arch/x86/pci/intel_mid_pci.c - kernel/msm-4.9 - Gitiles

 /*
  * Intel MID PCI support
  *   Copyright (c) 2008 Intel Corporation
  *     Jesse Barnes <jesse.barnes@intel.com>
  *
  * Moorestown has an interesting PCI implementation:
  *   - configuration space is memory mapped (as defined by MCFG)
  *   - Lincroft devices also have a real, type 1 configuration space
  *   - Early Lincroft silicon has a type 1 access bug that will cause
  *     a hang if non-existent devices are accessed
  *   - some devices have the "fixed BAR" capability, which means
  *     they can't be relocated or modified; check for that during
  *     BAR sizing
  *
  * So, we use the MCFG space for all reads and writes, but also send
  * Lincroft writes to type 1 space.  But only read/write if the device
  * actually exists, otherwise return all 1s for reads and bit bucket
  * the writes.
  */

 #include <linux/sched.h>
 #include <linux/pci.h>
 #include <linux/ioport.h>
 #include <linux/init.h>
 #include <linux/dmi.h>
 #include <linux/acpi.h>
 #include <linux/io.h>
 #include <linux/smp.h>

 #include <asm/segment.h>
 #include <asm/pci_x86.h>
 #include <asm/hw_irq.h>
 #include <asm/io_apic.h>
 #include <asm/intel-mid.h>

 #define PCIE_CAP_OFFSET	0x100

 /* Fixed BAR fields */
 #define PCIE_VNDR_CAP_ID_FIXED_BAR 0x00	/* Fixed BAR (TBD) */
 #define PCI_FIXED_BAR_0_SIZE	0x04
 #define PCI_FIXED_BAR_1_SIZE	0x08
 #define PCI_FIXED_BAR_2_SIZE	0x0c
 #define PCI_FIXED_BAR_3_SIZE	0x10
 #define PCI_FIXED_BAR_4_SIZE	0x14
 #define PCI_FIXED_BAR_5_SIZE	0x1c

 static int pci_soc_mode;

 /**
  * fixed_bar_cap - return the offset of the fixed BAR cap if found
  * @bus: PCI bus
  * @devfn: device in question
  *
  * Look for the fixed BAR cap on @bus and @devfn, returning its offset
  * if found or 0 otherwise.
  */
 static int fixed_bar_cap(struct pci_bus *bus, unsigned int devfn)
 {
 	int pos;
 	u32 pcie_cap = 0, cap_data;

 	pos = PCIE_CAP_OFFSET;

 	if (!raw_pci_ext_ops)
 		return 0;

 	while (pos) {
 		if (raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number,
 					  devfn, pos, 4, &pcie_cap))
 			return 0;

 		if (PCI_EXT_CAP_ID(pcie_cap) == 0x0000 ||
 			PCI_EXT_CAP_ID(pcie_cap) == 0xffff)
 			break;

 		if (PCI_EXT_CAP_ID(pcie_cap) == PCI_EXT_CAP_ID_VNDR) {
 			raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number,
 					      devfn, pos + 4, 4, &cap_data);
 			if ((cap_data & 0xffff) == PCIE_VNDR_CAP_ID_FIXED_BAR)
 				return pos;
 		}

 		pos = PCI_EXT_CAP_NEXT(pcie_cap);
 	}

 	return 0;
 }

 static int pci_device_update_fixed(struct pci_bus *bus, unsigned int devfn,
 				   int reg, int len, u32 val, int offset)
 {
 	u32 size;
 	unsigned int domain, busnum;
 	int bar = (reg - PCI_BASE_ADDRESS_0) >> 2;

 	domain = pci_domain_nr(bus);
 	busnum = bus->number;

 	if (val == ~0 && len == 4) {
 		unsigned long decode;

 		raw_pci_ext_ops->read(domain, busnum, devfn,
 			       offset + 8 + (bar * 4), 4, &size);

