On A64 with 2G of RAM words at following addresses were modified with 'aa55aa55' value: - 50000000 - 60000000 - 84000000 - 88000000 - 90000000 - A0000000 - A0000200
That made harder to pick memory range for persistent storage in RAM.
Signed-off-by: Andrey Skvortsov andrej.skvortzov@gmail.com --- arch/arm/mach-sunxi/dram_helpers.c | 16 ++++++++++++++-- arch/arm/mach-sunxi/dram_sunxi_dw.c | 16 ++++++++++++++-- 2 files changed, 28 insertions(+), 4 deletions(-)
diff --git a/arch/arm/mach-sunxi/dram_helpers.c b/arch/arm/mach-sunxi/dram_helpers.c index 2c873192e6..e3d236a4b3 100644 --- a/arch/arm/mach-sunxi/dram_helpers.c +++ b/arch/arm/mach-sunxi/dram_helpers.c @@ -32,12 +32,24 @@ void mctl_await_completion(u32 *reg, u32 mask, u32 val) #ifndef CONFIG_MACH_SUNIV bool mctl_mem_matches(u32 offset) { + unsigned long tmp_base; + unsigned long tmp_offset; + bool ret; + + /* Save original values */ + tmp_base = readl(CFG_SYS_SDRAM_BASE); + tmp_offset = readl((ulong)CFG_SYS_SDRAM_BASE + offset); + /* Try to write different values to RAM at two addresses */ writel(0, CFG_SYS_SDRAM_BASE); writel(0xaa55aa55, (ulong)CFG_SYS_SDRAM_BASE + offset); dsb(); /* Check if the same value is actually observed when reading back */ - return readl(CFG_SYS_SDRAM_BASE) == - readl((ulong)CFG_SYS_SDRAM_BASE + offset); + ret = readl(CFG_SYS_SDRAM_BASE) == readl((ulong)CFG_SYS_SDRAM_BASE + offset); + + /* Restore original values */ + writel(tmp_base, CFG_SYS_SDRAM_BASE); + writel(tmp_offset, (ulong)CFG_SYS_SDRAM_BASE + offset); + return ret; } #endif diff --git a/arch/arm/mach-sunxi/dram_sunxi_dw.c b/arch/arm/mach-sunxi/dram_sunxi_dw.c index 9107b114df..6245815fa2 100644 --- a/arch/arm/mach-sunxi/dram_sunxi_dw.c +++ b/arch/arm/mach-sunxi/dram_sunxi_dw.c @@ -657,13 +657,25 @@ static int mctl_channel_init(uint16_t socid, struct dram_para *para) */ static bool mctl_mem_matches_base(u32 offset, ulong base) { + unsigned long tmp_base; + unsigned long tmp_offset; + bool ret; + + /* Save original values */ + tmp_base = readl(base); + tmp_offset = readl((ulong)base + offset); + /* Try to write different values to RAM at two addresses */ writel(0, base); writel(0xaa55aa55, base + offset); dsb(); /* Check if the same value is actually observed when reading back */ - return readl(base) == - readl(base + offset); + ret = readl(base) == readl(base + offset); + + /* Restore original values */ + writel(tmp_base, base); + writel(tmp_offset, (ulong)base + offset); + return ret; }
static void mctl_auto_detect_dram_size_rank(uint16_t socid, struct dram_para *para, ulong base, struct rank_para *rank)