aspeed/smc: Cache AspeedSMCClass

Store a reference on the AspeedSMC class under the flash object and
use it when accessing the flash contents. Avoiding the class cast
checkers in these hot paths improves performance by 10% when running
the aspeed avocado tests.

Message-Id: <20220923084803.498337-7-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

hw/ssi/aspeed_smc.c

@@ -388,7 +388,7 @@ static inline int aspeed_smc_flash_cmd(const AspeedSMCFlash *fl)
 static inline int aspeed_smc_flash_addr_width(const AspeedSMCFlash *fl)
 {
     const AspeedSMCState *s = fl->controller;
-    AspeedSMCClass *asc = ASPEED_SMC_GET_CLASS(s);
+    AspeedSMCClass *asc = fl->asc;
 
     if (asc->addr_width) {
         return asc->addr_width(s);
@@ -420,7 +420,7 @@ static uint32_t aspeed_smc_check_segment_addr(const AspeedSMCFlash *fl,
                                               uint32_t addr)
 {
     const AspeedSMCState *s = fl->controller;
-    AspeedSMCClass *asc = ASPEED_SMC_GET_CLASS(s);
+    AspeedSMCClass *asc = fl->asc;
     AspeedSegments seg;
 
     asc->reg_to_segment(s, s->regs[R_SEG_ADDR0 + fl->cs], &seg);
@@ -1234,7 +1234,6 @@ static const TypeInfo aspeed_smc_info = {
 static void aspeed_smc_flash_realize(DeviceState *dev, Error **errp)
 {
     AspeedSMCFlash *s = ASPEED_SMC_FLASH(dev);
-    AspeedSMCClass *asc;
     g_autofree char *name = g_strdup_printf(TYPE_ASPEED_SMC_FLASH ".%d", s->cs);
 
     if (!s->controller) {
@@ -1242,14 +1241,14 @@ static void aspeed_smc_flash_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    asc = ASPEED_SMC_GET_CLASS(s->controller);
+    s->asc = ASPEED_SMC_GET_CLASS(s->controller);
 
     /*
      * Use the default segment value to size the memory region. This
      * can be changed by FW at runtime.
      */
     memory_region_init_io(&s->mmio, OBJECT(s), &aspeed_smc_flash_ops,
-                          s, name, asc->segments[s->cs].size);
+                          s, name, s->asc->segments[s->cs].size);
     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->mmio);
 }
 

include/hw/ssi/aspeed_smc.h

@@ -30,6 +30,7 @@
 #include "qom/object.h"
 
 struct AspeedSMCState;
+struct AspeedSMCClass;
 
 #define TYPE_ASPEED_SMC_FLASH "aspeed.smc.flash"
 OBJECT_DECLARE_SIMPLE_TYPE(AspeedSMCFlash, ASPEED_SMC_FLASH)
@@ -37,6 +38,7 @@ struct AspeedSMCFlash {
     SysBusDevice parent_obj;
 
     struct AspeedSMCState *controller;
+    struct AspeedSMCClass *asc;
     uint8_t cs;
 
     MemoryRegion mmio;