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-rw-r--r--arch/xtensa/lib/pci-auto.c316
1 files changed, 316 insertions, 0 deletions
diff --git a/arch/xtensa/lib/pci-auto.c b/arch/xtensa/lib/pci-auto.c
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+++ b/arch/xtensa/lib/pci-auto.c
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+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * arch/xtensa/lib/pci-auto.c
+ *
+ * PCI autoconfiguration library
+ *
+ * Copyright (C) 2001 - 2005 Tensilica Inc.
+ *
+ * Chris Zankel <zankel@tensilica.com, cez@zankel.net>
+ *
+ * Based on work from Matt Porter <mporter@mvista.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+
+#include <asm/pci-bridge.h>
+
+
+/*
+ *
+ * Setting up a PCI
+ *
+ * pci_ctrl->first_busno = <first bus number (0)>
+ * pci_ctrl->last_busno = <last bus number (0xff)>
+ * pci_ctrl->ops = <PCI config operations>
+ * pci_ctrl->map_irq = <function to return the interrupt number for a device>
+ *
+ * pci_ctrl->io_space.start = <IO space start address (PCI view)>
+ * pci_ctrl->io_space.end = <IO space end address (PCI view)>
+ * pci_ctrl->io_space.base = <IO space offset: address 0 from CPU space>
+ * pci_ctrl->mem_space.start = <MEM space start address (PCI view)>
+ * pci_ctrl->mem_space.end = <MEM space end address (PCI view)>
+ * pci_ctrl->mem_space.base = <MEM space offset: address 0 from CPU space>
+ *
+ * pcibios_init_resource(&pci_ctrl->io_resource, <IO space start>,
+ * <IO space end>, IORESOURCE_IO, "PCI host bridge");
+ * pcibios_init_resource(&pci_ctrl->mem_resources[0], <MEM space start>,
+ * <MEM space end>, IORESOURCE_MEM, "PCI host bridge");
+ *
+ * pci_ctrl->last_busno = pciauto_bus_scan(pci_ctrl,pci_ctrl->first_busno);
+ *
+ * int __init pciauto_bus_scan(struct pci_controller *pci_ctrl, int current_bus)
+ *
+ */
+
+static int pciauto_upper_iospc;
+static int pciauto_upper_memspc;
+
+static struct pci_dev pciauto_dev;
+static struct pci_bus pciauto_bus;
+
+/*
+ * Helper functions
+ */
+
+/* Initialize the bars of a PCI device. */
+
+static void __init
+pciauto_setup_bars(struct pci_dev *dev, int bar_limit)
+{
+ int bar_size;
+ int bar, bar_nr;
+ int *upper_limit;
+ int found_mem64 = 0;
+
+ for (bar = PCI_BASE_ADDRESS_0, bar_nr = 0;
+ bar <= bar_limit;
+ bar+=4, bar_nr++)
+ {
+ /* Tickle the BAR and get the size */
+ pci_write_config_dword(dev, bar, 0xffffffff);
+ pci_read_config_dword(dev, bar, &bar_size);
+
+ /* If BAR is not implemented go to the next BAR */
+ if (!bar_size)
+ continue;
+
+ /* Check the BAR type and set our address mask */
+ if (bar_size & PCI_BASE_ADDRESS_SPACE_IO)
+ {
+ bar_size &= PCI_BASE_ADDRESS_IO_MASK;
+ upper_limit = &pciauto_upper_iospc;
+ pr_debug("PCI Autoconfig: BAR %d, I/O, ", bar_nr);
+ }
+ else
+ {
+ if ((bar_size & PCI_BASE_ADDRESS_MEM_TYPE_MASK) ==
+ PCI_BASE_ADDRESS_MEM_TYPE_64)
+ found_mem64 = 1;
+
+ bar_size &= PCI_BASE_ADDRESS_MEM_MASK;
+ upper_limit = &pciauto_upper_memspc;
+ pr_debug("PCI Autoconfig: BAR %d, Mem, ", bar_nr);
+ }
+
+ /* Allocate a base address (bar_size is negative!) */
+ *upper_limit = (*upper_limit + bar_size) & bar_size;
+
+ /* Write it out and update our limit */
+ pci_write_config_dword(dev, bar, *upper_limit);
+
+ /*
+ * If we are a 64-bit decoder then increment to the
+ * upper 32 bits of the bar and force it to locate
+ * in the lower 4GB of memory.
