ACPI: processor: Move checks and availability of acpi_processor earlier

Make the per_cpu(processors, cpu) entries available earlier so that
they are available in arch_register_cpu() as ARM64 will need access
to the acpi_handle to distinguish between acpi_processor_add()
and earlier registration attempts (which will fail as _STA cannot
be checked).

Reorder the remove flow to clear this per_cpu() after
arch_unregister_cpu() has completed, allowing it to be used in
there as well.

Note that on x86 for the CPU hotplug case, the pr->id prior to
acpi_map_cpu() may be invalid. Thus the per_cpu() structures
must be initialized after that call or after checking the ID
is valid (not hotplug path).

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240529133446.28446-7-Jonathan.Cameron@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index 16e36e55a560dd03235913f36b2264f6bdd2b571..0bc0419adf6b9570200ed5466793990def2e0279 100644 (file)
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -183,8 +183,38 @@ static void __init acpi_pcc_cpufreq_init(void) {}
 #endif /* CONFIG_X86 */
 
 /* Initialization */
+static DEFINE_PER_CPU(void *, processor_device_array);
+
+static int acpi_processor_set_per_cpu(struct acpi_processor *pr,
+                                     struct acpi_device *device)
+{
+       BUG_ON(pr->id >= nr_cpu_ids);
+
+       /*
+        * Buggy BIOS check.
+        * ACPI id of processors can be reported wrongly by the BIOS.
+        * Don't trust it blindly
+        */
+       if (per_cpu(processor_device_array, pr->id) != NULL &&
+           per_cpu(processor_device_array, pr->id) != device) {
+               dev_warn(&device->dev,
+                        "BIOS reported wrong ACPI id %d for the processor\n",
+                        pr->id);
+               return -EINVAL;
+       }
+       /*
+        * processor_device_array is not cleared on errors to allow buggy BIOS
+        * checks.
+        */
+       per_cpu(processor_device_array, pr->id) = device;
+       per_cpu(processors, pr->id) = pr;
+
+       return 0;
+}
+
 #ifdef CONFIG_ACPI_HOTPLUG_CPU
-static int acpi_processor_hotadd_init(struct acpi_processor *pr)
+static int acpi_processor_hotadd_init(struct acpi_processor *pr,
+                                     struct acpi_device *device)
 {
        int ret;
 
@@ -198,8 +228,16 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr)
        if (ret)
                goto out;
 
+       ret = acpi_processor_set_per_cpu(pr, device);
+       if (ret) {
+               acpi_unmap_cpu(pr->id);
+               goto out;
+       }
+
        ret = arch_register_cpu(pr->id);
        if (ret) {
+               /* Leave the processor device array in place to detect buggy bios */
+               per_cpu(processors, pr->id) = NULL;
                acpi_unmap_cpu(pr->id);
                goto out;
        }
@@ -217,7 +255,8 @@ out:
        return ret;
 }
 #else
-static inline int acpi_processor_hotadd_init(struct acpi_processor *pr)
+static inline int acpi_processor_hotadd_init(struct acpi_processor *pr,
+                                            struct acpi_device *device)
 {
        return -ENODEV;
 }
@@ -232,6 +271,7 @@ static int acpi_processor_get_info(struct acpi_device *device)
        acpi_status status = AE_OK;
        static int cpu0_initialized;
        unsigned long long value;
+       int ret;
 
        acpi_processor_errata();
 
@@ -315,12 +355,12 @@ static int acpi_processor_get_info(struct acpi_device *device)
         *  NOTE: Even if the processor has a cpuid, it may not be present
         *  because cpuid <-> apicid mapping is persistent now.
         */
-       if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) {
-               int ret = acpi_processor_hotadd_init(pr);
-
-               if (ret)
-                       return ret;
-       }
+       if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id))
+               ret = acpi_processor_hotadd_init(pr, device);
+       else
+               ret = acpi_processor_set_per_cpu(pr, device);
+       if (ret)
+               return ret;
 
        /*
         * On some boxes several processors use the same processor bus id.
@@ -365,8 +405,6 @@ static int acpi_processor_get_info(struct acpi_device *device)
  * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
  * Such things have to be put in and set up by the processor driver's .probe().
  */
-static DEFINE_PER_CPU(void *, processor_device_array);
-
 static int acpi_processor_add(struct acpi_device *device,
                                        const struct acpi_device_id *id)
 {
@@ -395,28 +433,6 @@ static int acpi_processor_add(struct acpi_device *device,
        if (result) /* Processor is not physically present or unavailable */
                goto err_clear_driver_data;
 
-       BUG_ON(pr->id >= nr_cpu_ids);
-
-       /*
-        * Buggy BIOS check.
-        * ACPI id of processors can be reported wrongly by the BIOS.
-        * Don't trust it blindly
-        */
-       if (per_cpu(processor_device_array, pr->id) != NULL &&
-           per_cpu(processor_device_array, pr->id) != device) {
-               dev_warn(&device->dev,
-                       "BIOS reported wrong ACPI id %d for the processor\n",
-                       pr->id);
-               /* Give up, but do not abort the namespace scan. */
-               goto err_clear_driver_data;
-       }
-       /*
-        * processor_device_array is not cleared on errors to allow buggy BIOS
-        * checks.
-        */
-       per_cpu(processor_device_array, pr->id) = device;
-       per_cpu(processors, pr->id) = pr;
-
        dev = get_cpu_device(pr->id);
        if (!dev) {
                result = -ENODEV;
@@ -470,10 +486,6 @@ static void acpi_processor_remove(struct acpi_device *device)
        device_release_driver(pr->dev);
        acpi_unbind_one(pr->dev);
 
-       /* Clean up. */
-       per_cpu(processor_device_array, pr->id) = NULL;
-       per_cpu(processors, pr->id) = NULL;
-
        cpu_maps_update_begin();
        cpus_write_lock();
 
@@ -481,6 +493,10 @@ static void acpi_processor_remove(struct acpi_device *device)
        arch_unregister_cpu(pr->id);
        acpi_unmap_cpu(pr->id);
 
+       /* Clean up. */
+       per_cpu(processor_device_array, pr->id) = NULL;
+       per_cpu(processors, pr->id) = NULL;
+
        cpus_write_unlock();
        cpu_maps_update_done();