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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 02/21] arm: implement vpl011 (UART) emulator.
This is not interended to provide a full emulation, but rather just enough to
satisfy the use made by Linux' boot time decompressor code (which is too early
for DT etc)
Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
Acked-by: Tim Deegan <tim@xxxxxxx>
---
xen/arch/arm/Makefile | 1 +
xen/arch/arm/domain.c | 5 ++
xen/arch/arm/io.c | 1 +
xen/arch/arm/io.h | 1 +
xen/arch/arm/vpl011.c | 145 ++++++++++++++++++++++++++++++++++++++++++
xen/arch/arm/vpl011.h | 34 ++++++++++
xen/include/asm-arm/domain.h | 8 ++
7 files changed, 195 insertions(+), 0 deletions(-)
create mode 100644 xen/arch/arm/vpl011.c
create mode 100644 xen/arch/arm/vpl011.h
diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index 9440a21..5a87ba6 100644
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -25,6 +25,7 @@ obj-y += shutdown.o
obj-y += traps.o
obj-y += vgic.o
obj-y += vtimer.o
+obj-y += vpl011.o
#obj-bin-y += ....o
diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index 80387fd..d11be78 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -13,6 +13,7 @@
#include "gic.h"
#include "vtimer.h"
+#include "vpl011.h"
DEFINE_PER_CPU(struct vcpu *, curr_vcpu);
@@ -327,6 +328,10 @@ int arch_domain_create(struct domain *d, unsigned int
domcr_flags)
if ( (rc = domain_vgic_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 )
+ goto fail;
+
rc = 0;
fail:
return rc;
diff --git a/xen/arch/arm/io.c b/xen/arch/arm/io.c
index 4461225..18f6164 100644
--- a/xen/arch/arm/io.c
+++ b/xen/arch/arm/io.c
@@ -25,6 +25,7 @@
static const struct mmio_handler *const mmio_handlers[] =
{
&vgic_distr_mmio_handler,
+ &uart0_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 8cc5ca7..9a507f5 100644
--- a/xen/arch/arm/io.h
+++ b/xen/arch/arm/io.h
@@ -40,6 +40,7 @@ struct mmio_handler {
};
extern const struct mmio_handler vgic_distr_mmio_handler;
+extern const struct mmio_handler uart0_mmio_handler;
extern int handle_mmio(mmio_info_t *info);
diff --git a/xen/arch/arm/vpl011.c b/xen/arch/arm/vpl011.c
new file mode 100644
index 0000000..5dc8b28
--- /dev/null
+++ b/xen/arch/arm/vpl011.c
@@ -0,0 +1,145 @@
+/*
+ * xen/arch/arm/vpl011.c
+ *
+ * ARM PL011 UART Emulator (DEBUG)
+ *
+ * Ian Campbell <ian.campbell@xxxxxxxxxx>
+ * Copyright (c) 2012 Citrix Systems.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * 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 <xen/config.h>
+#include <xen/lib.h>
+#include <xen/sched.h>
+#include <xen/errno.h>
+#include <xen/ctype.h>
+
+#include "io.h"
+
+#define UART0_START 0x1c090000
+#define UART0_END (UART0_START+65536)
+
+#define UARTDR 0x000
+#define UARTFR 0x018
+
+int domain_uart0_init(struct domain *d)
+{
+ ASSERT( d->domain_id );
+
+ spin_lock_init(&d->arch.uart0.lock);
+ d->arch.uart0.idx = 0;
+
+ d->arch.uart0.buf = xzalloc_array(char, VPL011_BUF_SIZE);
+ if ( !d->arch.uart0.buf )
+ return -ENOMEM;
+
+ return 0;
+
+}
+
+static void uart0_print_char(char c)
+{
+ struct vpl011 *uart = ¤t->domain->arch.uart0;
+
+ /* Accept only printable characters, newline, and horizontal tab. */
+ if ( !isprint(c) && (c != '\n') && (c != '\t') )
+ return ;
+
+ spin_lock(&uart->lock);
+ uart->buf[uart->idx++] = c;
+ if ( (uart->idx == (VPL011_BUF_SIZE - 2)) || (c == '\n') )
+ {
+ if ( c != '\n' )
+ uart->buf[uart->idx++] = '\n';
+ uart->buf[uart->idx] = '\0';
+ printk(XENLOG_G_DEBUG "DOM%u: %s",
+ current->domain->domain_id, uart->buf);
+ uart->idx = 0;
+ }
+ spin_unlock(&uart->lock);
+}
+
+static int uart0_mmio_check(struct vcpu *v, paddr_t addr)
+{
+ return addr >= UART0_START && addr < UART0_END;
+}
+
+static int uart0_mmio_read(struct vcpu *v, mmio_info_t *info)
+{
+ struct hsr_dabt dabt = info->dabt;
+ struct cpu_user_regs *regs = guest_cpu_user_regs();
+ uint32_t *r = ®s->r0 + dabt.reg;
+ int offset = (int)(info->gpa - UART0_START);
+
+ 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();
+ }
+}
+
+static int uart0_mmio_write(struct vcpu *v, mmio_info_t *info)
+{
+ struct hsr_dabt dabt = info->dabt;
+ struct cpu_user_regs *regs = guest_cpu_user_regs();
+ uint32_t *r = ®s->r0 + dabt.reg;
+ int offset = (int)(info->gpa - UART0_START);
+
+ switch ( offset )
+ {
+ case UARTDR:
+ /* 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=%"PRIx32" offset %#08x\n",
+ dabt.reg, *r, offset);
+ domain_crash_synchronous();
+ }
+}
+
+const struct mmio_handler uart0_mmio_handler = {
+ .check_handler = uart0_mmio_check,
+ .read_handler = uart0_mmio_read,
+ .write_handler = uart0_mmio_write,
+};
+
+/*
+ * Local variables:
+ * mode: C
+ * c-set-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
+
diff --git a/xen/arch/arm/vpl011.h b/xen/arch/arm/vpl011.h
new file mode 100644
index 0000000..952d812
--- /dev/null
+++ b/xen/arch/arm/vpl011.h
@@ -0,0 +1,34 @@
+/*
+ * xen/arch/arm/vpl011.h
+ *
+ * ARM PL011 Emulation Support
+ *
+ * Ian Campbell <ian.campbell@xxxxxxxxxx>
+ * Copyright (c) 2012 Citrix Systems.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __ARCH_ARM_VPL011_H__
+#define __ARCH_ARM_VPL011_H__
+
+extern int domain_uart0_init(struct domain *d);
+
+#endif
+
+/*
+ * Local variables:
+ * mode: C
+ * c-set-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index 8907f22..620b26e 100644
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -48,6 +48,14 @@ struct arch_domain
struct vgic_irq_rank *shared_irqs;
struct pending_irq *pending_irqs;
} vgic;
+
+ struct vpl011 {
+#define VPL011_BUF_SIZE 128
+ char *buf;
+ int idx;
+ spinlock_t lock;
+ } uart0;
+
} __cacheline_aligned;
struct arch_vcpu
--
1.7.9.1
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