sfc: Add support for 'extra' channel types
Abstract some of the channel operations to allow for 'extra'
channels that do not have RX or TX queues.
- Try to assign a channel to each extra channel type that is enabled
for the NIC, but gracefully degrade if we can't allocate sufficient
MSI-X vectors
- Allow each extra channel type to generate its own channel name
- Allow channel types to disable reallocation and reinitialisation
of their channels
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 3260e71..94b0dca 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -54,6 +54,7 @@
#define EFX_MAX_CHANNELS 32U
#define EFX_MAX_RX_QUEUES EFX_MAX_CHANNELS
+#define EFX_MAX_EXTRA_CHANNELS 0U
/* Checksum generation is a per-queue option in hardware, so each
* queue visible to the networking core is backed by two hardware TX
@@ -311,6 +312,7 @@
*
* @efx: Associated Efx NIC
* @channel: Channel instance number
+ * @type: Channel type definition
* @enabled: Channel enabled indicator
* @irq: IRQ number (MSI and MSI-X only)
* @irq_moderation: IRQ moderation value (in hardware ticks)
@@ -341,6 +343,7 @@
struct efx_channel {
struct efx_nic *efx;
int channel;
+ const struct efx_channel_type *type;
bool enabled;
int irq;
unsigned int irq_moderation;
@@ -379,6 +382,26 @@
struct efx_tx_queue tx_queue[EFX_TXQ_TYPES];
};
+/**
+ * struct efx_channel_type - distinguishes traffic and extra channels
+ * @handle_no_channel: Handle failure to allocate an extra channel
+ * @pre_probe: Set up extra state prior to initialisation
+ * @post_remove: Tear down extra state after finalisation, if allocated.
+ * May be called on channels that have not been probed.
+ * @get_name: Generate the channel's name (used for its IRQ handler)
+ * @copy: Copy the channel state prior to reallocation. May be %NULL if
+ * reallocation is not supported.
+ * @keep_eventq: Flag for whether event queue should be kept initialised
+ * while the device is stopped
+ */
+struct efx_channel_type {
+ void (*handle_no_channel)(struct efx_nic *);
+ int (*pre_probe)(struct efx_channel *);
+ void (*get_name)(struct efx_channel *, char *buf, size_t len);
+ struct efx_channel *(*copy)(const struct efx_channel *);
+ bool keep_eventq;
+};
+
enum efx_led_mode {
EFX_LED_OFF = 0,
EFX_LED_ON = 1,
@@ -631,6 +654,8 @@
* @rx_queue: RX DMA queues
* @channel: Channels
* @channel_name: Names for channels and their IRQs
+ * @extra_channel_types: Types of extra (non-traffic) channels that
+ * should be allocated for this NIC
* @rxq_entries: Size of receive queues requested by user.
* @txq_entries: Size of transmit queues requested by user.
* @next_buffer_table: First available buffer table id
@@ -723,6 +748,8 @@
struct efx_channel *channel[EFX_MAX_CHANNELS];
char channel_name[EFX_MAX_CHANNELS][IFNAMSIZ + 6];
+ const struct efx_channel_type *
+ extra_channel_type[EFX_MAX_EXTRA_CHANNELS];
unsigned rxq_entries;
unsigned txq_entries;
@@ -921,6 +948,13 @@
_channel = (_channel->channel + 1 < (_efx)->n_channels) ? \
(_efx)->channel[_channel->channel + 1] : NULL)
+/* Iterate over all used channels in reverse */
+#define efx_for_each_channel_rev(_channel, _efx) \
+ for (_channel = (_efx)->channel[(_efx)->n_channels - 1]; \
+ _channel; \
+ _channel = _channel->channel ? \
+ (_efx)->channel[_channel->channel - 1] : NULL)
+
static inline struct efx_tx_queue *
efx_get_tx_queue(struct efx_nic *efx, unsigned index, unsigned type)
{