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Subject[PATCH 4.4 46/51] PCI: altera: Move retrain from fixup to altera_pcie_host_init()
Date
4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ley Foon Tan <lftan@altera.com>

commit ce4f1c7ad490aa7129bde5632d6e53943f8a866c upstream.

Previously we used a PCI early fixup to initiate a link retrain on Altera
devices. But Altera PCIe IP can be configured as either a Root Port or an
Endpoint, and they might have same vendor ID, so the fixup would be run for
both.

We only want to initiate a link retrain for Altera Root Port devices, not
for Endpoints, so move the link retrain functionality from the fixup to
altera_pcie_host_init().

[bhelgaas: changelog]
Signed-off-by: Ley Foon Tan <lftan@altera.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Claudius Heine <claudius.heine.ext@siemens.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/pci/host/pcie-altera.c | 151 ++++++++++++++++++++++++-----------------
1 file changed, 91 insertions(+), 60 deletions(-)

--- a/drivers/pci/host/pcie-altera.c
+++ b/drivers/pci/host/pcie-altera.c
@@ -43,6 +43,7 @@
#define RP_LTSSM_MASK 0x1f
#define LTSSM_L0 0xf

+#define PCIE_CAP_OFFSET 0x80
/* TLP configuration type 0 and 1 */
#define TLP_FMTTYPE_CFGRD0 0x04 /* Configuration Read Type 0 */
#define TLP_FMTTYPE_CFGWR0 0x44 /* Configuration Write Type 0 */
@@ -100,66 +101,6 @@ static bool altera_pcie_link_is_up(struc
return !!((cra_readl(pcie, RP_LTSSM) & RP_LTSSM_MASK) == LTSSM_L0);
}

-static void altera_wait_link_retrain(struct pci_dev *dev)
-{
- u16 reg16;
- unsigned long start_jiffies;
- struct altera_pcie *pcie = dev->bus->sysdata;
-
- /* Wait for link training end. */
- start_jiffies = jiffies;
- for (;;) {
- pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &reg16);
- if (!(reg16 & PCI_EXP_LNKSTA_LT))
- break;
-
- if (time_after(jiffies, start_jiffies + LINK_RETRAIN_TIMEOUT)) {
- dev_err(&pcie->pdev->dev, "link retrain timeout\n");
- break;
- }
- udelay(100);
- }
-
- /* Wait for link is up */
- start_jiffies = jiffies;
- for (;;) {
- if (altera_pcie_link_is_up(pcie))
- break;
-
- if (time_after(jiffies, start_jiffies + LINK_UP_TIMEOUT)) {
- dev_err(&pcie->pdev->dev, "link up timeout\n");
- break;
- }
- udelay(100);
- }
-}
-
-static void altera_pcie_retrain(struct pci_dev *dev)
-{
- u16 linkcap, linkstat;
- struct altera_pcie *pcie = dev->bus->sysdata;
-
- if (!altera_pcie_link_is_up(pcie))
- return;
-
- /*
- * Set the retrain bit if the PCIe rootport support > 2.5GB/s, but
- * current speed is 2.5 GB/s.
- */
- pcie_capability_read_word(dev, PCI_EXP_LNKCAP, &linkcap);
-
- if ((linkcap & PCI_EXP_LNKCAP_SLS) <= PCI_EXP_LNKCAP_SLS_2_5GB)
- return;
-
- pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &linkstat);
- if ((linkstat & PCI_EXP_LNKSTA_CLS) == PCI_EXP_LNKSTA_CLS_2_5GB) {
- pcie_capability_set_word(dev, PCI_EXP_LNKCTL,
- PCI_EXP_LNKCTL_RL);
- altera_wait_link_retrain(dev);
- }
-}
-DECLARE_PCI_FIXUP_EARLY(0x1172, PCI_ANY_ID, altera_pcie_retrain);
-
/*
* Altera PCIe port uses BAR0 of RC's configuration space as the translation
* from PCI bus to native BUS. Entire DDR region is mapped into PCIe space
@@ -434,6 +375,90 @@ static struct pci_ops altera_pcie_ops =
.write = altera_pcie_cfg_write,
};

