Commit e0af22d9 authored by Thomas Petazzoni's avatar Thomas Petazzoni Committed by David S. Miller

net: mvpp2: add comments about smp_processor_id() usage

A previous commit modified a number of smp_processor_id() used in
migration-enabled contexts into get_cpu/put_cpu sections. However, a few
smp_processor_id() calls remain in the driver, and this commit adds
comments explaining why they can be kept.
Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0c461e05
...@@ -4162,7 +4162,10 @@ static inline void mvpp2_interrupts_disable(struct mvpp2_port *port) ...@@ -4162,7 +4162,10 @@ static inline void mvpp2_interrupts_disable(struct mvpp2_port *port)
MVPP2_ISR_DISABLE_INTERRUPT(cpu_mask)); MVPP2_ISR_DISABLE_INTERRUPT(cpu_mask));
} }
/* Mask the current CPU's Rx/Tx interrupts */ /* Mask the current CPU's Rx/Tx interrupts
* Called by on_each_cpu(), guaranteed to run with migration disabled,
* using smp_processor_id() is OK.
*/
static void mvpp2_interrupts_mask(void *arg) static void mvpp2_interrupts_mask(void *arg)
{ {
struct mvpp2_port *port = arg; struct mvpp2_port *port = arg;
...@@ -4171,7 +4174,10 @@ static void mvpp2_interrupts_mask(void *arg) ...@@ -4171,7 +4174,10 @@ static void mvpp2_interrupts_mask(void *arg)
MVPP2_ISR_RX_TX_MASK_REG(port->id), 0); MVPP2_ISR_RX_TX_MASK_REG(port->id), 0);
} }
/* Unmask the current CPU's Rx/Tx interrupts */ /* Unmask the current CPU's Rx/Tx interrupts.
* Called by on_each_cpu(), guaranteed to run with migration disabled,
* using smp_processor_id() is OK.
*/
static void mvpp2_interrupts_unmask(void *arg) static void mvpp2_interrupts_unmask(void *arg)
{ {
struct mvpp2_port *port = arg; struct mvpp2_port *port = arg;
...@@ -4554,7 +4560,11 @@ mvpp2_txq_next_desc_get(struct mvpp2_tx_queue *txq) ...@@ -4554,7 +4560,11 @@ mvpp2_txq_next_desc_get(struct mvpp2_tx_queue *txq)
return txq->descs + tx_desc; return txq->descs + tx_desc;
} }
/* Update HW with number of aggregated Tx descriptors to be sent */ /* Update HW with number of aggregated Tx descriptors to be sent
*
* Called only from mvpp2_tx(), so migration is disabled, using
* smp_processor_id() is OK.
*/
static void mvpp2_aggr_txq_pend_desc_add(struct mvpp2_port *port, int pending) static void mvpp2_aggr_txq_pend_desc_add(struct mvpp2_port *port, int pending)
{ {
/* aggregated access - relevant TXQ number is written in TX desc */ /* aggregated access - relevant TXQ number is written in TX desc */
...@@ -4565,6 +4575,9 @@ static void mvpp2_aggr_txq_pend_desc_add(struct mvpp2_port *port, int pending) ...@@ -4565,6 +4575,9 @@ static void mvpp2_aggr_txq_pend_desc_add(struct mvpp2_port *port, int pending)
/* Check if there are enough free descriptors in aggregated txq. /* Check if there are enough free descriptors in aggregated txq.
* If not, update the number of occupied descriptors and repeat the check. * If not, update the number of occupied descriptors and repeat the check.
*
* Called only from mvpp2_tx(), so migration is disabled, using
* smp_processor_id() is OK.
*/ */
static int mvpp2_aggr_desc_num_check(struct mvpp2 *priv, static int mvpp2_aggr_desc_num_check(struct mvpp2 *priv,
struct mvpp2_tx_queue *aggr_txq, int num) struct mvpp2_tx_queue *aggr_txq, int num)
...@@ -4583,7 +4596,12 @@ static int mvpp2_aggr_desc_num_check(struct mvpp2 *priv, ...@@ -4583,7 +4596,12 @@ static int mvpp2_aggr_desc_num_check(struct mvpp2 *priv,
return 0; return 0;
} }
/* Reserved Tx descriptors allocation request */ /* Reserved Tx descriptors allocation request
*
* Called only from mvpp2_txq_reserved_desc_num_proc(), itself called
* only by mvpp2_tx(), so migration is disabled, using
* smp_processor_id() is OK.
*/
static int mvpp2_txq_alloc_reserved_desc(struct mvpp2 *priv, static int mvpp2_txq_alloc_reserved_desc(struct mvpp2 *priv,
struct mvpp2_tx_queue *txq, int num) struct mvpp2_tx_queue *txq, int num)
{ {
...@@ -4687,6 +4705,10 @@ static u32 mvpp2_txq_desc_csum(int l3_offs, int l3_proto, ...@@ -4687,6 +4705,10 @@ static u32 mvpp2_txq_desc_csum(int l3_offs, int l3_proto,
/* Get number of sent descriptors and decrement counter. /* Get number of sent descriptors and decrement counter.
* The number of sent descriptors is returned. * The number of sent descriptors is returned.
* Per-CPU access * Per-CPU access
*
* Called only from mvpp2_txq_done(), called from mvpp2_tx()
* (migration disabled) and from the TX completion tasklet (migration
* disabled) so using smp_processor_id() is OK.
*/ */
static inline int mvpp2_txq_sent_desc_proc(struct mvpp2_port *port, static inline int mvpp2_txq_sent_desc_proc(struct mvpp2_port *port,
struct mvpp2_tx_queue *txq) struct mvpp2_tx_queue *txq)
...@@ -4701,6 +4723,9 @@ static inline int mvpp2_txq_sent_desc_proc(struct mvpp2_port *port, ...@@ -4701,6 +4723,9 @@ static inline int mvpp2_txq_sent_desc_proc(struct mvpp2_port *port,
MVPP2_TRANSMITTED_COUNT_OFFSET; MVPP2_TRANSMITTED_COUNT_OFFSET;
} }
/* Called through on_each_cpu(), so runs on all CPUs, with migration
* disabled, therefore using smp_processor_id() is OK.
*/
static void mvpp2_txq_sent_counter_clear(void *arg) static void mvpp2_txq_sent_counter_clear(void *arg)
{ {
struct mvpp2_port *port = arg; struct mvpp2_port *port = arg;
......
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