linux_dsm_epyc7002/drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c
Giuseppe CAVALLARO 62a2ab935c stmmac: add Rx watchdog support to mitigate the DMA irqs
GMAC devices newer than databook 3.40 has an embedded timer
that can be used for mitigating the number of interrupts.
So this patch adds this optimizations.

At any rate, the Rx watchdog can be disable (on bugged HW) by
passing from the platform the riwt_off field.

In this implementation the rx timer stored in the Reg9 is fixed
to the max value. This will be tuned by using ethtool.

V2: added a platform parameter to force to disable the rx-watchdog
for example on new core where it is bugged.

V3: do not disable NAPI when Rx watchdog is used.

V4: a new extra statistic field has been added to show the early
receive status in the interrupt handler.
This patch also adds an extra check to avoid to call
napi_schedule when the DMA_INTR_ENA_RIE bit is disabled in the
Interrupt Mask register.

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-26 17:22:12 -05:00

290 lines
7.8 KiB
C

/*******************************************************************************
Copyright (C) 2007-2009 STMicroelectronics Ltd
This program is free software; you can redistribute it and/or modify it
under the terms and conditions of the GNU General Public License,
version 2, as published by the Free Software Foundation.
This program is distributed in the hope it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
The full GNU General Public License is included in this distribution in
the file called "COPYING".
Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
*******************************************************************************/
#include <linux/io.h>
#include "common.h"
#include "dwmac_dma.h"
#undef DWMAC_DMA_DEBUG
#ifdef DWMAC_DMA_DEBUG
#define DWMAC_LIB_DBG(fmt, args...) printk(fmt, ## args)
#else
#define DWMAC_LIB_DBG(fmt, args...) do { } while (0)
#endif
#define GMAC_HI_REG_AE 0x80000000
/* CSR1 enables the transmit DMA to check for new descriptor */
void dwmac_enable_dma_transmission(void __iomem *ioaddr)
{
writel(1, ioaddr + DMA_XMT_POLL_DEMAND);
}
void dwmac_enable_dma_irq(void __iomem *ioaddr)
{
writel(DMA_INTR_DEFAULT_MASK, ioaddr + DMA_INTR_ENA);
}
void dwmac_disable_dma_irq(void __iomem *ioaddr)
{
writel(0, ioaddr + DMA_INTR_ENA);
}
void dwmac_dma_start_tx(void __iomem *ioaddr)
{
u32 value = readl(ioaddr + DMA_CONTROL);
value |= DMA_CONTROL_ST;
writel(value, ioaddr + DMA_CONTROL);
}
void dwmac_dma_stop_tx(void __iomem *ioaddr)
{
u32 value = readl(ioaddr + DMA_CONTROL);
value &= ~DMA_CONTROL_ST;
writel(value, ioaddr + DMA_CONTROL);
}
void dwmac_dma_start_rx(void __iomem *ioaddr)
{
u32 value = readl(ioaddr + DMA_CONTROL);
value |= DMA_CONTROL_SR;
writel(value, ioaddr + DMA_CONTROL);
}
void dwmac_dma_stop_rx(void __iomem *ioaddr)
{
u32 value = readl(ioaddr + DMA_CONTROL);
value &= ~DMA_CONTROL_SR;
writel(value, ioaddr + DMA_CONTROL);
}
#ifdef DWMAC_DMA_DEBUG
static void show_tx_process_state(unsigned int status)
{
unsigned int state;
state = (status & DMA_STATUS_TS_MASK) >> DMA_STATUS_TS_SHIFT;
switch (state) {
case 0:
pr_info("- TX (Stopped): Reset or Stop command\n");
break;
case 1:
pr_info("- TX (Running):Fetching the Tx desc\n");
break;
case 2:
pr_info("- TX (Running): Waiting for end of tx\n");
break;
case 3:
pr_info("- TX (Running): Reading the data "
"and queuing the data into the Tx buf\n");
break;
case 6:
pr_info("- TX (Suspended): Tx Buff Underflow "
"or an unavailable Transmit descriptor\n");
break;
case 7:
pr_info("- TX (Running): Closing Tx descriptor\n");
break;
default:
break;
}
}
static void show_rx_process_state(unsigned int status)
{
unsigned int state;
state = (status & DMA_STATUS_RS_MASK) >> DMA_STATUS_RS_SHIFT;
switch (state) {
case 0:
pr_info("- RX (Stopped): Reset or Stop command\n");
break;
case 1:
pr_info("- RX (Running): Fetching the Rx desc\n");
break;
case 2:
pr_info("- RX (Running):Checking for end of pkt\n");
break;
case 3:
pr_info("- RX (Running): Waiting for Rx pkt\n");
break;
case 4:
pr_info("- RX (Suspended): Unavailable Rx buf\n");
break;
case 5:
pr_info("- RX (Running): Closing Rx descriptor\n");
