[PATCH] PCI Hotplug: shpchp: AMD POGO errata fix

This patch fixes the AMD POGO errata on the hotplug controller where the
platform will lock up or reboot if PERR/SERR generation is enabled and a
slot is sent an enable command.  This fix disables PERR/SERR generation
before a slot is sent the enable command by first saving related
registers, turning off SERR/PERR generation, enabling the slot, then
restoring the registers.

Signed-off-by: David Keck <david.keck@amd.com>
Cc: Kristen Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 105 insertions, 1 deletions

diff --git a/drivers/pci/hotplug/shpchp.h b/drivers/pci/hotplug/shpchp.h
index ce0e9b6ce833..7d6f521d02ea 100644
--- a/drivers/pci/hotplug/shpchp.h
+++ b/drivers/pci/hotplug/shpchp.h
@@ -95,6 +95,7 @@ struct controller {
         u8 function;
         u8 slot_device_offset;
         u8 add_support;
+        u32 pcix_misc2_reg;     /* for amd pogo errata */
         enum pci_bus_speed speed;
         u32 first_slot;         /* First physical slot number */
         u8 slot_bus;            /* Bus where the slots handled by this controller sit */
@@ -113,6 +114,26 @@ struct hotplug_params {
 
 /* Define AMD SHPC ID  */
 #define PCI_DEVICE_ID_AMD_GOLAM_7450    0x7450 
+#define PCI_DEVICE_ID_AMD_POGO_7458     0x7458
+
+/* AMD PCIX bridge registers */
+
+#define PCIX_MEM_BASE_LIMIT_OFFSET      0x1C
+#define PCIX_MISCII_OFFSET              0x48
+#define PCIX_MISC_BRIDGE_ERRORS_OFFSET  0x80
+
+/* AMD PCIX_MISCII masks and offsets */
+#define PERRNONFATALENABLE_MASK         0x00040000
+#define PERRFATALENABLE_MASK            0x00080000
+#define PERRFLOODENABLE_MASK            0x00100000
+#define SERRNONFATALENABLE_MASK         0x00200000
+#define SERRFATALENABLE_MASK            0x00400000
+
+/* AMD PCIX_MISC_BRIDGE_ERRORS masks and offsets */
+#define PERR_OBSERVED_MASK              0x00000001
+
+/* AMD PCIX_MEM_BASE_LIMIT masks */
+#define RSE_MASK                        0x40000000
 
 #define INT_BUTTON_IGNORE               0
 #define INT_PRESENCE_ON                 1
@@ -333,6 +354,79 @@ static inline int wait_for_ctrl_irq (struct controller *ctrl)
         return retval;
 }
 
