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c5e76fa05b
The expectation is that when calling of_read_drc_info_cell()
repeatedly to parse multiple drc-info records that the in/out curval
parameter points at the start of the next record on return. However,
the current behavior has curval still pointing at the final value of
the record just parsed. The result of which is that if the
ibm,drc-info property contains multiple properties the parsed value
of the drc_type for any record after the first has the power_domain
value of the previous record appended to the type string.
eg: observed the following 0xffffffff prepended to PHB
drc-info: type: \xff\xff\xff\xffPHB, prefix: PHB , index_start: 0x20000001
drc-info: suffix_start: 1, sequential_elems: 3072, sequential_inc: 1
drc-info: power-domain: 0xffffffff, last_index: 0x20000c00
In practice PHBs are the only type of connector in the ibm,drc-info
property that has multiple records. So, it breaks PHB hotplug, but by
chance not PCI, CPU, slot, or memory because they happen to only ever
be a single record.
Fix by incrementing curval past the power_domain value to point at
drc_type string of next record.
Fixes: e83636ac33 ("pseries/drc-info: Search DRC properties for CPU indexes")
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Acked-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200307024547.5748-1-tyreld@linux.ibm.com
97 lines
2.4 KiB
C
97 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/string.h>
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#include <linux/err.h>
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#include <linux/slab.h>
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#include <linux/of.h>
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#include <asm/prom.h>
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#include "of_helpers.h"
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/**
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* pseries_of_derive_parent - basically like dirname(1)
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* @path: the full_name of a node to be added to the tree
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*
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* Returns the node which should be the parent of the node
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* described by path. E.g., for path = "/foo/bar", returns
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* the node with full_name = "/foo".
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*/
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struct device_node *pseries_of_derive_parent(const char *path)
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{
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struct device_node *parent;
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char *parent_path = "/";
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const char *tail;
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/* We do not want the trailing '/' character */
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tail = kbasename(path) - 1;
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/* reject if path is "/" */
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if (!strcmp(path, "/"))
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return ERR_PTR(-EINVAL);
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if (tail > path) {
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parent_path = kstrndup(path, tail - path, GFP_KERNEL);
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if (!parent_path)
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return ERR_PTR(-ENOMEM);
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}
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parent = of_find_node_by_path(parent_path);
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if (strcmp(parent_path, "/"))
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kfree(parent_path);
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return parent ? parent : ERR_PTR(-EINVAL);
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}
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/* Helper Routines to convert between drc_index to cpu numbers */
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int of_read_drc_info_cell(struct property **prop, const __be32 **curval,
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struct of_drc_info *data)
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{
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const char *p = (char *)(*curval);
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const __be32 *p2;
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if (!data)
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return -EINVAL;
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/* Get drc-type:encode-string */
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data->drc_type = (char *)p;
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p = of_prop_next_string(*prop, p);
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if (!p)
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return -EINVAL;
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/* Get drc-name-prefix:encode-string */
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data->drc_name_prefix = (char *)p;
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p = of_prop_next_string(*prop, p);
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if (!p)
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return -EINVAL;
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/* Get drc-index-start:encode-int */
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p2 = (const __be32 *)p;
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data->drc_index_start = be32_to_cpu(*p2);
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/* Get drc-name-suffix-start:encode-int */
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p2 = of_prop_next_u32(*prop, p2, &data->drc_name_suffix_start);
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if (!p2)
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return -EINVAL;
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/* Get number-sequential-elements:encode-int */
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p2 = of_prop_next_u32(*prop, p2, &data->num_sequential_elems);
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if (!p2)
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return -EINVAL;
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/* Get sequential-increment:encode-int */
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p2 = of_prop_next_u32(*prop, p2, &data->sequential_inc);
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if (!p2)
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return -EINVAL;
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/* Get drc-power-domain:encode-int */
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p2 = of_prop_next_u32(*prop, p2, &data->drc_power_domain);
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if (!p2)
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return -EINVAL;
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/* Should now know end of current entry */
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(*curval) = (void *)(++p2);
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data->last_drc_index = data->drc_index_start +
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((data->num_sequential_elems - 1) * data->sequential_inc);
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return 0;
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}
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EXPORT_SYMBOL(of_read_drc_info_cell);
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