[PATCH AUTOSEL 6.9 29/44] of/irq: Factor out parsing of interrupt-map parent phandle+args from of_irq_parse_raw()

Sasha Levin
2024-06-18T12:37:25Z

From: "Rob Herring (Arm)" <robh@kernel.org>

[ Upstream commit 935df1bd40d43c4ee91838c42a20e9af751885cc ]

Factor out the parsing of interrupt-map interrupt parent phandle and its
arg cells to a separate function, of_irq_parse_imap_parent(), so that it
can be used in other parsing scenarios (e.g. fw_devlink).

There was a refcount leak on non-matching entries when iterating thru
"interrupt-map" which is fixed.

Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Anup Patel <apatel@ventanamicro.com>
Link: https://lore.kernel.org/r/20240529-dt-interrupt-map-fix-v2-1-ef86dc5bcd2a@kernel.org
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/of/irq.c | 125 ++++++++++++++++++++++++----------------
drivers/of/of_private.h | 3 +
2 files changed, 77 insertions(+), 51 deletions(-)

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 174900072c18c..462375b293e47 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -25,6 +25,8 @@
#include <linux/string.h>
#include <linux/slab.h>

+#include "of_private.h"
+
/**
* irq_of_parse_and_map - Parse and map an interrupt into linux virq space
* @dev: Device node of the device whose interrupt is to be mapped
@@ -96,6 +98,57 @@ static const char * const of_irq_imap_abusers[] = {
NULL,
};

+const __be32 *of_irq_parse_imap_parent(const __be32 *imap, int len, struct of_phandle_args *out_irq)
+{
+ u32 intsize, addrsize;
+ struct device_node *np;
+
+ /* Get the interrupt parent */
+ if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
+ np = of_node_get(of_irq_dflt_pic);
+ else
+ np = of_find_node_by_phandle(be32_to_cpup(imap));
+ imap++;
+
+ /* Check if not found */
+ if (!np) {
+ pr_debug(" -> imap parent not found !\n");
+ return NULL;
+ }
+
+ /* Get #interrupt-cells and #address-cells of new parent */
+ if (of_property_read_u32(np, "#interrupt-cells",
+ &intsize)) {
+ pr_debug(" -> parent lacks #interrupt-cells!\n");
+ of_node_put(np);
+ return NULL;
+ }
+ if (of_property_read_u32(np, "#address-cells",
+ &addrsize))
+ addrsize = 0;
+
+ pr_debug(" -> intsize=%d, addrsize=%d\n",
+ intsize, addrsize);
+
+ /* Check for malformed properties */
+ if (WARN_ON(addrsize + intsize > MAX_PHANDLE_ARGS)
+ || (len < (addrsize + intsize))) {
+ of_node_put(np);
+ return NULL;
+ }
+
+ pr_debug(" -> imaplen=%d\n", len);
+
+ imap += addrsize + intsize;
+
+ out_irq->np = np;
+ for (int i = 0; i < intsize; i++)
+ out_irq->args[i] = be32_to_cpup(imap - intsize + i);
+ out_irq->args_count = intsize;
+
+ return imap;
+}
+
/**
* of_irq_parse_raw - Low level interrupt tree parsing
* @addr: address specifier (start of "reg" property of the device) in be32 format
@@ -112,12 +165,12 @@ static const char * const of_irq_imap_abusers[] = {
*/
int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
{
- struct device_node *ipar, *tnode, *old = NULL, *newpar = NULL;
+ struct device_node *ipar, *tnode, *old = NULL;
__be32 initial_match_array[MAX_PHANDLE_ARGS];
const __be32 *match_array = initial_match_array;
- const __be32 *tmp, *imap, *imask, dummy_imask[] = { [0 ... MAX_PHANDLE_ARGS] = cpu_to_be32(~0) };
- u32 intsize = 1, addrsize, newintsize = 0, newaddrsize = 0;
- int imaplen, match, i, rc = -EINVAL;
+ const __be32 *tmp, dummy_imask[] = { [0 ... MAX_PHANDLE_ARGS] = cpu_to_be32(~0) };
+ u32 intsize = 1, addrsize;
+ int i, rc = -EINVAL;