 		/* Turn the size into a decode pattern for the sizing code */
 		if (size) {
 			decode = size - 1;
 			decode |= decode >> 1;
 			decode |= decode >> 2;
 			decode |= decode >> 4;
 			decode |= decode >> 8;
 			decode |= decode >> 16;
 			decode++;
 			decode = ~(decode - 1);
 		} else {
 			decode = 0;
 		}

 		/*
 		 * If val is all ones, the core code is trying to size the reg,
 		 * so update the mmconfig space with the real size.
 		 *
 		 * Note: this assumes the fixed size we got is a power of two.
 		 */
 		return raw_pci_ext_ops->write(domain, busnum, devfn, reg, 4,
 				       decode);
 	}

 	/* This is some other kind of BAR write, so just do it. */
 	return raw_pci_ext_ops->write(domain, busnum, devfn, reg, len, val);
 }

 /**
  * type1_access_ok - check whether to use type 1
  * @bus: bus number
  * @devfn: device & function in question
  *
  * If the bus is on a Lincroft chip and it exists, or is not on a Lincroft at
  * all, the we can go ahead with any reads & writes.  If it's on a Lincroft,
  * but doesn't exist, avoid the access altogether to keep the chip from
  * hanging.
  */
 static bool type1_access_ok(unsigned int bus, unsigned int devfn, int reg)
 {
 	/*
 	 * This is a workaround for A0 LNC bug where PCI status register does
 	 * not have new CAP bit set. can not be written by SW either.
 	 *
 	 * PCI header type in real LNC indicates a single function device, this
 	 * will prevent probing other devices under the same function in PCI
 	 * shim. Therefore, use the header type in shim instead.
 	 */
 	if (reg >= 0x100 || reg == PCI_STATUS || reg == PCI_HEADER_TYPE)
 		return false;
 	if (bus == 0 && (devfn == PCI_DEVFN(2, 0)
 				|| devfn == PCI_DEVFN(0, 0)
 				|| devfn == PCI_DEVFN(3, 0)))
 		return true;
 	return false; /* Langwell on others */
 }

 static int pci_read(struct pci_bus *bus, unsigned int devfn, int where,
 		    int size, u32 *value)
 {
 	if (type1_access_ok(bus->number, devfn, where))
 		return pci_direct_conf1.read(pci_domain_nr(bus), bus->number,
 					devfn, where, size, value);
 	return raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number,
 			      devfn, where, size, value);
 }

 static int pci_write(struct pci_bus *bus, unsigned int devfn, int where,
 		     int size, u32 value)
 {
 	int offset;

 	/*
 	 * On MRST, there is no PCI ROM BAR, this will cause a subsequent read
 	 * to ROM BAR return 0 then being ignored.
 	 */
 	if (where == PCI_ROM_ADDRESS)
 		return 0;

 	/*
 	 * Devices with fixed BARs need special handling:
 	 *   - BAR sizing code will save, write ~0, read size, restore
 	 *   - so writes to fixed BARs need special handling
 	 *   - other writes to fixed BAR devices should go through mmconfig
 	 */
 	offset = fixed_bar_cap(bus, devfn);
 	if (offset &&
 	    (where >= PCI_BASE_ADDRESS_0 && where <= PCI_BASE_ADDRESS_5)) {
 		return pci_device_update_fixed(bus, devfn, where, size, value,
 					       offset);
 	}

 	/*
 	 * On Moorestown update both real & mmconfig space
 	 * Note: early Lincroft silicon can't handle type 1 accesses to
 	 *       non-existent devices, so just eat the write in that case.
 	 */
 	if (type1_access_ok(bus->number, devfn, where))
 		return pci_direct_conf1.write(pci_domain_nr(bus), bus->number,
 					      devfn, where, size, value);
 	return raw_pci_ext_ops->write(pci_domain_nr(bus), bus->number, devfn,
 			       where, size, value);
 }

 static int intel_mid_pci_irq_enable(struct pci_dev *dev)
 {
 	int polarity;

 	if (dev->irq_managed && dev->irq > 0)
 		return 0;

 	if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER)
 		polarity = 0; /* active high */
 	else
 		polarity = 1; /* active low */

