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author | Gavin Shan <gwshan@linux.vnet.ibm.com> | 2017-05-24 12:30:23 +1000 |
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committer | Stewart Smith <stewart@linux.vnet.ibm.com> | 2017-06-19 14:49:29 +1000 |
commit | d065caf3b3101400744d4afb915edf57755a0c95 (patch) | |
tree | 942551ef104847c84d6689ea9c299e6847b12863 /hw/phb4.c | |
parent | 92d7ccf00bdd6c994341feb013390c28993652bf (diff) | |
download | skiboot-d065caf3b3101400744d4afb915edf57755a0c95.zip skiboot-d065caf3b3101400744d4afb915edf57755a0c95.tar.gz skiboot-d065caf3b3101400744d4afb915edf57755a0c95.tar.bz2 |
hw/phb4: Rework phb4_get_presence_state()
There are two issues in current implementation: It should return errcode
visibile to Linux, which has prefix OPAL_*. The code isn't very obvious.
This returns OPAL_HARDWARE when the PHB is broken. Otherwise, OPAL_SUCCESS
is always returned. In the mean while, It refactors the code to make it
obvious: OPAL_PCI_SLOT_PRESENT is returned when the presence signal (low active)
or PCIe link is active. Otherwise, OPAL_PCI_SLOT_EMPTY is returned.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Diffstat (limited to 'hw/phb4.c')
-rw-r--r-- | hw/phb4.c | 32 |
1 files changed, 11 insertions, 21 deletions
@@ -1845,36 +1845,26 @@ static int64_t phb4_get_presence_state(struct pci_slot *slot, uint8_t *val) if (p->state == PHB4_STATE_BROKEN) return OPAL_HARDWARE; - /* Read hotplug status */ + /* Check hotplug status */ hps = in_be64(p->regs + PHB_PCIE_HOTPLUG_STATUS); - - /* Read link status */ - dtctl = in_be64(p->regs + PHB_PCIE_DLP_TRAIN_CTL); - - PHBDBG(p, "hp_status=0x%016llx, dlp_train_ctl=0x%016llx\n", - hps, dtctl); - - *val = OPAL_PCI_SLOT_PRESENT; - /* Check presence detect */ - if (hps & PHB_PCIE_HPSTAT_PRESENCE) { - /* If it says not present but link is up, then we assume + if (!(hps & PHB_PCIE_HPSTAT_PRESENCE)) { + *val = OPAL_PCI_SLOT_PRESENT; + } else { + /* + * If it says not present but link is up, then we assume * we are on a broken simulation environment and still * return a valid presence. Otherwise, not present. */ + dtctl = in_be64(p->regs + PHB_PCIE_DLP_TRAIN_CTL); if (dtctl & PHB_PCIE_DLP_TL_LINKACT) { PHBERR(p, "Presence detect 0 but link set !\n"); - return OPAL_SHPC_DEV_PRESENT; + *val = OPAL_PCI_SLOT_PRESENT; + } else { + *val = OPAL_PCI_SLOT_EMPTY; } - *val = OPAL_PCI_SLOT_EMPTY; - return OPAL_SHPC_DEV_NOT_PRESENT; } - /* - * Anything else, we assume device present, the link state - * machine will perform an early bail out if no electrical - * signaling is established after a second. - */ - return OPAL_SHPC_DEV_PRESENT; + return OPAL_SUCCESS; } static int64_t phb4_get_link_state(struct pci_slot *slot, uint8_t *val) |