From nobody Mon Apr 6 18:06:53 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 33EFFC433FE for ; Tue, 4 Oct 2022 20:37:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229571AbiJDUhq (ORCPT ); Tue, 4 Oct 2022 16:37:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53340 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229500AbiJDUhn (ORCPT ); Tue, 4 Oct 2022 16:37:43 -0400 Received: from gloria.sntech.de (gloria.sntech.de [185.11.138.130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A5286BCC4 for ; Tue, 4 Oct 2022 13:37:39 -0700 (PDT) Received: from ip5b412258.dynamic.kabel-deutschland.de ([91.65.34.88] helo=phil.lan) by gloria.sntech.de with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1ofofT-0004n6-4O; Tue, 04 Oct 2022 22:37:31 +0200 From: Heiko Stuebner To: atishp@atishpatra.org, anup@brainfault.org, will@kernel.org, mark.rutland@arm.com, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Conor.Dooley@microchip.com, cmuellner@linux.com, samuel@sholland.org, Heiko Stuebner Subject: [PATCH 1/2] RISC-V: Cache SBI vendor values Date: Tue, 4 Oct 2022 22:37:23 +0200 Message-Id: <20221004203724.1459763-2-heiko@sntech.de> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221004203724.1459763-1-heiko@sntech.de> References: <20221004203724.1459763-1-heiko@sntech.de> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" sbi_get_mvendorid(), sbi_get_marchid() and sbi_get_mimpid() might get called multiple times, though the values of these CSRs should not change during the runtime of a specific machine. So cache the values in the functions and prevent multiple ecalls to read these values. Suggested-by: Atish Patra Signed-off-by: Heiko Stuebner --- arch/riscv/kernel/sbi.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c index 775d3322b422..5be8f90f325e 100644 --- a/arch/riscv/kernel/sbi.c +++ b/arch/riscv/kernel/sbi.c @@ -625,17 +625,32 @@ static inline long sbi_get_firmware_version(void) =20 long sbi_get_mvendorid(void) { - return __sbi_base_ecall(SBI_EXT_BASE_GET_MVENDORID); + static long id =3D -1; + + if (id < 0) + id =3D __sbi_base_ecall(SBI_EXT_BASE_GET_MVENDORID); + + return id; } =20 long sbi_get_marchid(void) { - return __sbi_base_ecall(SBI_EXT_BASE_GET_MARCHID); + static long id =3D -1; + + if (id < 0) + id =3D __sbi_base_ecall(SBI_EXT_BASE_GET_MARCHID); + + return id; } =20 long sbi_get_mimpid(void) { - return __sbi_base_ecall(SBI_EXT_BASE_GET_MIMPID); + static long id =3D -1; + + if (id < 0) + id =3D __sbi_base_ecall(SBI_EXT_BASE_GET_MIMPID); + + return id; } =20 static void sbi_send_cpumask_ipi(const struct cpumask *target) --=20 2.35.1 From nobody Mon Apr 6 18:06:53 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 483B8C433FE for ; Tue, 4 Oct 2022 20:37:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229644AbiJDUhu (ORCPT ); Tue, 4 Oct 2022 16:37:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53342 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229482AbiJDUhn (ORCPT ); Tue, 4 Oct 2022 16:37:43 -0400 Received: from gloria.sntech.de (gloria.sntech.de [185.11.138.130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A7BF6BCCA for ; Tue, 4 Oct 2022 13:37:39 -0700 (PDT) Received: from ip5b412258.dynamic.kabel-deutschland.de ([91.65.34.88] helo=phil.lan) by gloria.sntech.de with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1ofofT-0004n6-QX; Tue, 04 Oct 2022 22:37:31 +0200 From: Heiko Stuebner To: atishp@atishpatra.org, anup@brainfault.org, will@kernel.org, mark.rutland@arm.com, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Conor.Dooley@microchip.com, cmuellner@linux.com, samuel@sholland.org, Heiko Stuebner Subject: [PATCH 2/2] drivers/perf: riscv_pmu_sbi: add support for PMU variant on T-Head C9xx cores Date: Tue, 4 Oct 2022 22:37:24 +0200 