drm/amd/pm: Replace one-element array with flexible-array in struct phm_ppt_v1_pcie_table

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_pcie_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/5f7db0bc.7Xivn4K83f7XW0ug%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 e11298c..729615a 100644 (file)
--- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/hwmgr_ppt.h
+++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/hwmgr_ppt.h
@@ -103,7 +103,7 @@ typedef struct phm_ppt_v1_pcie_record phm_ppt_v1_pcie_record;
 
 struct phm_ppt_v1_pcie_table {
        uint32_t count;                                            /* Number of entries. */
-       phm_ppt_v1_pcie_record entries[1];                         /* Dynamically allocate count entries. */
+       phm_ppt_v1_pcie_record entries[];                          /* Dynamically allocate count entries. */
 };
 typedef struct phm_ppt_v1_pcie_table phm_ppt_v1_pcie_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 426655b..4fa5861 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
@@ -478,7 +478,7 @@ static int get_pcie_table(
                PPTable_Generic_SubTable_Header const *ptable
                )
 {
-       uint32_t table_size, i, pcie_count;
+       uint32_t i, pcie_count;
        phm_ppt_v1_pcie_table *pcie_table;
        struct phm_ppt_v1_information *pp_table_information =
                (struct phm_ppt_v1_information *)(hwmgr->pptable);
@@ -491,12 +491,10 @@ static int get_pcie_table(
                PP_ASSERT_WITH_CODE((atom_pcie_table->ucNumEntries != 0),
                        "Invalid PowerPlay Table!", return -1);
 
-               table_size = sizeof(uint32_t) +
-                       sizeof(phm_ppt_v1_pcie_record) * atom_pcie_table->ucNumEntries;
-
-               pcie_table = kzalloc(table_size, GFP_KERNEL);
-
-               if (pcie_table == NULL)
+               pcie_table = kzalloc(struct_size(pcie_table, entries,
+                                                atom_pcie_table->ucNumEntries),
+                                    GFP_KERNEL);
+               if (!pcie_table)
                        return -ENOMEM;
 
                /*
@@ -530,12 +528,10 @@ static int get_pcie_table(
                PP_ASSERT_WITH_CODE((atom_pcie_table->ucNumEntries != 0),
                        "Invalid PowerPlay Table!", return -1);
 
-               table_size = sizeof(uint32_t) +
-                       sizeof(phm_ppt_v1_pcie_record) * atom_pcie_table->ucNumEntries;
-
-               pcie_table = kzalloc(table_size, GFP_KERNEL);
-
-               if (pcie_table == NULL)
+               pcie_table = kzalloc(struct_size(pcie_table, entries,
+                                                atom_pcie_table->ucNumEntries),
+                                    GFP_KERNEL);
+               if (!pcie_table)
                        return -ENOMEM;
 
                /*

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 3d7f915..535404d 100644 (file)
--- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega10_processpptables.c
+++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega10_processpptables.c
@@ -784,7 +784,7 @@ static int get_pcie_table(struct pp_hwmgr *hwmgr,
                struct phm_ppt_v1_pcie_table **vega10_pcie_table,
                const Vega10_PPTable_Generic_SubTable_Header *table)
 {
-       uint32_t table_size, i, pcie_count;
+       uint32_t i, pcie_count;
        struct phm_ppt_v1_pcie_table *pcie_table;
        struct phm_ppt_v2_information *table_info =
                        (struct phm_ppt_v2_information *)(hwmgr->pptable);
@@ -795,12 +795,8 @@ static int get_pcie_table(struct pp_hwmgr *hwmgr,
                        "Invalid PowerPlay Table!",
                        return 0);
 
-       table_size = sizeof(uint32_t) +
-                       sizeof(struct phm_ppt_v1_pcie_record) *
-                       atom_pcie_table->ucNumEntries;
-
-       pcie_table = kzalloc(table_size, GFP_KERNEL);
-
+       pcie_table = kzalloc(struct_size(pcie_table, entries, atom_pcie_table->ucNumEntries),
+                            GFP_KERNEL);
        if (!pcie_table)
                return -ENOMEM;