Re: [PATCH RFC net-next 11/19] net: mvpp2: add flow control RXQ and BM pool config callbacks
From: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Date: 2021-01-10 18:07:27
Also in:
lkml
On Sun, Jan 10, 2021 at 05:30:15PM +0200, stefanc@marvell.com wrote:
quoted hunk ↗ jump to hunk
From: Stefan Chulski <redacted> This patch did not change any functionality. Added flow control RXQ and BM pool config callbacks that would be used to configure RXQ and BM pool thresholds. APIs also will disable/enable RXQ and pool Flow Control polling. In this stage BM pool and RXQ has same stop/start thresholds defined in code. Also there are common thresholds for all RXQs. Signed-off-by: Stefan Chulski <redacted> --- drivers/net/ethernet/marvell/mvpp2/mvpp2.h | 51 +++++- drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 169 ++++++++++++++++++++ 2 files changed, 216 insertions(+), 4 deletions(-)diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h index 4d58af6..0ba0598 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h@@ -763,10 +763,53 @@ ((kb) * 1024 - MVPP2_TX_FIFO_THRESHOLD_MIN) /* MSS Flow control */ -#define MSS_SRAM_SIZE 0x800 -#define FC_QUANTA 0xFFFF -#define FC_CLK_DIVIDER 0x140 -#define MSS_THRESHOLD_STOP 768 +#define MSS_SRAM_SIZE 0x800 +#define MSS_FC_COM_REG 0 +#define FLOW_CONTROL_ENABLE_BIT BIT(0) +#define FLOW_CONTROL_UPDATE_COMMAND_BIT BIT(31) +#define FC_QUANTA 0xFFFF +#define FC_CLK_DIVIDER 0x140 + +#define MSS_BUF_POOL_BASE 0x40 +#define MSS_BUF_POOL_OFFS 4 +#define MSS_BUF_POOL_REG(id) (MSS_BUF_POOL_BASE \ + + (id) * MSS_BUF_POOL_OFFS) + +#define MSS_BUF_POOL_STOP_MASK 0xFFF +#define MSS_BUF_POOL_START_MASK (0xFFF << MSS_BUF_POOL_START_OFFS) +#define MSS_BUF_POOL_START_OFFS 12 +#define MSS_BUF_POOL_PORTS_MASK (0xF << MSS_BUF_POOL_PORTS_OFFS) +#define MSS_BUF_POOL_PORTS_OFFS 24 +#define MSS_BUF_POOL_PORT_OFFS(id) (0x1 << \ + ((id) + MSS_BUF_POOL_PORTS_OFFS)) + +#define MSS_RXQ_TRESH_BASE 0x200 +#define MSS_RXQ_TRESH_OFFS 4 +#define MSS_RXQ_TRESH_REG(q, fq) (MSS_RXQ_TRESH_BASE + (((q) + (fq)) \ + * MSS_RXQ_TRESH_OFFS)) + +#define MSS_RXQ_TRESH_START_MASK 0xFFFF +#define MSS_RXQ_TRESH_STOP_MASK (0xFFFF << MSS_RXQ_TRESH_STOP_OFFS) +#define MSS_RXQ_TRESH_STOP_OFFS 16 + +#define MSS_RXQ_ASS_BASE 0x80 +#define MSS_RXQ_ASS_OFFS 4 +#define MSS_RXQ_ASS_PER_REG 4 +#define MSS_RXQ_ASS_PER_OFFS 8 +#define MSS_RXQ_ASS_PORTID_OFFS 0 +#define MSS_RXQ_ASS_PORTID_MASK 0x3 +#define MSS_RXQ_ASS_HOSTID_OFFS 2 +#define MSS_RXQ_ASS_HOSTID_MASK 0x3F + +#define MSS_RXQ_ASS_Q_BASE(q, fq) ((((q) + (fq)) % MSS_RXQ_ASS_PER_REG) \ + * MSS_RXQ_ASS_PER_OFFS) +#define MSS_RXQ_ASS_PQ_BASE(q, fq) ((((q) + (fq)) / MSS_RXQ_ASS_PER_REG) \ + * MSS_RXQ_ASS_OFFS) +#define MSS_RXQ_ASS_REG(q, fq) (MSS_RXQ_ASS_BASE + MSS_RXQ_ASS_PQ_BASE(q, fq)) + +#define MSS_THRESHOLD_STOP 768 +#define MSS_THRESHOLD_START 1024 + /* RX buffer constants */ #define MVPP2_SKB_SHINFO_SIZE \diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c index bc4b8069..19648c4 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c@@ -744,6 +744,175 @@ static void *mvpp2_buf_alloc(struct mvpp2_port *port, return data; } +/* Routine calculate single queue shares address space */ +static int mvpp22_calc_shared_addr_space(struct mvpp2_port *port) +{ + /* If number of CPU's greater than number of threads, return last + * address space + */ + if (num_active_cpus() >= MVPP2_MAX_THREADS) + return MVPP2_MAX_THREADS - 1; + + return num_active_cpus();
Firstly - this can be written as: return min(num_active_cpus(), MVPP2_MAX_THREADS - 1); Secondly - what if the number of active CPUs change, for example due to hotplug activity. What if we boot with maxcpus=1 and then bring the other CPUs online after networking has been started? The number of active CPUs is dynamically managed via the scheduler as CPUs are brought online or offline.
+/* Routine enable flow control for RXQs conditon */ +void mvpp2_rxq_enable_fc(struct mvpp2_port *port)
...
+/* Routine disable flow control for RXQs conditon */ +void mvpp2_rxq_disable_fc(struct mvpp2_port *port)
Nothing seems to call these in this patch, so on its own, it's not obvious how these are being called, and therefore what remedy to suggest for num_active_cpus(). -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!