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Message-Id: <20200605140253.217864212@linuxfoundation.org>
Date: Fri, 5 Jun 2020 16:15:16 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Anju T Sudhakar <anju@...ux.vnet.ibm.com>,
Nageswara R Sastry <nasastry@...ibm.com>,
Michael Ellerman <mpe@...erman.id.au>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.19 14/28] powerpc/powernv: Avoid re-registration of imc debugfs directory
From: Anju T Sudhakar <anju@...ux.vnet.ibm.com>
[ Upstream commit 48e626ac85b43cc589dd1b3b8004f7f85f03544d ]
export_imc_mode_and_cmd() function which creates the debugfs interface
for imc-mode and imc-command, is invoked when each nest pmu units is
registered.
When the first nest pmu unit is registered, export_imc_mode_and_cmd()
creates 'imc' directory under `/debug/powerpc/`. In the subsequent
invocations debugfs_create_dir() function returns, since the directory
already exists.
The recent commit <c33d442328f55> (debugfs: make error message a bit
more verbose), throws a warning if we try to invoke
`debugfs_create_dir()` with an already existing directory name.
Address this warning by making the debugfs directory registration in
the opal_imc_counters_probe() function, i.e invoke
export_imc_mode_and_cmd() function from the probe function.
Signed-off-by: Anju T Sudhakar <anju@...ux.vnet.ibm.com>
Tested-by: Nageswara R Sastry <nasastry@...ibm.com>
Signed-off-by: Michael Ellerman <mpe@...erman.id.au>
Link: https://lore.kernel.org/r/20191127072035.4283-1-anju@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
arch/powerpc/platforms/powernv/opal-imc.c | 39 ++++++++++-------------
1 file changed, 16 insertions(+), 23 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/opal-imc.c b/arch/powerpc/platforms/powernv/opal-imc.c
index 649fb268f446..5399682797d0 100644
--- a/arch/powerpc/platforms/powernv/opal-imc.c
+++ b/arch/powerpc/platforms/powernv/opal-imc.c
@@ -63,10 +63,6 @@ static void export_imc_mode_and_cmd(struct device_node *node,
imc_debugfs_parent = debugfs_create_dir("imc", powerpc_debugfs_root);
- /*
- * Return here, either because 'imc' directory already exists,
- * Or failed to create a new one.
- */
if (!imc_debugfs_parent)
return;
@@ -139,7 +135,6 @@ static int imc_get_mem_addr_nest(struct device_node *node,
}
pmu_ptr->imc_counter_mmaped = true;
- export_imc_mode_and_cmd(node, pmu_ptr);
kfree(base_addr_arr);
kfree(chipid_arr);
return 0;
@@ -155,7 +150,7 @@ static int imc_get_mem_addr_nest(struct device_node *node,
* and domain as the inputs.
* Allocates memory for the struct imc_pmu, sets up its domain, size and offsets
*/
-static int imc_pmu_create(struct device_node *parent, int pmu_index, int domain)
+static struct imc_pmu *imc_pmu_create(struct device_node *parent, int pmu_index, int domain)
{
int ret = 0;
struct imc_pmu *pmu_ptr;
@@ -163,27 +158,23 @@ static int imc_pmu_create(struct device_node *parent, int pmu_index, int domain)
/* Return for unknown domain */
if (domain < 0)
- return -EINVAL;
+ return NULL;
/* memory for pmu */
pmu_ptr = kzalloc(sizeof(*pmu_ptr), GFP_KERNEL);
if (!pmu_ptr)
- return -ENOMEM;
+ return NULL;
/* Set the domain */
pmu_ptr->domain = domain;
ret = of_property_read_u32(parent, "size", &pmu_ptr->counter_mem_size);
- if (ret) {
- ret = -EINVAL;
+ if (ret)
goto free_pmu;
- }
if (!of_property_read_u32(parent, "offset", &offset)) {
- if (imc_get_mem_addr_nest(parent, pmu_ptr, offset)) {
- ret = -EINVAL;
+ if (imc_get_mem_addr_nest(parent, pmu_ptr, offset))
goto free_pmu;
- }
}
/* Function to register IMC pmu */
@@ -194,14 +185,14 @@ static int imc_pmu_create(struct device_node *parent, int pmu_index, int domain)
if (pmu_ptr->domain == IMC_DOMAIN_NEST)
kfree(pmu_ptr->mem_info);
kfree(pmu_ptr);
- return ret;
+ return NULL;
}
- return 0;
+ return pmu_ptr;
free_pmu:
kfree(pmu_ptr);
- return ret;
+ return NULL;
}
static void disable_nest_pmu_counters(void)
@@ -258,6 +249,7 @@ int get_max_nest_dev(void)
static int opal_imc_counters_probe(struct platform_device *pdev)
{
struct device_node *imc_dev = pdev->dev.of_node;
+ struct imc_pmu *pmu;
int pmu_count = 0, domain;
bool core_imc_reg = false, thread_imc_reg = false;
u32 type;
@@ -273,6 +265,7 @@ static int opal_imc_counters_probe(struct platform_device *pdev)
}
for_each_compatible_node(imc_dev, NULL, IMC_DTB_UNIT_COMPAT) {
+ pmu = NULL;
if (of_property_read_u32(imc_dev, "type", &type)) {
pr_warn("IMC Device without type property\n");
continue;
@@ -294,9 +287,13 @@ static int opal_imc_counters_probe(struct platform_device *pdev)
break;
}
- if (!imc_pmu_create(imc_dev, pmu_count, domain)) {
- if (domain == IMC_DOMAIN_NEST)
+ pmu = imc_pmu_create(imc_dev, pmu_count, domain);
+ if (pmu != NULL) {
+ if (domain == IMC_DOMAIN_NEST) {
+ if (!imc_debugfs_parent)
+ export_imc_mode_and_cmd(imc_dev, pmu);
pmu_count++;
+ }
if (domain == IMC_DOMAIN_CORE)
core_imc_reg = true;
if (domain == IMC_DOMAIN_THREAD)
@@ -304,10 +301,6 @@ static int opal_imc_counters_probe(struct platform_device *pdev)
}
}
- /* If none of the nest units are registered, remove debugfs interface */
- if (pmu_count == 0)
- debugfs_remove_recursive(imc_debugfs_parent);
-
/* If core imc is not registered, unregister thread-imc */
if (!core_imc_reg && thread_imc_reg)
unregister_thread_imc();
--
2.25.1
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