+static int altera_read_cap_word(struct altera_pcie *pcie, u8 busno,
+ unsigned int devfn, int offset, u16 *value)
+{
+ u32 data;
+ int ret;
+
+ ret = _altera_pcie_cfg_read(pcie, busno, devfn,
+ PCIE_CAP_OFFSET + offset, sizeof(*value),
+ &data);
+ *value = data;
+ return ret;
+}
+
+static int altera_write_cap_word(struct altera_pcie *pcie, u8 busno,
+ unsigned int devfn, int offset, u16 value)
+{
+ return _altera_pcie_cfg_write(pcie, busno, devfn,
+ PCIE_CAP_OFFSET + offset, sizeof(value),
+ value);
+}
+
+static void altera_wait_link_retrain(struct altera_pcie *pcie)
+{
+ u16 reg16;
+ unsigned long start_jiffies;
+
+ /* Wait for link training end. */
+ start_jiffies = jiffies;
+ for (;;) {
+ altera_read_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN,
+ PCI_EXP_LNKSTA, &reg16);
+ if (!(reg16 & PCI_EXP_LNKSTA_LT))
+ break;
+
+ if (time_after(jiffies, start_jiffies + LINK_RETRAIN_TIMEOUT)) {
+ dev_err(&pcie->pdev->dev, "link retrain timeout\n");
+ break;
+ }
+ udelay(100);
+ }
+
+ /* Wait for link is up */
+ start_jiffies = jiffies;
+ for (;;) {
+ if (altera_pcie_link_is_up(pcie))
+ break;
+
+ if (time_after(jiffies, start_jiffies + LINK_UP_TIMEOUT)) {
+ dev_err(&pcie->pdev->dev, "link up timeout\n");
+ break;
+ }
+ udelay(100);
+ }
+}
+
+static void altera_pcie_retrain(struct altera_pcie *pcie)
+{
+ u16 linkcap, linkstat, linkctl;
+
+ if (!altera_pcie_link_is_up(pcie))
+ return;
+
+ /*
+ * Set the retrain bit if the PCIe rootport support > 2.5GB/s, but
+ * current speed is 2.5 GB/s.
+ */
+ altera_read_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN, PCI_EXP_LNKCAP,
+ &linkcap);
+ if ((linkcap & PCI_EXP_LNKCAP_SLS) <= PCI_EXP_LNKCAP_SLS_2_5GB)
+ return;
+
+ altera_read_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN, PCI_EXP_LNKSTA,
+ &linkstat);
+ if ((linkstat & PCI_EXP_LNKSTA_CLS) == PCI_EXP_LNKSTA_CLS_2_5GB) {
+ altera_read_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN,
+ PCI_EXP_LNKCTL, &linkctl);
+ linkctl |= PCI_EXP_LNKCTL_RL;
+ altera_write_cap_word(pcie, pcie->root_bus_nr, RP_DEVFN,
+ PCI_EXP_LNKCTL, linkctl);
+
+ altera_wait_link_retrain(pcie);
+ }
+}
+
static int altera_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
irq_hw_number_t hwirq)
{
@@ -568,6 +593,11 @@ static int altera_pcie_parse_dt(struct a
return 0;
}

+static void altera_pcie_host_init(struct altera_pcie *pcie)
+{
+ altera_pcie_retrain(pcie);
+}
+
static int altera_pcie_probe(struct platform_device *pdev)
{
struct altera_pcie *pcie;
@@ -605,6 +635,7 @@ static int altera_pcie_probe(struct plat
cra_writel(pcie, P2A_INT_STS_ALL, P2A_INT_STATUS);
/* enable all interrupts */
cra_writel(pcie, P2A_INT_ENA_ALL, P2A_INT_ENABLE);
+ altera_pcie_host_init(pcie);

bus = pci_scan_root_bus(&pdev->dev, pcie->root_bus_nr, &altera_pcie_ops,
pcie, &pcie->resources);

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