[PATCH 01/11] imx: implement get_effective_memsize

[Peng Fan]

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 at 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 at nxp.com>
> 
> Should not just configuring CONFIG_MAX_MEM_MAPPED properly avoid that issue?

No, unless I decrease PHYS_SDRAM_SIZE.

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
>>