linux-brain/include/linux/msi.h
Marc Zyngier f3b0946d62 genirq/msi: Make sure PCI MSIs are activated early
Bharat Kumar Gogada reported issues with the generic MSI code, where the
end-point ended up with garbage in its MSI configuration (both for the vector
and the message).

It turns out that the two MSI paths in the kernel are doing slightly different
things:

generic MSI: disable MSI -> allocate MSI -> enable MSI -> setup EP
PCI MSI: disable MSI -> allocate MSI -> setup EP -> enable MSI

And it turns out that end-points are allowed to latch the content of the MSI
configuration registers as soon as MSIs are enabled.  In Bharat's case, the
end-point ends up using whatever was there already, which is not what you
want.

In order to make things converge, we introduce a new MSI domain flag
(MSI_FLAG_ACTIVATE_EARLY) that is unconditionally set for PCI/MSI. When set,
this flag forces the programming of the end-point as soon as the MSIs are
allocated.

A consequence of this is that we have an extra activate in irq_startup, but
that should be without much consequence.

tglx: 

 - Several people reported a VMWare regression with PCI/MSI-X passthrough. It
   turns out that the patch also cures that issue.

 - We need to have a look at the MSI disable interrupt path, where we write
   the msg to all zeros without disabling MSI in the PCI device. Is that
   correct?

Fixes: 52f518a3a7 "x86/MSI: Use hierarchical irqdomains to manage MSI interrupts"
Reported-and-tested-by: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
Reported-and-tested-by: Foster Snowhill <forst@forstwoof.ru>
Reported-by: Matthias Prager <linux@matthiasprager.de>
Reported-by: Jason Taylor <jason.taylor@simplivity.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1468426713-31431-1-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-08-09 09:19:32 +02:00

