Subject: [RFT PATCH v2 02/42] drivers: pci: host: iproc: Convert link check to raw PCI config accessors

From: [email-masked] (Lorenzo Pieralisi)
Date: Mon, 12 Jun 2017 17:13:58 +0100

On Sun, Jun 11, 2017 at 09:42:34AM +0530, Oza Oza wrote:
> On Thu, Jun 8, 2017 at 10:06 PM, Lorenzo Pieralisi
> <[email-masked]> wrote:
> > [dropped rock-chips maintainers, email bounces]
> >
> > On Thu, Jun 08, 2017 at 08:56:05AM -0700, Ray Jui wrote:
> >> Hi Lorenzo,
> >>
> >> Thanks, I'll try my best to find time to test this along 15/42 and
> >> 33/42 patches. Hopefully I can get to that some time next week.
> >>
> >> I have not yet reviewed these patches in details. Do they have
> >> dependency on other patches to the generic framework code you
> >> changed?
> >>
> >> If so, is there a repo I can pull them?
> >
> > I added it in the cover letter but anyway here it is:
> >
> > git://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/linux.git pci/pci-fixup-irqs-removal-v2
> 
> Hi Lorenzo,
> 
> I picked up your changes, and tested on iproc based SOC,
> and ran basic fio data transfer.. and it looks okay.

Thank you. If you could also check it is all OK from a legacy
IRQ allocation (ie same as before applying series) I'd be grateful.

