6 +102,11 @@
 /* CSSELR definitions */
 #define LEVEL_SHIFT		U(1)
 
+/* ID_DFR1_EL1 definitions */
+#define ID_DFR1_MTPMU_SHIFT	U(0)
+#define ID_DFR1_MTPMU_MASK	U(0xf)
+#define ID_DFR1_MTPMU_SUPPORTED	U(1)
+
 /* ID_MMFR4 definitions */
 #define ID_MMFR4_CNP_SHIFT	U(12)
 #define ID_MMFR4_CNP_LENGTH	U(4)
@@ -126,6 +131,9 @@
 #define ID_PFR1_GENTIMER_MASK	U(0xf)
 #define ID_PFR1_GIC_SHIFT	U(28)
 #define ID_PFR1_GIC_MASK	U(0xf)
+#define ID_PFR1_SEC_SHIFT	U(4)
+#define ID_PFR1_SEC_MASK	U(0xf)
+#define ID_PFR1_ELx_ENABLED	U(1)
 
 /* SCTLR definitions */
 #define SCTLR_RES1_DEF		((U(1) << 23) | (U(1) << 22) | (U(1) << 4) | \
@@ -164,6 +172,7 @@
 #define SDCR_SCCD_BIT		(U(1) << 23)
 #define SDCR_SPME_BIT		(U(1) << 17)
 #define SDCR_RESET_VAL		U(0x0)
+#define SDCR_MTPME_BIT		(U(1) << 28)
 
 /* HSCTLR definitions */
 #define HSCTLR_RES1	((U(1) << 29) | (U(1) << 28) | (U(1) << 23) | \
@@ -244,6 +253,7 @@
 #define VTTBR_BADDR_SHIFT	U(0)
 
 /* HDCR definitions */
+#define HDCR_MTPME_BIT		(U(1) << 28)
 #define HDCR_HLP_BIT		(U(1) << 26)
 #define HDCR_HPME_BIT		(U(1) << 7)
 #define HDCR_RESET_VAL		U(0x0)
@@ -503,6 +513,7 @@
 #define CTR		p15, 0, c0, c0, 1
 #define CNTFRQ		p15, 0, c14, c0, 0
 #define ID_MMFR4	p15, 0, c0, c2, 6
+#define ID_DFR1		p15, 0, c0, c3, 5
 #define ID_PFR0		p15, 0, c0, c1, 0
 #define ID_PFR1		p15, 0, c0, c1, 1
 #define MAIR0		p15, 0, c10, c2, 0

include/arch/aarch32/el3_common_macros.S

@@ -242,6 +242,10 @@
 	cps	#MODE32_mon
 	isb
 
+#if DISABLE_MTPMU
+	bl	mtpmu_disable
+#endif
+
 	.if \_warm_boot_mailbox
 		/* -------------------------------------------------------------
 		 * This code will be executed for both warm and cold resets.

include/arch/aarch64/arch.h

@@ -188,6 +188,11 @@
 #define ID_AA64DFR0_PMS_SHIFT	U(32)
 #define ID_AA64DFR0_PMS_MASK	ULL(0xf)
 
+/* ID_AA64DFR0_EL1.MTPMU definitions (for ARMv8.6+) */
+#define ID_AA64DFR0_MTPMU_SHIFT		U(48)
+#define ID_AA64DFR0_MTPMU_MASK		ULL(0xf)
+#define ID_AA64DFR0_MTPMU_SUPPORTED	ULL(1)
+
 /* ID_AA64ISAR1_EL1 definitions */
 #define ID_AA64ISAR1_EL1	S3_0_C0_C6_1
 #define ID_AA64ISAR1_GPI_SHIFT	U(28)
@@ -421,6 +426,7 @@
 #define SCR_RESET_VAL		SCR_RES1_BITS
 