break;
case 6:
pr_info("- RX(Running): Flushing the current frame"
" from the Rx buf\n");
break;
case 7:
pr_info("- RX (Running): Queuing the Rx frame"
" from the Rx buf into memory\n");
break;
default:
break;
}
}
#endif
int dwmac_dma_interrupt(void __iomem *ioaddr,
struct stmmac_extra_stats *x)
{
int ret = 0;
/* read the status register (CSR5) */
u32 intr_status = readl(ioaddr + DMA_STATUS);
DWMAC_LIB_DBG(KERN_INFO "%s: [CSR5: 0x%08x]\n", __func__, intr_status);
#ifdef DWMAC_DMA_DEBUG
/* It displays the DMA process states (CSR5 register) */
show_tx_process_state(intr_status);
show_rx_process_state(intr_status);
#endif
/* ABNORMAL interrupts */
if (unlikely(intr_status & DMA_STATUS_AIS)) {
DWMAC_LIB_DBG(KERN_INFO "CSR5[15] DMA ABNORMAL IRQ: ");
if (unlikely(intr_status & DMA_STATUS_UNF)) {
DWMAC_LIB_DBG(KERN_INFO "transmit underflow\n");
ret = tx_hard_error_bump_tc;
x->tx_undeflow_irq++;
}
if (unlikely(intr_status & DMA_STATUS_TJT)) {
DWMAC_LIB_DBG(KERN_INFO "transmit jabber\n");
x->tx_jabber_irq++;
}
if (unlikely(intr_status & DMA_STATUS_OVF)) {
DWMAC_LIB_DBG(KERN_INFO "recv overflow\n");
x->rx_overflow_irq++;
}
if (unlikely(intr_status & DMA_STATUS_RU)) {
DWMAC_LIB_DBG(KERN_INFO "receive buffer unavailable\n");
x->rx_buf_unav_irq++;
}
if (unlikely(intr_status & DMA_STATUS_RPS)) {
DWMAC_LIB_DBG(KERN_INFO "receive process stopped\n");
x->rx_process_stopped_irq++;
}
if (unlikely(intr_status & DMA_STATUS_RWT)) {
DWMAC_LIB_DBG(KERN_INFO "receive watchdog\n");
x->rx_watchdog_irq++;
}
if (unlikely(intr_status & DMA_STATUS_ETI)) {
DWMAC_LIB_DBG(KERN_INFO "transmit early interrupt\n");
x->tx_early_irq++;
}
if (unlikely(intr_status & DMA_STATUS_TPS)) {
DWMAC_LIB_DBG(KERN_INFO "transmit process stopped\n");
x->tx_process_stopped_irq++;
ret = tx_hard_error;
}
if (unlikely(intr_status & DMA_STATUS_FBI)) {
DWMAC_LIB_DBG(KERN_INFO "fatal bus error\n");
x->fatal_bus_error_irq++;
ret = tx_hard_error;
}
}
/* TX/RX NORMAL interrupts */
if (likely(intr_status & DMA_STATUS_NIS)) {
x->normal_irq_n++;
if (likely(intr_status & DMA_STATUS_RI)) {
u32 value = readl(ioaddr + DMA_INTR_ENA);
/* to schedule NAPI on real RIE event. */
if (likely(value & DMA_INTR_ENA_RIE)) {
x->rx_normal_irq_n++;
ret |= handle_rx;
}
}
if (likely(intr_status & DMA_STATUS_TI)) {
x->tx_normal_irq_n++;
ret |= handle_tx;
}
if (unlikely(intr_status & DMA_STATUS_ERI))
x->rx_early_irq++;
}
/* Optional hardware blocks, interrupts should be disabled */
if (unlikely(intr_status &
(DMA_STATUS_GPI | DMA_STATUS_GMI | DMA_STATUS_GLI)))
pr_info("%s: unexpected status %08x\n", __func__, intr_status);
/* Clear the interrupt by writing a logic 1 to the CSR5[15-0] */
writel((intr_status & 0x1ffff), ioaddr + DMA_STATUS);
DWMAC_LIB_DBG(KERN_INFO "\n\n");
return ret;
}
void dwmac_dma_flush_tx_fifo(void __iomem *ioaddr)
{
u32 csr6 = readl(ioaddr + DMA_CONTROL);
writel((csr6 | DMA_CONTROL_FTF), ioaddr + DMA_CONTROL);
do {} while ((readl(ioaddr + DMA_CONTROL) & DMA_CONTROL_FTF));
}
void stmmac_set_mac_addr(void __iomem *ioaddr, u8 addr[6],
unsigned int high, unsigned int low)
{
unsigned long data;
data = (addr[5] << 8) | addr[4];
/* For MAC Addr registers se have to set the Address Enable (AE)
* bit that has no effect on the High Reg 0 where the bit 31 (MO)
* is RO.
*/
writel(data | GMAC_HI_REG_AE, ioaddr + high);
data = (addr[3] << 24) | (addr[2] << 16) | (addr[1] << 8) | addr[0];
writel(data, ioaddr + low);
}
/* Enable disable MAC RX/TX */
void stmmac_set_mac(void __iomem *ioaddr, bool enable)
{
u32 value = readl(ioaddr + MAC_CTRL_REG);
if (enable)
value |= MAC_RNABLE_RX | MAC_ENABLE_TX;
else
value &= ~(MAC_ENABLE_TX | MAC_RNABLE_RX);
writel(value, ioaddr + MAC_CTRL_REG);
}
void stmmac_get_mac_addr(void __iomem *ioaddr, unsigned char *addr,
unsigned int high, unsigned int low)
{
unsigned int hi_addr, lo_addr;
/* Read the MAC address from the hardware */
hi_addr = readl(ioaddr + high);
lo_addr = readl(ioaddr + low);
/* Extract the MAC address from the high and low words */
addr[0] = lo_addr & 0xff;
addr[1] = (lo_addr >> 8) & 0xff;
addr[2] = (lo_addr >> 16) & 0xff;
addr[3] = (lo_addr >> 24) & 0xff;
addr[4] = hi_addr & 0xff;
addr[5] = (hi_addr >> 8) & 0xff;
}