[linux-yocto] [PATCH 12/48] drivers/pci: Work Around a Hardware Defect on Axxia
Daniel Dragomir
daniel.dragomir at windriver.com
Mon Dec 11 05:13:42 PST 2017
From: John Jacques <john.jacques at intel.com>
Some Axxia devices require a work around while establishing a
PCIe link. The work around is as follows.
Enable the LTSSM, and while a link has not been established,
do the following for all lanes in use.
If the rate is 2 (LANE0_DIG_ASIC_RX_ASIC_IN_0 bits 8:7), then
If bit 2 is set (LANE0_DIG_ASIC_RX_ASIC_OUT_0 bit 1)
Write 0x4700 to LANE0_DIG_ASIC_RX_OVRD_IN_0.
Else
Write 0x0700 to LANE0_DIG_ASIC_RX_OVRD_IN_0.
Signed-off-by: John Jacques <john.jacques at intel.com>
---
drivers/pci/host/pcie-axxia.c | 254 ++++++++++++++++++++++++++++++++++++++++--
1 file changed, 245 insertions(+), 9 deletions(-)
diff --git a/drivers/pci/host/pcie-axxia.c b/drivers/pci/host/pcie-axxia.c
index 10e4769..0efcae1 100644
--- a/drivers/pci/host/pcie-axxia.c
+++ b/drivers/pci/host/pcie-axxia.c
@@ -26,6 +26,8 @@
#include <linux/of_pci.h>
#include <linux/proc_fs.h>
#include <linux/axxia-pei.h>
+#include <linux/time.h>
+#include <linux/lsi-ncr.h>
#include "pcie-axxia.h"
@@ -108,6 +110,9 @@
/* SYSCON */
#define AXXIA_SYSCON_BASE 0x8002C00000
+static int enable_los_wa = 1;
+module_param(enable_los_wa, int, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+MODULE_PARM_DESC(enable_los_wa, "Enable the LOS Work Around");
static inline uint32_t axxia_mmio_read_32(uintptr_t addr)
{
@@ -581,6 +586,217 @@ int axxia_pcie_link_up(struct pcie_port *pp)
return 1;
}
+static int
+axxia_pcie_los_wa(struct pcie_port *pp)
+{
+ unsigned int value;
+ int rc = 1;
+ unsigned int control;
+ struct timeval start;
+ struct timeval now;
+
+ /*
+ * There are four SerDes, each with 2 lanes or channels. The
+ * following uses one byte for each SerDes, and in each byte,
+ * one nibble for each lane. Only lanes that are in RC mode
+ * and configured for PCIe should be part of the work around.
+ */
+
+ unsigned int lane_mask = 0;
+
+ int max_target;
+ unsigned int lane0_dig_asic_rx_asic_in_0;
+ unsigned int lane0_dig_asic_rx_asic_out_0;
+ unsigned int lane0_idg_asic_rx_ovrd_in_0;
+ unsigned int lane1_dig_asic_rx_asic_in_0;
+ unsigned int lane1_dig_asic_rx_asic_out_0;
+ unsigned int lane1_idg_asic_rx_ovrd_in_0;
+
+ if (0 == axxia_pei_is_control_set())
+ return -1;
+
+ control = axxia_pei_get_control();
+
+ /* If PEI0, make sure it is configured as the root complex. */
+ if ((0 == pp->pei_nr) && (0 == (control & 0x80)))
+ return 0;
+
+ /*
+ * The "control" value in the parameters defines the number of
+ * lanes used. Use bits 25:22 to initialize "lane_mask".
