| Message ID | 20220630100324.3153655-5-nikos.nikoleris@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | EFI and ACPI support for arm64 | expand |
On Thu, Jun 30, 2022 at 11:03:01AM +0100, Nikos Nikoleris wrote: > XSDT provides pointers to other ACPI tables much like RSDT. However, > contrary to RSDT that provides 32-bit addresses, XSDT provides 64-bit > pointers. ACPI requires that if XSDT is valid then it takes precedence > over RSDT. > > Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com> > --- > lib/acpi.h | 6 ++++++ > lib/acpi.c | 37 +++++++++++++++++++++++++++++++------ > 2 files changed, 37 insertions(+), 6 deletions(-) > > diff --git a/lib/acpi.h b/lib/acpi.h > index b853a55..c5f0aa5 100644 > --- a/lib/acpi.h > +++ b/lib/acpi.h > @@ -14,6 +14,7 @@ > > #define RSDP_SIGNATURE ACPI_SIGNATURE('R','S','D','P') > #define RSDT_SIGNATURE ACPI_SIGNATURE('R','S','D','T') > +#define XSDT_SIGNATURE ACPI_SIGNATURE('X','S','D','T') > #define FACP_SIGNATURE ACPI_SIGNATURE('F','A','C','P') > #define FACS_SIGNATURE ACPI_SIGNATURE('F','A','C','S') > > @@ -57,6 +58,11 @@ struct rsdt_descriptor_rev1 { > u32 table_offset_entry[1]; > }; > > +struct acpi_table_xsdt { > + ACPI_TABLE_HEADER_DEF > + u64 table_offset_entry[1]; > +}; > + > struct fadt_descriptor_rev1 > { > ACPI_TABLE_HEADER_DEF /* ACPI common table header */ > diff --git a/lib/acpi.c b/lib/acpi.c > index b7fd923..240a922 100644 > --- a/lib/acpi.c > +++ b/lib/acpi.c > @@ -40,6 +40,7 @@ void *find_acpi_table_addr(u32 sig) > { > struct rsdp_descriptor *rsdp; > struct rsdt_descriptor_rev1 *rsdt; > + struct acpi_table_xsdt *xsdt = NULL; > void *end; > int i; > > @@ -64,17 +65,41 @@ void *find_acpi_table_addr(u32 sig) > > rsdt = (void *)(ulong)rsdp->rsdt_physical_address; > if (!rsdt || rsdt->signature != RSDT_SIGNATURE) > - return NULL; > + rsdt = NULL; Now that we set rsdt to NULL in the body of this if, the condition may look a bit better as (rsdt && rsdt->signature != RSDT_SIGNATURE) > > if (sig == RSDT_SIGNATURE) > return rsdt; > > - end = (void *)rsdt + rsdt->length; > - for (i = 0; (void *)&rsdt->table_offset_entry[i] < end; i++) { > - struct acpi_table *t = (void *)(ulong)rsdt->table_offset_entry[i]; > - if (t && t->signature == sig) { > - return t; > + /* > + * When the system implements APCI 2.0 and above and XSDT is > + * valid we have use XSDT to find other ACPI tables, ^ to > + * otherwise, we use RSDT. > + */ > + if (rsdp->revision == 2) > + xsdt = (void *)(ulong)rsdp->xsdt_physical_address; The (ulong) cast shouldn't be necessary maybe add a blank line here > + if (!xsdt || xsdt->signature != XSDT_SIGNATURE) Same comment as above > + xsdt = NULL; > + > + if (sig == XSDT_SIGNATURE) > + return xsdt; > + > + if (xsdt) { > + end = (void *)(ulong)xsdt + xsdt->length; The (ulong) cast shouldn't be necessary. > + for (i = 0; (void *)&xsdt->table_offset_entry[i] < end; i++) { > + struct acpi_table *t = (void *)xsdt->table_offset_entry[i]; > + > + if (t && t->signature == sig) > + return t; > + } > + } else if (rsdt) { > + end = (void *)rsdt + rsdt->length; > + for (i = 0; (void *)&rsdt->table_offset_entry[i] < end; i++) { > + struct acpi_table *t = (void *)(ulong)rsdt->table_offset_entry[i]; > + > + if (t && t->signature == sig) > + return t; > } > } > + > return NULL; > } > -- > 2.25.1 > Besides the nits Reviewed-by: Andrew Jones <andrew.jones@linux.dev> Thanks, drew
