582 lines
15 KiB
C
582 lines
15 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/pci.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/ioport.h>
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#include <linux/wait.h>
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#include "pci.h"
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/*
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* This interrupt-safe spinlock protects all accesses to PCI
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* configuration space.
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*/
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DEFINE_RAW_SPINLOCK(pci_lock);
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/*
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* Wrappers for all PCI configuration access functions. They just check
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* alignment, do locking and call the low-level functions pointed to
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* by pci_dev->ops.
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*/
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#define PCI_byte_BAD 0
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#define PCI_word_BAD (pos & 1)
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#define PCI_dword_BAD (pos & 3)
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#ifdef CONFIG_PCI_LOCKLESS_CONFIG
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# define pci_lock_config(f) do { (void)(f); } while (0)
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# define pci_unlock_config(f) do { (void)(f); } while (0)
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#else
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# define pci_lock_config(f) raw_spin_lock_irqsave(&pci_lock, f)
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# define pci_unlock_config(f) raw_spin_unlock_irqrestore(&pci_lock, f)
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#endif
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#define PCI_OP_READ(size, type, len) \
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int noinline pci_bus_read_config_##size \
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(struct pci_bus *bus, unsigned int devfn, int pos, type *value) \
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{ \
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int res; \
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unsigned long flags; \
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u32 data = 0; \
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if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
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pci_lock_config(flags); \
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res = bus->ops->read(bus, devfn, pos, len, &data); \
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*value = (type)data; \
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pci_unlock_config(flags); \
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return res; \
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}
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#define PCI_OP_WRITE(size, type, len) \
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int noinline pci_bus_write_config_##size \
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(struct pci_bus *bus, unsigned int devfn, int pos, type value) \
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{ \
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int res; \
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unsigned long flags; \
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if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
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pci_lock_config(flags); \
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res = bus->ops->write(bus, devfn, pos, len, value); \
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pci_unlock_config(flags); \
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return res; \
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}
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PCI_OP_READ(byte, u8, 1)
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PCI_OP_READ(word, u16, 2)
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PCI_OP_READ(dword, u32, 4)
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PCI_OP_WRITE(byte, u8, 1)
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PCI_OP_WRITE(word, u16, 2)
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PCI_OP_WRITE(dword, u32, 4)
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EXPORT_SYMBOL(pci_bus_read_config_byte);
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EXPORT_SYMBOL(pci_bus_read_config_word);
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EXPORT_SYMBOL(pci_bus_read_config_dword);
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EXPORT_SYMBOL(pci_bus_write_config_byte);
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EXPORT_SYMBOL(pci_bus_write_config_word);
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EXPORT_SYMBOL(pci_bus_write_config_dword);
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int pci_generic_config_read(struct pci_bus *bus, unsigned int devfn,
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int where, int size, u32 *val)
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{
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void __iomem *addr;
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addr = bus->ops->map_bus(bus, devfn, where);
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if (!addr) {
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*val = ~0;
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return PCIBIOS_DEVICE_NOT_FOUND;
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}
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if (size == 1)
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*val = readb(addr);
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else if (size == 2)
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*val = readw(addr);
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else
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*val = readl(addr);
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return PCIBIOS_SUCCESSFUL;
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}
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EXPORT_SYMBOL_GPL(pci_generic_config_read);
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int pci_generic_config_write(struct pci_bus *bus, unsigned int devfn,
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int where, int size, u32 val)
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{
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void __iomem *addr;
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addr = bus->ops->map_bus(bus, devfn, where);
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if (!addr)
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return PCIBIOS_DEVICE_NOT_FOUND;
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if (size == 1)
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writeb(val, addr);
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else if (size == 2)
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writew(val, addr);
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else
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writel(val, addr);
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return PCIBIOS_SUCCESSFUL;
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}
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EXPORT_SYMBOL_GPL(pci_generic_config_write);
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int pci_generic_config_read32(struct pci_bus *bus, unsigned int devfn,
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int where, int size, u32 *val)
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{
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void __iomem *addr;
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addr = bus->ops->map_bus(bus, devfn, where & ~0x3);
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if (!addr) {
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*val = ~0;
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return PCIBIOS_DEVICE_NOT_FOUND;
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}
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*val = readl(addr);
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if (size <= 2)
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*val = (*val >> (8 * (where & 3))) & ((1 << (size * 8)) - 1);
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return PCIBIOS_SUCCESSFUL;
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}
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EXPORT_SYMBOL_GPL(pci_generic_config_read32);
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int pci_generic_config_write32(struct pci_bus *bus, unsigned int devfn,
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int where, int size, u32 val)
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{
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void __iomem *addr;
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u32 mask, tmp;
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addr = bus->ops->map_bus(bus, devfn, where & ~0x3);
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if (!addr)
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return PCIBIOS_DEVICE_NOT_FOUND;
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if (size == 4) {
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writel(val, addr);
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return PCIBIOS_SUCCESSFUL;
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}
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/*
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* In general, hardware that supports only 32-bit writes on PCI is
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* not spec-compliant. For example, software may perform a 16-bit
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* write. If the hardware only supports 32-bit accesses, we must
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* do a 32-bit read, merge in the 16 bits we intend to write,
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* followed by a 32-bit write. If the 16 bits we *don't* intend to
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* write happen to have any RW1C (write-one-to-clear) bits set, we
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* just inadvertently cleared something we shouldn't have.
