[PATCH 0/4] IB/hfi1: Read platform configuration file from EPROM

[PATCH 0/4] IB/hfi1: Read platform configuration file from EPROM

[Dennis Dalessandro]

Doug,

This series adds the capability to read configuration information used to init
the link from the EPROM.

It partially undoes some of the work that was removed when we removed the
user access. This is not done though in support of user access. This is only so
the driver can read the EPROM. All user access is still only through resource0.

Series applies on previously submitted patches and should apply cleanly to your
for-4.9 branch. Can also be seen in GitHub at:
https://github.com/ddalessa/kernel/tree/for-4.9

---

Dean Luick (4):
      IB/hfi1: Restore EPROM read ability
      IB/hfi1: Change EPROM read for internal use
      IB/hfi1: Add ability to read platform config from the EPROM
      IB/hfi1: Use EPROM platform configuration read


 drivers/infiniband/hw/hfi1/chip.c     |    9 +-
 drivers/infiniband/hw/hfi1/eprom.c    |  185 +++++++++++++++++++++++++++++++++
 drivers/infiniband/hw/hfi1/eprom.h    |    4 -
 drivers/infiniband/hw/hfi1/file_ops.c |    1 
 drivers/infiniband/hw/hfi1/platform.c |   32 ++++--
 5 files changed, 213 insertions(+), 18 deletions(-)

--
-Denny
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[PATCH 1/4] IB/hfi1: Restore EPROM read ability

[Dennis Dalessandro]

From: Dean Luick <dean.luick-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

Partially revert commit d07903174202 ("IB/hfi1: Remove
EPROM functionality from data device"), bringing back
the ability to read from the EPROM.

This code will be used for driver-only acccess to the EPROM.

Reviewed-by: Easwar Hariharan <easwar.hariharan-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Dean Luick <dean.luick-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/infiniband/hw/hfi1/eprom.c |   59 ++++++++++++++++++++++++++++++++++++
 1 files changed, 59 insertions(+), 0 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/eprom.c b/drivers/infiniband/hw/hfi1/eprom.c
index 36b7794..5a11bee 100644
--- a/drivers/infiniband/hw/hfi1/eprom.c
+++ b/drivers/infiniband/hw/hfi1/eprom.c
@@ -49,7 +49,25 @@
 #include "common.h"
 #include "eprom.h"
 
+/*
+ * The EPROM is logically divided into three partitions:
+ *	partition 0: the first 128K, visible from PCI ROM BAR
+ *	partition 1: 4K config file (sector size)
+ *	partition 2: the rest
+ */
+#define P0_SIZE (128 * 1024)
+#define P1_SIZE   (4 * 1024)
+#define P1_START P0_SIZE
+#define P2_START (P0_SIZE + P1_SIZE)
+
+/* controller page size, in bytes */
+#define EP_PAGE_SIZE 256
+#define EEP_PAGE_MASK (EP_PAGE_SIZE - 1)
+
+/* controller commands */
 #define CMD_SHIFT 24
+#define CMD_NOP			    (0)
+#define CMD_READ_DATA(addr)	    ((0x03 << CMD_SHIFT) | addr)
 #define CMD_RELEASE_POWERDOWN_NOID  ((0xab << CMD_SHIFT))
 
