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Add a way to map arm64 non-posted device memory

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On arm64 we currently use a non-posted write for device memory, however
we should move to use posted writes. This is expected to work on most
hardware, however we will need to support a non-posted option for some
broken hardware.

Reviewed by:	imp, manu, bcr (manpage)
Differential Revision:	https://reviews.freebsd.org/D29722
This commit is contained in:
Andrew Turner 2021-04-08 11:54:20 +00:00
parent a6ca7519f8
commit 2abd4f8581
5 changed files with 20 additions and 2 deletions
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7
share/man/man9/bus_space.9
View File

@ -52,7 +52,7 @@
.\"
.\" $FreeBSD$
.\"
.Dd July 7, 2020
.Dd May 1, 2021
.Dt BUS_SPACE 9
.Os
.Sh NAME
@ -876,6 +876,11 @@ call should fail.
If this
flag is not specified, the system may map the space in whatever way is
most convenient.
.It Dv BUS_SPACE_MAP_NONPOSTED
Try to map the space using non-posted device memory.
This is to support buses and devices where mapping with posted device
memory is unsupported or broken.
This flag is currently only available on arm64.
.El
.Pp
Not all combinations of flags make sense or are supported with all

6
sys/arm64/arm64/bus_machdep.c
View File

@ -99,9 +99,13 @@ static int
generic_bs_map(void *t, bus_addr_t bpa, bus_size_t size, int flags,
bus_space_handle_t *bshp)
{
vm_memattr_t ma;
void *va;
va = pmap_mapdev(bpa, size);
ma = VM_MEMATTR_DEVICE;
if (flags == BUS_SPACE_MAP_NONPOSTED)
ma = VM_MEMATTR_DEVICE_NP;
va = pmap_mapdev_attr(bpa, size, ma);
if (va == NULL)
return (ENOMEM);
*bshp = (bus_space_handle_t)va;

1
sys/arm64/include/bus.h
View File

@ -85,6 +85,7 @@
#define BUS_SPACE_MAP_CACHEABLE 0x01
#define BUS_SPACE_MAP_LINEAR 0x02
#define BUS_SPACE_MAP_PREFETCHABLE 0x04
#define BUS_SPACE_MAP_NONPOSTED 0x08
#define BUS_SPACE_UNRESTRICTED (~0)

5
sys/arm64/include/vm.h
View File

@ -36,7 +36,12 @@
#define VM_MEMATTR_WRITE_THROUGH 3
#define VM_MEMATTR_DEVICE_nGnRE 4
/*
* VM_MEMATTR_DEVICE can be changed to VM_MEMATTR_DEVICE_nGnRE when
* the PCI drivers use VM_MEMATTR_DEVICE_NP for their config space.
*/
#define VM_MEMATTR_DEVICE VM_MEMATTR_DEVICE_nGnRnE
#define VM_MEMATTR_DEVICE_NP VM_MEMATTR_DEVICE_nGnRnE
#ifdef _KERNEL
/* If defined vmstat will try to use both of these in a switch statement */

3
usr.bin/vmstat/vmstat.c
View File

@ -1570,6 +1570,9 @@ display_object(struct kinfo_vmobject *kvo)
#ifdef VM_MEMATTR_DEVICE
MEMATTR_STR(VM_MEMATTR_DEVICE, "DEV")
#endif
#ifdef VM_MEMATTR_DEVICE_NP
MEMATTR_STR(VM_MEMATTR_DEVICE, "NP")
#endif
#ifdef VM_MEMATTR_CACHEABLE
MEMATTR_STR(VM_MEMATTR_CACHEABLE, "C")
#endif