Hi Rafael and all,
Could you take a look at this patch? The mentioned bug blocks EINJ testing
when a firmware can correctly support ACPI 6.4 spec.
On Fri, Apr 01, 2022 at 05:28:40PM +0000, james.liu@xxxxxxx wrote:
> From: James Liu <james.liu@xxxxxxx>
>
> Modify acpi_os_map_generic_address and acpi_os_unmap_generic_address
> to handle a case that a GAS table (i.e., Table 5.1 in ACPI 6.4) is used
> to address a data structure; in this case, the GAS has the field of
> "Register Bit Width" equal to 0.
>
> For example, "Injection Instruction Entry" (Table 18.25 in ACPI 6.4)
> has a RegisterRegion field that is a GAS that points to a data
> structure SET_ERROR_TYPE_WITH_ADDRESS (Table 18.30), which is required
> when using EINJ (Error Injection module).
>
> This fix preserves a fairly sufficient memory space (i.e., page size)
> to store the data structure so as to prevent EINJ module from loading
> failure if platform firmware can support Injection Instruction Entry in
> an EINJ table.
>
> Signed-off-by: James Liu <james.liu@xxxxxxx>
> ---
> drivers/acpi/osl.c | 23 +++++++++++++++++++++--
> 1 file changed, 21 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
> index 45c5c0e45..ab2f584b1 100644
> --- a/drivers/acpi/osl.c
> +++ b/drivers/acpi/osl.c
> @@ -457,9 +457,15 @@ void __iomem *acpi_os_map_generic_address(struct acpi_generic_address *gas)
> if (gas->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)
> return NULL;
>
> + /* Handle a case that GAS is used to address an ACPI data structure */
> + if (!gas->bit_width) {
> + pr_info("An ACPI data structure at 0x%llx is mapped\n", addr);
> + return acpi_os_map_iomem(addr, PAGE_SIZE);
> + }
> +
> /* Handle possible alignment issues */
> memcpy(&addr, &gas->address, sizeof(addr));
> - if (!addr || !gas->bit_width)
> + if (!addr)
> return NULL;
>
> return acpi_os_map_iomem(addr, gas->bit_width / 8);
> @@ -474,9 +480,22 @@ void acpi_os_unmap_generic_address(struct acpi_generic_address *gas)
> if (gas->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)
> return;
>
> + /* Handle a case that GAS is used to address an ACPI data structure */
> + if (!gas->bit_width) {
> + pr_info("An ACPI data structure at 0x%llx is unmapped\n", addr);
> + mutex_lock(&acpi_ioremap_lock);
> + map = acpi_map_lookup(addr, PAGE_SIZE);
> + if (!map) {
> + mutex_unlock(&acpi_ioremap_lock);
> + return;
> + }
> + acpi_os_drop_map_ref(map);
> + mutex_unlock(&acpi_ioremap_lock);
> + }
> +
> /* Handle possible alignment issues */
> memcpy(&addr, &gas->address, sizeof(addr));
> - if (!addr || !gas->bit_width)
> + if (!addr)
> return;
>
> mutex_lock(&acpi_ioremap_lock);
> --
> 2.25.1
>