+ */
+
+ if (axxia_is_x9()) {
+ switch ((control & 0x3c00000) >> 22) {
+ case 1:
+ /* PEI0x4 and PEI1x4 */
+ if (0 == pp->pei_nr)
+ lane_mask = 0x00001111;
+ else if (1 == pp->pei_nr)
+ lane_mask = 0x11110000;
+ else
+ return 0;
+
+ break;
+ case 2:
+ /* PEI0x2, PEI2x2, and PEI1x2 */
+ if (0 == pp->pei_nr)
+ lane_mask = 0x00000011;
+ else if (1 == pp->pei_nr)
+ lane_mask = 0x00110000;
+ else if (2 == pp->pei_nr)
+ lane_mask = 0x00001100;
+ else
+ return 0;
+
+ break;
+ case 3:
+ /* PEI0x2 and PEI2x2 */
+ if (0 == pp->pei_nr)
+ lane_mask = 0x00000011;
+ else if (2 == pp->pei_nr)
+ lane_mask = 0x11000000;
+ else
+ return 0;
+
+ break;
+ case 4:
+ /* PEI2x2 */
+ if (2 == pp->pei_nr)
+ lane_mask = 0x11000000;
+ else
+ return 0;
+
+ break;
+ case 5:
+ /* PEI1x2 and PEI2x2 */
+ if (1 == pp->pei_nr)
+ lane_mask = 0x00110000;
+ else if (2 == pp->pei_nr)
+ lane_mask = 0x11000000;
+ break;
+ case 15:
+ /* PEI1x4 */
+ if (1 == pp->pei_nr)
+ lane_mask = 0x11110000;
+ else
+ return 0;
+ break;
+ default:
+ return 0;
+ break;
+ }
+ } else {
+ switch ((control & 0x3c00000) >> 22) {
+ case 1:
+ lane_mask = 0x00000011;
+ break;
+ case 2:
+ lane_mask = 0x00000001;
+ break;
+ default:
+ return 0;
+ break;
+ }
+ }
+
+ /* Run the LOS work around until a link is established. */
+
+ if (axxia_is_x9()) {
+ max_target = 4;
+ lane0_dig_asic_rx_asic_in_0 = 0x2022;
+ lane0_dig_asic_rx_asic_out_0 = 0x202e;
+ lane0_idg_asic_rx_ovrd_in_0 = 0x200a;
+ lane1_dig_asic_rx_asic_in_0 = 0x2222;
+ lane1_dig_asic_rx_asic_out_0 = 0x222e;
+ lane1_idg_asic_rx_ovrd_in_0 = 0x220a;
+ } else {
+ max_target = 1;
+ lane0_dig_asic_rx_asic_in_0 = 0x4044;
+ lane0_dig_asic_rx_asic_out_0 = 0x405c;
+ lane0_idg_asic_rx_ovrd_in_0 = 0x4014;
+ lane1_dig_asic_rx_asic_in_0 = 0x4444;
+ lane1_dig_asic_rx_asic_out_0 = 0x445c;
+ lane1_idg_asic_rx_ovrd_in_0 = 0x4414;
+ }
+
+ do_gettimeofday(&start);
+
+ for (;;) {
+ int i;
+ unsigned short temp;
+
+ /*
+ * In all cases (see the initialization of lane_mask
+ * above), either both lanes or none are used in each
+ * HSS.