Message-Id: <20221004203724.1459763-3-heiko@sntech.de> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221004203724.1459763-1-heiko@sntech.de> References: <20221004203724.1459763-1-heiko@sntech.de> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" With the T-HEAD C9XX cores being designed before or during the ratification to the SSCOFPMF extension, it implements functionality very similar but not equal to it. It implements overflow handling and also some privilege-mode filtering. While SSCOFPMF supports this for all modes, the C9XX only implements the filtering for M-mode and S-mode but not user-mode. So add some adaptions to allow the C9XX to still handle its PMU through the regular SBI PMU interface instead of defining new interfaces or drivers. To work properly, this requires a matching change in SBI, though the actual interface between kernel and SBI does not change. The main differences are a the overflow CSR and irq number. As the reading of the overflow-csr is in the hot-path during irq handling, use an errata and alternatives to not introduce new conditionals there. Signed-off-by: Heiko Stuebner Reviewed-by: Andrew Jones Reviewed-by: Conor Dooley --- arch/riscv/Kconfig.erratas | 13 +++++++++++ arch/riscv/errata/thead/errata.c | 18 +++++++++++++++ arch/riscv/include/asm/errata_list.h | 16 +++++++++++++- drivers/perf/riscv_pmu_sbi.c | 33 +++++++++++++++++++--------- 4 files changed, 69 insertions(+), 11 deletions(-) diff --git a/arch/riscv/Kconfig.erratas b/arch/riscv/Kconfig.erratas index f3623df23b5f..69621ae6d647 100644 --- a/arch/riscv/Kconfig.erratas +++ b/arch/riscv/Kconfig.erratas @@ -66,4 +66,17 @@ config ERRATA_THEAD_CMO =20 If you don't know what to do here, say "Y". =20 +config ERRATA_THEAD_PMU + bool "Apply T-Head PMU errata" + depends on ERRATA_THEAD && RISCV_PMU_SBI + default y + help + The T-Head C9xx cores implement a PMU overflow extension very + similar to the core SSCOFPMF extension. + + This will apply the overflow errata to handle the non-standard + behaviour via the regular SBI PMU driver and interface. + + If you don't know what to do here, say "Y". + endmenu # "CPU errata selection" diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/err= ata.c index 21546937db39..67fa078f303f 100644 --- a/arch/riscv/errata/thead/errata.c +++ b/arch/riscv/errata/thead/errata.c @@ -47,6 +47,21 @@ static bool errata_probe_cmo(unsigned int stage, return true; } =20 +static bool errata_probe_pmu(unsigned int stage, + unsigned long arch_id, unsigned long impid) +{ + if (!IS_ENABLED(CONFIG_ERRATA_THEAD_PMU)) + return false; + + if (arch_id !=3D 0 || impid !=3D 0) + return false; + + if (stage =3D=3D RISCV_ALTERNATIVES_EARLY_BOOT) + return false; + + return true; +} + static u32 thead_errata_probe(unsigned int stage, unsigned long archid, unsigned long impid) { @@ -58,6 +73,9 @@ static u32 thead_errata_probe(unsigned int stage, if (errata_probe_cmo(stage, archid, impid)) cpu_req_errata |=3D BIT(ERRATA_THEAD_CMO); =20 + if (errata_probe_pmu(stage, archid, impid)) + cpu_req_errata |=3D BIT(ERRATA_THEAD_PMU); + return cpu_req_errata; } =20 diff --git a/arch/riscv/include/asm/errata_list.h b/arch/riscv/include/asm/= errata_list.h index 19a771085781..4180312d2a70 100644 --- a/arch/riscv/include/asm/errata_list.h +++ b/arch/riscv/include/asm/errata_list.h @@ -6,6 +6,7 @@ #define ASM_ERRATA_LIST_H =20 #include +#include #include =20 #ifdef CONFIG_ERRATA_SIFIVE @@ -17,7 +18,8 @@ #ifdef CONFIG_ERRATA_THEAD #define ERRATA_THEAD_PBMT 0 #define ERRATA_THEAD_CMO 1 -#define ERRATA_THEAD_NUMBER 2 +#define ERRATA_THEAD_PMU 2 +#define ERRATA_THEAD_NUMBER 3 #endif =20 #define CPUFEATURE_SVPBMT 0 @@ -142,6 +144,18 @@ asm volatile(ALTERNATIVE_2( \ "r"((unsigned long)(_start) + (_size)) \ : "a0") =20 +#define