From patchwork Mon Feb 13 10:17:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nikos Nikoleris X-Patchwork-Id: 13138169 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 23B9AC636D4 for ; Mon, 13 Feb 2023 10:18:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230334AbjBMKSa (ORCPT ); Mon, 13 Feb 2023 05:18:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53758 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230318AbjBMKS0 (ORCPT ); Mon, 13 Feb 2023 05:18:26 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6CF6714E90 for ; Mon, 13 Feb 2023 02:18:20 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5BC581D34; Mon, 13 Feb 2023 02:19:02 -0800 (PST) Received: from godel.lab.cambridge.arm.com (godel.lab.cambridge.arm.com [10.7.66.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C1B013F703; Mon, 13 Feb 2023 02:18:18 -0800 (PST) From: Nikos Nikoleris To: kvm@vger.kernel.org, kvmarm@lists.linux.dev, andrew.jones@linux.dev Cc: pbonzini@redhat.com, alexandru.elisei@arm.com, ricarkol@google.com, Andrew Jones Subject: [PATCH v4 13/30] arm64: Add support for discovering the UART through ACPI Date: Mon, 13 Feb 2023 10:17:42 +0000 Message-Id: <20230213101759.2577077-14-nikos.nikoleris@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230213101759.2577077-1-nikos.nikoleris@arm.com> References: <20230213101759.2577077-1-nikos.nikoleris@arm.com> MIME-Version: 1.0 X-ARM-No-Footer: FoSSMail Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org In systems with ACPI support and when a DT is not provided, we can use the SPCR to discover the serial port address range. This change implements this but retains the default behavior; we check if a valid DT is provided, if not, we try to discover the UART using ACPI. Signed-off-by: Nikos Nikoleris Reviewed-by: Andrew Jones Reviewed-by: Ricardo Koller --- lib/acpi.h | 25 +++++++++++++++++++++++++ lib/arm/io.c | 34 +++++++++++++++++++++++++++++----- 2 files changed, 54 insertions(+), 5 deletions(-) diff --git a/lib/acpi.h b/lib/acpi.h index 5ba6e29d..02ca8958 100644 --- a/lib/acpi.h +++ b/lib/acpi.h @@ -17,6 +17,7 @@ #define XSDT_SIGNATURE ACPI_SIGNATURE('X','S','D','T') #define FACP_SIGNATURE ACPI_SIGNATURE('F','A','C','P') #define FACS_SIGNATURE ACPI_SIGNATURE('F','A','C','S') +#define SPCR_SIGNATURE ACPI_SIGNATURE('S','P','C','R') #define ACPI_SIGNATURE_8BYTE(c1, c2, c3, c4, c5, c6, c7, c8) \ (((uint64_t)(ACPI_SIGNATURE(c1, c2, c3, c4))) | \ @@ -145,6 +146,30 @@ struct acpi_table_facs_rev1 { u8 reserved3[40]; /* Reserved - must be zero */ }; +struct spcr_descriptor { + ACPI_TABLE_HEADER_DEF /* ACPI common table header */ + u8 interface_type; /* 0=full 16550, 1=subset of 16550 */ + u8 reserved[3]; + struct acpi_generic_address serial_port; + u8 interrupt_type; + u8 pc_interrupt; + u32 interrupt; + u8 baud_rate; + u8 parity; + u8 stop_bits; + u8 flow_control; + u8 terminal_type; + u8 reserved1; + u16 pci_device_id; + u16 pci_vendor_id; + u8 pci_bus; + u8 pci_device; + u8 pci_function; + u32 pci_flags; + u8 pci_segment; + u32 reserved2; +}; + #pragma pack(0) void set_efi_rsdp(struct acpi_table_rsdp *rsdp); diff --git a/lib/arm/io.c b/lib/arm/io.c index 343e1082..19f93490 100644 --- a/lib/arm/io.c +++ b/lib/arm/io.c @@ -29,7 +29,7 @@ static struct spinlock uart_lock; #define UART_EARLY_BASE (u8 *)(unsigned long)CONFIG_UART_EARLY_BASE static volatile u8 *uart0_base = UART_EARLY_BASE; -static void uart0_init(void) +static void uart0_init_fdt(void) { /* * kvm-unit-tests uses the uart only for output. Both uart models have @@ -65,17 +65,41 @@ static void uart0_init(void) } uart0_base = ioremap(base.addr, base.size); +} + +#ifdef CONFIG_EFI + +#include + +static void uart0_init_acpi(void) +{ + struct spcr_descriptor *spcr = find_acpi_table_addr(SPCR_SIGNATURE); + + assert_msg(spcr, "Unable to find ACPI SPCR"); + uart0_base = ioremap(spcr->serial_port.address, spcr->serial_port.bit_width); +} +#else + +static void uart0_init_acpi(void) +{ + assert_msg(false, "ACPI not available"); +} + +#endif + +void io_init(void) +{ + if (dt_available()) + uart0_init_fdt(); + else + uart0_init_acpi(); if (uart0_base != UART_EARLY_BASE) { printf("WARNING: early print support may not work. " "Found uart at %p, but early base is %p.\n", uart0_base, UART_EARLY_BASE); } -} -void io_init(void) -{ - uart0_init(); chr_testdev_init(); }