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*/
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dev_warn_ratelimited(&bus->dev, "%d-byte config write to %04x:%02x:%02x.%d offset %#x may corrupt adjacent RW1C bits\n",
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size, pci_domain_nr(bus), bus->number,
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PCI_SLOT(devfn), PCI_FUNC(devfn), where);
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mask = ~(((1 << (size * 8)) - 1) << ((where & 0x3) * 8));
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tmp = readl(addr) & mask;
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tmp |= val << ((where & 0x3) * 8);
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writel(tmp, addr);
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return PCIBIOS_SUCCESSFUL;
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}
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EXPORT_SYMBOL_GPL(pci_generic_config_write32);
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/**
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* pci_bus_set_ops - Set raw operations of pci bus
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* @bus: pci bus struct
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* @ops: new raw operations
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*
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* Return previous raw operations
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*/
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struct pci_ops *pci_bus_set_ops(struct pci_bus *bus, struct pci_ops *ops)
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{
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struct pci_ops *old_ops;
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unsigned long flags;
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raw_spin_lock_irqsave(&pci_lock, flags);
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old_ops = bus->ops;
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bus->ops = ops;
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raw_spin_unlock_irqrestore(&pci_lock, flags);
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return old_ops;
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}
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EXPORT_SYMBOL(pci_bus_set_ops);
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/*
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* The following routines are to prevent the user from accessing PCI config
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* space when it's unsafe to do so. Some devices require this during BIST and
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* we're required to prevent it during D-state transitions.
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*
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* We have a bit per device to indicate it's blocked and a global wait queue
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* for callers to sleep on until devices are unblocked.
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*/
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static DECLARE_WAIT_QUEUE_HEAD(pci_cfg_wait);
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static noinline void pci_wait_cfg(struct pci_dev *dev)
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{
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DECLARE_WAITQUEUE(wait, current);
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__add_wait_queue(&pci_cfg_wait, &wait);
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do {
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set_current_state(TASK_UNINTERRUPTIBLE);
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raw_spin_unlock_irq(&pci_lock);
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schedule();
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raw_spin_lock_irq(&pci_lock);
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} while (dev->block_cfg_access);
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__remove_wait_queue(&pci_cfg_wait, &wait);
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}
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/* Returns 0 on success, negative values indicate error. */
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#define PCI_USER_READ_CONFIG(size, type) \
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int pci_user_read_config_##size \
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(struct pci_dev *dev, int pos, type *val) \
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{ \
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int ret = PCIBIOS_SUCCESSFUL; \
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u32 data = -1; \
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if (PCI_##size##_BAD) \
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return -EINVAL; \
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raw_spin_lock_irq(&pci_lock); \
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if (unlikely(dev->block_cfg_access)) \
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pci_wait_cfg(dev); \
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ret = dev->bus->ops->read(dev->bus, dev->devfn, \
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pos, sizeof(type), &data); \
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raw_spin_unlock_irq(&pci_lock); \
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*val = (type)data; \
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return pcibios_err_to_errno(ret); \
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} \
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EXPORT_SYMBOL_GPL(pci_user_read_config_##size);
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/* Returns 0 on success, negative values indicate error. */