THEAD_C9XX_RV_IRQ_PMU 17 +#define THEAD_C9XX_CSR_SCOUNTEROF 0x5c5 + +#define ALT_SBI_PMU_OVERFLOW(__ovl) \ +asm volatile(ALTERNATIVE( \ + "csrr %0, " __stringify(CSR_SSCOUNTOVF), \ + "csrr %0, " __stringify(THEAD_C9XX_CSR_SCOUNTEROF), \ + THEAD_VENDOR_ID, ERRATA_THEAD_PMU, \ + CONFIG_ERRATA_THEAD_PMU) \ + : "=3Dr" (__ovl) : \ + : "memory") + #endif /* __ASSEMBLY__ */ =20 #endif diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c index 8de4ca2fef21..ec0972c7c562 100644 --- a/drivers/perf/riscv_pmu_sbi.c +++ b/drivers/perf/riscv_pmu_sbi.c @@ -19,6 +19,7 @@ #include #include =20 +#include #include #include =20 @@ -46,6 +47,8 @@ static const struct attribute_group *riscv_pmu_attr_group= s[] =3D { * per_cpu in case of harts with different pmu counters */ static union sbi_pmu_ctr_info *pmu_ctr_list; +static bool riscv_pmu_use_irq; +static unsigned int riscv_pmu_irq_num; static unsigned int riscv_pmu_irq; =20 struct sbi_pmu_event_data { @@ -575,7 +578,7 @@ static irqreturn_t pmu_sbi_ovf_handler(int irq, void *d= ev) fidx =3D find_first_bit(cpu_hw_evt->used_hw_ctrs, RISCV_MAX_COUNTERS); event =3D cpu_hw_evt->events[fidx]; if (!event) { - csr_clear(CSR_SIP, SIP_LCOFIP); + csr_clear(CSR_SIP, BIT(riscv_pmu_irq_num)); return IRQ_NONE; } =20 @@ -583,13 +586,13 @@ static irqreturn_t pmu_sbi_ovf_handler(int irq, void = *dev) pmu_sbi_stop_hw_ctrs(pmu); =20 /* Overflow status register should only be read after counter are stopped= */ - overflow =3D csr_read(CSR_SSCOUNTOVF); + ALT_SBI_PMU_OVERFLOW(overflow); =20 /* * Overflow interrupt pending bit should only be cleared after stopping * all the counters to avoid any race condition. */ - csr_clear(CSR_SIP, SIP_LCOFIP); + csr_clear(CSR_SIP, BIT(riscv_pmu_irq_num)); =20 /* No overflow bit is set */ if (!overflow) @@ -651,10 +654,10 @@ static int pmu_sbi_starting_cpu(unsigned int cpu, str= uct hlist_node *node) /* Stop all the counters so that they can be enabled from perf */ pmu_sbi_stop_all(pmu); =20 - if (riscv_isa_extension_available(NULL, SSCOFPMF)) { + if (riscv_pmu_use_irq) { cpu_hw_evt->irq =3D riscv_pmu_irq; - csr_clear(CSR_IP, BIT(RV_IRQ_PMU)); - csr_set(CSR_IE, BIT(RV_IRQ_PMU)); + csr_clear(CSR_IP, BIT(riscv_pmu_irq_num)); + csr_set(CSR_IE, BIT(riscv_pmu_irq_num)); enable_percpu_irq(riscv_pmu_irq, IRQ_TYPE_NONE); } =20 @@ -663,9 +666,9 @@ static int pmu_sbi_starting_cpu(unsigned int cpu, struc= t hlist_node *node) =20 static int pmu_sbi_dying_cpu(unsigned int cpu, struct hlist_node *node) { - if (riscv_isa_extension_available(NULL, SSCOFPMF)) { + if (riscv_pmu_use_irq) { disable_percpu_irq(riscv_pmu_irq); - csr_clear(CSR_IE, BIT(RV_IRQ_PMU)); + csr_clear(CSR_IE, BIT(riscv_pmu_irq_num)); } =20 /* Disable all counters access for user mode now */ @@ -681,7 +684,17 @@ static int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, s= truct platform_device *pde struct device_node *cpu, *child; struct irq_domain *domain =3D NULL; =20 - if (!riscv_isa_extension_available(NULL, SSCOFPMF)) + if (riscv_isa_extension_available(NULL, SSCOFPMF)) { + riscv_pmu_irq_num =3D RV_IRQ_PMU; + riscv_pmu_use_irq =3D true; + } else if (IS_ENABLED(CONFIG_ERRATA_THEAD_PMU) && + sbi_get_mvendorid() =3D=3D THEAD_VENDOR_ID && + sbi_get_marchid() =3D=3D 0 && sbi_get_mimpid() =3D=3D 0) { + riscv_pmu_irq_num =3D THEAD_C9XX_RV_IRQ_PMU; + riscv_pmu_use_irq =3D true; + } + + if (!riscv_pmu_use_irq) return -EOPNOTSUPP; =20 for_each_of_cpu_node(cpu) { @@ -703,7 +716,7 @@ static int pmu_sbi_setup_irqs(struct riscv_pmu *pmu, st= ruct platform_device *pde return -ENODEV; } =20 - riscv_pmu_irq =3D irq_create_mapping(domain, RV_IRQ_PMU); + riscv_pmu_irq =3D irq_create_mapping(domain, riscv_pmu_irq_num); if (!riscv_pmu_irq) { pr_err("Failed to map PMU interrupt for node\n"); return -ENODEV; --=20 2.35.1