powerpc/fsl_msi: spread msi ints across different MSIRs

Allocate msis such that each time a new interrupt is requested,
the SRS (MSIR register select) to be used is allocated in a
round-robin fashion.
The end result is that the msi interrupts will be spread across
distinct MSIRs with the main benefit that now users can set
affinity to each msi int through the mpic irq backing up the
MSIR register.
This is achieved with the help of a newly introduced msi bitmap
api that allows specifying the starting point when searching
for a free msi interrupt.

Signed-off-by: Laurentiu Tudor <Laurentiu.Tudor@freescale.com>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/msi_bitmap.h b/arch/powerpc/include/asm/msi_bitmap.h
index 97ac3f46ae0d..96c2f9500574 100644
--- a/arch/powerpc/include/asm/msi_bitmap.h
+++ b/arch/powerpc/include/asm/msi_bitmap.h
@@ -25,6 +25,8 @@ int msi_bitmap_alloc_hwirqs(struct msi_bitmap *bmp, int num);
 void msi_bitmap_free_hwirqs(struct msi_bitmap *bmp, unsigned int offset,
                             unsigned int num);
 void msi_bitmap_reserve_hwirq(struct msi_bitmap *bmp, unsigned int hwirq);
+int msi_bitmap_alloc_hwirqs_from_offset(struct msi_bitmap *bmp, int offset,
+                                        int num);
 
 int msi_bitmap_reserve_dt_hwirqs(struct msi_bitmap *bmp);