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#define PCI_USER_WRITE_CONFIG(size, type) \
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int pci_user_write_config_##size \
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(struct pci_dev *dev, int pos, type val) \
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{ \
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int ret = PCIBIOS_SUCCESSFUL; \
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if (PCI_##size##_BAD) \
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return -EINVAL; \
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raw_spin_lock_irq(&pci_lock); \
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if (unlikely(dev->block_cfg_access)) \
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pci_wait_cfg(dev); \
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ret = dev->bus->ops->write(dev->bus, dev->devfn, \
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pos, sizeof(type), val); \
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raw_spin_unlock_irq(&pci_lock); \
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return pcibios_err_to_errno(ret); \
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} \
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EXPORT_SYMBOL_GPL(pci_user_write_config_##size);
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PCI_USER_READ_CONFIG(byte, u8)
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PCI_USER_READ_CONFIG(word, u16)
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PCI_USER_READ_CONFIG(dword, u32)
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PCI_USER_WRITE_CONFIG(byte, u8)
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PCI_USER_WRITE_CONFIG(word, u16)
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PCI_USER_WRITE_CONFIG(dword, u32)
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/**
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* pci_cfg_access_lock - Lock PCI config reads/writes
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* @dev: pci device struct
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*
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* When access is locked, any userspace reads or writes to config
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* space and concurrent lock requests will sleep until access is
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* allowed via pci_cfg_access_unlock() again.
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*/
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void pci_cfg_access_lock(struct pci_dev *dev)
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{
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might_sleep();
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raw_spin_lock_irq(&pci_lock);
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if (dev->block_cfg_access)
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pci_wait_cfg(dev);
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dev->block_cfg_access = 1;
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raw_spin_unlock_irq(&pci_lock);
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}
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EXPORT_SYMBOL_GPL(pci_cfg_access_lock);
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/**
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* pci_cfg_access_trylock - try to lock PCI config reads/writes
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* @dev: pci device struct
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*
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* Same as pci_cfg_access_lock, but will return 0 if access is
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* already locked, 1 otherwise. This function can be used from
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* atomic contexts.
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*/
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bool pci_cfg_access_trylock(struct pci_dev *dev)
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{
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unsigned long flags;
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bool locked = true;
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raw_spin_lock_irqsave(&pci_lock, flags);
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if (dev->block_cfg_access)
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locked = false;
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else
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dev->block_cfg_access = 1;
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raw_spin_unlock_irqrestore(&pci_lock, flags);
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return locked;
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}
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EXPORT_SYMBOL_GPL(pci_cfg_access_trylock);
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/**
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* pci_cfg_access_unlock - Unlock PCI config reads/writes
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* @dev: pci device struct
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*
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* This function allows PCI config accesses to resume.
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*/
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void pci_cfg_access_unlock(struct pci_dev *dev)
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{
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unsigned long flags;
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raw_spin_lock_irqsave(&pci_lock, flags);
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/*
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* This indicates a problem in the caller, but we don't need
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* to kill them, unlike a double-block above.