+ */
+
+ for (i = 1; i <= max_target; ++i) {
+ if (0 == (lane_mask & (0xff << ((i - 1) * 8))))
+ continue;
+
+ ncr_read(NCP_REGION_ID(0x115, i),
+ lane0_dig_asic_rx_asic_in_0, 2, &temp);
+
+ if (2 == ((temp & 0x180) >> 7)) {
+ ncr_read(NCP_REGION_ID(0x115, i),
+ lane0_dig_asic_rx_asic_out_0,
+ 2, &temp);
+
+ if (0 != (temp & 2))
+ temp = 0x4700;
+ else
+ temp = 0x0700;
+
+ ncr_write(NCP_REGION_ID(0x115, i),
+ lane0_idg_asic_rx_ovrd_in_0,
+ 2, &temp);
+ }
+
+ ncr_read(NCP_REGION_ID(0x115, i),
+ lane1_dig_asic_rx_asic_in_0,
+ 2, &temp);
+
+ if (2 == ((temp & 0x180) >> 7)) {
+ ncr_read(NCP_REGION_ID(0x115, i),
+ lane1_dig_asic_rx_asic_out_0,
+ 2, &temp);
+
+ if (0 != (temp & 2))
+ temp = 0x4700;
+ else
+ temp = 0x0700;
+
+ ncr_write(NCP_REGION_ID(0x115, i),
+ lane1_idg_asic_rx_ovrd_in_0,
+ 2, &temp);
+ }
+ }
+
+ axxia_cc_gpreg_readl(pp, PEI_SII_PWR_MGMT_REG, &value);
+
+ if (0 != (value & (1 << 12)) &&
+ 0x11 == ((value & 0x3f0) >> 4)) {
+ rc = 0;
+
+ break;
+ }
+
+ do_gettimeofday(&now);
+
+ if ((2 * 1000 * 1000) <
+ (((now.tv_sec * 1000 * 1000) + now.tv_usec) -
+ ((start.tv_sec * 1000 * 1000) + start.tv_usec))) {
+ rc = -1;
+
+ break;
+ }
+ }
+
+ return rc;
+}
+
void axxia_pcie_setup_rc(struct pcie_port *pp)
{
u32 val;
@@ -628,9 +844,6 @@ void axxia_pcie_setup_rc(struct pcie_port *pp)
}
axxia_pcie_wr_own_conf(pp, PCIE_PORT_LINK_CONTROL, 4, val);
- /* Add Mikes tweak for GEN3_EQ_CONTROL */
- axxia_pcie_writel_rc(pp, 0x1017201, PCIE_GEN3_EQ_CONTROL_OFF);
-
/* setup bus numbers */
axxia_pcie_readl_rc(pp, PCI_PRIMARY_BUS, &val);
val &= 0xff000000;
@@ -650,12 +863,35 @@ void axxia_pcie_setup_rc(struct pcie_port *pp)
PCI_COMMAND_MASTER | PCI_COMMAND_SERR;
axxia_pcie_writel_rc(pp, val, PCI_COMMAND);
- /* LTSSM enable */
- axxia_cc_gpreg_readl(pp, PEI_GENERAL_CORE_CTL_REG, &val);
- msleep(100);
- val |= 0x1;
- axxia_cc_gpreg_writel(pp, val, PEI_GENERAL_CORE_CTL_REG);
- msleep(100);
+ if (0 != enable_los_wa) {
+ /* Update GEN3_EQ_CONTROL */
+ axxia_pcie_writel_rc(pp, 0x1017221,
+ PCIE_GEN3_EQ_CONTROL_OFF);
+
+ /* LTSSM enable */
+ axxia_cc_gpreg_readl(pp,
+ PEI_GENERAL_CORE_CTL_REG, &val);
+ val |= 0x1;
+ axxia_cc_gpreg_writel(pp,
+ val, PEI_GENERAL_CORE_CTL_REG);
+
+ printk("%s:%d - Running LOS WA\n", __FILE__, __LINE__);
+ axxia_pcie_los_wa(pp);
+ } else {
+ /* Update GEN3_EQ_CONTROL */
+ axxia_pcie_writel_rc(pp, 0x1017201,
+ PCIE_GEN3_EQ_CONTROL_OFF);
+
+ /* LTSSM enable */
+ axxia_cc_gpreg_readl(pp,
+ PEI_GENERAL_CORE_CTL_REG, &val);
+ msleep(100);
+ val |= 0x1;
+ axxia_cc_gpreg_writel(pp,
+ val, PEI_GENERAL_CORE_CTL_REG);
+ printk("%s:%d - Skipping LOS WA\n", __FILE__, __LINE__);
+ msleep(100);
+ }
if (axxia_pcie_link_up(pp))
break;
--
2.7.4
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