 /* MDCR_EL3 definitions */
+#define MDCR_MTPME_BIT		(ULL(1) << 28)
 #define MDCR_SCCD_BIT		(ULL(1) << 23)
 #define MDCR_SPME_BIT		(ULL(1) << 17)
 #define MDCR_SDD_BIT		(ULL(1) << 16)
@@ -436,6 +442,7 @@
 #define MDCR_EL3_RESET_VAL	ULL(0x0)
 
 /* MDCR_EL2 definitions */
+#define MDCR_EL2_MTPME		(U(1) << 28)
 #define MDCR_EL2_HLP		(U(1) << 26)
 #define MDCR_EL2_HCCD		(U(1) << 23)
 #define MDCR_EL2_TTRF		(U(1) << 19)

include/arch/aarch64/el3_common_macros.S

@@ -277,6 +277,10 @@
 		isb
 	.endif /* _init_sctlr */
 
+#if DISABLE_MTPMU
+		bl	mtpmu_disable
+#endif
+
 	.if \_warm_boot_mailbox
 		/* -------------------------------------------------------------
 		 * This code will be executed for both warm and cold resets.

lib/extensions/mtpmu/aarch32/mtpmu.S

+/*
+ * Copyright (c) 2020, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch.h>
+#include <asm_macros.S>
+
+	.global	mtpmu_disable
+
+/* -------------------------------------------------------------
+ * The functions in this file are called at entrypoint, before
+ * the CPU has decided whether this is a cold or a warm boot.
+ * Therefore there are no stack yet to rely on for a C function
+ * call.
+ * -------------------------------------------------------------
+ */
+
+/*
+ * bool mtpmu_supported(void)
+ *
+ * Return a boolean indicating whether FEAT_MTPMU is supported or not.
+ *
+ * Trash registers: r0.
+ */
+func mtpmu_supported
+	ldcopr	r0, ID_DFR1
+	and	r0, r0, #(ID_DFR1_MTPMU_MASK >> ID_DFR1_MTPMU_SHIFT)
+	cmp	r0, #ID_DFR1_MTPMU_SUPPORTED
+	mov	r0, #0
+	addeq	r0, r0, #1
+	bx	lr
+endfunc mtpmu_supported
+
+/*
+ * bool el_implemented(unsigned int el)
+ *
+ * Return a boolean indicating if the specified EL (2 or 3) is implemented.
+ *
+ * Trash registers: r0
+ */
+func el_implemented
+	cmp	r0, #3
+	ldcopr	r0, ID_PFR1
+	lsreq	r0, r0, #ID_PFR1_SEC_SHIFT
+	lsrne	r0, r0, #ID_PFR1_VIRTEXT_SHIFT
+	/*
+	 * ID_PFR1_VIRTEXT_MASK is the same as ID_PFR1_SEC_MASK
+	 * so use any one of them
+	 */
+	and	r0, r0, #ID_PFR1_VIRTEXT_MASK
+	cmp	r0, #ID_PFR1_ELx_ENABLED
+	mov	r0, #0
+	addeq	r0, r0, #1
+	bx	lr
+endfunc el_implemented
+
+/*
+ * void mtpmu_disable(void)
+ *
+ * Disable mtpmu feature if supported.
+ *
+ * Trash register: r0, r1, r2
+ */
+func mtpmu_disable
+	mov	r2, lr
+	bl	mtpmu_supported
+	cmp	r0, #0
+	bxeq	r2	/* FEAT_MTPMU not supported */
+
+	/* FEAT_MTMPU Supported */
+	mov	r0, #3
+	bl	el_implemented
+	cmp	r0, #0
+	beq	1f
+
+	/* EL3 implemented */
+	ldcopr	r0, SDCR
+	ldr	r1, =SDCR_MTPME_BIT
+	bic	r0, r0, r1
+	stcopr	r0, SDCR
+
+	/*
+	 * If EL3 is implemented, HDCR.MTPME is implemented as Res0 and
+	 * FEAT_MTPMU is controlled only from EL3, so no need to perform
+	 * any operations for EL2.
+	 */
+	isb
+	bx	r2
+1:
+	/* EL3 not implemented */
+	mov	r0, #2
+	bl	el_implemented
+	cmp	r0, #0
+	bxeq	r2	/* No EL2 or EL3 implemented */
+
+	/* EL2 implemented */
+	ldcopr	r0, HDCR
+	ldr	r1, =HDCR_MTPME_BIT
+	orr	r0, r0, r1
+	stcopr	r0, HDCR
+	isb
+	bx	r2
+endfunc mtpmu_disable