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*/
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WARN_ON(!dev->block_cfg_access);
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dev->block_cfg_access = 0;
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raw_spin_unlock_irqrestore(&pci_lock, flags);
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wake_up_all(&pci_cfg_wait);
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}
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EXPORT_SYMBOL_GPL(pci_cfg_access_unlock);
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static inline int pcie_cap_version(const struct pci_dev *dev)
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{
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return pcie_caps_reg(dev) & PCI_EXP_FLAGS_VERS;
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}
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bool pcie_cap_has_lnkctl(const struct pci_dev *dev)
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{
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int type = pci_pcie_type(dev);
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return type == PCI_EXP_TYPE_ENDPOINT ||
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type == PCI_EXP_TYPE_LEG_END ||
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type == PCI_EXP_TYPE_ROOT_PORT ||
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type == PCI_EXP_TYPE_UPSTREAM ||
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type == PCI_EXP_TYPE_DOWNSTREAM ||
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type == PCI_EXP_TYPE_PCI_BRIDGE ||
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type == PCI_EXP_TYPE_PCIE_BRIDGE;
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}
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static inline bool pcie_cap_has_sltctl(const struct pci_dev *dev)
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{
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return pcie_downstream_port(dev) &&
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pcie_caps_reg(dev) & PCI_EXP_FLAGS_SLOT;
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}
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static inline bool pcie_cap_has_rtctl(const struct pci_dev *dev)
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{
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int type = pci_pcie_type(dev);
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return type == PCI_EXP_TYPE_ROOT_PORT ||
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type == PCI_EXP_TYPE_RC_EC;
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}
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static bool pcie_capability_reg_implemented(struct pci_dev *dev, int pos)
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{
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if (!pci_is_pcie(dev))
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return false;
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switch (pos) {
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case PCI_EXP_FLAGS:
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return true;
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case PCI_EXP_DEVCAP:
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case PCI_EXP_DEVCTL:
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case PCI_EXP_DEVSTA:
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return true;
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case PCI_EXP_LNKCAP:
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case PCI_EXP_LNKCTL:
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case PCI_EXP_LNKSTA:
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return pcie_cap_has_lnkctl(dev);
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case PCI_EXP_SLTCAP:
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case PCI_EXP_SLTCTL:
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case PCI_EXP_SLTSTA:
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return pcie_cap_has_sltctl(dev);
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case PCI_EXP_RTCTL:
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case PCI_EXP_RTCAP:
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case PCI_EXP_RTSTA:
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return pcie_cap_has_rtctl(dev);
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case PCI_EXP_DEVCAP2:
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case PCI_EXP_DEVCTL2:
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case PCI_EXP_LNKCAP2:
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case PCI_EXP_LNKCTL2:
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case PCI_EXP_LNKSTA2:
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return pcie_cap_version(dev) > 1;
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default:
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return false;
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}
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}
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/*
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* Note that these accessor functions are only for the "PCI Express
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* Capability" (see PCIe spec r3.0, sec 7.8). They do not apply to the
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* other "PCI Express Extended Capabilities" (AER, VC, ACS, MFVC, etc.)
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*/
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int pcie_capability_read_word(struct pci_dev *dev, int pos, u16 *val)
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{
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int ret;
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*val = 0;
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if (pos & 1)
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return -EINVAL;
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if (pcie_capability_reg_implemented(dev, pos)) {
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ret = pci_read_config_word(dev, pci_pcie_cap(dev) + pos, val);
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/*
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* Reset *val to 0 if pci_read_config_word() fails, it may
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* have been written as 0xFFFF if hardware error happens
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* during pci_read_config_word().
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*/
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if (ret)
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*val = 0;
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return ret;
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}
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/*
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* For Functions that do not implement the Slot Capabilities,
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* Slot Status, and Slot Control registers, these spaces must
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* be hardwired to 0b, with the exception of the Presence Detect
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* State bit in the Slot Status register of Downstream Ports,
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* which must be hardwired to 1b. (PCIe Base Spec 3.0, sec 7.8)
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*/
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if (pci_is_pcie(dev) && pcie_downstream_port(dev) &&
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pos == PCI_EXP_SLTSTA)
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*val = PCI_EXP_SLTSTA_PDS;
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return 0;
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}
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EXPORT_SYMBOL(pcie_capability_read_word);
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int pcie_capability_read_dword(struct pci_dev *dev, int pos, u32 *val)
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{
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int ret;
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*val = 0;
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if (pos & 3)
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return -EINVAL;
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if (pcie_capability_reg_implemented(dev, pos)) {
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ret = pci_read_config_dword(dev, pci_pcie_cap(dev) + pos, val);
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/*
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* Reset *val to 0 if pci_read_config_dword() fails, it may
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* have been written as 0xFFFFFFFF if hardware error happens
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* during pci_read_config_dword().
