drm/amd/pm: Replace one-element array with flexible-array in struct phm_ppt_v1_mm_clo...

There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members”[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].

Refactor the code according to the use of a flexible-array member in
struct phm_ppt_v1_mm_clock_voltage_dependency_table, instead of a
one-element array, and use the struct_size() helper to calculate the
size for the allocation.

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays

Build-tested-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/5f7d61e2.qiTVTyG2pVoG8bb0%25lkp@intel.com/
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/hwmgr_ppt.h b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/hwmgr_ppt.h
index c167083..923cc04 100644 (file)
--- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/hwmgr_ppt.h
+++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/hwmgr_ppt.h
@@ -71,7 +71,7 @@ typedef struct phm_ppt_v1_mm_clock_voltage_dependency_record phm_ppt_v1_mm_clock
 
 struct phm_ppt_v1_mm_clock_voltage_dependency_table {
        uint32_t count;                                                                                                 /* Number of entries. */
-       phm_ppt_v1_mm_clock_voltage_dependency_record entries[1];               /* Dynamically allocate count entries. */
+       phm_ppt_v1_mm_clock_voltage_dependency_record entries[];                /* Dynamically allocate count entries. */
 };
 typedef struct phm_ppt_v1_mm_clock_voltage_dependency_table phm_ppt_v1_mm_clock_voltage_dependency_table;
 

diff --git a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/process_pptables_v1_0.c b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/process_pptables_v1_0.c
index 0725531..5d8016c 100644 (file)
--- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/process_pptables_v1_0.c
+++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/process_pptables_v1_0.c
@@ -678,19 +678,16 @@ static int get_mm_clock_voltage_table(
                const ATOM_Tonga_MM_Dependency_Table * mm_dependency_table
                )
 {
-       uint32_t table_size, i;
+       uint32_t i;
        const ATOM_Tonga_MM_Dependency_Record *mm_dependency_record;
        phm_ppt_v1_mm_clock_voltage_dependency_table *mm_table;
        phm_ppt_v1_mm_clock_voltage_dependency_record *mm_table_record;
 
        PP_ASSERT_WITH_CODE((0 != mm_dependency_table->ucNumEntries),
                "Invalid PowerPlay Table!", return -1);
-       table_size = sizeof(uint32_t) +
-               sizeof(phm_ppt_v1_mm_clock_voltage_dependency_record)
-               * mm_dependency_table->ucNumEntries;
-       mm_table = kzalloc(table_size, GFP_KERNEL);
-
-       if (NULL == mm_table)
+       mm_table = kzalloc(struct_size(mm_table, entries, mm_dependency_table->ucNumEntries),
+                          GFP_KERNEL);
+       if (!mm_table)
                return -ENOMEM;
 
        mm_table->count = mm_dependency_table->ucNumEntries;

diff --git a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega10_processpptables.c b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega10_processpptables.c
index 787b23f..4f6a73a 100644 (file)
--- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega10_processpptables.c
+++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega10_processpptables.c
@@ -344,18 +344,15 @@ static int get_mm_clock_voltage_table(
                phm_ppt_v1_mm_clock_voltage_dependency_table **vega10_mm_table,
                const ATOM_Vega10_MM_Dependency_Table *mm_dependency_table)
 {
-       uint32_t table_size, i;
+       uint32_t i;
        const ATOM_Vega10_MM_Dependency_Record *mm_dependency_record;
        phm_ppt_v1_mm_clock_voltage_dependency_table *mm_table;
 
        PP_ASSERT_WITH_CODE((mm_dependency_table->ucNumEntries != 0),
                        "Invalid PowerPlay Table!", return -1);
 
-       table_size = sizeof(uint32_t) +
-                       sizeof(phm_ppt_v1_mm_clock_voltage_dependency_record) *
-                       mm_dependency_table->ucNumEntries;
-       mm_table = kzalloc(table_size, GFP_KERNEL);
-
+       mm_table = kzalloc(struct_size(mm_table, entries, mm_dependency_table->ucNumEntries),
+                          GFP_KERNEL);
        if (!mm_table)
                return -ENOMEM;