 	/*
 	 * MRST only have IOAPIC, the PCI irq lines are 1:1 mapped to
 	 * IOAPIC RTE entries, so we just enable RTE for the device.
 	 */
 	if (mp_set_gsi_attr(dev->irq, 1, polarity, dev_to_node(&dev->dev)))
 		return -EBUSY;
 	if (mp_map_gsi_to_irq(dev->irq, IOAPIC_MAP_ALLOC) < 0)
 		return -EBUSY;

 	dev->irq_managed = 1;

 	return 0;
 }

 static void intel_mid_pci_irq_disable(struct pci_dev *dev)
 {
 	if (!mp_should_keep_irq(&dev->dev) && dev->irq_managed &&
 	    dev->irq > 0) {
 		mp_unmap_irq(dev->irq);
 		dev->irq_managed = 0;
 	}
 }

 struct pci_ops intel_mid_pci_ops = {
 	.read = pci_read,
 	.write = pci_write,
 };

 /**
  * intel_mid_pci_init - installs intel_mid_pci_ops
  *
  * Moorestown has an interesting PCI implementation (see above).
  * Called when the early platform detection installs it.
  */
 int __init intel_mid_pci_init(void)
 {
 	pr_info("Intel MID platform detected, using MID PCI ops\n");
 	pci_mmcfg_late_init();
 	pcibios_enable_irq = intel_mid_pci_irq_enable;
 	pcibios_disable_irq = intel_mid_pci_irq_disable;
 	pci_root_ops = intel_mid_pci_ops;
 	pci_soc_mode = 1;
 	/* Continue with standard init */
 	return 1;
 }

 /*
  * Langwell devices are not true PCI devices; they are not subject to 10 ms
  * d3 to d0 delay required by PCI spec.
  */
 static void pci_d3delay_fixup(struct pci_dev *dev)
 {
 	/*
 	 * PCI fixups are effectively decided compile time. If we have a dual
 	 * SoC/non-SoC kernel we don't want to mangle d3 on non-SoC devices.
 	 */
 	if (!pci_soc_mode)
 		return;
 	/*
 	 * True PCI devices in Lincroft should allow type 1 access, the rest
 	 * are Langwell fake PCI devices.
 	 */
 	if (type1_access_ok(dev->bus->number, dev->devfn, PCI_DEVICE_ID))
 		return;
 	dev->d3_delay = 0;
 }
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_d3delay_fixup);

 static void mrst_power_off_unused_dev(struct pci_dev *dev)
 {
 	pci_set_power_state(dev, PCI_D3hot);
 }
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0801, mrst_power_off_unused_dev);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0809, mrst_power_off_unused_dev);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x080C, mrst_power_off_unused_dev);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0815, mrst_power_off_unused_dev);

 /*
  * Langwell devices reside at fixed offsets, don't try to move them.
  */
 static void pci_fixed_bar_fixup(struct pci_dev *dev)
 {
 	unsigned long offset;
 	u32 size;
 	int i;

 	if (!pci_soc_mode)
 		return;

 	/* Must have extended configuration space */
 	if (dev->cfg_size < PCIE_CAP_OFFSET + 4)
 		return;

