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sfc: refactor EF10 stats handling
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Separate the generation-count handling from the format conversion, to
 make it easier to re-use both for EF100.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Edward Cree authored and David S. Miller committed Jun 30, 2020
1 parent de5f32e commit d3142c1
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Showing 3 changed files with 82 additions and 34 deletions.
68 changes: 34 additions & 34 deletions drivers/net/ethernet/sfc/ef10.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1279,6 +1279,14 @@ static int efx_ef10_dimension_resources(struct efx_nic *efx)
return 0;
}

static void efx_ef10_fini_nic(struct efx_nic *efx)
{
struct efx_ef10_nic_data *nic_data = efx->nic_data;

kfree(nic_data->mc_stats);
nic_data->mc_stats = NULL;
}

static int efx_ef10_init_nic(struct efx_nic *efx)
{
struct efx_ef10_nic_data *nic_data = efx->nic_data;
Expand All @@ -1300,6 +1308,11 @@ static int efx_ef10_init_nic(struct efx_nic *efx)
efx->must_realloc_vis = false;
}

nic_data->mc_stats = kmalloc(efx->num_mac_stats * sizeof(__le64),
GFP_KERNEL);
if (!nic_data->mc_stats)
return -ENOMEM;

if (nic_data->must_restore_piobufs && nic_data->n_piobufs) {
rc = efx_ef10_alloc_piobufs(efx, nic_data->n_piobufs);
if (rc == 0) {
Expand Down Expand Up @@ -1775,55 +1788,42 @@ static size_t efx_ef10_update_stats_common(struct efx_nic *efx, u64 *full_stats,
return stats_count;
}

static int efx_ef10_try_update_nic_stats_pf(struct efx_nic *efx)
static size_t efx_ef10_update_stats_pf(struct efx_nic *efx, u64 *full_stats,
struct rtnl_link_stats64 *core_stats)
{
struct efx_ef10_nic_data *nic_data = efx->nic_data;
DECLARE_BITMAP(mask, EF10_STAT_COUNT);
__le64 generation_start, generation_end;
u64 *stats = nic_data->stats;
__le64 *dma_stats;

efx_ef10_get_stat_mask(efx, mask);

dma_stats = efx->stats_buffer.addr;

generation_end = dma_stats[efx->num_mac_stats - 1];
if (generation_end == EFX_MC_STATS_GENERATION_INVALID)
return 0;
rmb();
efx_nic_update_stats(efx_ef10_stat_desc, EF10_STAT_COUNT, mask,
stats, efx->stats_buffer.addr, false);
rmb();
generation_start = dma_stats[MC_CMD_MAC_GENERATION_START];
if (generation_end != generation_start)
return -EAGAIN;
efx_nic_copy_stats(efx, nic_data->mc_stats);
efx_nic_update_stats(efx_ef10_stat_desc, EF10_STAT_COUNT,
mask, stats, nic_data->mc_stats, false);

/* Update derived statistics */
efx_nic_fix_nodesc_drop_stat(efx,
&stats[EF10_STAT_port_rx_nodesc_drops]);
/* MC Firmware reads RX_BYTES and RX_GOOD_BYTES from the MAC.
* It then calculates RX_BAD_BYTES and DMAs it to us with RX_BYTES.
* We report these as port_rx_ stats. We are not given RX_GOOD_BYTES.
* Here we calculate port_rx_good_bytes.
*/
stats[EF10_STAT_port_rx_good_bytes] =
stats[EF10_STAT_port_rx_bytes] -
stats[EF10_STAT_port_rx_bytes_minus_good_bytes];

/* The asynchronous reads used to calculate RX_BAD_BYTES in
* MC Firmware are done such that we should not see an increase in
* RX_BAD_BYTES when a good packet has arrived. Unfortunately this
* does mean that the stat can decrease at times. Here we do not
* update the stat unless it has increased or has gone to zero
* (In the case of the NIC rebooting).
* Please see Bug 33781 for a discussion of why things work this way.
*/
efx_update_diff_stat(&stats[EF10_STAT_port_rx_bad_bytes],
stats[EF10_STAT_port_rx_bytes_minus_good_bytes]);
efx_update_sw_stats(efx, stats);
return 0;
}


static size_t efx_ef10_update_stats_pf(struct efx_nic *efx, u64 *full_stats,
struct rtnl_link_stats64 *core_stats)
{
int retry;

