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

From: David Daney
Date: Wed Oct 21 2015 - 11:40:17 EST


On 10/21/2015 08:14 AM, Bjorn Helgaas wrote:
[...]
Applied to pci/enhanced-allocation for v4.4, thanks, David!

I tweaked a couple trivial things and added a couple almost trivial patches
on top. Here are the additions; let me know if you see anything wrong.


Thanks for working with us on this.

Your additional changes look to be correct to me, I will give them a test within the next few days.

David Daney


Bjorn


commit 6457d085fade7d96a3aa6c5dca848fd82b4a4fa4
Author: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
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 <bhelgaas@xxxxxxxxxx>

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 <bhelgaas@xxxxxxxxxx>
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 <bhelgaas@xxxxxxxxxx>

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;
}

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