 	/* Fixup the BAR sizes for fixed BAR devices and make them unmoveable */
 	offset = fixed_bar_cap(dev->bus, dev->devfn);
 	if (!offset || PCI_DEVFN(2, 0) == dev->devfn ||
 	    PCI_DEVFN(2, 2) == dev->devfn)
 		return;

 	for (i = 0; i < PCI_ROM_RESOURCE; i++) {
 		pci_read_config_dword(dev, offset + 8 + (i * 4), &size);
 		dev->resource[i].end = dev->resource[i].start + size - 1;
 		dev->resource[i].flags |= IORESOURCE_PCI_FIXED;
 	}
 }
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_fixed_bar_fixup);
	/*
	* Intel MID PCI support
	* Copyright (c) 2008 Intel Corporation
	* Jesse Barnes <jesse.barnes@intel.com>
	*
	* Moorestown has an interesting PCI implementation:
	* - configuration space is memory mapped (as defined by MCFG)
	* - Lincroft devices also have a real, type 1 configuration space
	* - Early Lincroft silicon has a type 1 access bug that will cause
	* a hang if non-existent devices are accessed
	* - some devices have the "fixed BAR" capability, which means
	* they can't be relocated or modified; check for that during
	* BAR sizing
	*
	* So, we use the MCFG space for all reads and writes, but also send
	* Lincroft writes to type 1 space. But only read/write if the device
	* actually exists, otherwise return all 1s for reads and bit bucket
	* the writes.
	*/

	#include <linux/sched.h>
	#include <linux/pci.h>
	#include <linux/ioport.h>
	#include <linux/init.h>
	#include <linux/dmi.h>
	#include <linux/acpi.h>
	#include <linux/io.h>
	#include <linux/smp.h>

	#include <asm/segment.h>
	#include <asm/pci_x86.h>
	#include <asm/hw_irq.h>
	#include <asm/io_apic.h>
	#include <asm/intel-mid.h>

	#define PCIE_CAP_OFFSET 0x100

	/* Fixed BAR fields */
	#define PCIE_VNDR_CAP_ID_FIXED_BAR 0x00 /* Fixed BAR (TBD) */
	#define PCI_FIXED_BAR_0_SIZE 0x04
	#define PCI_FIXED_BAR_1_SIZE 0x08
	#define PCI_FIXED_BAR_2_SIZE 0x0c
	#define PCI_FIXED_BAR_3_SIZE 0x10
	#define PCI_FIXED_BAR_4_SIZE 0x14
	#define PCI_FIXED_BAR_5_SIZE 0x1c

	static int pci_soc_mode;

	/**
	* fixed_bar_cap - return the offset of the fixed BAR cap if found
	* @bus: PCI bus
	* @devfn: device in question
	*
	* Look for the fixed BAR cap on @bus and @devfn, returning its offset
	* if found or 0 otherwise.
	*/
	static int fixed_bar_cap(struct pci_bus *bus, unsigned int devfn)
	{
	int pos;
	u32 pcie_cap = 0, cap_data;

	pos = PCIE_CAP_OFFSET;

	if (!raw_pci_ext_ops)
	return 0;

	while (pos) {
	if (raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number,
	devfn, pos, 4, &pcie_cap))
	return 0;

	if (PCI_EXT_CAP_ID(pcie_cap) == 0x0000 \|\|
	PCI_EXT_CAP_ID(pcie_cap) == 0xffff)
	break;

	if (PCI_EXT_CAP_ID(pcie_cap) == PCI_EXT_CAP_ID_VNDR) {
	raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number,
	devfn, pos + 4, 4, &cap_data);
	if ((cap_data & 0xffff) == PCIE_VNDR_CAP_ID_FIXED_BAR)
	return pos;
	}

	pos = PCI_EXT_CAP_NEXT(pcie_cap);
	}

	return 0;
	}

	static int pci_device_update_fixed(struct pci_bus *bus, unsigned int devfn,
	int reg, int len, u32 val, int offset)
	{
	u32 size;
	unsigned int domain, busnum;
	int bar = (reg - PCI_BASE_ADDRESS_0) >> 2;

	domain = pci_domain_nr(bus);
	busnum = bus->number;

	if (val == ~0 && len == 4) {
	unsigned long decode;

	raw_pci_ext_ops->read(domain, busnum, devfn,
	offset + 8 + (bar * 4), 4, &size);

