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net: mscc: ocelot: auto-detect packet buffer size and number of frame references

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Instead of reading these values from the reference manual and writing
them down into the driver, it appears that the hardware gives us the
option of detecting them dynamically.

The number of frame references corresponds to what the reference manual
notes, however it seems that the frame buffers are reported as slightly
less than the books would indicate. On VSC9959 (Felix), the books say it
should have 128KB of packet buffer, but the registers indicate only
129840 bytes (126.79 KB). Also, the unit of measurement for FREECNT from
the documentation of all these devices is incorrect (taken from an older
generation). This was confirmed by Younes Leroul from Microchip support.

Not having anything better to do with these values at the moment* (this
will change soon), let's just print them.

*The frame buffer size is, in fact, used to calculate the tail dropping
watermarks.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Vladimir Oltean
2021-01-15 04:11:11 +02:00
committed by Jakub Kicinski
parent 2d9116be76
commit f6fe01d6fa
8 changed files with 26 additions and 7 deletions
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3
include/soc/mscc/ocelot.h
View File

@ -607,7 +607,8 @@ struct ocelot {
const struct ocelot_stat_layout *stats_layout;
unsigned int num_stats;
int shared_queue_sz;
int packet_buffer_size;
int num_frame_refs;
int num_mact_rows;
struct net_device *hw_bridge_dev;

3
include/soc/mscc/ocelot_qsys.h
View File

@ -77,6 +77,9 @@
#define QSYS_RES_STAT_MAXUSE(x) ((x) & GENMASK(11, 0))
#define QSYS_RES_STAT_MAXUSE_M GENMASK(11, 0)
#define QSYS_MMGT_EQ_CTRL_FP_FREE_CNT(x) ((x) & GENMASK(15, 0))
#define QSYS_MMGT_EQ_CTRL_FP_FREE_CNT_M GENMASK(15, 0)
#define QSYS_EVENTS_CORE_EV_FDC(x) (((x) << 2) & GENMASK(4, 2))
#define QSYS_EVENTS_CORE_EV_FDC_M GENMASK(4, 2)
#define QSYS_EVENTS_CORE_EV_FDC_X(x) (((x) & GENMASK(4, 2)) >> 2)