+static inline void amd_pogo_errata_save_misc_reg(struct slot *p_slot)
+{
+        u32 pcix_misc2_temp;
+
+        /* save MiscII register */
+        pci_read_config_dword(p_slot->ctrl->pci_dev, PCIX_MISCII_OFFSET, &pcix_misc2_temp);
+
+        p_slot->ctrl->pcix_misc2_reg = pcix_misc2_temp;
+
+        /* clear SERR/PERR enable bits */
+        pcix_misc2_temp &= ~SERRFATALENABLE_MASK;
+        pcix_misc2_temp &= ~SERRNONFATALENABLE_MASK;
+        pcix_misc2_temp &= ~PERRFLOODENABLE_MASK;
+        pcix_misc2_temp &= ~PERRFATALENABLE_MASK;
+        pcix_misc2_temp &= ~PERRNONFATALENABLE_MASK;
+        pci_write_config_dword(p_slot->ctrl->pci_dev, PCIX_MISCII_OFFSET, pcix_misc2_temp);
+}
+
+static inline void amd_pogo_errata_restore_misc_reg(struct slot *p_slot)
+{
+        u32 pcix_misc2_temp;
+        u32 pcix_bridge_errors_reg;
+        u32 pcix_mem_base_reg;
+        u8  perr_set;
+        u8  rse_set;
+
+        /* write-one-to-clear Bridge_Errors[ PERR_OBSERVED ] */
+        pci_read_config_dword(p_slot->ctrl->pci_dev, PCIX_MISC_BRIDGE_ERRORS_OFFSET, &pcix_bridge_errors_reg);
+        perr_set = pcix_bridge_errors_reg & PERR_OBSERVED_MASK;
+        if (perr_set) {
+                dbg ("%s  W1C: Bridge_Errors[ PERR_OBSERVED = %08X]\n",__FUNCTION__ , perr_set);
+
+                pci_write_config_dword(p_slot->ctrl->pci_dev, PCIX_MISC_BRIDGE_ERRORS_OFFSET, perr_set);
+        }
+
+        /* write-one-to-clear Memory_Base_Limit[ RSE ] */
+        pci_read_config_dword(p_slot->ctrl->pci_dev, PCIX_MEM_BASE_LIMIT_OFFSET, &pcix_mem_base_reg);
+        rse_set = pcix_mem_base_reg & RSE_MASK;
+        if (rse_set) {
+                dbg ("%s  W1C: Memory_Base_Limit[ RSE ]\n",__FUNCTION__ );
+
+                pci_write_config_dword(p_slot->ctrl->pci_dev, PCIX_MEM_BASE_LIMIT_OFFSET, rse_set);
+        }
+        /* restore MiscII register */
+        pci_read_config_dword( p_slot->ctrl->pci_dev, PCIX_MISCII_OFFSET, &pcix_misc2_temp );
+
+        if (p_slot->ctrl->pcix_misc2_reg & SERRFATALENABLE_MASK)
+                pcix_misc2_temp |= SERRFATALENABLE_MASK;
+        else
+                pcix_misc2_temp &= ~SERRFATALENABLE_MASK;
+
+        if (p_slot->ctrl->pcix_misc2_reg & SERRNONFATALENABLE_MASK)
+                pcix_misc2_temp |= SERRNONFATALENABLE_MASK;
+        else
+                pcix_misc2_temp &= ~SERRNONFATALENABLE_MASK;
+
+        if (p_slot->ctrl->pcix_misc2_reg & PERRFLOODENABLE_MASK)
+                pcix_misc2_temp |= PERRFLOODENABLE_MASK;
+        else
+                pcix_misc2_temp &= ~PERRFLOODENABLE_MASK;
+
+        if (p_slot->ctrl->pcix_misc2_reg & PERRFATALENABLE_MASK)
+                pcix_misc2_temp |= PERRFATALENABLE_MASK;
+        else
+                pcix_misc2_temp &= ~PERRFATALENABLE_MASK;
+
+        if (p_slot->ctrl->pcix_misc2_reg & PERRNONFATALENABLE_MASK)
+                pcix_misc2_temp |= PERRNONFATALENABLE_MASK;
+        else
+                pcix_misc2_temp &= ~PERRNONFATALENABLE_MASK;
+        pci_write_config_dword(p_slot->ctrl->pci_dev, PCIX_MISCII_OFFSET, pcix_misc2_temp);
+}
+
 #define SLOT_NAME_SIZE 10
 
 static inline void make_slot_name(char *buffer, int buffer_size, struct slot *slot)
diff --git a/drivers/pci/hotplug/shpchp_ctrl.c b/drivers/pci/hotplug/shpchp_ctrl.c
index 25ccb0e47593..643252d9bf3b 100644
--- a/drivers/pci/hotplug/shpchp_ctrl.c
+++ b/drivers/pci/hotplug/shpchp_ctrl.c
@@ -894,7 +894,17 @@ int shpchp_enable_slot (struct slot *p_slot)
         dbg("%s: p_slot->pwr_save %x\n", __FUNCTION__, p_slot->pwr_save);
         p_slot->hpc_ops->get_latch_status(p_slot, &getstatus);
 
-        rc = board_added(p_slot);
+        if(((p_slot->ctrl->pci_dev->vendor == PCI_VENDOR_ID_AMD) ||
+            (p_slot->ctrl->pci_dev->device == PCI_DEVICE_ID_AMD_POGO_7458))
+             && p_slot->ctrl->num_slots == 1) {
+                /* handle amd pogo errata; this must be done before enable  */
+                amd_pogo_errata_save_misc_reg(p_slot);
+                rc = board_added(p_slot);
+                /* handle amd pogo errata; this must be done after enable  */
+                amd_pogo_errata_restore_misc_reg(p_slot);
+        } else
+                rc = board_added(p_slot);
+
         if (rc) {
                 p_slot->hpc_ops->get_adapter_status(p_slot,
                                 &(p_slot->presence_save));