On Tuesday 08 November 2022 07:56:59 Peng Fan wrote:
Subject: Re: [PATCH 01/11] imx: implement get_effective_memsize
On Tuesday 08 November 2022 09:38:01 Peng Fan wrote:
On 11/7/2022 3:55 PM, Pali Rohár wrote:
On Monday 07 November 2022 16:00:06 Peng Fan (OSS) wrote:
From: Peng Fan peng.fan@nxp.com
To i.MX6/7 which has 2GB memory, the upper 4KB cut off, will cause the top 1MB not mapped as normal memory, because ARMV7-A use section mapping. So implement i.MX6/7 specific get_effective_memsize to fix the issue.
Fixes: 777aaaa706bc("common/memsize.c: Fix get_effective_memsize() to check for overflow") Signed-off-by: Peng Fan peng.fan@nxp.com
Should not just configuring CONFIG_MAX_MEM_MAPPED properly avoid
that issue?
No, unless I decrease PHYS_SDRAM_SIZE.
So, what is the issue? I just do not see what happens after 777aaaa706bc that RAM size is calculated incorrectly in your case. I did not catch the description from commit message. What are your gd->ram_size and CONFIG_MAX_MEM_MAPPED values that current code does not work?
The base is 2GB, the size is 2GB. With CONFIG_MAX_MEM_MAPPED, the ram_size already decreased by 4KB.
If base is 2GB and size is 2GB then ram_top is 4GB which cannot be represented in 32-bit phys_size_t type and hence some of other u-boot functions use 0 as ram_top. Mentioned commit tries to fix this issue. I guess that you have some other hidden problem and my change just showed implication of that. Could you check how is gd->ram_top configured with and without this change?
Regards, Peng.
Regards, Peng.
arch/arm/mach-imx/cache.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/arch/arm/mach-imx/cache.c b/arch/arm/mach-imx/cache.c index ab9b621a2a6..69a085abee7 100644 --- a/arch/arm/mach-imx/cache.c +++ b/arch/arm/mach-imx/cache.c @@ -7,10 +7,24 @@ #include <cpu_func.h> #include <asm/armv7.h> #include <asm/cache.h> +#include <asm/global_data.h> #include <asm/pl310.h> #include <asm/io.h> #include <asm/mach-imx/sys_proto.h> +DECLARE_GLOBAL_DATA_PTR;
+phys_size_t get_effective_memsize(void) { #ifndef +CONFIG_MAX_MEM_MAPPED
- return gd->ram_size;
+#else
- /* limit stack to what we can reasonable map */
- return ((gd->ram_size > CONFIG_MAX_MEM_MAPPED) ?
CONFIG_MAX_MEM_MAPPED : gd->ram_size); #endif }- void enable_ca7_smp(void) { u32 val;
-- 2.36.0