338 lines
11 KiB
C

#ifndef LINUX_MSI_H
#define LINUX_MSI_H
#include <linux/kobject.h>
#include <linux/list.h>
struct msi_msg {
u32 address_lo; /* low 32 bits of msi message address */
u32 address_hi; /* high 32 bits of msi message address */
u32 data; /* 16 bits of msi message data */
};
extern int pci_msi_ignore_mask;
/* Helper functions */
struct irq_data;
struct msi_desc;
struct pci_dev;
struct platform_msi_priv_data;
void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg);
void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg);
typedef void (*irq_write_msi_msg_t)(struct msi_desc *desc,
struct msi_msg *msg);
/**
* platform_msi_desc - Platform device specific msi descriptor data
* @msi_priv_data: Pointer to platform private data
* @msi_index: The index of the MSI descriptor for multi MSI
*/
struct platform_msi_desc {
struct platform_msi_priv_data *msi_priv_data;
u16 msi_index;
};
/**
* fsl_mc_msi_desc - FSL-MC device specific msi descriptor data
* @msi_index: The index of the MSI descriptor
*/
struct fsl_mc_msi_desc {
u16 msi_index;
};
/**
* struct msi_desc - Descriptor structure for MSI based interrupts
* @list: List head for management
* @irq: The base interrupt number
* @nvec_used: The number of vectors used
* @dev: Pointer to the device which uses this descriptor
* @msg: The last set MSI message cached for reuse
* @affinity: Optional pointer to a cpu affinity mask for this descriptor
*
* @masked: [PCI MSI/X] Mask bits
* @is_msix: [PCI MSI/X] True if MSI-X
* @multiple: [PCI MSI/X] log2 num of messages allocated
* @multi_cap: [PCI MSI/X] log2 num of messages supported
* @maskbit: [PCI MSI/X] Mask-Pending bit supported?
* @is_64: [PCI MSI/X] Address size: 0=32bit 1=64bit
* @entry_nr: [PCI MSI/X] Entry which is described by this descriptor
* @default_irq:[PCI MSI/X] The default pre-assigned non-MSI irq
* @mask_pos: [PCI MSI] Mask register position
* @mask_base: [PCI MSI-X] Mask register base address
* @platform: [platform] Platform device specific msi descriptor data
*/
struct msi_desc {
/* Shared device/bus type independent data */
struct list_head list;
unsigned int irq;
unsigned int nvec_used;
struct device *dev;
struct msi_msg msg;
const struct cpumask *affinity;
union {
/* PCI MSI/X specific data */
struct {
u32 masked;
struct {
__u8 is_msix : 1;
__u8 multiple : 3;
__u8 multi_cap : 3;
__u8 maskbit : 1;
__u8 is_64 : 1;
__u16 entry_nr;
unsigned default_irq;
} msi_attrib;
union {
u8 mask_pos;
void __iomem *mask_base;
};
};
/*
* Non PCI variants add their data structure here. New
* entries need to use a named structure. We want
* proper name spaces for this. The PCI part is
* anonymous for now as it would require an immediate
* tree wide cleanup.
*/
struct platform_msi_desc platform;
struct fsl_mc_msi_desc fsl_mc;
};
};
/* Helpers to hide struct msi_desc implementation details */
#define msi_desc_to_dev(desc) ((desc)->dev)
#define dev_to_msi_list(dev) (&(dev)->msi_list)
#define first_msi_entry(dev) \
list_first_entry(dev_to_msi_list((dev)), struct msi_desc, list)
#define for_each_msi_entry(desc, dev) \
list_for_each_entry((desc), dev_to_msi_list((dev)), list)
#ifdef CONFIG_PCI_MSI
#define first_pci_msi_entry(pdev) first_msi_entry(&(pdev)->dev)
#define for_each_pci_msi_entry(desc, pdev) \
for_each_msi_entry((desc), &(pdev)->dev)
struct pci_dev *msi_desc_to_pci_dev(struct msi_desc *desc);
void *msi_desc_to_pci_sysdata(struct msi_desc *desc);
#else /* CONFIG_PCI_MSI */
static inline void *msi_desc_to_pci_sysdata(struct msi_desc *desc)
{
return NULL;
}
#endif /* CONFIG_PCI_MSI */
struct msi_desc *alloc_msi_entry(struct device *dev);
void free_msi_entry(struct msi_desc *entry);
void __pci_read_msi_msg(struct msi_desc *entry, struct msi_msg *msg);
void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg);
void pci_write_msi_msg(unsigned int irq, struct msi_msg *msg);
u32 __pci_msix_desc_mask_irq(struct msi_desc *desc, u32 flag);
u32 __pci_msi_desc_mask_irq(struct msi_desc *desc, u32 mask, u32 flag);
void pci_msi_mask_irq(struct irq_data *data);
void pci_msi_unmask_irq(struct irq_data *data);
/* Conversion helpers. Should be removed after merging */
static inline void __write_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
{
__pci_write_msi_msg(entry, msg);
}
static inline void write_msi_msg(int irq, struct msi_msg *msg)
{
pci_write_msi_msg(irq, msg);
}
static inline void mask_msi_irq(struct irq_data *data)
{
pci_msi_mask_irq(data);
}
static inline void unmask_msi_irq(struct irq_data *data)
{
pci_msi_unmask_irq(data);
}
/*
* The arch hooks to setup up msi irqs. Those functions are
* implemented as weak symbols so that they /can/ be overriden by
* architecture specific code if needed.
*/
int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc);
void arch_teardown_msi_irq(unsigned int irq);
int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type);
void arch_teardown_msi_irqs(struct pci_dev *dev);
void arch_restore_msi_irqs(struct pci_dev *dev);
void default_teardown_msi_irqs(struct pci_dev *dev);
void default_restore_msi_irqs(struct pci_dev *dev);
struct msi_controller {
struct module *owner;
struct device *dev;
struct device_node *of_node;
struct list_head list;
int (*setup_irq)(struct msi_controller *chip, struct pci_dev *dev,
struct msi_desc *desc);
int (*setup_irqs)(struct msi_controller *chip, struct pci_dev *dev,
int nvec, int type);
void (*teardown_irq)(struct msi_controller *chip, unsigned int irq);
};
#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
