[PATCH 2/2] soc: fsl: qbman: fix unconditional WARN_ON() on Arm during fsl_qman_probe()
From: Vladimir Oltean
Date: Fri Jul 12 2024 - 05:57:49 EST
The blamed commit performed a lossy transformation of the original logic.
Due to it, on Arm DPAA1 platforms, we are now faced with this WARN on
each boot:
------------[ cut here ]------------
Unexpected architecture using non shared-dma-mem reservations
WARNING: CPU: 0 PID: 1 at drivers/soc/fsl/qbman/qman_ccsr.c:795 fsl_qman_probe+0x1d0/0x768
pc : fsl_qman_probe+0x1d0/0x768
lr : fsl_qman_probe+0x1b0/0x768
Call trace:
fsl_qman_probe+0x1d0/0x768
platform_probe+0xa8/0xd0
really_probe+0x128/0x2c8
Prior to the refactoring, the logic in fsl_qman_probe() was as follows:
if (fqd_a) { // previously found using RESERVEDMEM_OF_DECLARE("fsl,qman-fqd") [0]
#ifdef CONFIG_PPC
/*
* For PPC backward DT compatibility
* FQD memory MUST be zero'd by software
*/
zero_priv_mem(fqd_a, fqd_sz);
#else
WARN(1, "Unexpected architecture using non shared-dma-mem reservations");
#endif
} else {
// Find FQD using new-style device tree bindings [1]
ret = qbman_init_private_mem(dev, 0, &fqd_a, &fqd_sz);
}
After the refactoring, the search for the new-style and the old-style
got flipped, and both got absorbed into qbman_init_private_mem().
This creates a problem, because there is no longer a place to put the
"fqd_a != 0" branch within fsl_qman_probe(). The callee,
qbman_init_private_mem(), does not distinguish between FQD, PFDR and
FBPR, and zero_priv_mem() must execute only for FQD.
Split qbman_init_private_mem() into two different functions:
qbman_find_reserved_mem_by_idx() for new-style bindings, and
qbman_find_reserved_mem_by_compatible() for old-style.
Let callers explicitly call both, which permits fsl_qman_probe() to
zero-initialize the FQD memory on PowerPC if it matched on a compatible
string.
[0] Legacy bindings used by PowerPC:
/ {
reserved-memory {
qman_fqd: qman-fqd {
compatible = "fsl,qman-fqd";
alloc-ranges = <0 0 0x10000 0>;
size = <0 0x400000>;
alignment = <0 0x400000>;
};
};
};
[1] New bindings:
/ {
reserved-memory {
qman_fqd: qman-fqd {
compatible = "shared-dma-pool";
size = <0 0x800000>;
alignment = <0 0x800000>;
no-map;
};
qman_pfdr: qman-pfdr {
compatible = "shared-dma-pool";
size = <0 0x2000000>;
alignment = <0 0x2000000>;
no-map;
};
};
soc {
qman: qman@1880000 {
compatible = "fsl,qman";
reg = <0x0 0x1880000 0x0 0x10000>;
memory-region = <&qman_fqd &qman_pfdr>;
};
};
};
Fixes: 3e62273ac63a ("soc: fsl: qbman: Remove RESERVEDMEM_OF_DECLARE usage")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
---
drivers/soc/fsl/qbman/bman_ccsr.c | 11 ++++--
drivers/soc/fsl/qbman/dpaa_sys.c | 62 ++++++++++++++++++++++---------
drivers/soc/fsl/qbman/dpaa_sys.h | 7 ++--
drivers/soc/fsl/qbman/qman_ccsr.c | 40 +++++++++++++-------
4 files changed, 82 insertions(+), 38 deletions(-)
diff --git a/drivers/soc/fsl/qbman/bman_ccsr.c b/drivers/soc/fsl/qbman/bman_ccsr.c
index b0f26f6f731e..d8a440a265c5 100644
--- a/drivers/soc/fsl/qbman/bman_ccsr.c
