RPi4's memreserve use in fdt not handled by aarch64 fdt_get_reserved_mem (called via its initarm)
Mark Millard
marklmi at yahoo.com
Mon Feb 10 05:12:25 UTC 2020
aarch64 seems to be ignoring the RPi4B's memreserve use.
My hypothesis is that head -r356776 and later are
allocating RAM areas that overlap with the
memreserve area.
1st see separate submittals about the live dts text reported
by fdt print in u-boot on the example RPi4B 4 GiByte machine:
https://lists.freebsd.org/pipermail/freebsd-arm/2020-February/021207.html
https://lists.freebsd.org/pipermail/freebsd-arm/2020-February/021205.html
Then:
aarch64's initarm uses fdt_get_reserved_mem and not
fdt_get_reserved_regions. So, looking at what that
implies:
int
fdt_get_reserved_mem(struct mem_region *reserved, int *mreserved)
{
pcell_t reg[FDT_REG_CELLS];
phandle_t child, root;
int addr_cells, size_cells;
int i, rv;
root = OF_finddevice("/reserved-memory");
if (root == -1) {
return (ENXIO);
}
. . . (I'll not list it all to show the lack of
memreserve handling) . . .
This does not check for and handle memreserve.
By contrast armv7 and armv6 each have an initarm
that uses fdt_get_reserved_regions and that in
turn has:
int
fdt_get_reserved_regions(struct mem_region *mr, int *mrcnt)
{
pcell_t reserve[FDT_REG_CELLS * FDT_MEM_REGIONS];
pcell_t *reservep;
phandle_t memory, root;
int addr_cells, size_cells;
int i, res_len, rv, tuple_size, tuples;
root = OF_finddevice("/");
memory = OF_finddevice("/memory");
if (memory == -1) {
rv = ENXIO;
goto out;
}
if ((rv = fdt_addrsize_cells(OF_parent(memory), &addr_cells,
&size_cells)) != 0)
goto out;
if (addr_cells > 2) {
rv = ERANGE;
goto out;
}
tuple_size = sizeof(pcell_t) * (addr_cells + size_cells);
res_len = OF_getproplen(root, "memreserve");
if (res_len <= 0 || res_len > sizeof(reserve)) {
rv = ERANGE;
goto out;
}
if (OF_getprop(root, "memreserve", reserve, res_len) <= 0) {
rv = ENXIO;
goto out;
}
. . .
So this handles memreserve but not /reserved-memory .
It appears that for the RPi4B's the 32-bit "normal use"
has lead to aarch64 having memreserve instead of
/reserved-memory .
===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)
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