diff --git a/lib/acpi.h b/lib/acpi.h index b853a55..c5f0aa5 100644 --- a/lib/acpi.h +++ b/lib/acpi.h @@ -14,6 +14,7 @@ #define RSDP_SIGNATURE ACPI_SIGNATURE('R','S','D','P') #define RSDT_SIGNATURE ACPI_SIGNATURE('R','S','D','T') +#define XSDT_SIGNATURE ACPI_SIGNATURE('X','S','D','T') #define FACP_SIGNATURE ACPI_SIGNATURE('F','A','C','P') #define FACS_SIGNATURE ACPI_SIGNATURE('F','A','C','S') @@ -57,6 +58,11 @@ struct rsdt_descriptor_rev1 { u32 table_offset_entry[1]; }; +struct acpi_table_xsdt { + ACPI_TABLE_HEADER_DEF + u64 table_offset_entry[1]; +}; + struct fadt_descriptor_rev1 { ACPI_TABLE_HEADER_DEF /* ACPI common table header */ diff --git a/lib/acpi.c b/lib/acpi.c index b7fd923..240a922 100644 --- a/lib/acpi.c +++ b/lib/acpi.c @@ -40,6 +40,7 @@ void *find_acpi_table_addr(u32 sig) { struct rsdp_descriptor *rsdp; struct rsdt_descriptor_rev1 *rsdt; + struct acpi_table_xsdt *xsdt = NULL; void *end; int i; @@ -64,17 +65,41 @@ void *find_acpi_table_addr(u32 sig) rsdt = (void *)(ulong)rsdp->rsdt_physical_address; if (!rsdt || rsdt->signature != RSDT_SIGNATURE) - return NULL; + rsdt = NULL; if (sig == RSDT_SIGNATURE) return rsdt; - end = (void *)rsdt + rsdt->length; - for (i = 0; (void *)&rsdt->table_offset_entry[i] < end; i++) { - struct acpi_table *t = (void *)(ulong)rsdt->table_offset_entry[i]; - if (t && t->signature == sig) { - return t; + /* + * When the system implements APCI 2.0 and above and XSDT is + * valid we have use XSDT to find other ACPI tables, + * otherwise, we use RSDT. + */ + if (rsdp->revision == 2) + xsdt = (void *)(ulong)rsdp->xsdt_physical_address; + if (!xsdt || xsdt->signature != XSDT_SIGNATURE) + xsdt = NULL; + + if (sig == XSDT_SIGNATURE) + return xsdt; + + if (xsdt) { + end = (void *)(ulong)xsdt + xsdt->length; + for (i = 0; (void *)&xsdt->table_offset_entry[i] < end; i++) { + struct acpi_table *t = (void *)xsdt->table_offset_entry[i]; + + if (t && t->signature == sig) + return t; + } + } else if (rsdt) { + end = (void *)rsdt + rsdt->length; + for (i = 0; (void *)&rsdt->table_offset_entry[i] < end; i++) { + struct acpi_table *t = (void *)(ulong)rsdt->table_offset_entry[i]; + + if (t && t->signature == sig) + return t; } } + return NULL; }
XSDT provides pointers to other ACPI tables much like RSDT. However, contrary to RSDT that provides 32-bit addresses, XSDT provides 64-bit pointers. ACPI requires that if XSDT is valid then it takes precedence over RSDT. Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com> --- lib/acpi.h | 6 ++++++ lib/acpi.c | 37 +++++++++++++++++++++++++++++++------ 2 files changed, 37 insertions(+), 6 deletions(-)