+++ b/drivers/soc/fsl/qbman/bman_ccsr.c
@@ -231,11 +231,14 @@ static int fsl_bman_probe(struct platform_device *pdev)
return -ENODEV;
}
- ret = qbman_init_private_mem(dev, 0, "fsl,bman-fbpr", &fbpr_a, &fbpr_sz);
+ ret = qbman_find_reserved_mem_by_idx(dev, 0, &fbpr_a, &fbpr_sz);
+ if (ret)
+ ret = qbman_find_reserved_mem_by_compatible(dev, "fsl,bman-fbpr",
+ &fbpr_a, &fbpr_sz);
if (ret) {
- dev_err(dev, "qbman_init_private_mem() failed 0x%x\n",
- ret);
- return -ENODEV;
+ dev_err(dev, "Failed to find FBPR reserved-memory region: %pe\n",
+ ERR_PTR(ret));
+ return ret;
}
dev_dbg(dev, "Allocated FBPR 0x%llx 0x%zx\n", fbpr_a, fbpr_sz);
diff --git a/drivers/soc/fsl/qbman/dpaa_sys.c b/drivers/soc/fsl/qbman/dpaa_sys.c
index b1cee145cbd7..7c775c4c8a21 100644
--- a/drivers/soc/fsl/qbman/dpaa_sys.c
+++ b/drivers/soc/fsl/qbman/dpaa_sys.c
@@ -31,28 +31,14 @@
#include <linux/dma-mapping.h>
#include "dpaa_sys.h"
-/*
- * Initialize a devices private memory region
- */
-int qbman_init_private_mem(struct device *dev, int idx, const char *compat,
- dma_addr_t *addr, size_t *size)
+static int qbman_reserved_mem_lookup(struct device_node *mem_node,
+ dma_addr_t *addr, size_t *size)
{
- struct device_node *mem_node;
struct reserved_mem *rmem;
- mem_node = of_parse_phandle(dev->of_node, "memory-region", idx);
- if (!mem_node) {
- mem_node = of_find_compatible_node(NULL, NULL, compat);
- if (!mem_node) {
- dev_err(dev, "No memory-region found for index %d or compatible '%s'\n",
- idx, compat);
- return -ENODEV;
- }
- }
-
rmem = of_reserved_mem_lookup(mem_node);
if (!rmem) {
- dev_err(dev, "of_reserved_mem_lookup() returned NULL\n");
+ pr_err("of_reserved_mem_lookup(%pOF) returned NULL\n", mem_node);
return -ENODEV;
}
*addr = rmem->base;
@@ -60,3 +46,45 @@ int qbman_init_private_mem(struct device *dev, int idx, const char *compat,
return 0;
}
+
+/**
+ * qbman_find_reserved_mem_by_idx() - Find QBMan reserved-memory node
+ * @dev: Pointer to QMan or BMan device structure
+ * @idx: for BMan, pass 0 for the FBPR region.
+ * for QMan, pass 0 for the FQD region and 1 for the PFDR region.
+ * @addr: Pointer to storage for the region's base address.
+ * @size: Pointer to storage for the region's size.
+ */
+int qbman_find_reserved_mem_by_idx(struct device *dev, int idx,
+ dma_addr_t *addr, size_t *size)
+{
+ struct device_node *mem_node;
+
+ mem_node = of_parse_phandle(dev->of_node, "memory-region", idx);
+ if (!mem_node)
+ return -ENODEV;
+
+ return qbman_reserved_mem_lookup(mem_node, addr, size);
+}
+
+/**
+ * qbman_find_reserved_mem_by_compatible() - Find QBMan reserved-memory node (PowerPC)
+ * @dev: Pointer to QMan or BMan device structure
+ * @compat: one of "fsl,bman-fbpr", "fsl,qman-fqd" or "fsl,qman-pfdr"
+ * @addr: Pointer to storage for the region's base address.
+ * @size: Pointer to storage for the region's size.
+ *
+ * This is a legacy variant of qbman_find_reserved_mem_by_idx(), which should
+ * only be used for backwards compatibility with certain PowerPC device trees.
