Re: [PATCH v2 4/4] fpga: remove compat_id from fpga_manager and fpga_region
From: Tom Rix
Date: Mon Jul 12 2021 - 11:54:02 EST
On 7/11/21 6:40 PM, Wu, Hao wrote:
-----Original Message-----
From: trix@xxxxxxxxxx <trix@xxxxxxxxxx>
Sent: Friday, July 9, 2021 9:42 PM
To: mdf@xxxxxxxxxx; corbet@xxxxxxx; Wu, Hao <hao.wu@xxxxxxxxx>
Cc: linux-fpga@xxxxxxxxxxxxxxx; linux-doc@xxxxxxxxxxxxxxx; linux-
kernel@xxxxxxxxxxxxxxx; Tom Rix <trix@xxxxxxxxxx>
Subject: [PATCH v2 4/4] fpga: remove compat_id from fpga_manager and
fpga_region
From: Tom Rix <trix@xxxxxxxxxx>
compat_id is implementation specific. So the data should be
stored at the implemeation layer, not the infrastructure layer.
Remove the compat_id elements and supporting code.
I think current compat_id format can meet the checking requirement.
Actually I hope other hardware which needs compatible checking
to expose the same format compat_id. Then we can have more
unified/common code, e.g. userspace application/lib handling.
v2 does not change the current ABI. The dfl output is the same as
before, the other nonusers get -ENOENT.
For dfl compat_id is 2 64 bit registers.
For compat_id to be useful to the others, they need the flexibility to
print to the sysfs in the manner that aligns with whatever their user
library interface is, 2 64 values isn't going to work for everyone. ex/
xrt likely would be a uuid_t printed out a special way. someone else
maybe just string in the board fw, maybe some has a 8 or 256 bits of
compat_id etc.
as a driver region specific op, others are free to do whatever is required.
Currently I didn't see any other usage or requirement on this part
now, only DFL uses it. So should we leave it here at this moment?
I feel we don't have to change it for now to move it to a
Per-fpga-mgr format. : )
The motivation for doing this now is the 'use standard class dev release
.. ' patchset
I really do not like 2 register functions.
By moving compat_id, the 2 register functions reduces down to 1.
I did a poc here
https://lore.kernel.org/linux-fpga/20210709184511.2521508-1-trix@xxxxxxxxxx/
Tom
Thanks
Hao
Printing out the compat_id is done with the fpga_region
compat_id_show() op.
Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
---
drivers/fpga/dfl-fme-mgr.c | 7 -------
drivers/fpga/dfl-fme-region.c | 1 -
drivers/fpga/fpga-region.c | 7 +------
include/linux/fpga/fpga-mgr.h | 13 -------------
include/linux/fpga/fpga-region.h | 2 --
5 files changed, 1 insertion(+), 29 deletions(-)
diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
index cd0b9157ea6e5..8c5423eeffe75 100644
--- a/drivers/fpga/dfl-fme-mgr.c
+++ b/drivers/fpga/dfl-fme-mgr.c
@@ -292,7 +292,6 @@ EXPORT_SYMBOL_GPL(fme_mgr_get_compat_id);
static int fme_mgr_probe(struct platform_device *pdev)
{
struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
- struct fpga_compat_id *compat_id;
struct device *dev = &pdev->dev;
struct fme_mgr_priv *priv;
struct fpga_manager *mgr;
@@ -312,10 +311,6 @@ static int fme_mgr_probe(struct platform_device
*pdev)
return PTR_ERR(priv->ioaddr);
}
- compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
- if (!compat_id)
- return -ENOMEM;
-
_fme_mgr_get_compat_id(priv->ioaddr, &priv->compat_id);
mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
@@ -323,8 +318,6 @@ static int fme_mgr_probe(struct platform_device *pdev)
if (!mgr)
return -ENOMEM;
- mgr->compat_id = compat_id;
-
return devm_fpga_mgr_register(dev, mgr);
}
diff --git a/drivers/fpga/dfl-fme-region.c b/drivers/fpga/dfl-fme-region.c
index d21eacbf2469f..be1d57ee37666 100644
--- a/drivers/fpga/dfl-fme-region.c
+++ b/drivers/fpga/dfl-fme-region.c
@@ -64,7 +64,6 @@ static int fme_region_probe(struct platform_device *pdev)
}
region->priv = pdata;
- region->compat_id = mgr->compat_id;
platform_set_drvdata(pdev, region);
ret = fpga_region_register(region);
diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c
index 864dd4f290e3b..b08d3914716f0 100644
--- a/drivers/fpga/fpga-region.c
+++ b/drivers/fpga/fpga-region.c
@@ -172,12 +172,7 @@ static ssize_t compat_id_show(struct device *dev,
if (region->rops && region->rops->compat_id_show)
return region->rops->compat_id_show(region, buf);
- if (!region->compat_id)
- return -ENOENT;
-
- return sprintf(buf, "%016llx%016llx\n",
- (unsigned long long)region->compat_id->id_h,
- (unsigned long long)region->compat_id->id_l);
+ return -ENOENT;
}
static DEVICE_ATTR_RO(compat_id);
diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
index ec2cd8bfceb00..ebdea215a8643 100644
--- a/include/linux/fpga/fpga-mgr.h
+++ b/include/linux/fpga/fpga-mgr.h
@@ -143,24 +143,12 @@ struct fpga_manager_ops {
#define FPGA_MGR_STATUS_IP_PROTOCOL_ERR BIT(3)
#define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR BIT(4)
-/**
- * struct fpga_compat_id - id for compatibility check
- *
- * @id_h: high 64bit of the compat_id
- * @id_l: low 64bit of the compat_id
- */
-struct fpga_compat_id {
- u64 id_h;
- u64 id_l;
-};
-
/**
* struct fpga_manager - fpga manager structure
* @name: name of low level fpga manager
* @dev: fpga manager device
* @ref_mutex: only allows one reference to fpga manager
* @state: state of fpga manager
- * @compat_id: FPGA manager id for compatibility check.
* @mops: pointer to struct of fpga manager ops
* @priv: low level driver private date
*/
@@ -169,7 +157,6 @@ struct fpga_manager {
struct device dev;
struct mutex ref_mutex;
enum fpga_mgr_states state;
- struct fpga_compat_id *compat_id;
const struct fpga_manager_ops *mops;
void *priv;
};
diff --git a/include/linux/fpga/fpga-region.h b/include/linux/fpga/fpga-region.h
index 236d3819f1c13..afc79784b2823 100644
--- a/include/linux/fpga/fpga-region.h
+++ b/include/linux/fpga/fpga-region.h
@@ -30,7 +30,6 @@ struct fpga_region_ops {
* @bridge_list: list of FPGA bridges specified in region
* @mgr: FPGA manager
* @info: FPGA image info
- * @compat_id: FPGA region id for compatibility check.
* @priv: private data
* @rops: optional pointer to struct for fpga region ops
*/
@@ -40,7 +39,6 @@ struct fpga_region {
struct list_head bridge_list;
struct fpga_manager *mgr;
struct fpga_image_info *info;
- struct fpga_compat_id *compat_id;
void *priv;
const struct fpga_region_ops *rops;
};
--
2.26.3