[SeaBIOS] Alt SeaBIOS SSDT cpu hotplug
Kevin O'Connor
kevin at koconnor.net
Fri Jul 9 07:35:07 CEST 2010
On Thu, Jul 08, 2010 at 09:19:13PM +0800, Liu, Jinsong wrote:
> Avi Kivity wrote:
> > Very nice. I thought about doing this but abandoned it as
> > unmaintainable. Using external functions and the ID variable,
> > however, reduces the mess to tolerable proportions, and gains us a
> > lot of flexibility. We can now have any combinations of sockets and
> > installed cpus.
>
> Agree, only 1 concern
> will it bring debugable/ scalable issue by hardcode aml code?
I've updated the patch (see below). This version documents how one
can build a new version of the Processor() ssdt snippet.
I've tested this under linux - there were a few bugs in the previous
patch. I also had to replace the dynamically created CPUS array with
a dynamically created NTFY method - which is a bit more complicated.
-Kevin
diff --git a/src/acpi-dsdt.dsl b/src/acpi-dsdt.dsl
index cc31112..24674fc 100644
--- a/src/acpi-dsdt.dsl
+++ b/src/acpi-dsdt.dsl
@@ -648,6 +648,78 @@ DefinitionBlock (
Zero /* reserved */
})
+ /* CPU hotplug */
+ Scope(\_SB) {
+ /* Objects filled in by run-time generated SSDT */
+ External(NTFY, MethodObj)
+ External(CPON, PkgObj)
+
+ /* Methods called by run-time generated SSDT Processor objects */
+ Method (CPMA, 1, NotSerialized) {
+ // _MAT method - create an madt apic buffer
+ // Local0 = CPON flag for this cpu
+ Store(DerefOf(Index(CPON, Arg0)), Local0)
+ // Local1 = Buffer (in madt apic form) to return
+ Store(Buffer(8) {0x00, 0x08, 0x00, 0x00, 0x00, 0, 0, 0}, Local1)
+ // Update the processor id, lapic id, and enable/disable status
+ Store(Arg0, Index(Local1, 2))
+ Store(Arg0, Index(Local1, 3))
+ Store(Local0, Index(Local1, 4))
+ Return (Local1)
+ }
+ Method (CPST, 1, NotSerialized) {
+ // _STA method - return ON status of cpu
+ // Local0 = CPON flag for this cpu
+ Store(DerefOf(Index(CPON, Arg0)), Local0)
+ If (Local0) { Return(0xF) } Else { Return(0x0) }
+ }
+ Method (CPEJ, 2, NotSerialized) {
+ // _EJ0 method - eject callback
+ Sleep (0xC8)
+ }
+
+ /* CPU hotplug notify method */
+ OperationRegion(PRST, SystemIO, 0xaf00, 32)
+ Field (PRST, ByteAcc, NoLock, Preserve)
+ {
+ PRS, 256
+ }
+ Method(PRSC, 0) {
+ // Local5 = active cpu bitmap
+ Store (PRS, Local5)
+ // Local2 = last read byte from bitmap
+ Store (Zero, Local2)
+ // Local0 = cpuid iterator
+ Store (Zero, Local0)
+ While (LLess(Local0, SizeOf(CPON))) {
+ // Local1 = CPON flag for this cpu
+ Store(DerefOf(Index(CPON, Local0)), Local1)
+ If (And(Local0, 0x07)) {
+ // Shift down previously read bitmap byte
+ ShiftRight(Local2, 1, Local2)
+ } Else {
+ // Read next byte from cpu bitmap
+ Store(DerefOf(Index(Local5, ShiftRight(Local0, 3))), Local2)
+ }
+ // Local3 = active state for this cpu
+ Store(And(Local2, 1), Local3)
+
+ If (LNotEqual(Local1, Local3)) {
+ // State change - update CPON with new state
+ Store(Local3, Index(CPON, Local0))
+ // Do CPU notify
+ If (LEqual(Local3, 1)) {
+ NTFY(Local0, 1)
+ } Else {
+ NTFY(Local0, 3)
+ }
+ }
+ Increment(Local0)
+ }
+ Return(One)
+ }
+ }
+
Scope (\_GPE)
{
Name(_HID, "ACPI0006")
@@ -701,7 +773,8 @@ DefinitionBlock (
}
Method(_L02) {
- Return(0x01)
+ // CPU hotplug event
+ Return(\_SB.PRSC())
}
Method(_L03) {
Return(0x01)
diff --git a/src/acpi.c b/src/acpi.c
index 0559443..082ef73 100644
--- a/src/acpi.c
+++ b/src/acpi.c
@@ -406,16 +406,56 @@ build_madt(void)
return madt;
}
+// Encode a hex value
+static inline char getHex(u32 val) {
+ val &= 0x0f;
+ return (val <= 9) ? ('0' + val) : ('A' + val - 10);
+}
+
+// Encode a length in an SSDT.