	/* Turn the size into a decode pattern for the sizing code */
	if (size) {
	decode = size - 1;
	decode \|= decode >> 1;
	decode \|= decode >> 2;
	decode \|= decode >> 4;
	decode \|= decode >> 8;
	decode \|= decode >> 16;
	decode++;
	decode = ~(decode - 1);
	} else {
	decode = 0;
	}

	/*
	* If val is all ones, the core code is trying to size the reg,
	* so update the mmconfig space with the real size.
	*
	* Note: this assumes the fixed size we got is a power of two.
	*/
	return raw_pci_ext_ops->write(domain, busnum, devfn, reg, 4,
	decode);
	}

	/* This is some other kind of BAR write, so just do it. */
	return raw_pci_ext_ops->write(domain, busnum, devfn, reg, len, val);
	}

	/**
	* type1_access_ok - check whether to use type 1
	* @bus: bus number
	* @devfn: device & function in question
	*
	* If the bus is on a Lincroft chip and it exists, or is not on a Lincroft at
	* all, the we can go ahead with any reads & writes. If it's on a Lincroft,
	* but doesn't exist, avoid the access altogether to keep the chip from
	* hanging.
	*/
	static bool type1_access_ok(unsigned int bus, unsigned int devfn, int reg)
	{
	/*
	* This is a workaround for A0 LNC bug where PCI status register does
	* not have new CAP bit set. can not be written by SW either.
	*
	* PCI header type in real LNC indicates a single function device, this
	* will prevent probing other devices under the same function in PCI
	* shim. Therefore, use the header type in shim instead.
	*/
	if (reg >= 0x100 \|\| reg == PCI_STATUS \|\| reg == PCI_HEADER_TYPE)
	return false;
	if (bus == 0 && (devfn == PCI_DEVFN(2, 0)
	\|\| devfn == PCI_DEVFN(0, 0)
	\|\| devfn == PCI_DEVFN(3, 0)))
	return true;
	return false; /* Langwell on others */
	}

	static int pci_read(struct pci_bus *bus, unsigned int devfn, int where,
	int size, u32 *value)
	{
	if (type1_access_ok(bus->number, devfn, where))
	return pci_direct_conf1.read(pci_domain_nr(bus), bus->number,
	devfn, where, size, value);
	return raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number,
	devfn, where, size, value);
	}

	static int pci_write(struct pci_bus *bus, unsigned int devfn, int where,
	int size, u32 value)
	{
	int offset;

	/*
	* On MRST, there is no PCI ROM BAR, this will cause a subsequent read
	* to ROM BAR return 0 then being ignored.
	*/
	if (where == PCI_ROM_ADDRESS)
	return 0;

	/*
	* Devices with fixed BARs need special handling:
	* - BAR sizing code will save, write ~0, read size, restore
	* - so writes to fixed BARs need special handling
	* - other writes to fixed BAR devices should go through mmconfig
	*/
	offset = fixed_bar_cap(bus, devfn);
	if (offset &&
	(where >= PCI_BASE_ADDRESS_0 && where <= PCI_BASE_ADDRESS_5)) {
	return pci_device_update_fixed(bus, devfn, where, size, value,
	offset);
	}

	/*
	* On Moorestown update both real & mmconfig space
	* Note: early Lincroft silicon can't handle type 1 accesses to
	* non-existent devices, so just eat the write in that case.
	*/
	if (type1_access_ok(bus->number, devfn, where))
	return pci_direct_conf1.write(pci_domain_nr(bus), bus->number,
	devfn, where, size, value);
	return raw_pci_ext_ops->write(pci_domain_nr(bus), bus->number, devfn,
	where, size, value);
	}

	static int intel_mid_pci_irq_enable(struct pci_dev *dev)
	{
	int polarity;

	if (dev->irq_managed && dev->irq > 0)
	return 0;

	if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER)
	polarity = 0; /* active high */
	else
	polarity = 1; /* active low */

