arch/xtensa/lib/pci-auto.c - linux - Git at Google

 // 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/bitfield.h>
 #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;
 	unsigned short vid;
 	unsigned char header_type;
 	struct pci_dev *dev = &pciauto_dev;
 	bool found_multi = false;

 	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 = FIELD_GET(PCI_HEADER_TYPE_MFD, header_type);
 		pci_read_config_word(dev, PCI_VENDOR_ID, &vid);

 		if (vid == 0xffff || vid == 0x0000) {
 			found_multi = false;
 			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;
 }
	// 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/bitfield.h>
	#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;
	unsigned short vid;
	unsigned char header_type;
	struct pci_dev *dev = &pciauto_dev;
	bool found_multi = false;

	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 = FIELD_GET(PCI_HEADER_TYPE_MFD, header_type);
	pci_read_config_word(dev, PCI_VENDOR_ID, &vid);

	if (vid == 0xffff \|\| vid == 0x0000) {
	found_multi = false;
	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;
	}