| Current File : //usr/share/man/man9f/ddi_intr_dup_handler.9f |
'\" te
.\" Copyright (c) 2006, Sun Microsystems, Inc. All Rights Reserved.
.TH ddi_intr_dup_handler 9F "09 May 2006" "SunOS 5.11" "Kernel Functions for Drivers"
.SH NAME
ddi_intr_dup_handler \- reuse interrupt handler and arguments for MSI-X interrupts
.SH SYNOPSIS
.LP
.nf
#include <sys/types.h>
#include <sys/conf.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
\fBint\fR \fBddi_intr_dup_handler\fR(\fBddi_intr_handle_t\fR \fIprimary\fR, \fBint\fR \fIvector\fR,
\fBddi_intr_handle_t *\fR\fInew\fR);
.fi
.SH INTERFACE LEVEL
.sp
.LP
Solaris DDI specific (Solaris DDI).
.SH PARAMETERS
.sp
.ne 2
.mk
.na
\fB\fIprimary\fR\fR
.ad
.RS 11n
.rt
Original DDI interrupt handle
.RE
.sp
.ne 2
.mk
.na
\fB\fIvector\fR\fR
.ad
.RS 11n
.rt
Interrupt number to duplicate
.RE
.sp
.ne 2
.mk
.na
\fB\fInew\fR\fR
.ad
.RS 11n
.rt
Pointer to new DDI interrupt handle
.RE
.SH DESCRIPTION
.sp
.LP
The \fBddi_intr_dup_handler()\fR function is a feature for MSI-X interrupts that allows an unallocated interrupt vector of a device to use a previously initialized or added primary MSI-X interrupt vector in order to share the same vector address, vector data, interrupt handler, and handler arguments. This feature allows a driver to alias the resources provided by the Solaris Operating System to the unallocated interrupt vectors on an associated device. For example, if 2 MSI-X interrupts were allocated to a driver and 32 interrupts were supported on the device, the driver could alias the 2 interrupts it received to the 30 remaining on the device.
.sp
.LP
The \fBddi_intr_dup_handler()\fR function must be called after the primary interrupt handle has been added to the system or enabled by \fBddi_intr_add_handler\fR(9F) and \fBddi_intr_enable\fR(9F) calls, respectively. If successful, the function returns the new interrupt handle for a given vector in the \fInew\fR argument passed to the function. The new interrupt handle must not have been previously allocated with \fBddi_intr_alloc\fR(9F). Otherwise, the \fBddi_intr_dup_handler()\fR call will fail.
.sp
.LP
The only supported calls on \fIdup-ed\fR interrupt handles are \fBddi_intr_set_mask\fR(9F), \fBddi_intr_clr_mask\fR(9F), \fBddi_intr_get_pending\fR(9F), \fBddi_intr_enable\fR(9F), \fBddi_intr_disable\fR(9F), and \fBddi_intr_free\fR(9F).
.sp
.LP
A call to \fBddi_intr_dup_handler()\fR does not imply that the interrupt source is automatically enabled. Initially, the dup-ed handle is in the disabled state and must be enabled before it can be used by calling \fBddi_intr_enable()\fR. Likewise, \fBddi_intr_disable()\fR must be called to disable the enabled dup-ed interrupt source.
.sp
.LP
A dup-ed interrupt is removed by calling \fBddi_intr_free()\fR after it has been disabled. The \fBddi_intr_remove_handler\fR(9F) call is not required for a dup-ed handle.
.sp
.LP
Before removing the original MSI-X interrupt handler, all dup-ed interrupt handlers associated with this MSI-X interrupt must have been disabled and freed. Otherwise, calls to \fBddi_intr_remove_handler()\fR will fail with \fBDDI_FAILURE\fR.
.sp
.LP
See the EXAMPLES section for code that illustrates the use of the \fBddi_intr_dup_handler()\fR function.
.SH RETURN VALUES
.sp
.LP
The \fBddi_intr_dup_handler()\fR function returns:
.sp
.ne 2
.mk
.na
\fB\fBDDI_SUCCESS\fR\fR
.ad
.RS 15n
.rt
On success.
.sp
Note that the interface should be verified to ensure that the return value is not equal to \fBDDI_SUCCESS\fR. Incomplete checking for failure codes could result in inconsistent behavior among platforms.
.RE
.sp
.ne 2
.mk
.na
\fB\fBDDI_EINVAL\fR\fR
.ad
.RS 15n
.rt
On encountering invalid input parameters. \fBDDI_EINVAL\fR is also returned if a dup is attempted from a dup-ed interrupt or if the hardware device is found not to support MSI-X interrupts.
.RE
.sp
.ne 2
.mk
.na
\fB\fBDDI_FAILURE\fR\fR
.ad
.RS 15n
.rt
On any implementation specific failure.
.RE
.SH EXAMPLES
.LP
\fBExample 1 \fRUsing the \fBddi_intr_dup_handler()\fR function
.sp
.in +2
.nf
int
add_msix_interrupts(intr_state_t *state)
{
int x, y;
/*
* For this example, assume the device supports multiple
* interrupt vectors, but only request to be allocated
* 1 MSI-X to use and then dup the rest.
