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powerpc/kexec_file: fix cpus node update to FDT

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While updating the cpus node, commit 40c753993e3a ("powerpc/kexec_file:
 Use current CPU info while setting up FDT") first deletes all subnodes
under the /cpus node. However, while adding sub-nodes back, it missed
adding cpus subnodes whose device_type != "cpu", such as l2-cache*,
l3-cache*, ibm,powerpc-cpu-features.

Fix this by only deleting cpus sub-nodes of device_type == "cpus" and
then adding all available nodes with device_type == "cpu".

Fixes: 40c753993e3a ("powerpc/kexec_file: Use current CPU info while setting up FDT")
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240510102235.2269496-3-sourabhjain@linux.ibm.com
This commit is contained in:
Sourabh Jain 2024-05-10 15:52:35 +05:30 committed by Michael Ellerman
parent 0d3ff06733
commit 932bed4121
1 changed files with 38 additions and 17 deletions
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55
arch/powerpc/kexec/core_64.c
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@ -456,9 +456,15 @@ static int add_node_props(void *fdt, int node_offset, const struct device_node *
* @fdt: Flattened device tree of the kernel.
*
* Returns 0 on success, negative errno on error.
*
* Note: expecting no subnodes under /cpus/<node> with device_type == "cpu".
* If this changes, update this function to include them.
*/
int update_cpus_node(void *fdt)
{
int prev_node_offset;
const char *device_type;
const struct fdt_property *prop;
struct device_node *cpus_node, *dn;
int cpus_offset, cpus_subnode_offset, ret = 0;
@ -469,30 +475,44 @@ int update_cpus_node(void *fdt)
return cpus_offset;
}
if (cpus_offset > 0) {
ret = fdt_del_node(fdt, cpus_offset);
if (ret < 0) {
pr_err("Error deleting /cpus node: %s\n", fdt_strerror(ret));
return -EINVAL;
prev_node_offset = cpus_offset;
/* Delete sub-nodes of /cpus node with device_type == "cpu" */
for (cpus_subnode_offset = fdt_first_subnode(fdt, cpus_offset); cpus_subnode_offset >= 0;) {
/* Ignore nodes that do not have a device_type property or device_type != "cpu" */
prop = fdt_get_property(fdt, cpus_subnode_offset, "device_type", NULL);
if (!prop || strcmp(prop->data, "cpu")) {
prev_node_offset = cpus_subnode_offset;
goto next_node;
}
ret = fdt_del_node(fdt, cpus_subnode_offset);
if (ret < 0) {
pr_err("Failed to delete a cpus sub-node: %s\n", fdt_strerror(ret));
return ret;
}
next_node:
if (prev_node_offset == cpus_offset)
cpus_subnode_offset = fdt_first_subnode(fdt, cpus_offset);
else
cpus_subnode_offset = fdt_next_subnode(fdt, prev_node_offset);
}
/* Add cpus node to fdt */
cpus_offset = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"), "cpus");
if (cpus_offset < 0) {
pr_err("Error creating /cpus node: %s\n", fdt_strerror(cpus_offset));
cpus_node = of_find_node_by_path("/cpus");
/* Fail here to avoid kexec/kdump kernel boot hung */
if (!cpus_node) {
pr_err("No /cpus node found\n");
return -EINVAL;
}
/* Add cpus node properties */
cpus_node = of_find_node_by_path("/cpus");
ret = add_node_props(fdt, cpus_offset, cpus_node);
of_node_put(cpus_node);
if (ret < 0)
return ret;
/* Add all /cpus sub-nodes of device_type == "cpu" to FDT */
for_each_child_of_node(cpus_node, dn) {
/* Ignore device nodes that do not have a device_type property
* or device_type != "cpu".
*/
device_type = of_get_property(dn, "device_type", NULL);
if (!device_type || strcmp(device_type, "cpu"))
continue;
/* Loop through all subnodes of cpus and add them to fdt */
for_each_node_by_type(dn, "cpu") {
cpus_subnode_offset = fdt_add_subnode(fdt, cpus_offset, dn->full_name);
if (cpus_subnode_offset < 0) {
pr_err("Unable to add %s subnode: %s\n", dn->full_name,
@ -506,6 +526,7 @@ int update_cpus_node(void *fdt)
goto out;
}
out:
of_node_put(cpus_node);
of_node_put(dn);
return ret;
}