[PATCH] seabios: call pci_init_device on resume

[Michael S. Tsirkin]

PIIX spec says that most its registers are reset on suspend.
However, QEMU didn't reset most of them properly.
Now that it started doing that, resume is broken.
Fix it up by probing system devices on bus 0 and re-initializing them.

Signed-off-by: Michael S. Tsirkin 
Reported-by: Gal Hammer 
Reviewed-by: Marcel Apfelbaum 
Tested-by: Marcel Apfelbaum 
---
 src/hw/pci.h     |  1 +
 src/util.h       |  1 +
 src/fw/pciinit.c |  5 +++++
 src/hw/pci.c     | 31 ++++++++++++++++++++-----------
 src/resume.c     |  8 ++++++++
 5 files changed, 35 insertions(+), 11 deletions(-)

diff --git a/src/hw/pci.h b/src/hw/pci.h
index 9c7351d..a64f7c5 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_probe_device(int bdf, struct pci_device *dev);
 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/util.h b/src/util.h
index e6a6cb5..3a24dba 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_bios_resume_device(struct pci_device *pci);
 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);
diff --git a/src/fw/pciinit.c b/src/fw/pciinit.c
index 34279a4..a4cedfb 100644
--- a/src/fw/pciinit.c
+++ b/src/fw/pciinit.c
@@ -293,6 +293,11 @@ static const struct pci_device_id pci_device_tbl[] = {
     PCI_DEVICE_END,
 };

+void pci_bios_resume_device(struct pci_device *pci)
+{
+    pci_init_device(pci_device_tbl, pci, NULL);
+}
+
 static void pci_bios_init_device(struct pci_device *pci)
 {
     u16 bdf = pci->bdf;
diff --git a/src/hw/pci.c b/src/hw/pci.c
index 6c9aa81..c2873c3 100644
--- a/src/hw/pci.c
+++ b/src/hw/pci.c
@@ -105,6 +105,24 @@ pci_probe_host(void)
     return 0;
 }

+void
+pci_probe_device(int bdf, struct pci_device *dev)
+{
+    dev->bdf = bdf;
+    u32 vendev = pci_config_readl(bdf, PCI_VENDOR_ID);
+    dev->vendor = vendev & 0xffff;
+    dev->device = vendev >> 16;
+    u32 classrev = pci_config_readl(bdf, PCI_CLASS_REVISION);
+    dev->class = classrev >> 16;
+    dev->prog_if = classrev >> 8;
+    dev->revision = classrev & 0xff;
+    dev->header_type = pci_config_readb(bdf, PCI_HEADER_TYPE);
+    u8 v = dev->header_type & 0x7f;
+    if (v == PCI_HEADER_TYPE_BRIDGE || v == PCI_HEADER_TYPE_CARDBUS) {
+        u8 secbus = pci_config_readb(bdf, PCI_SECONDARY_BUS);
+        dev->secondary_bus = secbus;
+    }
+}
 // Find all PCI devices and populate PCIDevices linked list.
 void
 pci_probe_devices(void)
@@ -145,21 +163,12 @@ pci_probe_devices(void)
             }

// Populate pci_device info.
-            dev->bdf = bdf;
+            pci_probe_device(bdf, dev);
             dev->parent = parent;
             dev->rootbus = rootbus;
-            u32 vendev = pci_config_readl(bdf, PCI_VENDOR_ID);
-            dev->vendor = vendev & 0xffff;
-            dev->device = vendev >> 16;
-            u32 classrev = pci_config_readl(bdf, PCI_CLASS_REVISION);
-            dev->class = classrev >> 16;
-            dev->prog_if = classrev >> 8;
-            dev->revision = classrev & 0xff;
-            dev->header_type = pci_config_readb(bdf, PCI_HEADER_TYPE);
             u8 v = dev->header_type & 0x7f;
             if (v == PCI_HEADER_TYPE_BRIDGE || v == PCI_HEADER_TYPE_CARDBUS) {
-                u8 secbus = pci_config_readb(bdf, PCI_SECONDARY_BUS);
-                dev->secondary_bus = secbus;
+                u8 secbus = dev->secondary_bus;
                 if (secbus > bus && !busdevs[secbus])
                     busdevs[secbus] = dev;
                 if (secbus > MaxPCIBus)
diff --git a/src/resume.c b/src/resume.c
index fc2fee9..9aac853 100644
--- a/src/resume.c
+++ b/src/resume.c
@@ -101,6 +101,14 @@ s3_resume(void)
     pic_setup();
     smm_setup();

+    int bdf;
+    foreachbdf(bdf, 0) {
+        // Create new pci_device struct and add to list.
+        struct pci_device pci;
+        pci_probe_device(bdf, &pci);
+        pci_bios_resume_device(&pci);
+    }
+
     s3_resume_vga();

make_bios_readonly();