 /* controller interface speeds */
@@ -61,6 +79,47 @@
  * Double it for safety.
  */
 #define EPROM_TIMEOUT 80000 /* ms */
+
+/*
+ * Read a 256 byte (64 dword) EPROM page.
+ * All callers have verified the offset is at a page boundary.
+ */
+static void read_page(struct hfi1_devdata *dd, u32 offset, u32 *result)
+{
+	int i;
+
+	write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_READ_DATA(offset));
+	for (i = 0; i < EP_PAGE_SIZE / sizeof(u32); i++)
+		result[i] = (u32)read_csr(dd, ASIC_EEP_DATA);
+	write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_NOP); /* close open page */
+}
+
+/*
+ * Read length bytes starting at offset.  Copy to user address addr.
+ */
+static int read_length(struct hfi1_devdata *dd, u32 start, u32 len, u64 addr)
+{
+	u32 offset;
+	u32 buffer[EP_PAGE_SIZE / sizeof(u32)];
+	int ret = 0;
+
+	/* reject anything not on an EPROM page boundary */
+	if ((start & EEP_PAGE_MASK) || (len & EEP_PAGE_MASK))
+		return -EINVAL;
+
+	for (offset = 0; offset < len; offset += EP_PAGE_SIZE) {
+		read_page(dd, start + offset, buffer);
+		if (copy_to_user((void __user *)(addr + offset),
+				 buffer, EP_PAGE_SIZE)) {
+			ret = -EFAULT;
+			goto done;
+		}
+	}
+
+done:
+	return ret;
+}
+
 /*
  * Initialize the EPROM handler.
  */

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[PATCH 2/4] IB/hfi1: Change EPROM read for internal use

[Dennis Dalessandro]

From: Dean Luick <dean.luick-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

Change the EPROM read to save to a buffer and allow any offset.
Remove missed includes and left over declarations.

Reviewed-by: Easwar Hariharan <easwar.hariharan-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Dean Luick <dean.luick-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/infiniband/hw/hfi1/eprom.c    |   78 ++++++++++++++++++++++++++-------
 drivers/infiniband/hw/hfi1/eprom.h    |    2 -
 drivers/infiniband/hw/hfi1/file_ops.c |    1 
 3 files changed, 61 insertions(+), 20 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/eprom.c b/drivers/infiniband/hw/hfi1/eprom.c
index 5a11bee..30ecd94 100644
--- a/drivers/infiniband/hw/hfi1/eprom.c
+++ b/drivers/infiniband/hw/hfi1/eprom.c
@@ -62,7 +62,8 @@
 
 /* controller page size, in bytes */
 #define EP_PAGE_SIZE 256
-#define EEP_PAGE_MASK (EP_PAGE_SIZE - 1)
+#define EP_PAGE_MASK (EP_PAGE_SIZE - 1)
+#define EP_PAGE_DWORDS (EP_PAGE_SIZE / sizeof(u32))
 
 /* controller commands */
 #define CMD_SHIFT 24
@@ -89,35 +90,78 @@ static void read_page(struct hfi1_devdata *dd, u32 offset, u32 *result)
 	int i;
 
 	write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_READ_DATA(offset));
-	for (i = 0; i < EP_PAGE_SIZE / sizeof(u32); i++)
+	for (i = 0; i < EP_PAGE_DWORDS; i++)
 		result[i] = (u32)read_csr(dd, ASIC_EEP_DATA);
 	write_csr(dd, ASIC_EEP_ADDR_CMD, CMD_NOP); /* close open page */
 }
 
 /*
- * Read length bytes starting at offset.  Copy to user address addr.
+ * Read length bytes starting at offset from the start of the EPROM.
  */
-static int read_length(struct hfi1_devdata *dd, u32 start, u32 len, u64 addr)
+static int read_length(struct hfi1_devdata *dd, u32 start, u32 len, void *dest)
 {
-	u32 offset;
-	u32 buffer[EP_PAGE_SIZE / sizeof(u32)];
-	int ret = 0;
+	u32 buffer[EP_PAGE_DWORDS];
+	u32 end;
+	u32 start_offset;
+	u32 read_start;
+	u32 bytes;
+
+	if (len == 0)
+		return 0;
 
-	/* reject anything not on an EPROM page boundary */
-	if ((start & EEP_PAGE_MASK) || (len & EEP_PAGE_MASK))
+	end = start + len;
+
+	/*
+	 * Make sure the read range is not outside of the controller read
+	 * command address range.  Note that '>' is correct below - the end
+	 * of the range is OK if it stops at the limit, but no higher.
+	 */
+	if (end > (1 << CMD_SHIFT))
 		return -EINVAL;
 
