From patchwork Wed Jul 31 15:38:25 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Grall X-Patchwork-Id: 18714 Return-Path: X-Original-To: linaro@patches.linaro.org Delivered-To: linaro@patches.linaro.org Received: from mail-yh0-f71.google.com (mail-yh0-f71.google.com [209.85.213.71]) by ip-10-151-82-157.ec2.internal (Postfix) with ESMTPS id F27BE246CC for ; Wed, 31 Jul 2013 15:38:46 +0000 (UTC) Received: by mail-yh0-f71.google.com with SMTP id f64sf1104823yha.6 for ; Wed, 31 Jul 2013 08:38:46 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:x-beenthere:x-forwarded-to:x-forwarded-for :delivered-to:from:to:cc:subject:date:message-id:x-mailer :in-reply-to:references:x-gm-message-state:x-removed-original-auth :x-original-sender:x-original-authentication-results:precedence :mailing-list:list-id:x-google-group-id:list-post:list-help :list-archive:list-unsubscribe; bh=InAsC1HCRCA+8+9BxW2DGSAohLrCz+sL3Tc+f8TLJSw=; b=MAgNLPYmpXd2m+SFadLSVX+Vc4tGTyZAGa4SMGb1i7FdH9zqfyCsFUKX1sbpN0cIK1 V5eF1vMRet3o8zWD+Uhs5q7OENYl7AOcZutjrTG6tLUgQOkIg/GOyDIvNR6zjC9wKjoG smvXNqY3cXJoglJDt/ABT2r/HSvfHPeE+WEjy/N4X989yVJpqBRwfT8We3eaSD8fByFK oSMvir6uCblcqn4JACBJJbCNVNmHaEwvNJ15X4eP7ChGmDo1TLZ4VdNgDRhEpWaUNi3W Ntc8g8Nx3w2DopLCq4Ww0htQQaKSzviazEHD1k90/tK8qyDL3vA/i/kjTBjmGXUHI6Bw 9DaQ== X-Received: by 10.236.78.198 with SMTP id g46mr35000196yhe.56.1375285126696; Wed, 31 Jul 2013 08:38:46 -0700 (PDT) MIME-Version: 1.0 X-BeenThere: patchwork-forward@linaro.org Received: by 10.49.118.227 with SMTP id kp3ls663880qeb.19.gmail; Wed, 31 Jul 2013 08:38:46 -0700 (PDT) X-Received: by 10.58.197.5 with SMTP id iq5mr29364372vec.30.1375285126555; Wed, 31 Jul 2013 08:38:46 -0700 (PDT) Received: from mail-ve0-f172.google.com (mail-ve0-f172.google.com [209.85.128.172]) by mx.google.com with ESMTPS id uw3si422843vec.20.2013.07.31.08.38.46 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 31 Jul 2013 08:38:46 -0700 (PDT) Received-SPF: neutral (google.com: 209.85.128.172 is neither permitted nor denied by best guess record for domain of patch+caf_=patchwork-forward=linaro.org@linaro.org) client-ip=209.85.128.172; Received: by mail-ve0-f172.google.com with SMTP id oz10so965842veb.3 for ; Wed, 31 Jul 2013 08:38:46 -0700 (PDT) X-Received: by 10.220.164.138 with SMTP id e10mr11702447vcy.27.1375285126378; Wed, 31 Jul 2013 08:38:46 -0700 (PDT) X-Forwarded-To: patchwork-forward@linaro.org X-Forwarded-For: patch@linaro.org patchwork-forward@linaro.org Delivered-To: patches@linaro.org Received: by 10.221.11.8 with SMTP id pc8csp243369vcb; Wed, 31 Jul 2013 08:38:45 -0700 (PDT) X-Received: by 10.194.123.69 with SMTP id ly5mr50371541wjb.29.1375285125279; Wed, 31 Jul 2013 08:38:45 -0700 (PDT) Received: from mail-wg0-f54.google.com (mail-wg0-f54.google.com [74.125.82.54]) by mx.google.com with ESMTPS id x2si1051468wjy.161.2013.07.31.08.38.44 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 31 Jul 2013 08:38:45 -0700 (PDT) Received-SPF: neutral (google.com: 74.125.82.54 is neither permitted nor denied by best guess record for domain of julien.grall@linaro.org) client-ip=74.125.82.54; Received: by mail-wg0-f54.google.com with SMTP id n11so735553wgh.33 for ; Wed, 31 Jul 2013 08:38:44 -0700 (PDT) X-Received: by 10.194.242.134 with SMTP id wq6mr49555295wjc.94.1375285124835; Wed, 31 Jul 2013 08:38:44 -0700 (PDT) Received: from belegaer.uk.xensource.com. (firewall.ctxuk.citrix.com. [46.33.159.2]) by mx.google.com with ESMTPSA id u9sm3135483wif.6.2013.07.31.08.38.42 for (version=TLSv1.2 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 31 Jul 2013 08:38:43 -0700 (PDT) From: Julien Grall To: xen-devel@lists.xen.org, ian.campbell@citrix.com Cc: stefano.stabellini@eu.citrix.com, patches@linaro.org, Julien Grall Subject: [PATCH v2 5/8] xen/arm: Implement a virtual UART Date: Wed, 31 Jul 2013 16:38:25 +0100 Message-Id: <1375285109-3053-6-git-send-email-julien.grall@linaro.