mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
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30da552428
commit 2ca1af9aa3285c6a5f103ed31ad09f7399fc65d7 "PCI: MSI: Remove
unsafe and unnecessary hardware access" changed read_msi_msg_desc() to
return the last MSI message written instead of reading it from the
device, since it may be called while the device is in a reduced
power state.
However, the pSeries platform code really does need to read messages
from the device, since they are initially written by firmware.
Therefore:
- Restore the previous behaviour of read_msi_msg_desc()
- Add new functions get_cached_msi_msg{,_desc}() which return the
last MSI message written
- Use the new functions where appropriate
Acked-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
59 lines
1.8 KiB
C
59 lines
1.8 KiB
C
#ifndef LINUX_MSI_H
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#define LINUX_MSI_H
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#include <linux/list.h>
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struct msi_msg {
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u32 address_lo; /* low 32 bits of msi message address */
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u32 address_hi; /* high 32 bits of msi message address */
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u32 data; /* 16 bits of msi message data */
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};
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/* Helper functions */
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struct irq_desc;
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extern void mask_msi_irq(unsigned int irq);
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extern void unmask_msi_irq(unsigned int irq);
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extern void read_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg);
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extern void get_cached_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg);
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extern void write_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg);
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extern void read_msi_msg(unsigned int irq, struct msi_msg *msg);
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extern void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg);
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extern void write_msi_msg(unsigned int irq, struct msi_msg *msg);
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struct msi_desc {
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struct {
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__u8 is_msix : 1;
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__u8 multiple: 3; /* log2 number of messages */
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__u8 maskbit : 1; /* mask-pending bit supported ? */
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__u8 is_64 : 1; /* Address size: 0=32bit 1=64bit */
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__u8 pos; /* Location of the msi capability */
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__u16 entry_nr; /* specific enabled entry */
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unsigned default_irq; /* default pre-assigned irq */
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} msi_attrib;
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u32 masked; /* mask bits */
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unsigned int irq;
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struct list_head list;
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union {
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void __iomem *mask_base;
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u8 mask_pos;
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};
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struct pci_dev *dev;
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/* Last set MSI message */
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struct msi_msg msg;
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};
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/*
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* The arch hook for setup up msi irqs
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*/
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int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc);
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void arch_teardown_msi_irq(unsigned int irq);
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extern int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type);
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extern void arch_teardown_msi_irqs(struct pci_dev *dev);
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extern int arch_msi_check_device(struct pci_dev* dev, int nvec, int type);
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#endif /* LINUX_MSI_H */
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