/* If we're unlucky enough to read statistics during the DMA, wait
* up to 10ms for it to finish (typically takes <500us)
*/
for (retry = 0; retry < 100; ++retry) {
if (efx_ef10_try_update_nic_stats_pf(efx) == 0)
break;
udelay(100);
}

return efx_ef10_update_stats_common(efx, full_stats, core_stats);
}
Expand Down Expand Up @@ -4033,7 +4033,7 @@ const struct efx_nic_type efx_hunt_a0_vf_nic_type = {
.remove = efx_ef10_remove,
.dimension_resources = efx_ef10_dimension_resources,
.init = efx_ef10_init_nic,
.fini = efx_port_dummy_op_void,
.fini = efx_ef10_fini_nic,
.map_reset_reason = efx_ef10_map_reset_reason,
.map_reset_flags = efx_ef10_map_reset_flags,
.reset = efx_ef10_reset,
Expand Down Expand Up @@ -4142,7 +4142,7 @@ const struct efx_nic_type efx_hunt_a0_nic_type = {
.remove = efx_ef10_remove,
.dimension_resources = efx_ef10_dimension_resources,
.init = efx_ef10_init_nic,
.fini = efx_port_dummy_op_void,
.fini = efx_ef10_fini_nic,
.map_reset_reason = efx_ef10_map_reset_reason,
.map_reset_flags = efx_ef10_map_reset_flags,
.reset = efx_ef10_reset,
Expand Down
45 changes: 45 additions & 0 deletions drivers/net/ethernet/sfc/nic.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,8 @@
#include "farch_regs.h"
#include "io.h"
#include "workarounds.h"
#include "mcdi_port_common.h"
#include "mcdi_pcol.h"

/**************************************************************************
*
Expand Down Expand Up @@ -470,6 +472,49 @@ size_t efx_nic_describe_stats(const struct efx_hw_stat_desc *desc, size_t count,
return visible;
}

/**
* efx_nic_copy_stats - Copy stats from the DMA buffer in to an
* intermediate buffer. This is used to get a consistent
* set of stats while the DMA buffer can be written at any time
* by the NIC.
* @efx: The associated NIC.
* @dest: Destination buffer. Must be the same size as the DMA buffer.
*/
int efx_nic_copy_stats(struct efx_nic *efx, __le64 *dest)
{
__le64 *dma_stats = efx->stats_buffer.addr;
__le64 generation_start, generation_end;
int rc = 0, retry;

if (!dest)
return 0;

if (!dma_stats)
goto return_zeroes;

/* If we're unlucky enough to read statistics during the DMA, wait
* up to 10ms for it to finish (typically takes <500us)
*/
for (retry = 0; retry < 100; ++retry) {
generation_end = dma_stats[efx->num_mac_stats - 1];
if (generation_end == EFX_MC_STATS_GENERATION_INVALID)
goto return_zeroes;
rmb();
memcpy(dest, dma_stats, efx->num_mac_stats * sizeof(__le64));
rmb();
generation_start = dma_stats[MC_CMD_MAC_GENERATION_START];
if (generation_end == generation_start)
return 0; /* return good data */
udelay(100);
}

rc = -EIO;

return_zeroes:
memset(dest, 0, efx->num_mac_stats * sizeof(u64));
return rc;
}

/**
* efx_nic_update_stats - Convert statistics DMA buffer to array of u64
* @desc: Array of &struct efx_hw_stat_desc describing the DMA buffer
Expand Down
3 changes: 3 additions & 0 deletions drivers/net/ethernet/sfc/nic.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -368,6 +368,7 @@ enum {
* @piobuf_size: size of a single PIO buffer
* @must_restore_piobufs: Flag: PIO buffers have yet to be restored after MC
* reboot
* @mc_stats: Scratch buffer for converting statistics to the kernel's format
* @stats: Hardware statistics
* @workaround_35388: Flag: firmware supports workaround for bug 35388
* @workaround_26807: Flag: firmware supports workaround for bug 26807
Expand Down Expand Up @@ -404,6 +405,7 @@ struct efx_ef10_nic_data {
unsigned int piobuf_handle[EF10_TX_PIOBUF_COUNT];
u16 piobuf_size;
bool must_restore_piobufs;
__le64 *mc_stats;
u64 stats[EF10_STAT_COUNT];
bool workaround_35388;
bool workaround_26807;
Expand Down Expand Up @@ -674,6 +676,7 @@ void efx_nic_get_regs(struct efx_nic *efx, void *buf);

size_t efx_nic_describe_stats(const struct efx_hw_stat_desc *desc, size_t count,
const unsigned long *mask, u8 *names);
int efx_nic_copy_stats(struct efx_nic *efx, __le64 *dest);
void efx_nic_update_stats(const struct efx_hw_stat_desc *desc, size_t count,
const unsigned long *mask, u64 *stats,
const void *dma_buf, bool accumulate);
Expand Down

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