linux/include/asm-generic/msi.h
Marc Zyngier 91f90daa4f platform-msi: Track shared domain allocation
We have two flavours of platform-MSI:

- MSIs generated by devices for themselves (the usual case)

- MSIs generated on behalf of other devices, as the generating
  device is some form of bridge (either a wire-to-MSI bridge,
  or even a non-transparent PCI bridge that repaints the PCI
  requester ID).

In the latter case, the underlying interrupt architecture may need
to track this in order to keep the mapping alive even when no MSI
are currently being generated.

Add a set of flags to the generic msi_alloc_info_t structure, as
well as the MSI_ALLOC_FLAGS_PROXY_DEVICE flag that will get
advertized by the platform-MSI code when allocating an irqdomain
for a device.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/20201129135208.680293-2-maz@kernel.org
2020-12-11 14:47:50 +00:00

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C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_GENERIC_MSI_H
#define __ASM_GENERIC_MSI_H
#include <linux/types.h>
#ifndef NUM_MSI_ALLOC_SCRATCHPAD_REGS
# define NUM_MSI_ALLOC_SCRATCHPAD_REGS 2
#endif
struct msi_desc;
/**
* struct msi_alloc_info - Default structure for MSI interrupt allocation.
* @desc: Pointer to msi descriptor
* @hwirq: Associated hw interrupt number in the domain
* @scratchpad: Storage for implementation specific scratch data
*
* Architectures can provide their own implementation by not including
* asm-generic/msi.h into their arch specific header file.
*/
typedef struct msi_alloc_info {
struct msi_desc *desc;
irq_hw_number_t hwirq;
unsigned long flags;
union {
unsigned long ul;
void *ptr;
} scratchpad[NUM_MSI_ALLOC_SCRATCHPAD_REGS];
} msi_alloc_info_t;
/* Device generating MSIs is proxying for another device */
#define MSI_ALLOC_FLAGS_PROXY_DEVICE (1UL << 0)
#define GENERIC_MSI_DOMAIN_OPS 1
#endif