#include <linux/irqhandler.h>
#include <asm/msi.h>
struct irq_domain;
struct irq_domain_ops;
struct irq_chip;
struct device_node;
struct fwnode_handle;
struct msi_domain_info;
/**
* struct msi_domain_ops - MSI interrupt domain callbacks
* @get_hwirq: Retrieve the resulting hw irq number
* @msi_init: Domain specific init function for MSI interrupts
* @msi_free: Domain specific function to free a MSI interrupts
* @msi_check: Callback for verification of the domain/info/dev data
* @msi_prepare: Prepare the allocation of the interrupts in the domain
* @msi_finish: Optional callback to finalize the allocation
* @set_desc: Set the msi descriptor for an interrupt
* @handle_error: Optional error handler if the allocation fails
*
* @get_hwirq, @msi_init and @msi_free are callbacks used by
* msi_create_irq_domain() and related interfaces
*
* @msi_check, @msi_prepare, @msi_finish, @set_desc and @handle_error
* are callbacks used by msi_domain_alloc_irqs() and related
* interfaces which are based on msi_desc.
*/
struct msi_domain_ops {
irq_hw_number_t (*get_hwirq)(struct msi_domain_info *info,
msi_alloc_info_t *arg);
int (*msi_init)(struct irq_domain *domain,
struct msi_domain_info *info,
unsigned int virq, irq_hw_number_t hwirq,
msi_alloc_info_t *arg);
void (*msi_free)(struct irq_domain *domain,
struct msi_domain_info *info,
unsigned int virq);
int (*msi_check)(struct irq_domain *domain,
struct msi_domain_info *info,
struct device *dev);
int (*msi_prepare)(struct irq_domain *domain,
struct device *dev, int nvec,
msi_alloc_info_t *arg);
void (*msi_finish)(msi_alloc_info_t *arg, int retval);
void (*set_desc)(msi_alloc_info_t *arg,
struct msi_desc *desc);
int (*handle_error)(struct irq_domain *domain,
struct msi_desc *desc, int error);
};
/**
* struct msi_domain_info - MSI interrupt domain data
* @flags: Flags to decribe features and capabilities
* @ops: The callback data structure
* @chip: Optional: associated interrupt chip
* @chip_data: Optional: associated interrupt chip data
* @handler: Optional: associated interrupt flow handler
* @handler_data: Optional: associated interrupt flow handler data
* @handler_name: Optional: associated interrupt flow handler name
* @data: Optional: domain specific data
*/
struct msi_domain_info {
u32 flags;
struct msi_domain_ops *ops;
struct irq_chip *chip;
void *chip_data;
irq_flow_handler_t handler;
void *handler_data;
const char *handler_name;
void *data;
};
/* Flags for msi_domain_info */
enum {
/*
* Init non implemented ops callbacks with default MSI domain
* callbacks.
*/
MSI_FLAG_USE_DEF_DOM_OPS = (1 << 0),
/*
* Init non implemented chip callbacks with default MSI chip
* callbacks.
*/
MSI_FLAG_USE_DEF_CHIP_OPS = (1 << 1),
/* Support multiple PCI MSI interrupts */
MSI_FLAG_MULTI_PCI_MSI = (1 << 2),
/* Support PCI MSIX interrupts */
MSI_FLAG_PCI_MSIX = (1 << 3),
/* Needs early activate, required for PCI */
MSI_FLAG_ACTIVATE_EARLY = (1 << 4),
};
int msi_domain_set_affinity(struct irq_data *data, const struct cpumask *mask,
bool force);
struct irq_domain *msi_create_irq_domain(struct fwnode_handle *fwnode,
struct msi_domain_info *info,
struct irq_domain *parent);
int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
int nvec);
void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev);
struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain);
struct irq_domain *platform_msi_create_irq_domain(struct fwnode_handle *fwnode,
struct msi_domain_info *info,
struct irq_domain *parent);
int platform_msi_domain_alloc_irqs(struct device *dev, unsigned int nvec,
irq_write_msi_msg_t write_msi_msg);
void platform_msi_domain_free_irqs(struct device *dev);
/* When an MSI domain is used as an intermediate domain */
int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev,
int nvec, msi_alloc_info_t *args);
int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev,
int virq, int nvec, msi_alloc_info_t *args);
struct irq_domain *
platform_msi_create_device_domain(struct device *dev,
unsigned int nvec,
irq_write_msi_msg_t write_msi_msg,
const struct irq_domain_ops *ops,
void *host_data);
int platform_msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
unsigned int nr_irqs);
void platform_msi_domain_free(struct irq_domain *domain, unsigned int virq,
unsigned int nvec);
void *platform_msi_get_host_data(struct irq_domain *domain);
#endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */
#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
void pci_msi_domain_write_msg(struct irq_data *irq_data, struct msi_msg *msg);
struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode,
struct msi_domain_info *info,
struct irq_domain *parent);
int pci_msi_domain_alloc_irqs(struct irq_domain *domain, struct pci_dev *dev,
int nvec, int type);
void pci_msi_domain_free_irqs(struct irq_domain *domain, struct pci_dev *dev);
struct irq_domain *pci_msi_create_default_irq_domain(struct fwnode_handle *fwnode,
struct msi_domain_info *info, struct irq_domain *parent);
irq_hw_number_t pci_msi_domain_calc_hwirq(struct pci_dev *dev,
struct msi_desc *desc);
int pci_msi_domain_check_cap(struct irq_domain *domain,
struct msi_domain_info *info, struct device *dev);
u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev);
struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev);
#else
static inline struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
{
return NULL;
}
#endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */
#endif /* LINUX_MSI_H */