On Tue, May 17, 2022 at 7:56 PM James Liu <james.liu@xxxxxxx> wrote:
>
> Hi Rafael and all,
> Could you take a look into this patches? The mentioned bug blocks EINJ
> testing whenever a system firmware can correctly support GAS according
> to ACPI 6.4.
The kernel test robot reported an issue with it. Have you seen that report?
> 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
> >