-	for (offset = 0; offset < len; offset += EP_PAGE_SIZE) {
-		read_page(dd, start + offset, buffer);
-		if (copy_to_user((void __user *)(addr + offset),
-				 buffer, EP_PAGE_SIZE)) {
-			ret = -EFAULT;
-			goto done;
+	/* read the first partial page */
+	start_offset = start & EP_PAGE_MASK;
+	if (start_offset) {
+		/* partial starting page */
+
+		/* align and read the page that contains the start */
+		read_start = start & ~EP_PAGE_MASK;
+		read_page(dd, read_start, buffer);
+
+		/* the rest of the page is available data */
+		bytes = EP_PAGE_SIZE - start_offset;
+
+		if (len <= bytes) {
+			/* end is within this page */
+			memcpy(dest, (u8 *)buffer + start_offset, len);
+			return 0;
 		}
+
+		memcpy(dest, (u8 *)buffer + start_offset, bytes);
+
+		start += bytes;
+		len -= bytes;
+		dest += bytes;
 	}
+	/* start is now page aligned */
 
-done:
-	return ret;
+	/* read whole pages */
+	while (len >= EP_PAGE_SIZE) {
+		read_page(dd, start, buffer);
+		memcpy(dest, buffer, EP_PAGE_SIZE);
+
+		start += EP_PAGE_SIZE;
+		len -= EP_PAGE_SIZE;
+		dest += EP_PAGE_SIZE;
+	}
+
+	/* read the last partial page */
+	if (len) {
+		read_page(dd, start, buffer);
+		memcpy(dest, buffer, len);
+	}
+
+	return 0;
 }
 
 /*
diff --git a/drivers/infiniband/hw/hfi1/eprom.h b/drivers/infiniband/hw/hfi1/eprom.h
index d41f0b1..b7ac9ce 100644
--- a/drivers/infiniband/hw/hfi1/eprom.h
+++ b/drivers/infiniband/hw/hfi1/eprom.h
@@ -45,8 +45,6 @@
  *
  */
 
-struct hfi1_cmd;
 struct hfi1_devdata;
 
 int eprom_init(struct hfi1_devdata *dd);
-int handle_eprom_command(struct file *fp, const struct hfi1_cmd *cmd);
diff --git a/drivers/infiniband/hw/hfi1/file_ops.c b/drivers/infiniband/hw/hfi1/file_ops.c
index 13bb6a5..677efa0 100644
--- a/drivers/infiniband/hw/hfi1/file_ops.c
+++ b/drivers/infiniband/hw/hfi1/file_ops.c
@@ -58,7 +58,6 @@
 #include "trace.h"
 #include "user_sdma.h"
 #include "user_exp_rcv.h"
-#include "eprom.h"
 #include "aspm.h"
 #include "mmu_rb.h"
 

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[PATCH 3/4] IB/hfi1: Add ability to read platform config from the EPROM

[Dennis Dalessandro]

From: Dean Luick <dean.luick-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

Add a function to read the platform configuration file from
the EPROM.

