[PATCH v2 12/13] armv8: layerscape: relocate spin table if EFI_LOADER is enabled

[Heinrich Schuchardt]

On 6/1/20 9:53 PM, Michael Walle wrote:
> On ARM64, a 64kb region is reserved for the runtime services code.
> Unfortunately, this code overlaps with the spin table code, which also
> needs to be reserved. Thus now that the code is relocatable, allocate a
> new page from EFI, copy the spin table code into it, update any pointers
> to the old region and the start the secondary CPUs.
>
> Signed-off-by: Michael Walle <michael at walle.cc>
> ---
>  arch/arm/cpu/armv8/fsl-layerscape/mp.c | 36 ++++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
>
> diff --git a/arch/arm/cpu/armv8/fsl-layerscape/mp.c b/arch/arm/cpu/armv8/fsl-layerscape/mp.c
> index d50c5a437b..bd85351705 100644
> --- a/arch/arm/cpu/armv8/fsl-layerscape/mp.c
> +++ b/arch/arm/cpu/armv8/fsl-layerscape/mp.c
> @@ -79,6 +79,10 @@ int fsl_layerscape_wake_seconday_cores(void)
>  	u32 cores, cpu_up_mask = 1;
>  	int i, timeout = 10;
>  	u64 *table;
> +#ifdef CONFIG_EFI_LOADER
> +	u64 reloc_addr = U32_MAX;
> +	efi_status_t ret;
> +#endif
>
>  #ifdef COUNTER_FREQUENCY_REAL
>  	/* update for secondary cores */
> @@ -87,6 +91,38 @@ int fsl_layerscape_wake_seconday_cores(void)
>  			   (unsigned long)&__real_cntfrq + 8);
>  #endif
>
> +#ifdef CONFIG_EFI_LOADER
> +	/*
> +	 * EFI will reserve 64kb for its runtime services. This will probably
> +	 * overlap with our spin table code, which is why we have to relocate
> +	 * it.
> +	 * Keep this after the __real_cntfrq update, so we have it when we
> +	 * copy the complete section here.
> +	 */
> +	ret = efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS,
> +				 EFI_RESERVED_MEMORY_TYPE,
> +				 efi_size_in_pages(secondary_boot_code_size),
> +				 &reloc_addr);
> +	if (ret == EFI_SUCCESS) {
> +		debug("Relocating spin table from %llx to %llx (size %lx)\n",
> +		      (u64)secondary_boot_code_start, reloc_addr,
> +		      secondary_boot_code_size);
> +		memcpy((void *)reloc_addr, secondary_boot_code_start,
> +		       secondary_boot_code_size);
> +		flush_dcache_range(reloc_addr,
> +				   reloc_addr + secondary_boot_code_size);
> +
> +		/* set new entry point for secondary cores */
> +		secondary_boot_addr += (void *)reloc_addr -
> +				       secondary_boot_code_start;
> +		flush_dcache_range((unsigned long)&secondary_boot_addr,
> +				   (unsigned long)&secondary_boot_addr + 8);

Wouldn't you want to flush the complete target range of memcpy() and
afterwards call invalidate_icache_all(). At least this is what we do in
other cases after copying instructions. Cf. efi_runtime_relocate().

Best regards

Heinrich

> +
> +		/* this will be used to reserve the memory */
> +		secondary_boot_code_start = (void *)reloc_addr;
> +	}
> +#endif
> +
>  	cores = cpu_mask();
>  	/* Clear spin table so that secondary processors
>  	 * observe the correct value after waking up from wfe.
>