lib/extensions/mtpmu/aarch64/mtpmu.S

+/*
+ * Copyright (c) 2020, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch.h>
+#include <asm_macros.S>
+
+	.global	mtpmu_disable
+
+/* -------------------------------------------------------------
+ * The functions in this file are called at entrypoint, before
+ * the CPU has decided whether this is a cold or a warm boot.
+ * Therefore there are no stack yet to rely on for a C function
+ * call.
+ * -------------------------------------------------------------
+ */
+
+/*
+ * bool mtpmu_supported(void)
+ *
+ * Return a boolean indicating whether FEAT_MTPMU is supported or not.
+ *
+ * Trash registers: x0, x1
+ */
+func mtpmu_supported
+	mrs	x0, id_aa64dfr0_el1
+	mov_imm	x1, ID_AA64DFR0_MTPMU_MASK
+	and	x0, x1, x0, LSR #ID_AA64DFR0_MTPMU_SHIFT
+	cmp	x0, ID_AA64DFR0_MTPMU_SUPPORTED
+	cset	x0, eq
+	ret
+endfunc mtpmu_supported
+
+/*
+ * bool el_implemented(unsigned int el_shift)
+ *
+ * Return a boolean indicating if the specified EL is implemented.
+ * The EL is represented as the bitmask shift on id_aa64pfr0_el1 register.
+ *
+ * Trash registers: x0, x1
+ */
+func el_implemented
+	mrs	x1, id_aa64pfr0_el1
+	lsr	x1, x1, x0
+	cmp	x1, #ID_AA64PFR0_ELX_MASK
+	cset	x0, eq
+	ret
+endfunc el_implemented
+
+/*
+ * void mtpmu_disable(void)
+ *
+ * Disable mtpmu feature if supported.
+ *
+ * Trash register: x0, x1, x30
+ */
+func mtpmu_disable
+	mov	x10, x30
+	bl	mtpmu_supported
+	cbz	x0, exit_disable
+
+	/* FEAT_MTMPU Supported */
+	mov_imm	x0, ID_AA64PFR0_EL3_SHIFT
+	bl	el_implemented
+	cbz	x0, 1f
+
+	/* EL3 implemented */
+	mrs	x0, mdcr_el3
+	mov_imm x1, MDCR_MTPME_BIT
+	bic	x0, x0, x1
+	msr	mdcr_el3, x0
+
+	/*
+	 * If EL3 is implemented, MDCR_EL2.MTPME is implemented as Res0 and
+	 * FEAT_MTPMU is controlled only from EL3, so no need to perform
+	 * any operations for EL2.
+	 */
+	isb
+exit_disable:
+	ret	x10
+1:
+	/* EL3 not implemented */
+	mov_imm	x0, ID_AA64PFR0_EL2_SHIFT
+	bl	el_implemented
+	cbz	x0, exit_disable
+
+	/* EL2 implemented */
+	mrs	x0, mdcr_el2
+	mov_imm x1, MDCR_EL2_MTPME
+	bic	x0, x0, x1
+	msr	mdcr_el2, x0
+	isb
+	ret	x10
+endfunc mtpmu_disable

make_helpers/defaults.mk

@@ -79,6 +79,10 @@ DEFAULT_PLAT			:= fvp
 # Disable the generation of the binary image (ELF only).
 DISABLE_BIN_GENERATION		:= 0
 
+# Disable MTPMU if FEAT_MTPMU is supported. Default is 0 to keep backwards
+# compatibility.
+DISABLE_MTPMU			:= 0
+
 # Enable capability to disable authentication dynamically. Only meant for
 # development platforms.
 DYN_DISABLE_AUTH		:= 0