[SeaBIOS] [RFC PATCH v4 11/30] acpi_piix4 : Implement memory device hotplug registers
Vasilis Liaskovitis
vasilis.liaskovitis at profitbricks.com
Tue Dec 18 13:41:39 CET 2012
A 32-byte register is used to present up to 256 hotplug-able memory devices
to BIOS and OSPM. Hot-add and hot-remove functions trigger an ACPI hotplug
event through these. Only reads are allowed from these registers.
An ACPI hot-remove event but needs to wait for OSPM to eject the device.
We use a single-byte register to know when OSPM has called the _EJ function
for a particular dimm. A write to this byte will depopulate the respective dimm.
Only writes are allowed to this byte.
v1->v2:
mems_sts address moved from 0xaf20 to 0xaf80 (to accomodate more space for
cpu-hotplugging in the future).
_EJ array is reduced to a single byte.
Add documentation in docs/specs/acpi_hotplug.txt
v3->v4: Removed hot-remove functions, will be added separately. Updated for
memory API.
Signed-off-by: Vasilis Liaskovitis <vasilis.liaskovitis at profitbricks.com>
---
docs/specs/acpi_hotplug.txt | 14 +++++++++
hw/acpi.h | 5 +++
hw/acpi_piix4.c | 65 +++++++++++++++++++++++++++++++++++++++++-
3 files changed, 82 insertions(+), 2 deletions(-)
create mode 100644 docs/specs/acpi_hotplug.txt
diff --git a/docs/specs/acpi_hotplug.txt b/docs/specs/acpi_hotplug.txt
new file mode 100644
index 0000000..8391713
--- /dev/null
+++ b/docs/specs/acpi_hotplug.txt
@@ -0,0 +1,14 @@
+QEMU<->ACPI BIOS hotplug interface
+--------------------------------------
+This document describes the interface between QEMU and the ACPI BIOS for non-PCI
+space. For the PCI interface please look at docs/specs/acpi_pci_hotplug.txt
+
+QEMU<->ACPI BIOS memory hotplug interface
+--------------------------------------
+
+Memory Dimm status array (IO port 0xaf80-0xaf9f, 1-byte access):
+---------------------------------------------------------------
+Dimm hot-plug notification pending. One bit per slot.
+
+Read by ACPI BIOS GPE.3 handler to notify OS of memory hot-add or hot-remove
+events. Read-only.
diff --git a/hw/acpi.h b/hw/acpi.h
index afda153..dc617d3 100644
--- a/hw/acpi.h
+++ b/hw/acpi.h
@@ -120,6 +120,11 @@ struct ACPIREGS {
Notifier wakeup;
};
+#include "dimm.h"
+struct gpe_regs {
+ uint8_t mems_sts[DIMM_BITMAP_BYTES];
+};
+
/* PM_TMR */
void acpi_pm_tmr_update(ACPIREGS *ar, bool enable);
void acpi_pm_tmr_calc_overflow_time(ACPIREGS *ar);
diff --git a/hw/acpi_piix4.c b/hw/acpi_piix4.c
index 0b5b0d3..879d8a0 100644
--- a/hw/acpi_piix4.c
+++ b/hw/acpi_piix4.c
@@ -29,6 +29,8 @@
#include "ioport.h"
#include "fw_cfg.h"
#include "exec-memory.h"
+#include "sysbus.h"
+#include "dimm.h"
//#define DEBUG
@@ -47,7 +49,9 @@
#define PCI_DOWN_BASE 0xae04
#define PCI_EJ_BASE 0xae08
#define PCI_RMV_BASE 0xae0c
+#define MEM_BASE 0xaf80
+#define PIIX4_MEM_HOTPLUG_STATUS 8
#define PIIX4_PCI_HOTPLUG_STATUS 2
struct pci_status {
@@ -60,6 +64,7 @@ typedef struct PIIX4PMState {
MemoryRegion io;
MemoryRegion io_gpe;
MemoryRegion io_pci;
+ MemoryRegion io_memhp;
ACPIREGS ar;
APMState apm;
@@ -74,6 +79,7 @@ typedef struct PIIX4PMState {
Notifier powerdown_notifier;
/* for pci hotplug */
+ struct gpe_regs gperegs;
