From ca53350a71858c7b363e5536227753d5cb485d50 Mon Sep 17 00:00:00 2001
From: Simon Shields <simon.shields@data61.csiro.au>
Date: Thu, 14 Feb 2019 15:42:13 +1100
Subject: [PATCH] hardware_gen: Add support for /reserved-memory node
Parse the /reserved-memory node per the Linux spec[1].
Ignore regions marked as 'no-map', but keep other regions
as they should be OK to use as RAM.
[1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt?h=v5.0-rc6
---
tools/hardware_gen.py | 28 +++++++++++++++++++++++++++-
1 file changed, 27 insertions(+), 1 deletion(-)
diff --git a/tools/hardware_gen.py b/tools/hardware_gen.py
index 6eaa5ece9..328df00db 100755
--- a/tools/hardware_gen.py
+++ b/tools/hardware_gen.py
@@ -614,12 +614,33 @@ def should_parse_regions(root, node):
except ValueError:
return False
+def parse_reserved_memory(node, devices, cfg, by_phandle):
+ regions = []
+ for child in node.walk():
+ name = child[0]
+ child = child[1]
+ if not isinstance(child, pyfdt.pyfdt.FdtNode):
+ continue
+
+ dev = devices[child.path]
+ # reserved memory regions overlap with physical RAM.
+ # never expose them to userspace (even if they are mappable)
+ del devices[child.path]
+
+ if 'reg' in dev and 'no-map' in dev:
+ reg, _ = dev.regions(cfg, by_phandle)
+ for r in reg:
+ regions.append({'address': r.start, 'size': r.size})
+
+ return regions
+
def find_devices(dtb, cfg):
devices = {}
nodes = {}
by_phandle = {}
chosen = None
aliases = None
+ reserved_memory = []
root = dtb.get_rootnode()
root.path = '/'
devices[root.name] = Device(root, None, '/')
@@ -860,6 +881,11 @@ def main(args):
memory, user, kernel = set(), set(), set()
fdt = pyfdt.pyfdt.FdtBlobParse(args.dtb).to_fdt()
devices, by_phandle = find_devices(fdt, cfg)
+
+ rsvmem = []
+ if '/reserved-memory' in devices:
+ rsvmem = parse_reserved_memory(devices['/reserved-memory'].node, devices, cfg, by_phandle)
+ rsvmem += fdt.reserve_entries
kernel_irqs = set()
for d in devices.values():
kernel_irqs.update(d.get_interrupts(cfg, by_phandle))
@@ -867,7 +893,7 @@ def main(args):
m, _ = d.regions(cfg, by_phandle) # second set is always empty for memory
res = set()
for e in m:
- res.update(set(e.remove_subregions(fdt.reserve_entries)))
+ res.update(set(e.remove_subregions(rsvmem)))
memory.update(res)
else:
(u, k) = d.regions(cfg, by_phandle)
--
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