path: root/sys/sys/_types.h
diff options
authorJustin Hibbits <jhibbits@FreeBSD.org>2016-03-18 01:28:41 +0000
committerJustin Hibbits <jhibbits@FreeBSD.org>2016-03-18 01:28:41 +0000
commitda1b038af9f9551a0b2f33d312b4eede00aa1542 (patch)
tree79d2db0783ae236486e47ff49d1e85214325a9e0 /sys/sys/_types.h
parent7b54043f1718af1af1549296b25d0803f72799cf (diff)
Use uintmax_t (typedef'd to rman_res_t type) for rman ranges.
On some architectures, u_long isn't large enough for resource definitions. Particularly, powerpc and arm allow 36-bit (or larger) physical addresses, but type `long' is only 32-bit. This extends rman's resources to uintmax_t. With this change, any resource can feasibly be placed anywhere in physical memory (within the constraints of the driver). Why uintmax_t and not something machine dependent, or uint64_t? Though it's possible for uintmax_t to grow, it's highly unlikely it will become 128-bit on 32-bit architectures. 64-bit architectures should have plenty of RAM to absorb the increase on resource sizes if and when this occurs, and the number of resources on memory-constrained systems should be sufficiently small as to not pose a drastic overhead. That being said, uintmax_t was chosen for source clarity. If it's specified as uint64_t, all printf()-like calls would either need casts to uintmax_t, or be littered with PRI*64 macros. Casts to uintmax_t aren't horrible, but it would also bake into the API for resource_list_print_type() either a hidden assumption that entries get cast to uintmax_t for printing, or these calls would need the PRI*64 macros. Since source code is meant to be read more often than written, I chose the clearest path of simply using uintmax_t. Tested on a PowerPC p5020-based board, which places all device resources in 0xfxxxxxxxx, and has 8GB RAM. Regression tested on qemu-system-i386 Regression tested on qemu-system-mips (malta profile) Tested PAE and devinfo on virtualbox (live CD) Special thanks to bz for his testing on ARM. Reviewed By: bz, jhb (previous) Relnotes: Yes Sponsored by: Alex Perez/Inertial Computing Differential Revision: https://reviews.freebsd.org/D4544
Notes: svn path=/head/; revision=297000
Diffstat (limited to 'sys/sys/_types.h')
1 files changed, 1 insertions, 1 deletions
diff --git a/sys/sys/_types.h b/sys/sys/_types.h
index 3b3c16d3684e..16039a6da16b 100644
--- a/sys/sys/_types.h
+++ b/sys/sys/_types.h
@@ -112,6 +112,6 @@ typedef union {
__int64_t _mbstateL; /* for alignment */
} __mbstate_t;
-typedef unsigned long __rman_res_t;
+typedef __uintmax_t __rman_res_t;
#endif /* !_SYS__TYPES_H_ */