From: "Michael S. Tsirkin" <mst@redhat.com>
To: qemu-devel@nongnu.org
Cc: Igor Mammedov <imammedo@redhat.com>
Subject: [Qemu-devel] [PATCH 4/3] pcie: minor cleanups for slot control/status
Date: Mon, 1 Jul 2019 05:34:54 -0400 [thread overview]
Message-ID: <20190701093232.28575-1-mst@redhat.com> (raw)
In-Reply-To: <20190621064615.20099-1-mst@redhat.com>
Rename function arguments to make intent clearer.
Better documentation for slot control logic.
Suggested-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
include/hw/pci/pcie.h | 3 ++-
hw/pci/pcie.c | 17 +++++++++++------
2 files changed, 13 insertions(+), 7 deletions(-)
diff --git a/include/hw/pci/pcie.h b/include/hw/pci/pcie.h
index 8d90c0e193..34f277735c 100644
--- a/include/hw/pci/pcie.h
+++ b/include/hw/pci/pcie.h
@@ -108,7 +108,8 @@ void pcie_cap_lnkctl_reset(PCIDevice *dev);
void pcie_cap_slot_init(PCIDevice *dev, uint16_t slot);
void pcie_cap_slot_reset(PCIDevice *dev);
void pcie_cap_slot_get(PCIDevice *dev, uint16_t *slot_ctl, uint16_t *slt_sta);
-void pcie_cap_slot_write_config(PCIDevice *dev, uint16_t slot_ctl, uint16_t slt_sta,
+void pcie_cap_slot_write_config(PCIDevice *dev,
+ uint16_t old_slot_ctl, uint16_t old_slt_sta,
uint32_t addr, uint32_t val, int len);
int pcie_cap_slot_post_load(void *opaque, int version_id);
void pcie_cap_slot_push_attention_button(PCIDevice *dev);
diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index c605d32dd4..a6beb567bd 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -602,7 +602,8 @@ void pcie_cap_slot_get(PCIDevice *dev, uint16_t *slt_ctl, uint16_t *slt_sta)
*slt_sta = pci_get_word(exp_cap + PCI_EXP_SLTSTA);
}
-void pcie_cap_slot_write_config(PCIDevice *dev, uint16_t slt_ctl, uint16_t slt_sta,
+void pcie_cap_slot_write_config(PCIDevice *dev,
+ uint16_t old_slt_ctl, uint16_t old_slt_sta,
uint32_t addr, uint32_t val, int len)
{
uint32_t pos = dev->exp.exp_cap;
@@ -625,8 +626,8 @@ void pcie_cap_slot_write_config(PCIDevice *dev, uint16_t slt_ctl, uint16_t slt_s
PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC | \
PCI_EXP_SLTSTA_CC)
- if (val & ~slt_sta & PCIE_SLOT_EVENTS) {
- sltsta = (sltsta & ~PCIE_SLOT_EVENTS) | (slt_sta & PCIE_SLOT_EVENTS);
+ if (val & ~old_slt_sta & PCIE_SLOT_EVENTS) {
+ sltsta = (sltsta & ~PCIE_SLOT_EVENTS) | (old_slt_sta & PCIE_SLOT_EVENTS);
pci_set_word(exp_cap + PCI_EXP_SLTSTA, sltsta);
}
hotplug_event_clear(dev);
@@ -646,13 +647,17 @@ void pcie_cap_slot_write_config(PCIDevice *dev, uint16_t slt_ctl, uint16_t slt_s
}
/*
- * If the slot is polulated, power indicator is off and power
+ * If the slot is populated, power indicator is off and power
* controller is off, it is safe to detach the devices.
+ *
+ * Note: don't detach if condition was already true:
+ * this is a work around for guests that overwrite
+ * control of powered off slots before powering them on.
*/
if ((sltsta & PCI_EXP_SLTSTA_PDS) && (val & PCI_EXP_SLTCTL_PCC) &&
(val & PCI_EXP_SLTCTL_PIC_OFF) == PCI_EXP_SLTCTL_PIC_OFF &&
- (!(slt_ctl & PCI_EXP_SLTCTL_PCC) ||
- (slt_ctl & PCI_EXP_SLTCTL_PIC_OFF) != PCI_EXP_SLTCTL_PIC_OFF)) {
+ (!(old_slt_ctl & PCI_EXP_SLTCTL_PCC) ||
+ (old_slt_ctl & PCI_EXP_SLTCTL_PIC_OFF) != PCI_EXP_SLTCTL_PIC_OFF)) {
PCIBus *sec_bus = pci_bridge_get_sec_bus(PCI_BRIDGE(dev));
pci_for_each_device(sec_bus, pci_bus_num(sec_bus),
pcie_unplug_device, NULL);
--
MST
next prev parent reply other threads:[~2019-07-01 9:39 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-21 6:46 [Qemu-devel] [PATCH 0/3] pcie: hotplug fixes Michael S. Tsirkin
2019-06-21 6:46 ` [Qemu-devel] [PATCH 1/3] pcie: don't skip multi-mask events Michael S. Tsirkin
2019-06-25 11:14 ` Igor Mammedov
2019-07-01 7:01 ` Marcel Apfelbaum
2019-07-01 9:56 ` Philippe Mathieu-Daudé
2019-06-21 6:46 ` [Qemu-devel] [PATCH 2/3] pcie: check that slt ctrl changed before deleting Michael S. Tsirkin
2019-06-25 12:45 ` Igor Mammedov
2019-07-01 9:23 ` Michael S. Tsirkin
2019-07-01 7:03 ` Marcel Apfelbaum
2019-07-01 13:07 ` Igor Mammedov
2019-06-21 6:46 ` [Qemu-devel] [PATCH 3/3] pcie: work around for racy guest init Michael S. Tsirkin
2019-06-25 13:07 ` Igor Mammedov
2019-07-01 9:20 ` Michael S. Tsirkin
2019-07-01 12:04 ` Igor Mammedov
2019-07-01 12:08 ` Michael S. Tsirkin
2019-07-01 7:04 ` Marcel Apfelbaum
[not found] ` <20190701105708.5d28f497@redhat.com>
2019-07-01 9:12 ` Marcel Apfelbaum
2019-07-01 9:13 ` Marcel Apfelbaum
2019-07-01 13:01 ` Igor Mammedov
2019-07-01 9:34 ` Michael S. Tsirkin [this message]
2019-07-01 9:56 ` [Qemu-devel] [PATCH 4/3] pcie: minor cleanups for slot control/status Philippe Mathieu-Daudé
2019-07-01 13:07 ` Igor Mammedov
2019-07-01 13:51 ` Christophe de Dinechin
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