freebsd-dev/sys/arm64
Hans Petter Selasky 65b017b420 Avoid use of contiguous memory allocations in busdma when possible.
This patch improves the boundary checks in busdma to allow more cases
using the regular page based kernel memory allocator. Especially in
the case of having a non-zero boundary in the parent DMA tag. For
example AMD64 based platforms set the PCI DMA tag boundary to
PCI_DMA_BOUNDARY, 4GB, which before this patch caused contiguous
memory allocations to be preferred when allocating more than PAGE_SIZE
bytes. Even if the required alignment was less than PAGE_SIZE bytes.

This patch also fixes the nsegments check for using kmem_alloc_attr()
when the maximum segment size is less than PAGE_SIZE bytes.

Updated some comments describing the code in question.

Differential Revision:	https://reviews.freebsd.org/D10645
Reviewed by:		kib, jhb, gallatin, scottl
MFC after:		1 week
Sponsored by:		Mellanox Technologies
2017-05-16 14:21:37 +00:00
..
acpica Add support to find the arm64 serial using the ACPI tables. This uses the 2016-11-21 19:26:58 +00:00
arm64 Avoid use of contiguous memory allocations in busdma when possible. 2017-05-16 14:21:37 +00:00
cavium If ofw_bus_msimap fails don't try to use the invalid MSI/MSI-X parent node. 2017-03-16 17:49:37 +00:00
cloudabi64 Stop providing the compat_3_brand. 2017-03-23 14:12:21 +00:00
conf Add 'device iic' to bring in userland I2C driver. 2017-03-24 22:33:03 +00:00
include Allocate a cacheline when reading or writing to write through memory. The 2017-05-13 13:03:20 +00:00