Re: [PATCH 04/14] x86, ACPI: make acpi override finding work with32bit flat mode
From: Yinghai Lu
Date: Fri Mar 08 2013 - 01:57:44 EST
On Thu, Mar 7, 2013 at 9:50 PM, Tejun Heo <tj@xxxxxxxxxx> wrote:
> On Thu, Mar 07, 2013 at 08:58:30PM -0800, Yinghai Lu wrote:
>> We will find acpi tables in initrd during head_32.S in 32bit flat mode.
>>
>> So need acpi_initrd_override_find could take phys directly.
>
> The patch description doesn't explain even half of what's going on.
hope HPA could understand.
Access initrd before relocate_initrd and init_memory mapping.
>
>> @@ -552,38 +552,47 @@ u8 __init acpi_table_checksum(u8 *buffer, u32 length)
>> return sum;
>> }
>>
>> -/* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
>> -static const char * const table_sigs[] = {
>> - ACPI_SIG_BERT, ACPI_SIG_CPEP, ACPI_SIG_ECDT, ACPI_SIG_EINJ,
>> - ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT, ACPI_SIG_MSCT,
>> - ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT, ACPI_SIG_ASF,
>> - ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR, ACPI_SIG_HPET,
>> - ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG, ACPI_SIG_MCHI,
>> - ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI, ACPI_SIG_TCPA,
>> - ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT, ACPI_SIG_WDDT,
>> - ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT, ACPI_SIG_PSDT,
>> - ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT, NULL };
>
> Why is this table made a stack variable? What's the benefit of doing
> that?
so I do need to switch global variables to phys and access it.
>
>> /* Non-fatal errors: Affected tables/files are ignored */
>> #define INVALID_TABLE(x, path, name) \
>> - { pr_err("ACPI OVERRIDE: " x " [%s%s]\n", path, name); continue; }
>> + do { pr_err("ACPI OVERRIDE: " x " [%s%s]\n", path, name); } while (0)
>
> Might as well rename the macro to something which indicates it's just
> printing error message. Urgh... who thought embedding control flow
> directive like continue inside a macro was a good idea? :(
so I removed it.
>
>> -void __init acpi_initrd_override_find(void *data, size_t size)
>> +void __init acpi_initrd_override_find(void *data, size_t size, bool is_phys)
>
> Is it really necessary to make the function take both virtual and
> physical addresses? Can't we just make the function take phys_addr_t
> and update everyone to call with physaddr? Also @is_phys isn't simple
> address switch. It also changes error reporting. If you're gonna
> keep @is_phys, let's at least write up a function comment explaining
> what's going on and why we need it. But, really, if at all possible,
> let's change the function to take single type of argument and
> predicate error message printing on something else (e.g. early printk
> initialized or whatever).
yes, one for 32bit from head_32.S, phys.
one for 64bit from head64.c. with _va.
Not sure if I could use early_printk from head_32.S, as Fenghua does
not print out
from microcode updating early in the same parts.
Will check that.
>
>> @@ -654,11 +677,14 @@ void __init acpi_initrd_override_copy(void)
>> arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
>>
>> for (no = 0; no < table_nr; no++) {
>> + unsigned long phys_addr = (unsigned long)early_initrd_files[no].data;
>
> Can we please use phys_addr_t for physical addresses?
ok.
>
>> unsigned long size = early_initrd_files[no].size;
>>
>> + q = early_ioremap(phys_addr, size);
>> + pr_info("%4.4s ACPI table found in initrd [%#010lx-%#010lx]\n",
>> + ((struct acpi_table_header *)q)->signature,
>> + phys_addr, phys_addr + size - 1);
>
> Maybe putting pr_info after ioremapping both p and q would be easier
> on the eyes?
ok.
>
>> p = early_ioremap(acpi_tables_addr + total_offset, size);
>> - q = early_ioremap((unsigned long)early_initrd_files[no].data,
>> - size);
>> memcpy(p, q, size);
>> early_iounmap(q, size);
>> early_iounmap(p, size);
Thanks
Yinghai
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