On Wed, 2014-01-15 at 14:20 +0200, Marcel Apfelbaum wrote:
> On resume, the OS queries the power management event that
> caused it. In order to complete this task, it executes some
> reads to the piix pm io space. This all happens before the
> OS has a chance to restore the PCI config space for devices,
> so it is bios's responsibility to make sure the pm IO space
> is configured correctly. (During suspend, the piix pm
> configuration space is lost).
>
> Note: For 'ordinary' pci devices the config space is
> saved by the OS on sleep and restored on resume.
>
> Signed-off-by: Marcel Apfelbaum <marce...@redhat.com>
Ooops! I put a [Qemu-devel] prefix, it is going to be a problem?
Thanks,
Marcel
> ---
> v1 -> v2:
> Addressed Kevin O'Connor comments
> - Simplified patch by remembering PM device bdf
>
> Notes:
> - Without this patch the OS gets stuck because it tries repeatedly
> to read/write to pm io space, but the
> memory region is not enabled, so -1 is returned.
> - After resume the OS does not actually use the pm base address
> configured by the bios to get the IO ports, but uses
> the value from the ACPI FADT table actually. However, as a side effect
> of the configuration, the pm-io space is enabled by Qemu and
> the OS can continue the the boot sequence.
> - Bioses used for hardware like coreboot have the same init
> sequence for piix, see enable_pm from
> src/southbridge/intel/i82371eb/early_pm.c.
>
>
> src/fw/pciinit.c | 24 +++++++++++++++++++++---
> src/hw/pci.h | 1 +
> src/resume.c | 2 ++
> src/util.h | 1 +
> 4 files changed, 25 insertions(+), 3 deletions(-)
>
> diff --git a/src/fw/pciinit.c b/src/fw/pciinit.c
> index a24b8ff..11c92ae 100644
> --- a/src/fw/pciinit.c
> +++ b/src/fw/pciinit.c
> @@ -230,10 +230,8 @@ static void apple_macio_setup(struct pci_device *pci,
> void *arg)
> pci_set_io_region_addr(pci, 0, 0x80800000, 0);
> }
>
> -/* PIIX4 Power Management device (for ACPI) */
> -static void piix4_pm_setup(struct pci_device *pci, void *arg)
> +static void piix4_pm_config_setup(u16 bdf)
> {
> - u16 bdf = pci->bdf;
> // acpi sci is hardwired to 9
> pci_config_writeb(bdf, PCI_INTERRUPT_LINE, 9);
>
> @@ -241,6 +239,15 @@ static void piix4_pm_setup(struct pci_device *pci, void
> *arg)
> pci_config_writeb(bdf, 0x80, 0x01); /* enable PM io space */
> pci_config_writel(bdf, 0x90, PORT_SMB_BASE | 1);
> pci_config_writeb(bdf, 0xd2, 0x09); /* enable SMBus io space */
> +}
> +
> +static int PiixPmBDF = -1;
> +
> +/* PIIX4 Power Management device (for ACPI) */
> +static void piix4_pm_setup(struct pci_device *pci, void *arg)
> +{
> + PiixPmBDF = pci->bdf;
> + piix4_pm_config_setup(pci->bdf);
>
> acpi_pm1a_cnt = PORT_ACPI_PM_BASE + 0x04;
> pmtimer_setup(PORT_ACPI_PM_BASE + 0x08);
> @@ -295,6 +302,17 @@ static const struct pci_device_id pci_device_tbl[] = {
> PCI_DEVICE_END,
> };
>
> +void pci_resume(void)
> +{
> + if (!CONFIG_QEMU) {
> + return;
> + }
> +
> + if (PiixPmBDF >= 0) {
> + piix4_pm_config_setup(PiixPmBDF);
> + }
> +}
> +
> static void pci_bios_init_device(struct pci_device *pci)
> {
> u16 bdf = pci->bdf;
> diff --git a/src/hw/pci.h b/src/hw/pci.h
> index 9c7351d..17689a8 100644
> --- a/src/hw/pci.h
> +++ b/src/hw/pci.h
> @@ -66,6 +66,7 @@ extern u64 pcimem64_start, pcimem64_end;
> extern struct hlist_head PCIDevices;
> extern int MaxPCIBus;
> int pci_probe_host(void);
> +void pci_resume(void);
> void pci_probe_devices(void);
> static inline u32 pci_classprog(struct pci_device *pci) {
> return (pci->class << 8) | pci->prog_if;
> diff --git a/src/resume.c b/src/resume.c
> index d69429c..9ad2e4f 100644
> --- a/src/resume.c
> +++ b/src/resume.c
> @@ -101,6 +101,8 @@ s3_resume(void)
> pic_setup();
> smm_setup();
>
> + pci_resume();
> +
> s3_resume_vga();
>
> make_bios_readonly();
> diff --git a/src/util.h b/src/util.h
> index 1b7d525..3f53f4d 100644
> --- a/src/util.h
> +++ b/src/util.h
> @@ -28,6 +28,7 @@ void boot_add_cbfs(void *data, const char *desc, int prio);
> void interactive_bootmenu(void);
> void bcv_prepboot(void);
> struct pci_device;
> +void pci_resume(void);
> int bootprio_find_pci_device(struct pci_device *pci);
> int bootprio_find_scsi_device(struct pci_device *pci, int target, int lun);
> int bootprio_find_ata_device(struct pci_device *pci, int chanid, int slave);
