[PATCH v1 3/4] sparc32/PCI/PCIC: Converge device enable path

From: Bjorn Helgaas
Date: Mon May 21 2018 - 19:36:22 EST


From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>

Most architectures turn on PCI_COMMAND_IO and PCI_COMMAND_MEMORY in
pci_enable_device() when a driver claims the device. Sparc PCIC did it in
pcibios_fixup_bus(), which is called during enumeration, before any drivers
are attached.

Implement pcibios_enable_device() for PCIC so it will do the same as other
architectures. This implementation is copied verbatim from sparc64.

Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
arch/sparc/kernel/pcic.c | 63 ++++++++++++++++++++++------------------------
1 file changed, 30 insertions(+), 33 deletions(-)

diff --git a/arch/sparc/kernel/pcic.c b/arch/sparc/kernel/pcic.c
index 22f8774977d5..5b9244f328aa 100644
--- a/arch/sparc/kernel/pcic.c
+++ b/arch/sparc/kernel/pcic.c
@@ -624,39 +624,6 @@ void pcibios_fixup_bus(struct pci_bus *bus)
}

list_for_each_entry(dev, &bus->devices, bus_list) {
-
- /*
- * Comment from i386 branch:
- * There are buggy BIOSes that forget to enable I/O and memory
- * access to PCI devices. We try to fix this, but we need to
- * be sure that the BIOS didn't forget to assign an address
- * to the device. [mj]
- * OBP is a case of such BIOS :-)
- */
- has_io = has_mem = 0;
- for(i=0; i<6; i++) {
- unsigned long f = dev->resource[i].flags;
- if (f & IORESOURCE_IO) {
- has_io = 1;
- } else if (f & IORESOURCE_MEM)
- has_mem = 1;
- }
- pcic_read_config(dev->bus, dev->devfn, PCI_COMMAND, 2, &cmd);
- if (has_io && !(cmd & PCI_COMMAND_IO)) {
- printk("PCIC: Enabling I/O for device %02x:%02x\n",
- dev->bus->number, dev->devfn);
- cmd |= PCI_COMMAND_IO;
- pcic_write_config(dev->bus, dev->devfn,
- PCI_COMMAND, 2, cmd);
- }
- if (has_mem && !(cmd & PCI_COMMAND_MEMORY)) {
- printk("PCIC: Enabling memory for device %02x:%02x\n",
- dev->bus->number, dev->devfn);
- cmd |= PCI_COMMAND_MEMORY;
- pcic_write_config(dev->bus, dev->devfn,
- PCI_COMMAND, 2, cmd);
- }
-
node = pdev_to_pnode(&pcic->pbm, dev);
if(node == 0)
node = -1;
@@ -675,6 +642,36 @@ void pcibios_fixup_bus(struct pci_bus *bus)
}
}

+int pcibios_enable_device(struct pci_dev *dev, int mask)
+{
+ u16 cmd, oldcmd;
+ int i;
+
+ pci_read_config_word(dev, PCI_COMMAND, &cmd);
+ oldcmd = cmd;
+
+ for (i = 0; i < PCI_NUM_RESOURCES; i++) {
+ struct resource *res = &dev->resource[i];
+
+ /* Only set up the requested stuff */
+ if (!(mask & (1<<i)))
+ continue;
+
+ if (res->flags & IORESOURCE_IO)
+ cmd |= PCI_COMMAND_IO;
+ if (res->flags & IORESOURCE_MEM)
+ cmd |= PCI_COMMAND_MEMORY;
+ }
+
+ if (cmd != oldcmd) {
+ printk(KERN_DEBUG "PCI: Enabling device: (%s), cmd %x\n",
+ pci_name(dev), cmd);
+ /* Enable the appropriate bits in the PCI command register. */
+ pci_write_config_word(dev, PCI_COMMAND, cmd);
+ }
+ return 0;
+}
+
/* Makes compiler happy */
static volatile int pcic_timer_dummy;