+ */
+int qbman_find_reserved_mem_by_compatible(struct device *dev, const char *compat,
+ dma_addr_t *addr, size_t *size)
+{
+ struct device_node *mem_node;
+
+ mem_node = of_find_compatible_node(NULL, NULL, compat);
+ if (!mem_node)
+ return -ENODEV;
+
+ return qbman_reserved_mem_lookup(mem_node, addr, size);
+}
diff --git a/drivers/soc/fsl/qbman/dpaa_sys.h b/drivers/soc/fsl/qbman/dpaa_sys.h
index 16485bde9636..1c80244b34d1 100644
--- a/drivers/soc/fsl/qbman/dpaa_sys.h
+++ b/drivers/soc/fsl/qbman/dpaa_sys.h
@@ -100,9 +100,10 @@ static inline u8 dpaa_cyc_diff(u8 ringsize, u8 first, u8 last)
/* Offset applied to genalloc pools due to zero being an error return */
#define DPAA_GENALLOC_OFF 0x80000000
-/* Initialize the devices private memory region */
-int qbman_init_private_mem(struct device *dev, int idx, const char *compat,
- dma_addr_t *addr, size_t *size);
+int qbman_find_reserved_mem_by_idx(struct device *dev, int idx,
+ dma_addr_t *addr, size_t *size);
+int qbman_find_reserved_mem_by_compatible(struct device *dev, const char *compat,
+ dma_addr_t *addr, size_t *size);
/* memremap() attributes for different platforms */
#ifdef CONFIG_PPC
diff --git a/drivers/soc/fsl/qbman/qman_ccsr.c b/drivers/soc/fsl/qbman/qman_ccsr.c
index 392e54f14dbe..4735b450d97e 100644
--- a/drivers/soc/fsl/qbman/qman_ccsr.c
+++ b/drivers/soc/fsl/qbman/qman_ccsr.c
@@ -731,6 +731,7 @@ static int fsl_qman_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *node = dev->of_node;
+ bool fqd_found_by_compatible = false;
struct resource *res;
int ret, err_irq;
u16 id;
@@ -779,29 +780,40 @@ static int fsl_qman_probe(struct platform_device *pdev)
* in order to ensure allocations from the correct regions the
* driver initializes then allocates each piece in order
*/
- ret = qbman_init_private_mem(dev, 0, "fsl,qman-fqd", &fqd_a, &fqd_sz);
+ ret = qbman_find_reserved_mem_by_idx(dev, 0, &fqd_a, &fqd_sz);
if (ret) {
- dev_err(dev, "qbman_init_private_mem() for FQD failed 0x%x\n",
- ret);
- return -ENODEV;
+ ret = qbman_find_reserved_mem_by_compatible(dev, "fsl,qman-fqd",
+ &fqd_a, &fqd_sz);
+ if (ret == 0)
+ fqd_found_by_compatible = true;
}
+ if (ret) {
+ dev_err(dev, "Failed to find FQD reserved-memory region: %pe\n",
+ ERR_PTR(ret));
+ return ret;
+ }
+ if (fqd_found_by_compatible) {
#ifdef CONFIG_PPC
- /*
- * For PPC backward DT compatibility
- * FQD memory MUST be zero'd by software
- */
- zero_priv_mem(fqd_a, fqd_sz);
+ /*
+ * For PPC backward DT compatibility
+ * FQD memory MUST be zero'd by software
+ */
+ zero_priv_mem(fqd_a, fqd_sz);
#else
- WARN(1, "Unexpected architecture using non shared-dma-mem reservations");
+ WARN(1, "Unexpected architecture using non shared-dma-mem reservations");
#endif
+ }
dev_dbg(dev, "Allocated FQD 0x%llx 0x%zx\n", fqd_a, fqd_sz);
/* Setup PFDR memory */
- ret = qbman_init_private_mem(dev, 1, "fsl,qman-pfdr", &pfdr_a, &pfdr_sz);
+ ret = qbman_find_reserved_mem_by_idx(dev, 1, &pfdr_a, &pfdr_sz);
+ if (ret)
+ ret = qbman_find_reserved_mem_by_compatible(dev, "fsl,qman-pfdr",
+ &pfdr_a, &pfdr_sz);
if (ret) {
- dev_err(dev, "qbman_init_private_mem() for PFDR failed 0x%x\n",
- ret);
- return -ENODEV;
+ dev_err(dev, "Failed to find PFDR reserved-memory region: %pe\n",
+ ERR_PTR(ret));
+ return ret;
}
dev_dbg(dev, "Allocated PFDR 0x%llx 0x%zx\n", pfdr_a, pfdr_sz);
--
2.34.1