struct pci_status pci0_status;
uint32_t pci0_hotplug_enable;
uint32_t pci0_slot_device_present;
@@ -98,8 +104,8 @@ static void pm_update_sci(PIIX4PMState *s)
ACPI_BITMASK_POWER_BUTTON_ENABLE |
ACPI_BITMASK_GLOBAL_LOCK_ENABLE |
ACPI_BITMASK_TIMER_ENABLE)) != 0) ||
- (((s->ar.gpe.sts[0] & s->ar.gpe.en[0])
- & PIIX4_PCI_HOTPLUG_STATUS) != 0);
+ (((s->ar.gpe.sts[0] & s->ar.gpe.en[0]) &
+ (PIIX4_PCI_HOTPLUG_STATUS | PIIX4_MEM_HOTPLUG_STATUS)) != 0);
qemu_set_irq(s->irq, sci_level);
/* schedule a timer interruption if needed */
@@ -526,6 +532,29 @@ static const MemoryRegionOps piix4_gpe_ops = {
.endianness = DEVICE_LITTLE_ENDIAN,
};
+static uint32_t memhp_readb(void *opaque, uint32_t addr)
+{
+ PIIX4PMState *s = opaque;
+ uint32_t val = 0;
+ struct gpe_regs *g = &s->gperegs;
+ if (addr < DIMM_BITMAP_BYTES) {
+ val = (uint32_t) g->mems_sts[addr];
+ }
+ PIIX4_DPRINTF(stderr, "memhp read %x == %x\n", addr, val);
+ return val;
+}
+
+static const MemoryRegionOps piix4_memhp_ops = {
+ .old_portio = (MemoryRegionPortio[]) {
+ {
+ .offset = 0, .len = DIMM_BITMAP_BYTES, .size = 1,
+ .read = memhp_readb,
+ },
+ PORTIO_END_OF_LIST()
+ },
+ .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
static uint32_t pci_up_read(void *opaque, uint32_t addr)
{
PIIX4PMState *s = opaque;
@@ -592,9 +621,11 @@ static const MemoryRegionOps piix4_pci_ops = {
static int piix4_device_hotplug(DeviceState *qdev, PCIDevice *dev,
PCIHotplugState state);
+static int piix4_dimm_hotplug(DeviceState *qdev, DimmDevice *dev, int add);
static void piix4_acpi_system_hot_add_init(PCIBus *bus, PIIX4PMState *s)
{
+ int i = 0;
memory_region_init_io(&s->io_gpe, &piix4_gpe_ops, s, "apci-gpe0",
GPE_LEN);
memory_region_add_subregion(get_system_io(), GPE_BASE, &s->io_gpe);
@@ -603,7 +634,16 @@ static void piix4_acpi_system_hot_add_init(PCIBus *bus, PIIX4PMState *s)
PCI_HOTPLUG_SIZE);
memory_region_add_subregion(get_system_io(), PCI_HOTPLUG_ADDR,
&s->io_pci);
+ memory_region_init_io(&s->io_memhp, &piix4_memhp_ops, s, "apci-memhp0",
+ DIMM_BITMAP_BYTES);
+ memory_region_add_subregion(get_system_io(), MEM_BASE, &s->io_memhp);
+
+ for (i = 0; i < DIMM_BITMAP_BYTES; i++) {
+ s->gperegs.mems_sts[i] = 0;
+ }
+
pci_bus_hotplug(bus, piix4_device_hotplug, &s->dev.qdev);
+ dimm_bus_hotplug(piix4_dimm_hotplug, &s->dev.qdev);
}
static void enable_device(PIIX4PMState *s, int slot)
@@ -618,6 +658,27 @@ static void disable_device(PIIX4PMState *s, int slot)
s->pci0_status.down |= (1U << slot);
}
+static void enable_mem_device(PIIX4PMState *s, int memdevice)
+{
+ struct gpe_regs *g = &s->gperegs;
+ s->ar.gpe.sts[0] |= PIIX4_MEM_HOTPLUG_STATUS;
+ g->mems_sts[memdevice/8] |= (1 << (memdevice%8));
+}
+
+static int piix4_dimm_hotplug(DeviceState *qdev, DimmDevice *dev, int
+ add)
+{
+ PCIDevice *pci_dev = DO_UPCAST(PCIDevice, qdev, qdev);
+ PIIX4PMState *s = DO_UPCAST(PIIX4PMState, dev, pci_dev);
+ DimmDevice *slot = DIMM(dev);
+
+ if (add) {
+ enable_mem_device(s, slot->idx);
+ }
+ pm_update_sci(s);
+ return 0;
+}
+
static int piix4_device_hotplug(DeviceState *qdev, PCIDevice *dev,
PCIHotplugState state)
{
--
1.7.9
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