Thanks a lot,
Lorenzo

> Hi Bjorn,
> 
> please help to review following changes, to avoid merge conflicts
> since Lorenzo's changes in iproc driver is touching basic config APIs.
> 
> [PATCH v3 1/2] PCI: iproc: Retry request when CRS returned from EP
> [PATCH v3 2/2] PCI: iproc: add device shutdown for PCI RC
> 
> Regards,
> Oza.
> 
> 
> 
> >
> > Thanks for testing it, please let me know.
> >
> > Thank you !
> > Lorenzo
> >
> >>
> >> Thanks,
> >>
> >> Ray
> >>
> >>
> >> On 6/8/2017 7:13 AM, Lorenzo Pieralisi wrote:
> >> >Current iproc driver host bridge controller driver requires struct
> >> >pci_bus to be created in order to carry out PCI link checks with standard
> >> >PCI config space accessors.
> >> >
> >> >This struct pci_bus dependency is fictitious and burdens the driver
> >> >with unneeded constraints (eg to use separate APIs to create and scan
> >> >the root bus).
> >> >
> >> >Add PCI raw config space accessors to PCIe iproc driver and remove the
> >> >fictitious struct pci_bus dependency.
> >> >
> >> >Signed-off-by: Lorenzo Pieralisi <[email-masked]>
> >> >Cc: Scott Branden <[email-masked]>
> >> >Cc: Ray Jui <[email-masked]>
> >> >Cc: Jon Mason <[email-masked]>
> >> >---
> >> >  drivers/pci/host/pcie-iproc.c | 94 ++++++++++++++++++++++++++++++++++---------
> >> >  1 file changed, 74 insertions(+), 20 deletions(-)
> >> >
> >> >diff --git a/drivers/pci/host/pcie-iproc.c b/drivers/pci/host/pcie-iproc.c
> >> >index 0f39bd2..e48b8e2 100644
> >> >--- a/drivers/pci/host/pcie-iproc.c
> >> >+++ b/drivers/pci/host/pcie-iproc.c
> >> >@@ -452,14 +452,13 @@ static inline void iproc_pcie_apb_err_disable(struct pci_bus *bus,
> >> >   * Note access to the configuration registers are protected at the higher layer
> >> >   * by 'pci_lock' in drivers/pci/access.c
> >> >   */
> >> >-static void __iomem *iproc_pcie_map_cfg_bus(struct pci_bus *bus,
> >> >+static void __iomem *iproc_pcie_map_cfg_bus(struct iproc_pcie *pcie,
> >> >+                                        int busno,
> >> >                                         unsigned int devfn,
> >> >                                         int where)
> >> >  {
> >> >-    struct iproc_pcie *pcie = iproc_data(bus);
> >> >     unsigned slot = PCI_SLOT(devfn);
> >> >     unsigned fn = PCI_FUNC(devfn);
> >> >-    unsigned busno = bus->number;
> >> >     u32 val;
> >> >     u16 offset;
> >> >@@ -499,6 +498,58 @@ static void __iomem *iproc_pcie_map_cfg_bus(struct pci_bus *bus,
> >> >             return (pcie->base + offset);
> >> >  }
> >> >+static void __iomem *iproc_pcie_bus_map_cfg_bus(struct pci_bus *bus,
> >> >+                                            unsigned int devfn,
> >> >+                                            int where)
> >> >+{
> >> >+    return iproc_pcie_map_cfg_bus(iproc_data(bus), bus->number, devfn,
> >> >+                                  where);
> >> >+}
> >> >+
> >> >+static int iproc_pci_raw_config_read32(struct iproc_pcie *pcie,
> >> >+                                   unsigned int devfn, int where,
> >> >+                                   int size, u32 *val)
> >> >+{
> >> >+    void __iomem *addr;
> >> >+
> >> >+    addr = iproc_pcie_map_cfg_bus(pcie, 0, devfn, where & ~0x3);
> >> >+    if (!addr) {
> >> >+            *val = ~0;
> >> >+            return PCIBIOS_DEVICE_NOT_FOUND;
> >> >+    }
> >> >+
> >> >+    *val = readl(addr);
> >> >+
> >> >+    if (size <= 2)
> >> >+            *val = (*val >> (8 * (where & 3))) & ((1 << (size * 8)) - 1);
> >> >+
> >> >+    return PCIBIOS_SUCCESSFUL;
> >> >+}
> >> >+
> >> >+static int iproc_pci_raw_config_write32(struct iproc_pcie *pcie,
> >> >+                                    unsigned int devfn, int where,
> >> >+                                    int size, u32 val)
> >> >+{
> >> >+    void __iomem *addr;
> >> >+    u32 mask, tmp;
> >> >+
> >> >+    addr = iproc_pcie_map_cfg_bus(pcie, 0, devfn, where & ~0x3);
> >> >+    if (!addr)
> >> >+            return PCIBIOS_DEVICE_NOT_FOUND;
> >> >+
> >> >+    if (size == 4) {
> >> >+            writel(val, addr);
> >> >+            return PCIBIOS_SUCCESSFUL;
> >> >+    }
> >> >+
> >> >+    mask = ~(((1 << (size * 8)) - 1) << ((where & 0x3) * 8));
> >> >+    tmp = readl(addr) & mask;
> >> >+    tmp |= val << ((where & 0x3) * 8);
> >> >+    writel(tmp, addr);
> >> >+
> >> >+    return PCIBIOS_SUCCESSFUL;
> >> >+}
> >> >+
> >> >  static int iproc_pcie_config_read32(struct pci_bus *bus, unsigned int devfn,
> >> >                                 int where, int size, u32 *val)
> >> >  {
> >> >@@ -524,7 +575,7 @@ static int iproc_pcie_config_write32(struct pci_bus *bus, unsigned int devfn,
> >> >  }
