linux/drivers/char
Jason A. Donenfeld d349ab99ee random: handle archrandom with multiple longs
The archrandom interface was originally designed for x86, which supplies
RDRAND/RDSEED for receiving random words into registers, resulting in
one function to generate an int and another to generate a long. However,
other architectures don't follow this.

On arm64, the SMCCC TRNG interface can return between one and three
longs. On s390, the CPACF TRNG interface can return arbitrary amounts,
with four longs having the same cost as one. On UML, the os_getrandom()
interface can return arbitrary amounts.

So change the api signature to take a "max_longs" parameter designating
the maximum number of longs requested, and then return the number of
longs generated.

Since callers need to check this return value and loop anyway, each arch
implementation does not bother implementing its own loop to try again to
fill the maximum number of longs. Additionally, all existing callers
pass in a constant max_longs parameter. Taken together, these two things
mean that the codegen doesn't really change much for one-word-at-a-time
platforms, while performance is greatly improved on platforms such as
s390.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-07-25 13:26:14 +02:00
..
agp x86/amd_nb: Unexport amd_cache_northbridges() 2022-04-05 19:22:27 +02:00
hw_random random: remove CONFIG_ARCH_RANDOM 2022-07-18 15:03:37 +02:00
ipmi ipmi:ipmb: Fix refcount leak in ipmi_ipmb_probe 2022-05-12 10:00:04 -05:00
mwave char/mwave: Adjust io port register size 2021-12-03 14:27:06 +01:00
pcmcia Char / Misc / Other smaller driver subsystem updates for 5.19-rc1 2022-06-03 11:36:34 -07:00
tpm tpmdd updates for v5.19-rc1 2022-05-24 13:16:50 -07:00
xilinx_hwicap xilinx_hwicap: cleanup comments 2022-02-25 12:08:57 +01:00
xillybus char: xillybus: fix a refcount leak in cleanup_dev() 2022-04-24 17:30:45 +02:00
adi.c
apm-emulation.c
applicom.c applicom: unneed to initialise statics to 0 2021-12-21 10:14:08 +01:00
applicom.h
bsr.c powerpc/BSR: Make use of the helper macro LIST_HEAD() 2022-02-25 12:10:15 +01:00
ds1620.c
dsp56k.c
dtlk.c
hangcheck-timer.c
hpet.c hpet: remove unused writeq/readq function definitions 2022-02-04 16:45:39 +01:00
Kconfig random: remove CONFIG_ARCH_RANDOM 2022-07-18 15:03:37 +02:00
lp.c char: lp: remove redundant initialization of err 2022-06-10 15:29:50 +02:00
Makefile remove the raw driver 2021-06-04 15:35:03 +02:00
mem.c /dev/mem: make reads and writes interruptible 2022-04-24 17:31:01 +02:00
misc.c char: misc: remove usage of list iterator past the loop body 2022-04-24 17:15:12 +02:00
mspec.c
nsc_gpio.c
nvram.c
nwbutton.c
nwbutton.h
nwflash.c
pc8736x_gpio.c
powernv-op-panel.c powerpc/powernv: Fix fall-through warning for Clang 2021-07-13 19:21:41 -05:00
ppdev.c
ps3flash.c
random.c random: handle archrandom with multiple longs 2022-07-25 13:26:14 +02:00
scx200_gpio.c
sonypi.c
tb0219.c
tlclk.c
toshiba.c module: remove never implemented MODULE_SUPPORTED_DEVICE 2021-03-17 13:16:18 -07:00
ttyprintk.c char: ttyprintk: register console 2022-04-22 16:24:47 +02:00
uv_mmtimer.c
virtio_console.c Char/Misc and other driver updates for 5.18-rc1 2022-03-28 12:27:35 -07:00