drm/radeon/ni_dpm: Fix booting bug

Create new structure NISLANDS_SMC_SWSTATE_SINGLE, as initialState.levels
and ACPIState.levels are never actually used as flexible arrays. Those
arrays can be used as simple objects of type
NISLANDS_SMC_HW_PERFORMANCE_LEVEL, instead.

Currently, the code fails because flexible array _levels_ in
struct NISLANDS_SMC_SWSTATE doesn't allow for code that access
the first element of initialState.levels and ACPIState.levels
arrays:

drivers/gpu/drm/radeon/ni_dpm.c:
1690         table->initialState.levels[0].mclk.vMPLL_AD_FUNC_CNTL =
1691                 cpu_to_be32(ni_pi->clock_registers.mpll_ad_func_cntl);
...
1903:   table->ACPIState.levels[0].mclk.vMPLL_AD_FUNC_CNTL = cpu_to_be32(mpll_ad_func_cntl);
1904:   table->ACPIState.levels[0].mclk.vMPLL_AD_FUNC_CNTL_2 = cpu_to_be32(mpll_ad_func_cntl_2);

because such element cannot exist without previously allocating
any dynamic memory for it (which never actually happens).

That's why struct NISLANDS_SMC_SWSTATE should only be used as type
for object driverState and new struct SISLANDS_SMC_SWSTATE_SINGLE is
created as type for objects initialState, ACPIState and ULVState.

Also, with the change from one-element array to flexible-array member
in commit 434fb1e7 ("drm/radeon/nislands_smc.h: Replace one-element
array with flexible-array member in struct NISLANDS_SMC_SWSTATE"), the
size of dpmLevels in struct NISLANDS_SMC_STATETABLE should be fixed to
be NISLANDS_MAX_SMC_PERFORMANCE_LEVELS_PER_SWSTATE instead of
NISLANDS_MAX_SMC_PERFORMANCE_LEVELS_PER_SWSTATE - 1.

Bug: https://lore.kernel.org/dri-devel/3eedbe78-1fbd-4763-a7f3-ac5665e76a4a@xenosoft.de/
Fixes: 434fb1e7 ("drm/radeon/nislands_smc.h: Replace one-element array with flexible-array member in struct NISLANDS_SMC_SWSTATE")
Cc: stable@vger.kernel.org
Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Link: https://lore.kernel.org/dri-devel/9bb5fcbd-daf5-1669-b3e7-b8624b3c36f9@xenosoft.de/Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/nislands_smc.h

@@ -143,6 +143,14 @@ struct NISLANDS_SMC_SWSTATE
 
 typedef struct NISLANDS_SMC_SWSTATE NISLANDS_SMC_SWSTATE;
 
+struct NISLANDS_SMC_SWSTATE_SINGLE {
+	uint8_t                             flags;
+	uint8_t                             levelCount;
+	uint8_t                             padding2;
+	uint8_t                             padding3;
+	NISLANDS_SMC_HW_PERFORMANCE_LEVEL   level;
+};
+
 #define NISLANDS_SMC_VOLTAGEMASK_VDDC  0
 #define NISLANDS_SMC_VOLTAGEMASK_MVDD  1
 #define NISLANDS_SMC_VOLTAGEMASK_VDDCI 2
@@ -160,19 +168,19 @@ typedef struct NISLANDS_SMC_VOLTAGEMASKTABLE NISLANDS_SMC_VOLTAGEMASKTABLE;
 
 struct NISLANDS_SMC_STATETABLE
 {
-    uint8_t                             thermalProtectType;
-    uint8_t                             systemFlags;
-    uint8_t                             maxVDDCIndexInPPTable;
-    uint8_t                             extraFlags;
-    uint8_t                             highSMIO[NISLANDS_MAX_NO_VREG_STEPS];
-    uint32_t                            lowSMIO[NISLANDS_MAX_NO_VREG_STEPS];
-    NISLANDS_SMC_VOLTAGEMASKTABLE       voltageMaskTable;
-    PP_NIslands_DPM2Parameters          dpm2Params;
-    NISLANDS_SMC_SWSTATE                initialState;
-    NISLANDS_SMC_SWSTATE                ACPIState;
-    NISLANDS_SMC_SWSTATE                ULVState;
-    NISLANDS_SMC_SWSTATE                driverState;
-    NISLANDS_SMC_HW_PERFORMANCE_LEVEL   dpmLevels[NISLANDS_MAX_SMC_PERFORMANCE_LEVELS_PER_SWSTATE - 1];
+	uint8_t                             thermalProtectType;
+	uint8_t                             systemFlags;
+	uint8_t                             maxVDDCIndexInPPTable;
+	uint8_t                             extraFlags;
+	uint8_t                             highSMIO[NISLANDS_MAX_NO_VREG_STEPS];
+	uint32_t                            lowSMIO[NISLANDS_MAX_NO_VREG_STEPS];
+	NISLANDS_SMC_VOLTAGEMASKTABLE       voltageMaskTable;
+	PP_NIslands_DPM2Parameters          dpm2Params;
+	struct NISLANDS_SMC_SWSTATE_SINGLE  initialState;
+	struct NISLANDS_SMC_SWSTATE_SINGLE  ACPIState;
+	struct NISLANDS_SMC_SWSTATE_SINGLE  ULVState;
+	NISLANDS_SMC_SWSTATE                driverState;
+	NISLANDS_SMC_HW_PERFORMANCE_LEVEL   dpmLevels[NISLANDS_MAX_SMC_PERFORMANCE_LEVELS_PER_SWSTATE];
 };
 
 typedef struct NISLANDS_SMC_STATETABLE NISLANDS_SMC_STATETABLE;