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/*
* module.c
*
* Handles initial registration with pdb when the pdb module starts up
* and cleanup when the module goes away (sortof :)
* Also receives each request from pdb in domain 0 and dispatches to the
* appropriate debugger function.
*/
#include <linux/module.h>
#include <linux/interrupt.h>
#include <asm-xen/evtchn.h>
#include <asm-xen/ctrl_if.h>
#include <asm-xen/hypervisor.h>
#include <asm-xen/xen-public/io/domain_controller.h>
#include <asm-xen/xen-public/xen.h>
#include <asm-xen/xen-public/io/ring.h>
#include "pdb_module.h"
#define PDB_RING_SIZE __RING_SIZE((pdb_sring_t *)0, PAGE_SIZE)
static pdb_back_ring_t pdb_ring;
static unsigned int pdb_evtchn;
static unsigned int pdb_irq;
/*
* send response to a pdb request
*/
static void
pdb_send_response (pdb_response_t *response)
{
pdb_response_t *resp;
resp = RING_GET_RESPONSE(&pdb_ring, pdb_ring.rsp_prod_pvt);
memcpy(resp, response, sizeof(pdb_response_t));
wmb(); /* Ensure other side can see the response fields. */
pdb_ring.rsp_prod_pvt++;
RING_PUSH_RESPONSES(&pdb_ring);
notify_via_evtchn(pdb_evtchn);
return;
}
/*
* handle a debug command from the front end
*/
static void
pdb_process_request (pdb_request_t *request)
{
pdb_response_t resp;
switch (request->operation)
{
case PDB_OPCODE_ATTACH :
pdb_attach(request->process);
resp.status = PDB_RESPONSE_OKAY;
break;
case PDB_OPCODE_DETACH :
pdb_detach(request->process);
resp.status = PDB_RESPONSE_OKAY;
break;
case PDB_OPCODE_RD_REG :
pdb_read_register(request->process, &request->u.rd_reg,
(unsigned long *)&resp.value);
resp.status = PDB_RESPONSE_OKAY;
break;
case PDB_OPCODE_WR_REG :
pdb_write_register(request->process, &request->u.wr_reg);
resp.status = PDB_RESPONSE_OKAY;
break;
default:
printk("(pdb) unknown request operation %d\n", request->operation);
resp.status = PDB_RESPONSE_ERROR;
}
resp.operation = request->operation;
pdb_send_response (&resp);
return;
}
/*
* receive a pdb request
*/
static irqreturn_t
pdb_interrupt (int irq, void *dev_id, struct pt_regs *ptregs)
{
pdb_request_t *req;
RING_IDX i, rp;
rp = pdb_ring.sring->req_prod;
rmb();
for ( i = pdb_ring.req_cons;
(i != rp) && !RING_REQUEST_CONS_OVERFLOW(&pdb_ring, i);
i++ )
{
req = RING_GET_REQUEST(&pdb_ring, i);
pdb_process_request(req);
}
pdb_ring.req_cons = i;
return IRQ_HANDLED;
}
static void
pdb_send_connection_status(int status, memory_t ring)
{
ctrl_msg_t cmsg =
{
.type = CMSG_DEBUG,
.subtype = CMSG_DEBUG_CONNECTION_STATUS,
.length = sizeof(pdb_connection_t),
};
pdb_connection_t *conn = (pdb_connection_t *)cmsg.msg;
conn->status = status;
conn->ring = ring;
conn->evtchn = 0;
ctrl_if_send_message_block(&cmsg, NULL, 0, TASK_UNINTERRUPTIBLE);
}
/*
* this is called each time a message is received on the control channel
*/
static void
pdb_ctrlif_rx(ctrl_msg_t *msg, unsigned long id)
{
printk ("pdb ctrlif rx\n");
switch (msg->subtype)
{
case CMSG_DEBUG_CONNECTION_STATUS:
/* initialize event channel created by the pdb server */
pdb_evtchn = ((pdb_connection_p) msg->msg)->evtchn;
pdb_irq = bind_evtchn_to_irq(pdb_evtchn);
if ( request_irq(pdb_irq, pdb_interrupt,
SA_SAMPLE_RANDOM, "pdb", NULL) )
{
printk("(pdb) request irq failed: %d %d\n", pdb_evtchn, pdb_irq);
}
break;
default:
printk ("(pdb) unknown xcs control message: %d\n", msg->subtype);
break;
}
return;
}
static int __init
pdb_initialize(void)
{
pdb_sring_t *sring;
printk("----\npdb initialize %s %s\n", __DATE__, __TIME__);
/*
if ( xen_start_info.flags & SIF_INITDOMAIN )
return 1;
*/
(void)ctrl_if_register_receiver(CMSG_DEBUG, pdb_ctrlif_rx,
CALLBACK_IN_BLOCKING_CONTEXT);
/* rings */
sring = (pdb_sring_t *)__get_free_page(GFP_KERNEL);
SHARED_RING_INIT(sring);
BACK_RING_INIT(&pdb_ring, sring, PAGE_SIZE);
/* notify pdb in dom 0 */
pdb_send_connection_status(PDB_CONNECTION_STATUS_UP,
virt_to_machine(pdb_ring.sring) >> PAGE_SHIFT);
return 0;
}
static void __exit
pdb_terminate(void)
{
printk("pdb cleanup\n");
(void)ctrl_if_unregister_receiver(CMSG_DEBUG, pdb_ctrlif_rx);
if (pdb_irq)
{
free_irq(pdb_irq, NULL);
pdb_irq = 0;
}
if (pdb_evtchn)
{
unbind_evtchn_from_irq(pdb_evtchn);
pdb_evtchn = 0;
}
pdb_send_connection_status(PDB_CONNECTION_STATUS_DOWN, 0);
}
module_init(pdb_initialize);
module_exit(pdb_terminate);
/*
* Local variables:
* mode: C
* c-set-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/
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