[PATCH] SHPC: Fix SHPC Logical Slot Register bits access

Current SHPCHP driver doesn't take care of RsvdP/RsvdZ[*] bits
in logical slot registers. This might cause unpredicable results. This
patch fixes this bug.

[*] RsvdP and RsvdZ are defined in SHPC spec as follows:

    RsvdP - Reserved and Preserved. Register bits of this type are
    reserved for future use as R/W bits. The value read is
    undefined. Writes are ignored. Software must follow These rules
    when accessing RsvdP bits:

	- Software must ignore RsvdP bits when testing values read
          from these registers.
	- Software must not depend on RsvdP bit's ability to retain
          information when written
	- Software must always write back the value read in the RsvdP
	  bits when writing one of these registers.

    RsvdZ - Reserved and Zero. Register bits of this type are reserved
    for future use as R/WC bits. The value read is undefined. Writes
    are ignored. Software must follow these rules when accessing RsvdZ
    bits:

        - Software must ignore RsvdZ bits when testing values read
	  from these registers.
	- Software must not depends on a RsvdZ bit's ability to retain
	  information when written.
	- Software must always write 0 to RsvdZ bits when writing one
	  of these register.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Cc: Kristen Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 40 insertions, 9 deletions

diff --git a/drivers/pci/hotplug/shpchp_hpc.c b/drivers/pci/hotplug/shpchp_hpc.c
index 9731ee8224f2..285a21d36524 100644
--- a/drivers/pci/hotplug/shpchp_hpc.c
+++ b/drivers/pci/hotplug/shpchp_hpc.c
@@ -554,11 +554,25 @@ static int hpc_get_adapter_speed(struct slot *slot, enum pci_bus_speed *value)
         int retval = 0;
         struct controller *ctrl = slot->ctrl;
         u32 slot_reg = shpc_readl(ctrl, SLOT_REG(slot->hp_slot));
-        u8 pcix_cap = (slot_reg & PCIX_CAP_MASK_PI2) >> PCIX_CAP_SHIFT;
         u8 m66_cap  = !!(slot_reg & MHZ66_CAP);
+        u8 pi, pcix_cap;
 
         DBG_ENTER_ROUTINE 
 
+        if ((retval = hpc_get_prog_int(slot, &pi)))
+                return retval;
+
+        switch (pi) {
+        case 1:
+                pcix_cap = (slot_reg & PCIX_CAP_MASK_PI1) >> PCIX_CAP_SHIFT;
+                break;
+        case 2:
+                pcix_cap = (slot_reg & PCIX_CAP_MASK_PI2) >> PCIX_CAP_SHIFT;
+                break;
+        default:
+                return -ENODEV;
+        }
+
         dbg("%s: slot_reg = %x, pcix_cap = %x, m66_cap = %x\n",
             __FUNCTION__, slot_reg, pcix_cap, m66_cap);
 
@@ -773,6 +787,7 @@ static void hpc_release_ctlr(struct controller *ctrl)
         struct php_ctlr_state_s *php_ctlr = ctrl->hpc_ctlr_handle;
         struct php_ctlr_state_s *p, *p_prev;
         int i;
+        u32 slot_reg;
 
         DBG_ENTER_ROUTINE 
 
@@ -782,10 +797,17 @@ static void hpc_release_ctlr(struct controller *ctrl)
         }
 
         /*
-         * Mask all slot event interrupts
+         * Mask event interrupts and SERRs of all slots
          */
-        for (i = 0; i < ctrl->num_slots; i++)
-                shpc_writel(ctrl, SLOT_REG(i), 0xffff3fff);
+        for (i = 0; i < ctrl->num_slots; i++) {
+                slot_reg = shpc_readl(ctrl, SLOT_REG(i));
+                slot_reg |= (PRSNT_CHANGE_INTR_MASK | ISO_PFAULT_INTR_MASK |
+                             BUTTON_PRESS_INTR_MASK | MRL_CHANGE_INTR_MASK |
+                             CON_PFAULT_INTR_MASK   | MRL_CHANGE_SERR_MASK |
+                             CON_PFAULT_SERR_MASK);
+                slot_reg &= ~SLOT_REG_RSVDZ_MASK;
+                shpc_writel(ctrl, SLOT_REG(i), slot_reg);
+        }
 
         cleanup_slots(ctrl);
 
@@ -1072,7 +1094,7 @@ static irqreturn_t shpc_isr(int IRQ, void *dev_id, struct pt_regs *regs)
                                         hp_slot, php_ctlr->callback_instance_id);
                         
                         /* Clear all slot events */
-                        temp_dword = 0xe01f3fff;
+                        temp_dword &= ~SLOT_REG_RSVDZ_MASK;
                         shpc_writel(ctrl, SLOT_REG(hp_slot), temp_dword);
 
                         intr_loc2 = shpc_readl(ctrl, INTR_LOC);
@@ -1364,8 +1386,12 @@ int shpc_init(struct controller * ctrl, struct pci_dev * pdev)
                 slot_reg = shpc_readl(ctrl, SLOT_REG(hp_slot));
                 dbg("%s: Default Logical Slot Register %d value %x\n", __FUNCTION__,
                         hp_slot, slot_reg);
-                tempdword = 0xffff3fff;  
-                shpc_writel(ctrl, SLOT_REG(hp_slot), tempdword);
+                slot_reg |= (PRSNT_CHANGE_INTR_MASK | ISO_PFAULT_INTR_MASK |
+                             BUTTON_PRESS_INTR_MASK | MRL_CHANGE_INTR_MASK |
+                             CON_PFAULT_INTR_MASK   | MRL_CHANGE_SERR_MASK |
+                             CON_PFAULT_SERR_MASK);
+                slot_reg &= ~SLOT_REG_RSVDZ_MASK;
+                shpc_writel(ctrl, SLOT_REG(hp_slot), slot_reg);
         }
         
         if (shpchp_poll_mode)  {/* Install interrupt polling code */
@@ -1411,12 +1437,17 @@ int shpc_init(struct controller * ctrl, struct pci_dev * pdev)
 
         ctlr_seq_num++;
 
+        /*
+         * Unmask all event interrupts of all slots
+         */
         for (hp_slot = 0; hp_slot < php_ctlr->num_slots; hp_slot++) {
                 slot_reg = shpc_readl(ctrl, SLOT_REG(hp_slot));
                 dbg("%s: Default Logical Slot Register %d value %x\n", __FUNCTION__,
                         hp_slot, slot_reg);
-                tempdword = 0xe01f3fff;  
-                shpc_writel(ctrl, SLOT_REG(hp_slot), tempdword);
+                slot_reg &= ~(PRSNT_CHANGE_INTR_MASK | ISO_PFAULT_INTR_MASK |
+                              BUTTON_PRESS_INTR_MASK | MRL_CHANGE_INTR_MASK |
+                              CON_PFAULT_INTR_MASK | SLOT_REG_RSVDZ_MASK);
+                shpc_writel(ctrl, SLOT_REG(hp_slot), slot_reg);
         }
         if (!shpchp_poll_mode) {
                 /* Unmask all general input interrupts and SERR */