[U-Boot] [PATCH V2 2/2] board/tqm85xx: Create and tear down TLB for get_ram_size()

[Becky Bruce]

We need a TLB entry to call get_ram_size(); the common code
doesn't create one until *after* fixed_sdram() has determined
the size.  So we set up tlbs for the max possible size
and tear them down once we're done with get_ram_size(); the
common 85xx code will then set up a final set of tlb entries
for the *actual* detected size of ddr.

This prevents us from having TLB entries that are larger
than DDR sitting around for very long, which is not a recommended
scenario.

Signed-off-by: Becky Bruce <bec...@kernel.crashing.org>
---
 board/tqc/tqm85xx/sdram.c |    7 +++++++
 include/configs/TQM85xx.h |    6 ++++++
 2 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/board/tqc/tqm85xx/sdram.c b/board/tqc/tqm85xx/sdram.c
index 39a9e21..baf073e 100644
--- a/board/tqc/tqm85xx/sdram.c
+++ b/board/tqc/tqm85xx/sdram.c
@@ -363,6 +363,12 @@ static phys_size_t sdram_setup(int casl)
        udelay (1000);
 #endif /* CONFIG_TQM8548 */
 
+       /*
+        * get_ram_size() depends on having tlbs for the DDR, but they are
+        * not yet setup because we don't know the size.  Set up a temp
+        * mapping and delete it when done.
+        */
+       setup_ddr_tlbs(CONFIG_SYS_DDR_EARLY_SIZE_MB);
        for (i = 0; i < N_DDR_CS_CONF; i++) {
                ddr->cs0_config = ddr_cs_conf[i].reg;
 
@@ -376,6 +382,7 @@ static phys_size_t sdram_setup(int casl)
                        break;
                }
        }
+       clear_ddr_tlbs(CONFIG_SYS_DDR_EARLY_SIZE_MB);
 
 #ifdef CONFIG_TQM8548
        if (i < N_DDR_CS_CONF) {
diff --git a/include/configs/TQM85xx.h b/include/configs/TQM85xx.h
index 79a958d..b336723 100644
--- a/include/configs/TQM85xx.h
+++ b/include/configs/TQM85xx.h
@@ -147,10 +147,16 @@
  * DDR Setup
  */
 #define CONFIG_SYS_DDR_SDRAM_BASE      0x00000000      /* DDR is system memory 
*/
+
 #if defined(CONFIG_TQM_BIGFLASH) || \
        (!defined(CONFIG_TQM8548_AG) && !defined(CONFIG_TQM8548_BE))
 #define CONFIG_SYS_PPC_DDR_WIMGE (MAS2_I | MAS2_G)
+#define CONFIG_SYS_DDR_EARLY_SIZE_MB   (512)
+#else
+#define CONFIG_SYS_PPC_DDR_WIMGE (0)
+#define CONFIG_SYS_DDR_EARLY_SIZE_MB   (2 * 1024)
 #endif
+
 #define CONFIG_SYS_SDRAM_BASE          CONFIG_SYS_DDR_SDRAM_BASE
 #ifdef CONFIG_TQM8548_AG
 #define CONFIG_VERY_BIG_RAM
-- 
1.5.6.5


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