+ */
+
+ if (found_mem64)
+ pci_write_config_dword(dev, (bar+=4), 0x00000000);
+
+ pr_debug("size=0x%x, address=0x%x\n",
+ ~bar_size + 1, *upper_limit);
+ }
+}
+
+/* Initialize the interrupt number. */
+
+static void __init
+pciauto_setup_irq(struct pci_controller* pci_ctrl,struct pci_dev *dev,int devfn)
+{
+ u8 pin;
+ int irq = 0;
+
+ pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
+
+ /* Fix illegal pin numbers. */
+
+ if (pin == 0 || pin > 4)
+ pin = 1;
+
+ if (pci_ctrl->map_irq)
+ irq = pci_ctrl->map_irq(dev, PCI_SLOT(devfn), pin);
+
+ if (irq == -1)
+ irq = 0;
+
+ pr_debug("PCI Autoconfig: Interrupt %d, pin %d\n", irq, pin);
+
+ pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
+}
+
+
+static void __init
+pciauto_prescan_setup_bridge(struct pci_dev *dev, int current_bus,
+ int sub_bus, int *iosave, int *memsave)
+{
+ /* Configure bus number registers */
+ pci_write_config_byte(dev, PCI_PRIMARY_BUS, current_bus);
+ pci_write_config_byte(dev, PCI_SECONDARY_BUS, sub_bus + 1);
+ pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, 0xff);
+
+ /* Round memory allocator to 1MB boundary */
+ pciauto_upper_memspc &= ~(0x100000 - 1);
+ *memsave = pciauto_upper_memspc;
+
+ /* Round I/O allocator to 4KB boundary */
+ pciauto_upper_iospc &= ~(0x1000 - 1);
+ *iosave = pciauto_upper_iospc;
+
+ /* Set up memory and I/O filter limits, assume 32-bit I/O space */
+ pci_write_config_word(dev, PCI_MEMORY_LIMIT,
+ ((pciauto_upper_memspc - 1) & 0xfff00000) >> 16);
+ pci_write_config_byte(dev, PCI_IO_LIMIT,
+ ((pciauto_upper_iospc - 1) & 0x0000f000) >> 8);
+ pci_write_config_word(dev, PCI_IO_LIMIT_UPPER16,
+ ((pciauto_upper_iospc - 1) & 0xffff0000) >> 16);
+}
+
+static void __init
+pciauto_postscan_setup_bridge(struct pci_dev *dev, int current_bus, int sub_bus,
+ int *iosave, int *memsave)
+{
+ int cmdstat;
+
+ /* Configure bus number registers */
+ pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, sub_bus);
+
+ /*
+ * Round memory allocator to 1MB boundary.
+ * If no space used, allocate minimum.
+ */
+ pciauto_upper_memspc &= ~(0x100000 - 1);
+ if (*memsave == pciauto_upper_memspc)
+ pciauto_upper_memspc -= 0x00100000;
+
+ pci_write_config_word(dev, PCI_MEMORY_BASE, pciauto_upper_memspc >> 16);
+
+ /* Allocate 1MB for pre-fretch */
+ pci_write_config_word(dev, PCI_PREF_MEMORY_LIMIT,
+ ((pciauto_upper_memspc - 1) & 0xfff00000) >> 16);
+
+ pciauto_upper_memspc -= 0x100000;
+
+ pci_write_config_word(dev, PCI_PREF_MEMORY_BASE,
+ pciauto_upper_memspc >> 16);
+
+ /* Round I/O allocator to 4KB boundary */
+ pciauto_upper_iospc &= ~(0x1000 - 1);
+ if (*iosave == pciauto_upper_iospc)
+ pciauto_upper_iospc -= 0x1000;
+
+ pci_write_config_byte(dev, PCI_IO_BASE,
+ (pciauto_upper_iospc & 0x0000f000) >> 8);
+ pci_write_config_word(dev, PCI_IO_BASE_UPPER16,
+ pciauto_upper_iospc >> 16);
+
+ /* Enable memory and I/O accesses, enable bus master */
+ pci_read_config_dword(dev, PCI_COMMAND, &cmdstat);
+ pci_write_config_dword(dev, PCI_COMMAND,
+ cmdstat |
+ PCI_COMMAND_IO |
+ PCI_COMMAND_MEMORY |
+ PCI_COMMAND_MASTER);
+}
+
+/*
+ * Scan the current PCI bus.