	/*
	* MRST only have IOAPIC, the PCI irq lines are 1:1 mapped to
	* IOAPIC RTE entries, so we just enable RTE for the device.
	*/
	if (mp_set_gsi_attr(dev->irq, 1, polarity, dev_to_node(&dev->dev)))
	return -EBUSY;
	if (mp_map_gsi_to_irq(dev->irq, IOAPIC_MAP_ALLOC) < 0)
	return -EBUSY;

	dev->irq_managed = 1;

	return 0;
	}

	static void intel_mid_pci_irq_disable(struct pci_dev *dev)
	{
	if (!mp_should_keep_irq(&dev->dev) && dev->irq_managed &&
	dev->irq > 0) {
	mp_unmap_irq(dev->irq);
	dev->irq_managed = 0;
	}
	}

	struct pci_ops intel_mid_pci_ops = {
	.read = pci_read,
	.write = pci_write,
	};

	/**
	* intel_mid_pci_init - installs intel_mid_pci_ops
	*
	* Moorestown has an interesting PCI implementation (see above).
	* Called when the early platform detection installs it.
	*/
	int __init intel_mid_pci_init(void)
	{
	pr_info("Intel MID platform detected, using MID PCI ops\n");
	pci_mmcfg_late_init();
	pcibios_enable_irq = intel_mid_pci_irq_enable;
	pcibios_disable_irq = intel_mid_pci_irq_disable;
	pci_root_ops = intel_mid_pci_ops;
	pci_soc_mode = 1;
	/* Continue with standard init */
	return 1;
	}

	/*
	* Langwell devices are not true PCI devices; they are not subject to 10 ms
	* d3 to d0 delay required by PCI spec.
	*/
	static void pci_d3delay_fixup(struct pci_dev *dev)
	{
	/*
	* PCI fixups are effectively decided compile time. If we have a dual
	* SoC/non-SoC kernel we don't want to mangle d3 on non-SoC devices.
	*/
	if (!pci_soc_mode)
	return;
	/*
	* True PCI devices in Lincroft should allow type 1 access, the rest
	* are Langwell fake PCI devices.
	*/
	if (type1_access_ok(dev->bus->number, dev->devfn, PCI_DEVICE_ID))
	return;
	dev->d3_delay = 0;
	}
	DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_d3delay_fixup);

	static void mrst_power_off_unused_dev(struct pci_dev *dev)
	{
	pci_set_power_state(dev, PCI_D3hot);
	}
	DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0801, mrst_power_off_unused_dev);
	DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0809, mrst_power_off_unused_dev);
	DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x080C, mrst_power_off_unused_dev);
	DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0815, mrst_power_off_unused_dev);

	/*
	* Langwell devices reside at fixed offsets, don't try to move them.
	*/
	static void pci_fixed_bar_fixup(struct pci_dev *dev)
	{
	unsigned long offset;
	u32 size;
	int i;

	if (!pci_soc_mode)
	return;

	/* Must have extended configuration space */
	if (dev->cfg_size < PCIE_CAP_OFFSET + 4)
	return;

	/* Fixup the BAR sizes for fixed BAR devices and make them unmoveable */
	offset = fixed_bar_cap(dev->bus, dev->devfn);
	if (!offset \|\| PCI_DEVFN(2, 0) == dev->devfn \|\|
	PCI_DEVFN(2, 2) == dev->devfn)
	return;

	for (i = 0; i < PCI_ROM_RESOURCE; i++) {
	pci_read_config_dword(dev, offset + 8 + (i * 4), &size);
	dev->resource[i].end = dev->resource[i].start + size - 1;
	dev->resource[i].flags \|= IORESOURCE_PCI_FIXED;
	}
	}
	DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_fixed_bar_fixup);