+static u8 *
+encodeLen(u8 *ssdt_ptr, int length, int bytes)
+{
+ if (bytes <= 1) {
+ *ssdt_ptr = length & 0x3f;
+ return ssdt_ptr+1;
+ }
+ ssdt_ptr[0] = (((bytes-1) & 0x3) << 6) | (length & 0x0f);
+ ssdt_ptr[1] = ((length >> 4) & 0xff);
+ ssdt_ptr[2] = ((length >> 12) & 0xff);
+ ssdt_ptr[3] = ((length >> 20) & 0xff);
+ return ssdt_ptr + bytes;
+}
+
+// AML Processor() object. See src/ssdt-proc.dsl for info.
+static unsigned char ssdt_proc[] = {
+ 0x5b,0x83,0x43,0x05,0x43,0x50,0x41,0x41,
+ 0xaa,0x10,0xb0,0x00,0x00,0x06,0x08,0x49,
+ 0x44,0x5f,0x5f,0x0a,0xaa,0x08,0x5f,0x48,
+ 0x49,0x44,0x0d,0x41,0x43,0x50,0x49,0x30,
+ 0x30,0x30,0x37,0x00,0x14,0x0f,0x5f,0x4d,
+ 0x41,0x54,0x00,0xa4,0x43,0x50,0x4d,0x41,
+ 0x49,0x44,0x5f,0x5f,0x14,0x0f,0x5f,0x53,
+ 0x54,0x41,0x00,0xa4,0x43,0x50,0x53,0x54,
+ 0x49,0x44,0x5f,0x5f,0x14,0x10,0x5f,0x45,
+ 0x4a,0x30,0x01,0xa4,0x43,0x50,0x45,0x4a,
+ 0x49,0x44,0x5f,0x5f,0x68
+};
+#define SD_OFFSET_CPUHEX 6
+#define SD_OFFSET_CPUID1 8
+#define SD_OFFSET_CPUID2 20
+
#define SSDT_SIGNATURE 0x54445353 // SSDT
static void*
build_ssdt(void)
{
int acpi_cpus = MaxCountCPUs > 0xff ? 0xff : MaxCountCPUs;
- // calculate the length of processor block and scope block
- // excluding PkgLength
- int cpu_length = 13 * acpi_cpus + 4;
-
- int length = sizeof(struct acpi_table_header) + 3 + cpu_length;
+ // length = ssdt header + ScopeOp + procs + CPUS package + CPON package
+ int length = (sizeof(struct acpi_table_header)
+ + (1+3+4)
+ + (acpi_cpus * sizeof(ssdt_proc))
+ + (1+2+5+(12*acpi_cpus))
+ + (1+4+1+2+1+(1*acpi_cpus)));
u8 *ssdt = malloc_high(length);
if (! ssdt) {
warn_noalloc();
@@ -423,47 +463,66 @@ build_ssdt(void)
}
u8 *ssdt_ptr = ssdt;
- ssdt_ptr[9] = 0; // checksum;
ssdt_ptr += sizeof(struct acpi_table_header);
// build processor scope header
*(ssdt_ptr++) = 0x10; // ScopeOp
- if (cpu_length <= 0x3e) {
- /* Handle 1-4 CPUs with one byte encoding */
- *(ssdt_ptr++) = cpu_length + 1;
- } else {
- /* Handle 5-314 CPUs with two byte encoding */
- *(ssdt_ptr++) = 0x40 | ((cpu_length + 2) & 0xf);
- *(ssdt_ptr++) = (cpu_length + 2) >> 4;
- }
+ ssdt_ptr = encodeLen(ssdt_ptr, length-1, 3);