> >> >  static struct pci_ops iproc_pcie_ops = {
> >> >-    .map_bus = iproc_pcie_map_cfg_bus,
> >> >+    .map_bus = iproc_pcie_bus_map_cfg_bus,
> >> >     .read = iproc_pcie_config_read32,
> >> >     .write = iproc_pcie_config_write32,
> >> >  };
> >> >@@ -556,12 +607,11 @@ static void iproc_pcie_reset(struct iproc_pcie *pcie)
> >> >     msleep(100);
> >> >  }
> >> >-static int iproc_pcie_check_link(struct iproc_pcie *pcie, struct pci_bus *bus)
> >> >+static int iproc_pcie_check_link(struct iproc_pcie *pcie)
> >> >  {
> >> >     struct device *dev = pcie->dev;
> >> >-    u8 hdr_type;
> >> >-    u32 link_ctrl, class, val;
> >> >-    u16 pos = PCI_EXP_CAP, link_status;
> >> >+    u32 hdr_type, link_ctrl, link_status, class, val;
> >> >+    u16 pos = PCI_EXP_CAP;
> >> >     bool link_is_active = false;
> >> >     /*
> >> >@@ -578,7 +628,7 @@ static int iproc_pcie_check_link(struct iproc_pcie *pcie, struct pci_bus *bus)
> >> >     }
> >> >     /* make sure we are not in EP mode */
> >> >-    pci_bus_read_config_byte(bus, 0, PCI_HEADER_TYPE, &hdr_type);
> >> >+    iproc_pci_raw_config_read32(pcie,  0, PCI_HEADER_TYPE, 1, &hdr_type);
> >> >     if ((hdr_type & 0x7f) != PCI_HEADER_TYPE_BRIDGE) {
> >> >             dev_err(dev, "in EP mode, hdr=%#02x\n", hdr_type);
> >> >             return -EFAULT;
> >> >@@ -588,13 +638,16 @@ static int iproc_pcie_check_link(struct iproc_pcie *pcie, struct pci_bus *bus)
> >> >  #define PCI_BRIDGE_CTRL_REG_OFFSET 0x43c
> >> >  #define PCI_CLASS_BRIDGE_MASK      0xffff00
> >> >  #define PCI_CLASS_BRIDGE_SHIFT     8
> >> >-    pci_bus_read_config_dword(bus, 0, PCI_BRIDGE_CTRL_REG_OFFSET, &class);
> >> >+    iproc_pci_raw_config_read32(pcie, 0, PCI_BRIDGE_CTRL_REG_OFFSET,
> >> >+                                4, &class);
> >> >     class &= ~PCI_CLASS_BRIDGE_MASK;
> >> >     class |= (PCI_CLASS_BRIDGE_PCI << PCI_CLASS_BRIDGE_SHIFT);
> >> >-    pci_bus_write_config_dword(bus, 0, PCI_BRIDGE_CTRL_REG_OFFSET, class);
> >> >+    iproc_pci_raw_config_write32(pcie, 0, PCI_BRIDGE_CTRL_REG_OFFSET,
> >> >+                                 4, class);
> >> >     /* check link status to see if link is active */
> >> >-    pci_bus_read_config_word(bus, 0, pos + PCI_EXP_LNKSTA, &link_status);
> >> >+    iproc_pci_raw_config_read32(pcie, 0, pos + PCI_EXP_LNKSTA,
> >> >+                                2, &link_status);
> >> >     if (link_status & PCI_EXP_LNKSTA_NLW)
> >> >             link_is_active = true;
> >> >@@ -603,20 +656,21 @@ static int iproc_pcie_check_link(struct iproc_pcie *pcie, struct pci_bus *bus)
> >> >  #define PCI_TARGET_LINK_SPEED_MASK    0xf
> >> >  #define PCI_TARGET_LINK_SPEED_GEN2    0x2
> >> >  #define PCI_TARGET_LINK_SPEED_GEN1    0x1
> >> >-            pci_bus_read_config_dword(bus, 0,
> >> >-                                      pos + PCI_EXP_LNKCTL2,
> >> >+            iproc_pci_raw_config_read32(pcie, 0,
> >> >+                                      pos + PCI_EXP_LNKCTL2, 4,
> >> >                                       &link_ctrl);
> >> >             if ((link_ctrl & PCI_TARGET_LINK_SPEED_MASK) ==
> >> >                 PCI_TARGET_LINK_SPEED_GEN2) {
> >> >                     link_ctrl &= ~PCI_TARGET_LINK_SPEED_MASK;
> >> >                     link_ctrl |= PCI_TARGET_LINK_SPEED_GEN1;
> >> >-                    pci_bus_write_config_dword(bus, 0,
> >> >-                                       pos + PCI_EXP_LNKCTL2,
> >> >-                                       link_ctrl);
> >> >+                    iproc_pci_raw_config_write32(pcie, 0,
> >> >+                                            pos + PCI_EXP_LNKCTL2,
> >> >+                                            4, link_ctrl);
> >> >                     msleep(100);
> >> >-                    pci_bus_read_config_word(bus, 0, pos + PCI_EXP_LNKSTA,
> >> >-                                             &link_status);
> >> >+                    iproc_pci_raw_config_read32(pcie, 0,
> >> >+                                            pos + PCI_EXP_LNKSTA,
> >> >+                                            2, &link_status);
> >> >                     if (link_status & PCI_EXP_LNKSTA_NLW)
> >> >                             link_is_active = true;
> >> >             }
> >> >@@ -1260,7 +1314,7 @@ int iproc_pcie_setup(struct iproc_pcie *pcie, struct list_head *res)
> >> >     }
> >> >     pcie->root_bus = bus;
> >> >-    ret = iproc_pcie_check_link(pcie, bus);
> >> >+    ret = iproc_pcie_check_link(pcie);
> >> >     if (ret) {
> >> >             dev_err(dev, "no PCIe EP device detected\n");
> >> >             goto err_rm_root_bus;
> >>
> >
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