*/
if (ddi_intr_get_nintrs(state->dip, DDI_INTR_TYPE_MSIX,
&state->intr_count) != DDI_SUCCESS) {
cmn_err(CE_WARN, "Failed to retrieve the MSI-X interrupt count");
return (DDI_FAILURE);
}
state->intr_size = state->intr_count * sizeof (ddi_intr_handle_t);
state->intr_htable = kmem_zalloc(state->intr_size, KM_SLEEP);
/* Allocate one MSI-X interrupt handle */
if (ddi_intr_alloc(state->dip, state->intr_htable,
DDI_INTR_TYPE_MSIX, state->inum, 1, &state->actual,
DDI_INTR_ALLOC_STRICT) != DDI_SUCCESS) {
cmn_err(CE_WARN, "Failed to allocate MSI-X interrupt");
kmem_free(state->intr_htable, state->intr_size);
return (DDI_FAILURE);
}
/* Get the count of how many MSI-X interrupts we dup */
state->dup_cnt = state->intr_count - state->actual;
if (ddi_intr_get_pri(state->intr_htable[0],
&state->intr_pri) != DDI_SUCCESS) {
cmn_err(CE_WARN, "Failed to get interrupt priority");
goto error1;
}
/* Make sure the MSI-X priority is below 'high level' */
if (state->intr_pri >= ddi_intr_get_hilevel_pri()) {
cmn_err(CE_WARN, "Interrupt PRI is too high");
goto error1;
}
/*
* Add the handler for the interrupt
*/
if (ddi_intr_add_handler(state->intr_htable[0],
(ddi_intr_handler_t *)intr_isr, (caddr_t)state,
NULL) != DDI_SUCCESS) {
cmn_err(CE_WARN, "Failed to add interrupt handler");
goto error1;
}
/* Enable the main MSI-X handle first */
if (ddi_intr_enable(state->intr_htable[0]) != DDI_SUCCESS) {
cmn_err(CE_WARN, "Failed to enable interrupt");
goto error2;
}
/*
* Create and enable dups of the original MSI-X handler, note
* that the inum we are using starts at 0.
*/
for (x = 1; x < state->dup_cnt; x++) {
if (ddi_intr_dup_handler(state->intr_htable[0],
state->inum + x, &state->intr_htable[x]) != DDI_SUCCESS) {
for (y = x - 1; y > 0; y--) {
(void) ddi_intr_disable(state->intr_htable[y]);
(void) ddi_intr_free(state->intr_htable[y]);
}
goto error2;
}
if (ddi_intr_enable(state->intr_htable[x]) != DDI_SUCCESS) {
for (y = x; y > 0; y--) {
(void) ddi_intr_disable(state->intr_htable[y]);
(void) ddi_intr_free(state->intr_htable[y]);
}
goto error2;
}
}
return (DDI_SUCCESS);
error2:
(void) ddi_intr_remove_handler(state->intr_htable[0]);
error1:
(void) ddi_intr_free(state->intr_htable[0]);
kmem_free(state->intr_htable, state->intr_size);
return (DDI_FAILURE);
}
void
remove_msix_interrupts(intr_state_t *state)
{
int x;
/*
* Disable all the handles and free the dup-ed handles
* before we can remove the main MSI-X interrupt handle.
*/
for (x = 1; x < state->dup_cnt; x++) {
(void) ddi_intr_disable(state->intr_htable[x]);
(void) ddi_intr_free(state->intr_htable[x]);
}
/*
* We can remove and free the main MSI-X handler now
* that all the dups have been freed.
*/
(void) ddi_intr_disable(state->intr_htable[0]);
(void) ddi_intr_remove_handler(state->intr_htable[0]);
(void) ddi_intr_free(state->intr_htable[0]);
kmem_free(state->intr_htable, state->intr_size);
}
.fi
.in -2
.SH CONTEXT
.sp
.LP
The \fBddi_intr_dup_handler()\fR function can be called from kernel non-interrupt context.
.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp
.sp
.TS
tab() box;
cw(2.75i) |cw(2.75i)
lw(2.75i) |lw(2.75i)
.
ATTRIBUTE TYPEATTRIBUTE VALUE
_
Interface StabilityCommitted
.TE
.SH SEE ALSO
.sp
.LP
\fBattributes\fR(5), \fBddi_intr_add_handler\fR(9F), \fBddi_intr_alloc\fR(9F), \fBddi_intr_clr_mask\fR(9F), \fBddi_intr_disable\fR(9F), \fBddi_intr_enable\fR(9F), \fBddi_intr_free\fR(9F), \fBddi_intr_get_pending\fR(9F), \fBddi_intr_get_supported_types\fR(9F), \fBddi_intr_set_mask\fR(9F)
.sp
.LP
\fIWriting Device Drivers for Oracle Solaris 11.2\fR