#ifdef DEBUG
of_print_phandle_args("of_irq_parse_raw: ", out_irq);
@@ -176,6 +229,9 @@ int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)

/* Now start the actual "proper" walk of the interrupt tree */
while (ipar != NULL) {
+ int imaplen, match;
+ const __be32 *imap, *oldimap, *imask;
+ struct device_node *newpar;
/*
* Now check if cursor is an interrupt-controller and
* if it is then we are done, unless there is an
@@ -216,7 +272,7 @@ int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)

/* Parse interrupt-map */
match = 0;
- while (imaplen > (addrsize + intsize + 1) && !match) {
+ while (imaplen > (addrsize + intsize + 1)) {
/* Compare specifiers */
match = 1;
for (i = 0; i < (addrsize + intsize); i++, imaplen--)
@@ -224,48 +280,17 @@ int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)

pr_debug(" -> match=%d (imaplen=%d)\n", match, imaplen);

- /* Get the interrupt parent */
- if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
- newpar = of_node_get(of_irq_dflt_pic);
- else
- newpar = of_find_node_by_phandle(be32_to_cpup(imap));
- imap++;
- --imaplen;
-
- /* Check if not found */
- if (newpar == NULL) {
- pr_debug(" -> imap parent not found !\n");
- goto fail;
- }
-
- if (!of_device_is_available(newpar))
- match = 0;
-
- /* Get #interrupt-cells and #address-cells of new
- * parent
- */
- if (of_property_read_u32(newpar, "#interrupt-cells",
- &newintsize)) {
- pr_debug(" -> parent lacks #interrupt-cells!\n");
- goto fail;
- }
- if (of_property_read_u32(newpar, "#address-cells",
- &newaddrsize))
- newaddrsize = 0;
-
- pr_debug(" -> newintsize=%d, newaddrsize=%d\n",
- newintsize, newaddrsize);
-
- /* Check for malformed properties */
- if (WARN_ON(newaddrsize + newintsize > MAX_PHANDLE_ARGS)
- || (imaplen < (newaddrsize + newintsize))) {
- rc = -EFAULT;
+ oldimap = imap;
+ imap = of_irq_parse_imap_parent(oldimap, imaplen, out_irq);
+ if (!imap)
goto fail;
- }

- imap += newaddrsize + newintsize;
- imaplen -= newaddrsize + newintsize;
+ match &= of_device_is_available(out_irq->np);
+ if (match)
+ break;

+ of_node_put(out_irq->np);
+ imaplen -= imap - oldimap;
pr_debug(" -> imaplen=%d\n", imaplen);
}
if (!match) {
@@ -287,11 +312,11 @@ int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
* Successfully parsed an interrupt-map translation; copy new
* interrupt specifier into the out_irq structure
*/
- match_array = imap - newaddrsize - newintsize;
- for (i = 0; i < newintsize; i++)
- out_irq->args[i] = be32_to_cpup(imap - newintsize + i);
- out_irq->args_count = intsize = newintsize;
- addrsize = newaddrsize;
+ match_array = oldimap + 1;
+
+ newpar = out_irq->np;
+ intsize = out_irq->args_count;
+ addrsize = (imap - match_array) - intsize;

if (ipar == newpar) {
pr_debug("%pOF interrupt-map entry to self\n", ipar);
@@ -300,7 +325,6 @@ int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)

skiplevel:
/* Iterate again with new parent */
- out_irq->np = newpar;
pr_debug(" -> new parent: %pOF\n", newpar);
of_node_put(ipar);
ipar = newpar;
@@ -310,7 +334,6 @@ int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)

fail:
of_node_put(ipar);
- of_node_put(newpar);

return rc;
}
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index 485483524b7f1..b0609de49c7c4 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -158,6 +158,9 @@ extern void __of_sysfs_remove_bin_file(struct device_node *np,
extern int of_bus_n_addr_cells(struct device_node *np);
extern int of_bus_n_size_cells(struct device_node *np);

+const __be32 *of_irq_parse_imap_parent(const __be32 *imap, int len,
+ struct of_phandle_args *out_irq);
+
struct bus_dma_region;
#if defined(CONFIG_OF_ADDRESS) && defined(CONFIG_HAS_DMA)
int of_dma_get_range(struct device_node *np,
--
2.43.0