On Mon, Sep 19, 2011 at 7:38 PM, Huang Ying <ying.huang@xxxxxxxxx> wrote:
> Some firmware will access memory in ACPI NVS region via APEI. That
> is, instructions in APEI ERST/EINJ table will read/write ACPI NVS
> region. The original resource conflict checking in APEI code will
> check memory/ioport accessed by APEI via general resource management
> mech. But ACPI NVS region is marked as busy already, so that the
> false resource conflict will prevent APEI ERST/EINJ to work.
>
> To fix this, this patch excludes ACPI NVS regions when APEI components
> request resources. So that they will not conflict with ACPI NVS
> regions.
I think this is much, much too complicated.
Yinghai's three-line e820.c patch to leave ACPI NVS regions in the
iomem_resource tree, but as not busy, is far better.
Bjorn
> Reported-and-tested-by: Pavel Ivanov <paivanof@xxxxxxxxx>
> Signed-off-by: Huang Ying <ying.huang@xxxxxxxxx>
> ---
> drivers/acpi/apei/apei-base.c | 29 ++++++++++++++++++++++++++++-
> 1 file changed, 28 insertions(+), 1 deletion(-)
>
> --- a/drivers/acpi/apei/apei-base.c
> +++ b/drivers/acpi/apei/apei-base.c
> @@ -438,8 +438,19 @@ int apei_resources_sub(struct apei_resou
> }
> EXPORT_SYMBOL_GPL(apei_resources_sub);
>
> +static int apei_get_nvs_callback(__u64 start, __u64 size, void *data)
> +{
> + struct apei_resources *resources = data;
> + return apei_res_add(&resources->iomem, start, size);
> +}
> +
> +static int apei_get_nvs_resources(struct apei_resources *resources)
> +{
> + return acpi_nvs_for_each_region(apei_get_nvs_callback, resources);
> +}
> +
> /*
> - * IO memory/port rersource management mechanism is used to check
> + * IO memory/port resource management mechanism is used to check
> * whether memory/port area used by GARs conflicts with normal memory
> * or IO memory/port of devices.
> */
> @@ -448,12 +459,26 @@ int apei_resources_request(struct apei_r
> {
> struct apei_res *res, *res_bak = NULL;
> struct resource *r;
> + struct apei_resources nvs_resources;
> int rc;
>
> rc = apei_resources_sub(resources, &apei_resources_all);
> if (rc)
> return rc;
>
> + /*
> + * Some firmware uses ACPI NVS region, that has been marked as
> + * busy, so exclude it from APEI resources to avoid false
> + * conflict.
> + */
> + apei_resources_init(&nvs_resources);
> + rc = apei_get_nvs_resources(&nvs_resources);
> + if (rc)
> + goto res_fini;
> + rc = apei_resources_sub(resources, &nvs_resources);
> + if (rc)
> + goto res_fini;
> +
> rc = -EINVAL;
> list_for_each_entry(res, &resources->iomem, list) {
> r = request_mem_region(res->start, res->end - res->start,
> @@ -500,6 +525,8 @@ err_unmap_iomem:
> break;
> release_mem_region(res->start, res->end - res->start);
> }
> +res_fini:
> + apei_resources_fini(&nvs_resources);
> return rc;
> }
> EXPORT_SYMBOL_GPL(apei_resources_request);
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>
--
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