*(ssdt_ptr++) = '_'; // Name
- *(ssdt_ptr++) = 'P';
- *(ssdt_ptr++) = 'R';
+ *(ssdt_ptr++) = 'S';
+ *(ssdt_ptr++) = 'B';
*(ssdt_ptr++) = '_';
- // build object for each processor
+ // build Processor object for each processor
int i;
for (i=0; i<acpi_cpus; i++) {
- *(ssdt_ptr++) = 0x5B; // ProcessorOp
- *(ssdt_ptr++) = 0x83;
- *(ssdt_ptr++) = 0x0B; // Length
- *(ssdt_ptr++) = 'C'; // Name (CPUxx)
- *(ssdt_ptr++) = 'P';
- if ((i & 0xf0) != 0)
- *(ssdt_ptr++) = (i >> 4) < 0xa ? (i >> 4) + '0' : (i >> 4) + 'A' - 0xa;
- else
- *(ssdt_ptr++) = 'U';
- *(ssdt_ptr++) = (i & 0xf) < 0xa ? (i & 0xf) + '0' : (i & 0xf) + 'A' - 0xa;
+ memcpy(ssdt_ptr, ssdt_proc, sizeof(ssdt_proc));
+ ssdt_ptr[SD_OFFSET_CPUHEX] = getHex(i >> 4);
+ ssdt_ptr[SD_OFFSET_CPUHEX+1] = getHex(i);
+ ssdt_ptr[SD_OFFSET_CPUID1] = i;
+ ssdt_ptr[SD_OFFSET_CPUID2] = i;
+ ssdt_ptr += sizeof(ssdt_proc);
+ }
+
+ // build "Method(NTFY, 2) {If (LEqual(Arg0, 0x00)) {Notify(CP00, Arg1)} ...}"
+ *(ssdt_ptr++) = 0x14; // MethodOp
+ ssdt_ptr = encodeLen(ssdt_ptr, 2+5+(12*acpi_cpus), 2);
+ *(ssdt_ptr++) = 'N';
+ *(ssdt_ptr++) = 'T';
+ *(ssdt_ptr++) = 'F';
+ *(ssdt_ptr++) = 'Y';
+ *(ssdt_ptr++) = 0x02;
+ for (i=0; i<acpi_cpus; i++) {
+ *(ssdt_ptr++) = 0xA0; // IfOp
+ ssdt_ptr = encodeLen(ssdt_ptr, 11, 1);
+ *(ssdt_ptr++) = 0x93; // LEqualOp
+ *(ssdt_ptr++) = 0x68; // Arg0Op
+ *(ssdt_ptr++) = 0x0A; // BytePrefix
*(ssdt_ptr++) = i;
- *(ssdt_ptr++) = 0x10; // Processor block address
- *(ssdt_ptr++) = 0xb0;
- *(ssdt_ptr++) = 0;
- *(ssdt_ptr++) = 0;
- *(ssdt_ptr++) = 6; // Processor block length
+ *(ssdt_ptr++) = 0x86; // NotifyOp
+ *(ssdt_ptr++) = 'C';
+ *(ssdt_ptr++) = 'P';
+ *(ssdt_ptr++) = getHex(i >> 4);
+ *(ssdt_ptr++) = getHex(i);
+ *(ssdt_ptr++) = 0x69; // Arg1Op
}
+ // build "Name(CPON, Package() { One, One, ..., Zero, Zero, ... })"
+ *(ssdt_ptr++) = 0x08; // NameOp
+ *(ssdt_ptr++) = 'C';
+ *(ssdt_ptr++) = 'P';
+ *(ssdt_ptr++) = 'O';
+ *(ssdt_ptr++) = 'N';
+ *(ssdt_ptr++) = 0x12; // PackageOp
+ ssdt_ptr = encodeLen(ssdt_ptr, 2+1+(1*acpi_cpus), 2);
+ *(ssdt_ptr++) = acpi_cpus;
+ for (i=0; i<acpi_cpus; i++)
+ *(ssdt_ptr++) = (i < CountCPUs) ? 0x01 : 0x00;
