Re: [PATCH v6 0/5] PCI: Add support for PCI Enhanced Allocation "BARs"

Bjorn


commit 6457d085fade7d96a3aa6c5dca848fd82b4a4fa4
Author: Bjorn Helgaas [off-list ref]
Date:   Wed Oct 21 09:34:15 2015 -0500

     PCI: Make Enhanced Allocation bitmasks more obvious

     Expand bitmask #defines completely.  This puts the shift in the code
     instead of in the #define, but it makes it more obvious in the header file
     how fields in the register are laid out.

     No functional change.

     Signed-off-by: Bjorn Helgaas [off-list ref]

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 364f98b..e8330b6 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c

@@ -2195,7 +2195,7 @@ static int pci_ea_read(struct pci_dev *dev, int offset)
  	int ent_size, ent_offset = offset;
  	resource_size_t start, end;
  	unsigned long flags;
-	u32 dw0, base, max_offset;
+	u32 dw0, bei, base, max_offset;
  	u8 prop;
  	bool support_64 = (sizeof(resource_size_t) >= 8);

@@ -2208,20 +2208,21 @@ static int pci_ea_read(struct pci_dev *dev, int offset)
  	if (!(dw0 & PCI_EA_ENABLE)) /* Entry not enabled */
  		goto out;

-	prop = PCI_EA_PP(dw0);
+	bei = (dw0 & PCI_EA_BEI) >> 4;
+	prop = (dw0 & PCI_EA_PP) >> 8;
+
  	/*
  	 * If the Property is in the reserved range, try the Secondary
  	 * Property instead.
  	 */
  	if (prop > PCI_EA_P_BRIDGE_IO && prop < PCI_EA_P_MEM_RESERVED)
-		prop = PCI_EA_SP(dw0);
+		prop = (dw0 & PCI_EA_SP) >> 16;
  	if (prop > PCI_EA_P_BRIDGE_IO)
  		goto out;

-	res = pci_ea_get_resource(dev, PCI_EA_BEI(dw0), prop);
+	res = pci_ea_get_resource(dev, bei, prop);
  	if (!res) {
-		dev_err(&dev->dev, "Unsupported EA entry BEI: %u\n",
-			PCI_EA_BEI(dw0));
+		dev_err(&dev->dev, "Unsupported EA entry BEI: %u\n", bei);
  		goto out;
  	}

@@ -2293,7 +2294,7 @@ static int pci_ea_read(struct pci_dev *dev, int offset)
  	res->end = end;
  	res->flags = flags;
  	dev_printk(KERN_DEBUG, &dev->dev, "EA - BEI %2u, Prop 0x%02x: %pR\n",
-		   PCI_EA_BEI(dw0), prop, res);
+		   bei, prop, res);
  out:
  	return offset + ent_size;
  }

diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index f890876..1becea8 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h

@@ -361,7 +361,7 @@
  #define PCI_EA_FIRST_ENT	4	/* First EA Entry in List */
  #define PCI_EA_FIRST_ENT_BRIDGE	8	/* First EA Entry for Bridges */
  #define  PCI_EA_ES		0x00000007 /* Entry Size */
-#define  PCI_EA_BEI(x)	(((x) >> 4) & 0xf) /* BAR Equivalent Indicator */
+#define  PCI_EA_BEI		0x000000f0 /* BAR Equivalent Indicator */
  /* 0-5 map to BARs 0-5 respectively */
  #define   PCI_EA_BEI_BAR0		0
  #define   PCI_EA_BEI_BAR5		5

@@ -372,8 +372,8 @@
  #define   PCI_EA_BEI_VF_BAR0		9
  #define   PCI_EA_BEI_VF_BAR5		14
  #define   PCI_EA_BEI_RESERVED		15	/* Reserved - Treat like ENI */
-#define  PCI_EA_PP(x)	(((x) >>  8) & 0xff)	/* Primary Properties */
-#define  PCI_EA_SP(x)	(((x) >> 16) & 0xff)	/* Secondary Properties */
+#define  PCI_EA_PP		0x0000ff00	/* Primary Properties */
+#define  PCI_EA_SP		0x00ff0000	/* Secondary Properties */
  #define   PCI_EA_P_MEM			0x00	/* Non-Prefetch Memory */
  #define   PCI_EA_P_MEM_PREFETCH		0x01	/* Prefetchable Memory */
  #define   PCI_EA_P_IO			0x02	/* I/O Space */

commit 6985dcc83d70f019523ba9ff499898261f33c937
Author: Bjorn Helgaas [off-list ref]
Date:   Wed Oct 21 09:53:39 2015 -0500

     PCI: Expand Enhanced Allocation BAR output

     An Enhanced Allocation Capability entry with BEI 0 fills in
     dev->resource[0] just like a real BAR 0 would, but non-EA experts might not
     connect "EA - BEI 0" with BAR 0.

     Decode the EA jargon a little bit, e.g., change this:

       pci 0002:01:00.0: EA - BEI  0, Prop 0x00: [mem 0x84300000-0x84303fff]

     to this:

       pci 0002:01:00.0: BAR 0: [mem 0x84300000-0x84303fff] (from Enhanced Allocation, properties 0x00)

     Signed-off-by: Bjorn Helgaas [off-list ref]

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e8330b6..3a1454e 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c

@@ -2293,8 +2293,20 @@ static int pci_ea_read(struct pci_dev *dev, int offset)
  	res->start = start;
  	res->end = end;
  	res->flags = flags;
-	dev_printk(KERN_DEBUG, &dev->dev, "EA - BEI %2u, Prop 0x%02x: %pR\n",
-		   bei, prop, res);
+
+	if (bei <= PCI_EA_BEI_BAR5)
+		dev_printk(KERN_DEBUG, &dev->dev, "BAR %d: %pR (from Enhanced Allocation, properties %#02x)\n",
+			   bei, res, prop);
+	else if (bei == PCI_EA_BEI_ROM)
+		dev_printk(KERN_DEBUG, &dev->dev, "ROM: %pR (from Enhanced Allocation, properties %#02x)\n",
+			   res, prop);
+	else if (bei >= PCI_EA_BEI_VF_BAR0 && bei <= PCI_EA_BEI_VF_BAR5)
+		dev_printk(KERN_DEBUG, &dev->dev, "VF BAR %d: %pR (from Enhanced Allocation, properties %#02x)\n",
+			   bei - PCI_EA_BEI_VF_BAR0, res, prop);
+	else
+		dev_printk(KERN_DEBUG, &dev->dev, "BEI %d res: %pR (from Enhanced Allocation, properties %#02x)\n",
+			   bei, res, prop);
+
  out:
  	return offset + ent_size;
  }