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1375285109-3053-1-git-send-email-julien.grall@linaro.org> References: <1375285109-3053-1-git-send-email-julien.grall@linaro.org> X-Gm-Message-State: ALoCoQkVbCX798Phr3MVYPSly3wrY1LSczTjt2dYt0gY24jK1DUnzbbh3BsAz1LRs8QjmVgkhtJX X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: julien.grall@linaro.org X-Original-Authentication-Results: mx.google.com; spf=neutral (google.com: 209.85.128.172 is neither permitted nor denied by best guess record for domain of patch+caf_=patchwork-forward=linaro.org@linaro.org) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Precedence: list Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org List-ID: X-Google-Group-Id: 836684582541 List-Post: , List-Help: , List-Archive: List-Unsubscribe: , This code is based on the previous vuart0 implementation. Unlike the latter, it's intend to replace UART stolen by XEN to DOM0 via dtuart=... on its command line. It's useful when the kernel is compiled with early printk enabled or for a single platform. Most of the time, the hardcoded code to handle the UART will need 2 registers: status and data, the others registers can be implemented as RAZ/WI. Signed-off-by: Julien Grall --- Changes in v2: - Merge and update comments - Use the renamed callback --- xen/arch/arm/Makefile | 2 +- xen/arch/arm/domain.c | 12 ++-- xen/arch/arm/io.c | 2 +- xen/arch/arm/io.h | 2 +- xen/arch/arm/{vpl011.c => vuart.c} | 128 ++++++++++++++++++------------------ xen/arch/arm/{vpl011.h => vuart.h} | 16 ++--- xen/include/asm-arm/domain.h | 14 ++-- 7 files changed, 90 insertions(+), 86 deletions(-) rename xen/arch/arm/{vpl011.c => vuart.c} (43%) rename xen/arch/arm/{vpl011.h => vuart.h} (75%) diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile index 5c13a65..003ac84 100644 --- a/xen/arch/arm/Makefile +++ b/xen/arch/arm/Makefile @@ -27,7 +27,7 @@ obj-y += shutdown.o obj-y += traps.o obj-y += vgic.o obj-y += vtimer.o -obj-y += vpl011.o +obj-y += vuart.o obj-y += hvm.o obj-y += device.o obj-y += decode.o diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c index 4e9cece..cb0424d 100644 --- a/xen/arch/arm/domain.c +++ b/xen/arch/arm/domain.c @@ -32,7 +32,7 @@ #include #include "vtimer.h" -#include "vpl011.h" +#include "vuart.h" DEFINE_PER_CPU(struct vcpu *, curr_vcpu); @@ -525,8 +525,12 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags) if ( (rc = vcpu_domain_init(d)) != 0 ) goto fail; - /* Domain 0 gets a real UART not an emulated one */ - if ( d->domain_id && (rc = domain_uart0_init(d)) != 0 ) + /* + * Virtual UART is only used by linux early printk and decompress code. + * Only use it for dom0 because the linux kernel may not support + * multi-platform. + */ + if ( (d->domain_id == 0) && (rc = domain_vuart_init(d)) ) goto fail; return 0; @@ -542,7 +546,7 @@ void arch_domain_destroy(struct domain *d) { p2m_teardown(d); domain_vgic_free(d); - domain_uart0_free(d); + domain_vuart_free(d); free_xenheap_page(d->shared_info); } diff --git a/xen/arch/arm/io.c b/xen/arch/arm/io.c index ad28c26..a6db00b 100644 --- a/xen/arch/arm/io.c +++ b/xen/arch/arm/io.c @@ -25,7 +25,7 @@ static const struct mmio_handler *const mmio_handlers[] = { &vgic_distr_mmio_handler, - &uart0_mmio_handler, + &vuart_mmio_handler, }; #define MMIO_HANDLER_NR ARRAY_SIZE(mmio_handlers) diff --git a/xen/arch/arm/io.h b/xen/arch/arm/io.h index 661dce1..8d252c0 100644 --- a/xen/arch/arm/io.h +++ b/xen/arch/arm/io.h @@ -41,7 +41,7 @@ struct mmio_handler { }; extern const struct mmio_handler vgic_distr_mmio_handler; -extern const struct mmio_handler uart0_mmio_handler; +extern const struct mmio_handler vuart_mmio_handler; extern int handle_mmio(mmio_info_t *info); diff --git a/xen/arch/arm/vpl011.c b/xen/arch/arm/vuart.c similarity index 43% rename from xen/arch/arm/vpl011.c rename to xen/arch/arm/vuart.c index 13ba623..0d672d5 100644 --- a/xen/arch/arm/vpl011.c +++ b/xen/arch/arm/vuart.c @@ -1,8 +1,22 @@ /* - * xen/arch/arm/vpl011.c + * xen/arch/arm/vuart.c * - * ARM PL011 UART Emulator (DEBUG) + * Virtual UART Emulator. * + * This emulator uses the information from dtuart. This is not intended to be + * a full emulation of an UART device. Rather it is intended to provide a + * sufficient veneer of one that early code (such as Linux's boot time + * decompressor) which hardcodes output directly to such a device are able to + * make progress. + * + * The mininal register set to emulate an UART are: + * - Single byte transmit register + * - Single status register + * + * /!\ This device is not intended to be enumerable or exposed to the OS + * (e.g. via Device Tree). + * + * Julien Grall * Ian Campbell * Copyright (c) 2012 Citrix Systems. * @@ -17,53 +31,48 @@ * GNU General Public License for more details. */ -/* - * This is not intended to be a full emulation of a PL011 - * device. Rather it is intended to provide a sufficient veneer of one - * that early code (such as Linux's boot time decompressor) which - * hardcodes output directly to such a device are able to make progress. - * - * This device is not intended to be enumerable or exposed to the OS - * (e.g. via Device Tree). - */ #include #include #include #include #include +#include +#include "vuart.h" #include "io.h" -#define UART0_START 0x1c090000 -#define UART0_END (UART0_START+65536) - -#define UARTDR 0x000 -#define UARTFR 0x018 +#define domain_has_vuart(d) ((d)->arch.vuart.info != NULL) -int domain_uart0_init(struct domain *d) +int domain_vuart_init(struct domain *d) { - ASSERT( d->domain_id ); + ASSERT( !d->domain_id ); - spin_lock_init(&d->arch.uart0.lock); - d->arch.uart0.idx = 0; + d->arch.vuart.info = serial_vuart_info(SERHND_DTUART); + if ( !d->arch.vuart.info ) + return 0; - d->arch.uart0.buf = xzalloc_array(char, VPL011_BUF_SIZE); - if ( !d->arch.uart0.buf ) + spin_lock_init(&d->arch.vuart.lock); + d->arch.vuart.idx = 0; + + d->arch.vuart.buf = xzalloc_array(char, VUART_BUF_SIZE); + if ( !d->arch.vuart.buf ) return -ENOMEM; return 0; - } -void domain_uart0_free(struct domain *d) +void domain_vuart_free(struct domain *d) { - xfree(d->arch.uart0.buf); + if ( !domain_has_vuart(d) ) + return; + + xfree(d->arch.vuart.buf); } -static void uart0_print_char(char c) +static void vuart_print_char(char c) { - struct vpl011 *uart = ¤t->domain->arch.uart0; + struct vuart *uart = ¤t->domain->arch.vuart; /* Accept only printable characters, newline, and horizontal tab. */ if ( !isprint(c) && (c != '\n') && (c != '\t') ) @@ -71,7 +80,7 @@ static void uart0_print_char(char c) spin_lock(&uart->lock); uart->buf[uart->idx++] = c; - if ( (uart->idx == (VPL011_BUF_SIZE - 2)) || (c == '\n') ) + if ( (uart->idx == (VUART_BUF_SIZE - 2)) || (c == '\n') ) { if ( c != '\n' ) uart->buf[uart->idx++] = '\n'; @@ -83,62 +92,51 @@ static void uart0_print_char(char c) spin_unlock(&uart->lock); } -static int uart0_mmio_check(struct vcpu *v, paddr_t addr) +static int vuart_mmio_check(struct vcpu *v, paddr_t addr) { - struct domain *d = v->domain; + const struct vuart_info *info = v->domain->arch.vuart.info; - return d->domain_id != 0 && addr >= UART0_START && addr < UART0_END; + return (domain_has_vuart(v->domain) && addr >= info->base_addr && + addr <= (info->base_addr + info->size)); } -static int uart0_mmio_read(struct vcpu *v, mmio_info_t *info) +static int vuart_mmio_read(struct vcpu *v, mmio_info_t *info) { + struct domain *d = v->domain; struct hsr_dabt dabt = info->dabt; struct cpu_user_regs *regs = guest_cpu_user_regs(); register_t *r = select_user_reg(regs, dabt.reg); - int offset = (int)(info->gpa - UART0_START); + paddr_t offset = info->gpa - d->arch.vuart.info->base_addr; - switch ( offset ) - { - case UARTDR: - *r = 0; - return 1; - case UARTFR: - *r = 0x87; /* All holding registers empty, ready to send etc */ - return 1; - default: - printk("VPL011: unhandled read r%d offset %#08x\n", - dabt.reg, offset); - domain_crash_synchronous(); - } + /* By default zeroed the register */ + *r = 0; + + if ( offset == d->arch.vuart.info->status_off ) + /* All holding registers empty, ready to send etc */ + *r = d->arch.vuart.info->status; + + return 1; } -static int uart0_mmio_write(struct vcpu *v, mmio_info_t *info) +static int vuart_mmio_write(struct vcpu *v, mmio_info_t *info) { + struct domain *d = v->domain; struct hsr_dabt dabt = info->dabt; struct cpu_user_regs *regs = guest_cpu_user_regs(); register_t *r = select_user_reg(regs, dabt.reg); - int offset = (int)(info->gpa - UART0_START); + paddr_t offset = (int)(info->gpa - d->arch.vuart.info->base_addr); - switch ( offset ) - { - case UARTDR: + if ( offset == d->arch.vuart.info->data_off ) /* ignore any status bits */ - uart0_print_char((int)((*r) & 0xFF)); - return 1; - case UARTFR: - /* Silently ignore */ - return 1; - default: - printk("VPL011: unhandled write r%d=%"PRIregister" offset %#08x\n", - dabt.reg, *r, offset); - domain_crash_synchronous(); - } + vuart_print_char((int)((*r) & 0xFF)); + + return 1; } -const struct mmio_handler uart0_mmio_handler = { - .check_handler = uart0_mmio_check, - .read_handler = uart0_mmio_read, - .write_handler = uart0_mmio_write, +const struct mmio_handler vuart_mmio_handler = { + .check_handler = vuart_mmio_check, + .read_handler = vuart_mmio_read, + .write_handler = vuart_mmio_write, }; /* diff --git a/xen/arch/arm/vpl011.h b/xen/arch/arm/vuart.h similarity index 75% rename from xen/arch/arm/vpl011.h rename to xen/arch/arm/vuart.h index f0d0a82..9445e50 100644 --- a/xen/arch/arm/vpl011.h +++ b/xen/arch/arm/vuart.h @@ -1,7 +1,7 @@ -/* - * xen/arch/arm/vpl011.h +/* + * xen/arch/arm/vuart.h * - * ARM PL011 Emulation Support + * Virtual UART Emulation Support * * Ian Campbell * Copyright (c) 2012 Citrix Systems. @@ -17,13 +17,13 @@ * GNU General Public License for more details. */ -#ifndef __ARCH_ARM_VPL011_H__ -#define __ARCH_ARM_VPL011_H__ +#ifndef __ARCH_ARM_VUART_H__ +#define __ARCH_ARM_VUART_H__ -extern int domain_uart0_init(struct domain *d); -extern void domain_uart0_free(struct domain *d); +int domain_vuart_init(struct domain *d); +void domain_vuart_free(struct domain *d); -#endif +#endif /* __ARCH_ARM_VUART_H__ */ /* * Local variables: diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h index 89f88f6..67bfbbc 100644 --- a/xen/include/asm-arm/domain.h +++ b/xen/include/asm-arm/domain.h @@ -8,6 +8,7 @@ #include #include #include +#include /* Represents state corresponding to a block of 32 interrupts */ struct vgic_irq_rank { @@ -103,12 +104,13 @@ struct arch_domain paddr_t cbase; /* CPU base address */ } vgic; - struct vpl011 { -#define VPL011_BUF_SIZE 128 - char *buf; - int idx; - spinlock_t lock; - } uart0; + struct vuart { +#define VUART_BUF_SIZE 128 + char *buf; + int idx; + const struct vuart_info *info; + spinlock_t lock; + } vuart; } __cacheline_aligned;