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Protect ISR against failure to unhook.

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This commit is contained in:
Michael Brown 2007-07-10 04:34:53 +01:00
parent 4e14b020a5
commit edc4648c39
2 changed files with 19 additions and 34 deletions
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4
src/arch/i386/drivers/net/undiisr.S
View File

@ -22,6 +22,10 @@ undiisr:
pushw %ds
pushw %es
pusha
/* Check that we have an UNDI entry point */
cmpw $0, undinet_entry_point
je chain
/* Issue UNDI API call */
movw %cs:rm_ds, %ax

49
src/arch/i386/drivers/net/undinet.c
View File

@ -39,8 +39,6 @@
/** An UNDI NIC */
struct undi_nic {
/** Entry point */
SEGOFF16_t entry;
/** Assigned IRQ number */
unsigned int irq;
/** Currently processing ISR */
@ -167,7 +165,6 @@ static int undinet_call ( struct undi_nic *undinic, unsigned int function,
/* Copy parameter block and entry point */
assert ( params_len <= sizeof ( undinet_params ) );
memcpy ( &undinet_params, params, params_len );
undinet_entry_point = undinic->entry;
/* Call real-mode entry point. This calling convention will
* work with both the !PXE and the PXENV+ entry points.
@ -222,7 +219,8 @@ static int undinet_call ( struct undi_nic *undinic, unsigned int function,
DBGC ( undinic, "UNDINIC %p parameters at %04x:%04x length "
"%#02x, entry point at %04x:%04x\n", undinic,
rm_params.segment, rm_params.offset, params_len,
undinic->entry.segment, undinic->entry.offset );
undinet_entry_point.segment,
undinet_entry_point.offset );
DBGC ( undinic, "UNDINIC %p parameters provided:\n", undinic );
DBGC_HDA ( undinic, rm_params, params, params_len );
DBGC ( undinic, "UNDINIC %p parameters returned:\n", undinic );
@ -268,13 +266,6 @@ static unsigned int last_trigger_count = 0;
* Hook UNDI interrupt service routine
*
* @v irq IRQ number
*
* The UNDI ISR specifically does @b not chain to the previous
* interrupt handler. BIOSes seem to install somewhat perverse
* default interrupt handlers; some do nothing other than an iret (and
* so will cause a screaming interrupt if there really is another
* interrupting device) and some disable the interrupt at the PIC (and
* so will bring our own interrupts to a shuddering halt).
*/
static void undinet_hook_isr ( unsigned int irq ) {
@ -411,6 +402,15 @@ static int undinet_transmit ( struct net_device *netdev,
* so instead of doing it the easy way we have to go to all the hassle
* of installing a genuine interrupt service routine and dealing with
* the wonderful 8259 Programmable Interrupt Controller. Joy.
*
* Addendum (10/07/07). When doing things such as iSCSI boot, in
* which we have to co-operate with a running OS, we can't get away
* with the "ISR-just-increments-a-counter-and-returns" trick at all,
* because it involves tying up the PIC for far too long, and other
* interrupt-dependent components (e.g. local disks) start breaking.
* We therefore implement a "proper" ISR which calls PXENV_UNDI_ISR
* from within interrupt context in order to deassert the device
* interrupt, and sends EOI if applicable.
*/
static void undinet_poll ( struct net_device *netdev ) {
struct undi_nic *undinic = netdev->priv;
@ -425,28 +425,6 @@ static void undinet_poll ( struct net_device *netdev ) {
if ( ! undinet_isr_triggered() )
return;
#if 0
/* See if this was our interrupt */
memset ( &undi_isr, 0, sizeof ( undi_isr ) );
undi_isr.FuncFlag = PXENV_UNDI_ISR_IN_START;
if ( ( rc = undinet_call ( undinic, PXENV_UNDI_ISR, &undi_isr,
sizeof ( undi_isr ) ) ) != 0 )
return;
/* Send EOI to the PIC. In an ideal world, we'd do
* this only for interrupts which the UNDI stack
* reports as "ours". However, since we don't (can't)
* chain to the previous interrupt handler, we have to
* acknowledge all interrupts. See undinet_hook_isr()
* for more background.
*/
send_eoi ( undinic->irq );
/* If this wasn't our interrupt, exit now */
if ( undi_isr.FuncFlag != PXENV_UNDI_ISR_OUT_OURS )
return;
#endif
/* Start ISR processing */
undinic->isr_processing = 1;
undi_isr.FuncFlag = PXENV_UNDI_ISR_IN_PROCESS;
@ -651,7 +629,7 @@ int undinet_probe ( struct undi_device *undi ) {
undi_set_drvdata ( undi, netdev );
netdev->dev = &undi->dev;
memset ( undinic, 0, sizeof ( *undinic ) );
undinic->entry = undi->entry;
undinet_entry_point = undi->entry;
DBGC ( undinic, "UNDINIC %p using UNDI %p\n", undinic, undi );
/* Hook in UNDI stack */
@ -770,6 +748,9 @@ void undinet_remove ( struct undi_device *undi ) {
sizeof ( stop_undi ) );
undi->flags &= ~UNDI_FL_STARTED;
/* Clear entry point */
memset ( &undinet_entry_point, 0, sizeof ( undinet_entry_point ) );
/* Free network device */
netdev_nullify ( netdev );
netdev_put ( netdev );