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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 5/8] xen/arm: Implement a virtual UART
On 07/29/2013 05:26 PM, Ian Campbell wrote:
> On Thu, 2013-07-25 at 17:59 +0100, Julien Grall wrote:
>> 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 <julien.grall@xxxxxxxxxx>
>> ---
>> 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 | 152
>> ------------------------------------------
>> xen/arch/arm/vpl011.h | 35 ----------
>> xen/arch/arm/vuart.c | 150
>> +++++++++++++++++++++++++++++++++++++++++
>> xen/arch/arm/vuart.h | 35 ++++++++++
>
> Please can you use the -M option to format-patch/send-email so that the
> rename is handled in a way which lets us review the actual diff between
> the old and new files.
below the patch generated with -M option.
commit d5be5261c93abac0a9c50e4bdb69883e469fd49f
Author: Julien Grall <julien.grall@xxxxxxxxxx>
Date: Thu Jul 25 17:11:59 2013 +0100
xen/arm: Implement a virtual UART
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 <julien.grall@xxxxxxxxxx>
diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index 5ae5831..6e1208f 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
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 <asm/gic.h>
#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 51%
rename from xen/arch/arm/vpl011.c
rename to xen/arch/arm/vuart.c
index 13ba623..5c3a84c 100644
--- a/xen/arch/arm/vpl011.c
+++ b/xen/arch/arm/vuart.c
@@ -1,8 +1,13 @@
/*
- * xen/arch/arm/vpl011.c
+ * xen/arch/arm/vuart.c
*
- * ARM PL011 UART Emulator (DEBUG)
+ * Virtual UART Emulator.
*
+ * The emulator uses the information from dtuart. It will expose a basic
+ * UART which will allow the guest to log with an hardcode UART (early printk +
+ * decompressor).
+ *
+ * Julien Grall <julien.grall@xxxxxxxxxx>
* Ian Campbell <ian.campbell@xxxxxxxxxx>
* Copyright (c) 2012 Citrix Systems.
*
@@ -32,38 +37,42 @@
#include <xen/sched.h>
#include <xen/errno.h>
#include <xen/ctype.h>
+#include <xen/serial.h>
+#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_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 serial_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 <ian.campbell@xxxxxxxxxx>
* 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..394e574 100644
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -8,6 +8,7 @@
#include <asm/p2m.h>
#include <asm/vfp.h>
#include <public/hvm/params.h>
+#include <xen/serial.h>
/* 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 serial_info *info;
+ spinlock_t lock;
+ } vuart;
} __cacheline_aligned;
--
Julien
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