ACK: [F][PATCH 1/1] powerpc/powernv: Avoid re-registration of imc debugfs directory
Colin Ian King
colin.king at canonical.com
Thu Jan 30 12:09:32 UTC 2020
On 30/01/2020 12:03, frank.heimes at canonical.com wrote:
> From: Anju T Sudhakar <anju at linux.vnet.ibm.com>
>
> BugLink: https://bugs.launchpad.net/bugs/1861379
>
> 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 at linux.vnet.ibm.com>
> Tested-by: Nageswara R Sastry <nasastry at in.ibm.com>
> Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
> Link: https://lore.kernel.org/r/20191127072035.4283-1-anju@linux.vnet.ibm.com
> (cherry picked from commit 48e626ac85b43cc589dd1b3b8004f7f85f03544d)
> Signed-off-by: Frank Heimes <frank.heimes at canonical.com>
> ---
> 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 7ccc5c8..000b350 100644
> --- a/arch/powerpc/platforms/powernv/opal-imc.c
> +++ b/arch/powerpc/platforms/powernv/opal-imc.c
> @@ -59,10 +59,6 @@ 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;
>
> @@ -135,7 +131,6 @@ 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;
> @@ -151,7 +146,7 @@ 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;
> @@ -159,27 +154,23 @@ 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 */
> @@ -190,14 +181,14 @@ 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)
> @@ -254,6 +245,7 @@ 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;
> @@ -269,6 +261,7 @@ 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;
> @@ -300,9 +293,13 @@ 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)
> @@ -310,10 +307,6 @@ 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();
>
Upstream cherry pick, addresses the issue, so..
Acked-by: Colin Ian King <colin.king at canonical.com>
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