Re: [PATCH 03/10] microblaze: cache: improve dcache Kconfig options

[Michal Simek]

On 4/11/22 18:26, Ovidiu Panait wrote:
Replace CONFIG_DCACHE with a Kconfig option more limited in scope -
XILINX_MICROBLAZE0_USE_WDC. It should be enabled if the processor supports
the "wdc" (Write to Data Cache) instruction. It will be used to guard
"wdc" invocations in microblaze cache code.

Also, drop all ifdefs around flush_cache() calls and only keep one
CONFIG_IS_ENABLED() guard within flush_cache() itself.

Signed-off-by: Ovidiu Panait <ovpan...@gmail.com>
---

  arch/microblaze/Kconfig                 |  4 ----
  arch/microblaze/cpu/cache.c             | 15 ++++++++++-----
  arch/microblaze/lib/bootm.c             |  2 --
  board/xilinx/microblaze-generic/Kconfig |  7 +++++++
  4 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index d7d1b21970..5a2e91104f 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -25,10 +25,6 @@ config TARGET_MICROBLAZE_GENERIC
  
  endchoice
  
-config DCACHE
-       bool "Enable dcache support"
-       default y
-
  config ICACHE
        bool "Enable icache support"
        default y
diff --git a/arch/microblaze/cpu/cache.c b/arch/microblaze/cpu/cache.c
index b6126de194..4e8e228a22 100644
--- a/arch/microblaze/cpu/cache.c
+++ b/arch/microblaze/cpu/cache.c
@@ -49,26 +49,31 @@ void dcache_enable(void)
  
  void dcache_disable(void)
  {
-#ifdef CONFIG_DCACHE
        flush_cache(0, XILINX_DCACHE_BYTE_SIZE);
-#endif
+
        MSRCLR(0x80);
  }
  
  void flush_cache(ulong addr, ulong size)
  {
        int i;
-       for (i = 0; i < size; i += 4)
+       for (i = 0; i < size; i += 4) {
                asm volatile (
  #ifdef CONFIG_ICACHE
                                "wic       %0, r0;"
  #endif
                                "nop;"
-#ifdef CONFIG_DCACHE
+                               :
+                               : "r" (addr + i)
+                               : "memory");
+
+               if (CONFIG_IS_ENABLED(XILINX_MICROBLAZE0_USE_WDC)) {


Based on buildman your patch is removing cache handling from SPL.
Here is what I see that there are missing 2 instructions. And 4/10 you see that 
8 instructions are missing.

06: microblaze: cache: improve dcache Kconfig options
microblaze: (for 1/1 boards) spl/u-boot-spl:all -8.0 spl/u-boot-spl:text -8.0
            microblaze-generic: spl/u-boot-spl:all -8 spl/u-boot-spl:text -8
               spl-u-boot-spl: add: 0/0, grow: 0/-1 bytes: 0/-8 (-8)
                 function                                   old     new   delta
                 flush_cache                                 48      40      -8
07: microblaze: cache: improve icache Kconfig options
microblaze: (for 1/1 boards) spl/u-boot-spl:all -32.0 spl/u-boot-spl:text -32.0
            microblaze-generic: spl/u-boot-spl:all -32 spl/u-boot-spl:text -32
               spl-u-boot-spl: add: 0/0, grow: 0/-1 bytes: 0/-32 (-32)
                 function

This is going to macro explanation where it is clear that you don't define 
CONFIG_SPL_FOO you only define CONFIG_FOO.


104  * CONFIG_IS_ENABLED(FOO) expands to
105  *  1 if USE_HOSTCC is defined and CONFIG_TOOLS_FOO is set to 'y',
106  *  1 if CONFIG_SPL_BUILD is undefined and CONFIG_FOO is set to 'y',
107  *  1 if CONFIG_SPL_BUILD is defined and CONFIG_SPL_FOO is set to 'y',
108  *  1 if CONFIG_TPL_BUILD is defined and CONFIG_TPL_FOO is set to 'y',
109  *  0 otherwise.

It means you should use different macro or create one more with SPL.

Thanks,
Michal