From patchwork Mon Jan 27 20:25:59 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 13952145 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9CDE9C0218D for ; Tue, 28 Jan 2025 07:59:43 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tcgU1-00064O-0b; Tue, 28 Jan 2025 02:58:05 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tcgTh-0005jZ-Op; Tue, 28 Jan 2025 02:57:49 -0500 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tcgTf-0000m5-36; Tue, 28 Jan 2025 02:57:44 -0500 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id A0AA5E1AF3; Tue, 28 Jan 2025 10:54:25 +0300 (MSK) Received: from localhost.tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with ESMTP id 1BB391A62DA; Tue, 28 Jan 2025 10:54:51 +0300 (MSK) Received: by localhost.tls.msk.ru (Postfix, from userid 1000) id E0C7B5204B; Tue, 28 Jan 2025 10:54:50 +0300 (MSK) To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Ahmad Fatoum , Stafford Horne , Peter Maydell , Michael Tokarev Subject: [Stable-8.2.9 18/45] hw/openrisc/openrisc_sim: keep serial@90000000 as default Date: Mon, 27 Jan 2025 23:25:59 +0300 Message-Id: <20250127202630.3724367-18-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.5 In-Reply-To: References: MIME-Version: 1.0 From: Michael Tokarev Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -53 X-Spam_score: -5.4 X-Spam_bar: ----- X-Spam_report: (-5.4 / 5.0 requ) BAYES_00=-1.9, DATE_IN_PAST_06_12=1.543, RCVD_IN_DNSWL_HI=-5, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org We used to only have a single UART on the platform and it was located at address 0x90000000. When the number of UARTs was increased to 4, the first UART remained at it's location, but instead of being the first one to be registered, it became the last. This caused QEMU to pick 0x90000300 as the default UART, which broke software that hardcoded the address of 0x90000000 and expected it's output to be visible when the user configured only a single console. This caused regressions[1] in the barebox test suite when updating to a newer QEMU. As there seems to be no good reason to register the UARTs in inverse order, let's register them by ascending address, so existing software can remain oblivious to the additional UART ports. Changing the order of uart registration alone breaks Linux which was choosing the UART at 0x90000300 as the default for ttyS0. To fix Linux we fix three things in the device tree: 1. Define stdout-path only one time for the first registered UART instead of incorrectly defining for each UART. 2. Change the UART alias name from 'uart0' to 'serial0' as almost all Linux tty drivers look for an alias starting with "serial". 3. Add the UART nodes so they appear in the final DTB in the order starting with the lowest address and working upwards. In summary these changes mean that the QEMU default UART (serial_hd(0)) is now setup where: * serial_hd(0) is the lowest-address UART * serial_hd(0) is listed first in the DTB * serial_hd(0) is the /chosen/stdout-path one * the /aliases/serial0 alias points at serial_hd(0) [1]: https://lore.barebox.org/barebox/707e7c50-aad1-4459-8796-0cc54bab32e2@pengutronix.de/T/#m5da26e8a799033301489a938b5d5667b81cef6ad Fixes: 777784bda468 ("hw/openrisc: support 4 serial ports in or1ksim") Cc: qemu-stable@nongnu.org Signed-off-by: Ahmad Fatoum [stafford: Change to serial0 alias and update change message, reverse uart registration order] Signed-off-by: Stafford Horne Reviewed-by: Peter Maydell (cherry picked from commit 26dcf2be7e153defa289d20317707af034aca692) Signed-off-by: Michael Tokarev diff --git a/hw/openrisc/openrisc_sim.c b/hw/openrisc/openrisc_sim.c index 35da123aef..dc1fea8cd8 100644 --- a/hw/openrisc/openrisc_sim.c +++ b/hw/openrisc/openrisc_sim.c @@ -248,7 +248,7 @@ static void openrisc_sim_serial_init(Or1ksimState *state, hwaddr base, void *fdt = state->fdt; char *nodename; qemu_irq serial_irq; - char alias[sizeof("uart0")]; + char alias[sizeof("serial0")]; int i; if (num_cpus > 1) { @@ -263,7 +263,7 @@ static void openrisc_sim_serial_init(Or1ksimState *state, hwaddr base, serial_irq = get_cpu_irq(cpus, 0, irq_pin); } serial_mm_init(get_system_memory(), base, 0, serial_irq, 115200, - serial_hd(OR1KSIM_UART_COUNT - uart_idx - 1), + serial_hd(uart_idx), DEVICE_NATIVE_ENDIAN); /* Add device tree node for serial. */ @@ -275,10 +275,13 @@ static void openrisc_sim_serial_init(Or1ksimState *state, hwaddr base, qemu_fdt_setprop_cell(fdt, nodename, "clock-frequency", OR1KSIM_CLK_MHZ); qemu_fdt_setprop(fdt, nodename, "big-endian", NULL, 0); - /* The /chosen node is created during fdt creation. */ - qemu_fdt_setprop_string(fdt, "/chosen", "stdout-path", nodename); - snprintf(alias, sizeof(alias), "uart%d", uart_idx); + if (uart_idx == 0) { + /* The /chosen node is created during fdt creation. */ + qemu_fdt_setprop_string(fdt, "/chosen", "stdout-path", nodename); + } + snprintf(alias, sizeof(alias), "serial%d", uart_idx); qemu_fdt_setprop_string(fdt, "/aliases", alias, nodename); + g_free(nodename); } @@ -326,11 +329,22 @@ static void openrisc_sim_init(MachineState *machine) smp_cpus, cpus, OR1KSIM_OMPIC_IRQ); } - for (n = 0; n < OR1KSIM_UART_COUNT; ++n) + /* + * We create the UART nodes starting with the highest address and + * working downwards, because in QEMU the DTB nodes end up in the + * DTB in reverse order of creation. Correctly-written guest software + * will not care about the node order (it will look at stdout-path + * or the alias nodes), but for the benefit of guest software which + * just looks for the first UART node in the DTB, make sure the + * lowest-address UART (which is QEMU's first serial port) appears + * first in the DTB. + */ + for (n = OR1KSIM_UART_COUNT - 1; n >= 0; n--) { openrisc_sim_serial_init(state, or1ksim_memmap[OR1KSIM_UART].base + or1ksim_memmap[OR1KSIM_UART].size * n, or1ksim_memmap[OR1KSIM_UART].size, smp_cpus, cpus, OR1KSIM_UART_IRQ, n); + } load_addr = openrisc_load_kernel(ram_size, kernel_filename, &boot_info.bootstrap_pc);