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*/
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if (ret)
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*val = 0;
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return ret;
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}
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if (pci_is_pcie(dev) && pcie_downstream_port(dev) &&
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pos == PCI_EXP_SLTSTA)
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*val = PCI_EXP_SLTSTA_PDS;
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return 0;
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}
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EXPORT_SYMBOL(pcie_capability_read_dword);
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int pcie_capability_write_word(struct pci_dev *dev, int pos, u16 val)
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{
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if (pos & 1)
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return -EINVAL;
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if (!pcie_capability_reg_implemented(dev, pos))
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return 0;
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return pci_write_config_word(dev, pci_pcie_cap(dev) + pos, val);
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}
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EXPORT_SYMBOL(pcie_capability_write_word);
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int pcie_capability_write_dword(struct pci_dev *dev, int pos, u32 val)
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{
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if (pos & 3)
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return -EINVAL;
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if (!pcie_capability_reg_implemented(dev, pos))
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return 0;
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return pci_write_config_dword(dev, pci_pcie_cap(dev) + pos, val);
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}
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EXPORT_SYMBOL(pcie_capability_write_dword);
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int pcie_capability_clear_and_set_word(struct pci_dev *dev, int pos,
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u16 clear, u16 set)
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{
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int ret;
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u16 val;
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ret = pcie_capability_read_word(dev, pos, &val);
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if (!ret) {
|
|
val &= ~clear;
|
|
val |= set;
|
|
ret = pcie_capability_write_word(dev, pos, val);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(pcie_capability_clear_and_set_word);
|
|
|
|
int pcie_capability_clear_and_set_dword(struct pci_dev *dev, int pos,
|
|
u32 clear, u32 set)
|
|
{
|
|
int ret;
|
|
u32 val;
|
|
|
|
ret = pcie_capability_read_dword(dev, pos, &val);
|
|
if (!ret) {
|
|
val &= ~clear;
|
|
val |= set;
|
|
ret = pcie_capability_write_dword(dev, pos, val);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(pcie_capability_clear_and_set_dword);
|
|
|
|
int pci_read_config_byte(const struct pci_dev *dev, int where, u8 *val)
|
|
{
|
|
if (pci_dev_is_disconnected(dev)) {
|
|
*val = ~0;
|
|
return PCIBIOS_DEVICE_NOT_FOUND;
|
|
}
|
|
return pci_bus_read_config_byte(dev->bus, dev->devfn, where, val);
|
|
}
|
|
EXPORT_SYMBOL(pci_read_config_byte);
|
|
|
|
int pci_read_config_word(const struct pci_dev *dev, int where, u16 *val)
|
|
{
|
|
if (pci_dev_is_disconnected(dev)) {
|
|
*val = ~0;
|
|
return PCIBIOS_DEVICE_NOT_FOUND;
|
|
}
|
|
return pci_bus_read_config_word(dev->bus, dev->devfn, where, val);
|
|
}
|
|
EXPORT_SYMBOL(pci_read_config_word);
|
|
|
|
int pci_read_config_dword(const struct pci_dev *dev, int where,
|
|
u32 *val)
|
|
{
|
|
if (pci_dev_is_disconnected(dev)) {
|
|
*val = ~0;
|
|
return PCIBIOS_DEVICE_NOT_FOUND;
|
|
}
|
|
return pci_bus_read_config_dword(dev->bus, dev->devfn, where, val);
|
|
}
|
|
EXPORT_SYMBOL(pci_read_config_dword);
|
|
|
|
int pci_write_config_byte(const struct pci_dev *dev, int where, u8 val)
|
|
{
|
|
if (pci_dev_is_disconnected(dev))
|
|
return PCIBIOS_DEVICE_NOT_FOUND;
|
|
return pci_bus_write_config_byte(dev->bus, dev->devfn, where, val);
|
|
}
|
|
EXPORT_SYMBOL(pci_write_config_byte);
|
|
|
|
int pci_write_config_word(const struct pci_dev *dev, int where, u16 val)
|
|
{
|
|
if (pci_dev_is_disconnected(dev))
|
|
return PCIBIOS_DEVICE_NOT_FOUND;
|
|
return pci_bus_write_config_word(dev->bus, dev->devfn, where, val);
|
|
}
|
|
EXPORT_SYMBOL(pci_write_config_word);
|
|
|
|
int pci_write_config_dword(const struct pci_dev *dev, int where,
|
|
u32 val)
|
|
{
|
|
if (pci_dev_is_disconnected(dev))
|
|
return PCIBIOS_DEVICE_NOT_FOUND;
|
|
return pci_bus_write_config_dword(dev->bus, dev->devfn, where, val);
|
|
}
|
|
EXPORT_SYMBOL(pci_write_config_dword);
|