+ */
+
+
+int __init pciauto_bus_scan(struct pci_controller *pci_ctrl, int current_bus)
+{
+ int sub_bus, pci_devfn, pci_class, cmdstat, found_multi=0;
+ unsigned short vid;
+ unsigned char header_type;
+ struct pci_dev *dev = &pciauto_dev;
+
+ pciauto_dev.bus = &pciauto_bus;
+ pciauto_dev.sysdata = pci_ctrl;
+ pciauto_bus.ops = pci_ctrl->ops;
+
+ /*
+ * Fetch our I/O and memory space upper boundaries used
+ * to allocated base addresses on this pci_controller.
+ */
+
+ if (current_bus == pci_ctrl->first_busno)
+ {
+ pciauto_upper_iospc = pci_ctrl->io_resource.end + 1;
+ pciauto_upper_memspc = pci_ctrl->mem_resources[0].end + 1;
+ }
+
+ sub_bus = current_bus;
+
+ for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++)
+ {
+ /* Skip our host bridge */
+ if ((current_bus == pci_ctrl->first_busno) && (pci_devfn == 0))
+ continue;
+
+ if (PCI_FUNC(pci_devfn) && !found_multi)
+ continue;
+
+ pciauto_bus.number = current_bus;
+ pciauto_dev.devfn = pci_devfn;
+
+ /* If config space read fails from this device, move on */
+ if (pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type))
+ continue;
+
+ if (!PCI_FUNC(pci_devfn))
+ found_multi = header_type & 0x80;
+ pci_read_config_word(dev, PCI_VENDOR_ID, &vid);
+
+ if (vid == 0xffff || vid == 0x0000) {
+ found_multi = 0;
+ continue;
+ }
+
+ pci_read_config_dword(dev, PCI_CLASS_REVISION, &pci_class);
+
+ if ((pci_class >> 16) == PCI_CLASS_BRIDGE_PCI) {
+
+ int iosave, memsave;
+
+ pr_debug("PCI Autoconfig: Found P2P bridge, device %d\n",
+ PCI_SLOT(pci_devfn));
+
+ /* Allocate PCI I/O and/or memory space */
+ pciauto_setup_bars(dev, PCI_BASE_ADDRESS_1);
+
+ pciauto_prescan_setup_bridge(dev, current_bus, sub_bus,
+ &iosave, &memsave);
+ sub_bus = pciauto_bus_scan(pci_ctrl, sub_bus+1);
+ pciauto_postscan_setup_bridge(dev, current_bus, sub_bus,
+ &iosave, &memsave);
+ pciauto_bus.number = current_bus;
+
+ continue;
+
+ }
+
+ /*
+ * Found a peripheral, enable some standard
+ * settings
+ */
+
+ pci_read_config_dword(dev, PCI_COMMAND, &cmdstat);
+ pci_write_config_dword(dev, PCI_COMMAND,
+ cmdstat |
+ PCI_COMMAND_IO |
+ PCI_COMMAND_MEMORY |
+ PCI_COMMAND_MASTER);
+ pci_write_config_byte(dev, PCI_LATENCY_TIMER, 0x80);
+
+ /* Allocate PCI I/O and/or memory space */
+ pr_debug("PCI Autoconfig: Found Bus %d, Device %d, Function %d\n",
+ current_bus, PCI_SLOT(pci_devfn), PCI_FUNC(pci_devfn));
+
+ pciauto_setup_bars(dev, PCI_BASE_ADDRESS_5);
+ pciauto_setup_irq(pci_ctrl, dev, pci_devfn);
+ }
+ return sub_bus;
+}
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