+
build_header((void*)ssdt, SSDT_SIGNATURE, ssdt_ptr - ssdt, 1);
+ hexdump(ssdt, ssdt_ptr - ssdt);
+
return ssdt;
}
diff --git a/src/ssdt-proc.dsl b/src/ssdt-proc.dsl
new file mode 100644
index 0000000..c10d125
--- /dev/null
+++ b/src/ssdt-proc.dsl
@@ -0,0 +1,50 @@
+/* This file is the basis for the ssdt_proc[] variable in src/acpi.c.
+ * It defines the contents of the per-cpu Processor() object. At
+ * runtime, a dynamically generated SSDT will contain one copy of this
+ * AML snippet for every possible cpu in the system. The objects will
+ * be placed in the \_SB_ namespace.
+ *
+ * To generate a new ssdt_proc[], run the commands:
+ * cpp -P src/ssdt-proc.dsl > out/ssdt-proc.dsl.i
+ * iasl -ta -p out/ssdt-proc out/ssdt-proc.dsl.i
+ * tail -c +37 < out/ssdt-proc.aml | hexdump -e '" " 8/1 "0x%02x," "\n"'
+ * and then cut-and-paste the output into the src/acpi.c ssdt_proc[]
+ * array.
+ *
+ * In addition to the aml code generated from this file, the
+ * src/acpi.c file creates a NTFY method with an entry for each cpu:
+ * Method(NTFY, 2) {
+ * If (LEqual(Arg0, 0x00)) { Notify(CP00, Arg1) }
+ * If (LEqual(Arg0, 0x01)) { Notify(CP01, Arg1) }
+ * ...
+ * }
+ * and a CPON array with the list of active and inactive cpus:
+ * Name(CPON, Package() { One, One, ..., Zero, Zero, ... })
+ */
+DefinitionBlock ("ssdt-proc.aml", "SSDT", 0x01, "BXPC", "BXSSDT", 0x1)
+/* V------------------ DO NOT EDIT ------------------V */
+{
+ Processor (CPAA, 0xAA, 0x0000b010, 0x06) {
+ Name (ID, 0xAA)
+/* ^------------------ DO NOT EDIT ------------------^
+ *
+ * The src/acpi.c code requires the above layout so that it can update
+ * CPAA and 0xAA with the appropriate CPU id (see SD_OFFSET_CPUHEX,
+ * CPUID1, CPUID2). Don't change the above without also updating the
+ * C code.
+ */
+ Name (_HID, "ACPI0007")
+ External(CPMA, MethodObj)
+ External(CPST, MethodObj)
+ External(CPEJ, MethodObj)
+ Method(_MAT, 0) {
+ Return(CPMA(ID))
+ }
+ Method (_STA, 0) {
+ Return(CPST(ID))
+ }
+ Method (_EJ0, 1, NotSerialized) {
+ Return(CPEJ(ID, Arg0))
+ }
+ }
+}
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