Re: [PATCH v6 0/5] PCI: Add support for PCI Enhanced Allocation "BARs"
From: Bjorn Helgaas
Date: Wed Oct 21 2015 - 11:15:18 EST
On Tue, Oct 20, 2015 at 04:04:37PM -0700, David Daney wrote:
> From: David Daney <david.daney@xxxxxxxxxx>
>
> The original patches are from Sean O. Stalley. I made a few tweaks,
> but feel that it is substancially Sean's work, so I am keeping the
> patch set version numbering scheme going.
>
> Tested on Cavium ThunderX system with 4 Root Complexes containing 50
> devices/bridges provisioned with EA.
>
> Here is Sean's description of the patches:
>
> PCI Enhanced Allocation is a new method of allocating MMIO & IO
> resources for PCI devices & bridges. It can be used instead
> of the traditional PCI method of using BARs.
>
> EA entries are hardware-initialized to a fixed address.
> Unlike BARs, regions described by EA are cannot be moved.
> Because of this, only devices which are permanently connected to
> the PCI bus can use EA. A removable PCI card must not use EA.
>
> This patchset adds support for using EA entries instead of BARs
> on Root Complex Integrated Endpoints.
>
> The Enhanced Allocation ECN is publicly available here:
> https://www.pcisig.com/specifications/conventional/ECN_Enhanced_Allocation_23_Oct_2014_Final.pdf
>
>
> Changes from V1:
> - Use generic PCI resource claim functions (instead of EA-specific functions)
> - Only add support for RCiEPs (instead of all devices).
> - Removed some debugging messages leftover from early testing.
>
> Changes from V2 (By David Daney):
> - Add ea_cap to struct pci_device, to aid in finding the EA capability.
> - Factored EA entity decoding into a separate function.
> - Add functions to find EA entities by BEI or Property.
> - Add handling of EA provisioned bridges.
> - Add handling of EA SRIOV BARs.
> - Try to assign proper resource parent so that SRIOV device creation can occur.
>
> Changes from V3 (By David Daney):
> - Discarded V3 changes and started over fresh based on Sean's V2.
> - Add more support/checking for Entry Properties.
> - Allow EA behind bridges.
> - Rewrite some error messages.
> - Add patch 3/5 to prevent resizing, and better handle
> assigning, of fixed EA resources.
> - Add patch 4/5 to handle EA provisioned SRIOV devices.
> - Add patch 5/5 to handle EA provisioned bridges.
>
> Changes from V4 (By David Daney):
> - Drop patch 5/5 to handle EA provisioned bridges.
> - Drop cases for bridge resources in 2/5.
> - Drop unnecessary fallback resource parent handling in 3/5
> - Small code formatting improvements.
>
> Changes from V5: (By David Daney) cosmetic only, as requested by Bjorn Helgaas:
> - Split previous 3/4 into two patches, which are now 1/5 and 2/5
> - Improve indentation of register definitions.
> - Renamed PCI_EA_P_VIRT_MEM* to PCI_EA_P_VF_MEM*
> - Remove use of BIT() macro from register definitions.
> - Changed debug messages when probing EA entries to be like this:
> .
> .
> .
> pci 0002:01:00.0: [177d:a01e] type 00 class 0x020000
> pci 0002:01:00.0: EA - BEI 0, Prop 0x00: [mem 0x843000000000-0x84303fffffff 64bit]
> pci 0002:01:00.0: EA - BEI 4, Prop 0x00: [mem 0x843060000000-0x8430600fffff 64bit]
> pci 0002:01:00.0: EA - BEI 9, Prop 0x04: [mem 0x8430a0000000-0x8430a01fffff 64bit]
> pci 0002:01:00.0: EA - BEI 13, Prop 0x04: [mem 0x8430e0000000-0x8430e01fffff 64bit]
> pci 0002:01:00.0: VF(n) BAR0 space: [mem 0x8430a0000000-0x8430afffffff 64bit] (contains BAR0 for 128 VFs)
> pci 0002:01:00.0: VF(n) BAR4 space: [mem 0x8430e0000000-0x8430efffffff 64bit] (contains BAR4 for 128 VFs)
> .
> .
> .
> pci 0004:21:00.0: [1a03:2000] type 00 class 0x030000
> pci 0004:21:00.0: reg 0x10: [mem 0x881010000000-0x881010ffffff]
> pci 0004:21:00.0: reg 0x14: [mem 0x881011000000-0x88101101ffff]
> pci 0004:21:00.0: reg 0x18: [io 0x0000-0x007f]
> pci 0004:21:00.0: supports D1 D2
> .
> .
> .
>
> BEI and Prop values are represented as decimal and hexadecimal
> respectively to match the EA specification.
>
> David Daney (3):
> PCI: Handle IORESOURCE_PCI_FIXED when sizing resources.
> PCI: Handle IORESOURCE_PCI_FIXED when assigning resources.
> PCI: Handle Enhanced Allocation (EA) capability for SRIOV devices.
>
> Sean O. Stalley (2):
> PCI: Add Enhanced Allocation register entries
> PCI: Add support for Enhanced Allocation devices
>
> drivers/pci/iov.c | 11 ++-
> drivers/pci/pci.c | 183 ++++++++++++++++++++++++++++++++++++++++++
> drivers/pci/pci.h | 1 +
> drivers/pci/probe.c | 3 +
> drivers/pci/setup-bus.c | 50 +++++++++++-
> include/uapi/linux/pci_regs.h | 44 +++++++++-
> 6 files changed, 286 insertions(+), 6 deletions(-)
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.
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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