[RFC] pci: Rework config space blocking services

Commit Message

Brian King Sept. 7, 2011, 1:46 p.m. UTC

Here is how I would prefer to rework ipr. 

Thanks,

Brian

Patch

diff -puN drivers/scsi/ipr.c~ipr_new_pci_block drivers/scsi/ipr.c
--- linux-2.6/drivers/scsi/ipr.c~ipr_new_pci_block	2011-09-06 16:52:47.000000000 -0500
+++ linux-2.6-bjking1/drivers/scsi/ipr.c	2011-09-07 08:34:54.000000000 -0500
@@ -7639,8 +7639,12 @@  static int ipr_reset_restore_cfg_space(s
  **/
 static int ipr_reset_bist_done(struct ipr_cmnd *ipr_cmd)
 {
+	struct ipr_ioa_cfg *ioa_cfg = ipr_cmd->ioa_cfg;
+
 	ENTER;
-	pci_unblock_user_cfg_access(ipr_cmd->ioa_cfg->pdev);
+	if (ioa_cfg->ucfg_blocked)
+		pci_unblock_cfg_access(ioa_cfg->pdev);
+	ioa_cfg->ucfg_blocked = 0;
 	ipr_cmd->job_step = ipr_reset_restore_cfg_space;
 	LEAVE;
 	return IPR_RC_JOB_CONTINUE;
@@ -7661,8 +7665,6 @@  static int ipr_reset_start_bist(struct i
 	int rc = PCIBIOS_SUCCESSFUL;
 
 	ENTER;
-	pci_block_user_cfg_access(ioa_cfg->pdev);
-
 	if (ioa_cfg->ipr_chip->bist_method == IPR_MMIO)
 		writel(IPR_UPROCI_SIS64_START_BIST,
 		       ioa_cfg->regs.set_uproc_interrupt_reg32);
@@ -7674,7 +7676,9 @@  static int ipr_reset_start_bist(struct i
 		ipr_reset_start_timer(ipr_cmd, IPR_WAIT_FOR_BIST_TIMEOUT);
 		rc = IPR_RC_JOB_RETURN;
 	} else {
-		pci_unblock_user_cfg_access(ipr_cmd->ioa_cfg->pdev);
+		if (ioa_cfg->ucfg_blocked)
+			pci_unblock_cfg_access(ipr_cmd->ioa_cfg->pdev);
+		ioa_cfg->ucfg_blocked = 0;
 		ipr_cmd->s.ioasa.hdr.ioasc = cpu_to_be32(IPR_IOASC_PCI_ACCESS_ERROR);
 		rc = IPR_RC_JOB_CONTINUE;
 	}
@@ -7717,7 +7721,6 @@  static int ipr_reset_slot_reset(struct i
 	struct pci_dev *pdev = ioa_cfg->pdev;
 
 	ENTER;
-	pci_block_user_cfg_access(pdev);
 	pci_set_pcie_reset_state(pdev, pcie_warm_reset);
 	ipr_cmd->job_step = ipr_reset_slot_reset_done;
 	ipr_reset_start_timer(ipr_cmd, IPR_PCI_RESET_TIMEOUT);
@@ -7726,6 +7729,55 @@  static int ipr_reset_slot_reset(struct i
 }
 
 /**
+ * ipr_reset_block_config_access_wait - Wait for permission to block config access
+ * @ipr_cmd:	ipr command struct
+ *
+ * Description: This attempts to block config access to the IOA.
+ *
+ * Return value:
+ * 	IPR_RC_JOB_CONTINUE / IPR_RC_JOB_RETURN
+ **/
+static int ipr_reset_block_config_access_wait(struct ipr_cmnd *ipr_cmd)
+{
+	struct ipr_ioa_cfg *ioa_cfg = ipr_cmd->ioa_cfg;
+	int rc = IPR_RC_JOB_CONTINUE;
+
+	if (pci_block_cfg_access_in_atomic(ioa_cfg->pdev)) {
+		if (ipr_cmd->u.time_left) {
+			rc = IPR_RC_JOB_RETURN;
+			ipr_cmd->u.time_left -= IPR_CHECK_FOR_RESET_TIMEOUT;
+			ipr_reset_start_timer(ipr_cmd, IPR_CHECK_FOR_RESET_TIMEOUT);
+		} else {
+			ipr_cmd->job_step = ioa_cfg->reset;
+			dev_err(&ioa_cfg->pdev->dev,
+				"Timed out waiting to block config access. Resetting anyway.\n");
+		}
+	} else {
+		ioa_cfg->ucfg_blocked = 1;
+		ipr_cmd->job_step = ioa_cfg->reset;
+	}
+
+	return rc;
+}
+
+/**
+ * ipr_reset_block_config_access - Block config access to the IOA
+ * @ipr_cmd:	ipr command struct
+ *
+ * Description: This attempts to block config access to the IOA
+ *
+ * Return value:
+ * 	IPR_RC_JOB_CONTINUE
+ **/
+static int ipr_reset_block_config_access(struct ipr_cmnd *ipr_cmd)
+{
+	ipr_cmd->ioa_cfg->ucfg_blocked = 0;
+	ipr_cmd->job_step = ipr_reset_block_config_access_wait;
+	ipr_cmd->u.time_left = IPR_WAIT_FOR_RESET_TIMEOUT;
+	return IPR_RC_JOB_CONTINUE;
+}
+
+/**
  * ipr_reset_allowed - Query whether or not IOA can be reset
  * @ioa_cfg:	ioa config struct
  *
@@ -7764,7 +7816,7 @@  static int ipr_reset_wait_to_start_bist(
 		ipr_cmd->u.time_left -= IPR_CHECK_FOR_RESET_TIMEOUT;
 		ipr_reset_start_timer(ipr_cmd, IPR_CHECK_FOR_RESET_TIMEOUT);
 	} else {
-		ipr_cmd->job_step = ioa_cfg->reset;
+		ipr_cmd->job_step = ipr_reset_block_config_access;
 		rc = IPR_RC_JOB_CONTINUE;
 	}
 
@@ -7797,7 +7849,7 @@  static int ipr_reset_alert(struct ipr_cm
 		writel(IPR_UPROCI_RESET_ALERT, ioa_cfg->regs.set_uproc_interrupt_reg32);
 		ipr_cmd->job_step = ipr_reset_wait_to_start_bist;
 	} else {
-		ipr_cmd->job_step = ioa_cfg->reset;
+		ipr_cmd->job_step = ipr_reset_block_config_access;
 	}
 
 	ipr_cmd->u.time_left = IPR_WAIT_FOR_RESET_TIMEOUT;
diff -puN drivers/scsi/ipr.h~ipr_new_pci_block drivers/scsi/ipr.h
--- linux-2.6/drivers/scsi/ipr.h~ipr_new_pci_block	2011-09-07 07:29:20.000000000 -0500
+++ linux-2.6-bjking1/drivers/scsi/ipr.h	2011-09-07 08:10:29.000000000 -0500
@@ -1384,6 +1384,7 @@  struct ipr_ioa_cfg {
 	u8 needs_warm_reset:1;
 	u8 msi_received:1;
 	u8 sis64:1;
+	u8 ucfg_blocked:1;
 
 	u8 revid;