Re: [PATCH 1/1] pci: Block config access during BIST (resend)

Greg KH
2005-02-01T07:46:31Z

On Fri, Jan 28, 2005 at 08:35:46AM -0600, Brian King wrote:
> +#define PCI_USER_READ_CONFIG(size,type) \
> +int pci_user_read_config_##size \
> + (struct pci_dev *dev, int pos, type *val) \
> +{ \
> + unsigned long flags; \
> + int ret = 0; \
> + u32 data = -1; \
> + if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
> + spin_lock_irqsave(&pci_lock, flags); \
> + if (likely(!dev->block_ucfg_access)) \
> + ret = dev->bus->ops->read(dev->bus, dev->devfn, pos, sizeof(type), &data); \
> + else if (pos < sizeof(dev->saved_config_space)) \
> + data = dev->saved_config_space[pos/sizeof(dev->saved_config_space[0])]; \
> + spin_unlock_irqrestore(&pci_lock, flags); \
> + *val = (type)data; \
> + return ret; \
> +}
> +
> +#define PCI_USER_WRITE_CONFIG(size,type) \
> +int pci_user_write_config_##size \
> + (struct pci_dev *dev, int pos, type val) \
> +{ \
> + unsigned long flags; \
> + int ret = 0; \
> + if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
> + spin_lock_irqsave(&pci_lock, flags); \
> + if (likely(!dev->block_ucfg_access)) \
> + ret = dev->bus->ops->write(dev->bus, dev->devfn, pos, sizeof(type), val); \
> + spin_unlock_irqrestore(&pci_lock, flags); \
> + return ret; \
> +}
> +
> +PCI_USER_READ_CONFIG(byte, u8)
> +PCI_USER_READ_CONFIG(word, u16)
> +PCI_USER_READ_CONFIG(dword, u32)
> +PCI_USER_WRITE_CONFIG(byte, u8)
> +PCI_USER_WRITE_CONFIG(word, u16)
> +PCI_USER_WRITE_CONFIG(dword, u32)

Global but not exported? If so, they are local to the pci core, right?
And if so, please put them in the drivers/pci/pci.h file and not the
include/linux/pci.h file.

> +/**
> + * pci_block_user_cfg_access - Block userspace PCI config reads/writes
> + * @dev: pci device struct
> + *
> + * This function blocks any userspace PCI config accesses from occurring.
> + * When blocked, any writes will return -EBUSY and reads will return the
> + * data saved using pci_save_state for the first 64 bytes of config
> + * space and return -EBUSY for all other config reads.
> + *
> + * Return value:
> + * nothing

We know the return value is not needed by the way the function is
defined, these two lines are unneeded.

> +void pci_block_user_cfg_access(struct pci_dev *dev)
> +{
> + unsigned long flags;
> +
> + pci_save_state(dev);
> + spin_lock_irqsave(&pci_lock, flags);
> + dev->block_ucfg_access = 1;
> + spin_unlock_irqrestore(&pci_lock, flags);
> +}
> +EXPORT_SYMBOL(pci_block_user_cfg_access);

EXPORT_SYMBOL_GPL() please?

> +/**
> + * pci_unblock_user_cfg_access - Unblock userspace PCI config reads/writes
> + * @dev: pci device struct
> + *
> + * This function allows userspace PCI config accesses to resume.
> + *
> + * Return value:
> + * nothing

Same here as above.

> +void pci_unblock_user_cfg_access(struct pci_dev *dev)
> +{
> + unsigned long flags;
> +
> + spin_lock_irqsave(&pci_lock, flags);
> + dev->block_ucfg_access = 0;
> + spin_unlock_irqrestore(&pci_lock, flags);
> +}
> +EXPORT_SYMBOL(pci_unblock_user_cfg_access);

Same as above.

> @@ -896,6 +904,8 @@ extern void pci_disable_msix(struct pci_
> extern void msi_remove_pci_irq_vectors(struct pci_dev *dev);
> #endif
>
> +extern void pci_block_user_cfg_access(struct pci_dev *dev);
> +extern void pci_unblock_user_cfg_access(struct pci_dev *dev);
> #endif /* CONFIG_PCI */

Don't need empty functions for these if CONFIG_PCI is not enabled? Who
would be calling these functions, drivers? If so, please create the
empty functions.

Also, please CC the linux-pci mailing list for pci specific patches like
this.

thanks,

greg k-h