Reviewed-by: Easwar Hariharan <easwar.hariharan-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Dean Luick <dean.luick-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/infiniband/hw/hfi1/eprom.c |   82 ++++++++++++++++++++++++++++++++++++
 drivers/infiniband/hw/hfi1/eprom.h |    2 +
 2 files changed, 84 insertions(+), 0 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/eprom.c b/drivers/infiniband/hw/hfi1/eprom.c
index 30ecd94..e70c223 100644
--- a/drivers/infiniband/hw/hfi1/eprom.c
+++ b/drivers/infiniband/hw/hfi1/eprom.c
@@ -203,3 +203,85 @@ int eprom_init(struct hfi1_devdata *dd)
 done_asic:
 	return ret;
 }
+
+/* magic character sequence that trails an image */
+#define IMAGE_TRAIL_MAGIC "egamiAPO"
+
+/*
+ * Read all of partition 1.  The actual file is at the front.  Adjust
+ * the returned size if a trailing image magic is found.
+ */
+static int read_partition_platform_config(struct hfi1_devdata *dd, void **data,
+					  u32 *size)
+{
+	void *buffer;
+	void *p;
+	u32 length;
+	int ret;
+
+	buffer = kmalloc(P1_SIZE, GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+
+	ret = read_length(dd, P1_START, P1_SIZE, buffer);
+	if (ret) {
+		kfree(buffer);
+		return ret;
+	}
+
+	/* scan for image magic that may trail the actual data */
+	p = strnstr(buffer, IMAGE_TRAIL_MAGIC, P1_SIZE);
+	if (p)
+		length = p - buffer;
+	else
+		length = P1_SIZE;
+
+	*data = buffer;
+	*size = length;
+	return 0;
+}
+
+/*
+ * Read the platform configuration file from the EPROM.
+ *
+ * On success, an allocated buffer containing the data and its size are
+ * returned.  It is up to the caller to free this buffer.
+ *
+ * Return value:
+ *   0	      - success
+ *   -ENXIO   - no EPROM is available
+ *   -EBUSY   - not able to acquire access to the EPROM
+ *   -ENOENT  - no recognizable file written
+ *   -ENOMEM  - buffer could not be allocated
+ */
+int eprom_read_platform_config(struct hfi1_devdata *dd, void **data, u32 *size)
+{
+	u32 directory[EP_PAGE_DWORDS]; /* aligned buffer */
+	int ret;
+
+	if (!dd->eprom_available)
+		return -ENXIO;
+
+	ret = acquire_chip_resource(dd, CR_EPROM, EPROM_TIMEOUT);
+	if (ret)
+		return -EBUSY;
+
+	/* read the last page of P0 for the EPROM format magic */
+	ret = read_length(dd, P1_START - EP_PAGE_SIZE, EP_PAGE_SIZE, directory);
+	if (ret)
+		goto done;
+
+	/* last dword of P0 contains a magic indicator */
+	if (directory[EP_PAGE_DWORDS - 1] == 0) {
+		/* partition format */
+		ret = read_partition_platform_config(dd, data, size);
+		goto done;
+	}
+
+	/* nothing recognized */
+	ret = -ENOENT;
+
+done:
+	release_chip_resource(dd, CR_EPROM);
+	return ret;
+}
diff --git a/drivers/infiniband/hw/hfi1/eprom.h b/drivers/infiniband/hw/hfi1/eprom.h
index b7ac9ce..e774184 100644
--- a/drivers/infiniband/hw/hfi1/eprom.h
+++ b/drivers/infiniband/hw/hfi1/eprom.h
@@ -48,3 +48,5 @@
 struct hfi1_devdata;
 
 int eprom_init(struct hfi1_devdata *dd);
+int eprom_read_platform_config(struct hfi1_devdata *dd, void **buf_ret,
+			       u32 *size_ret);

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[PATCH 4/4] IB/hfi1: Use EPROM platform configuration read

[Dennis Dalessandro]

From: Dean Luick <dean.luick-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

The driver will now try to read directly from the EPROM as its
first choice for the platform configuration file.

Reviewed-by: Easwar Hariharan <easwar.hariharan-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Dean Luick <dean.luick-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/infiniband/hw/hfi1/chip.c     |    9 +++++----
 drivers/infiniband/hw/hfi1/platform.c |   32 +++++++++++++++++++++-----------
 2 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/chip.c b/drivers/infiniband/hw/hfi1/chip.c
index 88394cd..9bf5f23 100644
--- a/drivers/infiniband/hw/hfi1/chip.c
+++ b/drivers/infiniband/hw/hfi1/chip.c
@@ -14566,6 +14566,11 @@ struct hfi1_devdata *hfi1_init_dd(struct pci_dev *pdev,
 	if (ret)
 		goto bail_cleanup;
 
+	/* call before get_platform_config(), after init_chip_resources() */
+	ret = eprom_init(dd);
+	if (ret)
+		goto bail_free_rcverr;
+
 	/* Needs to be called before hfi1_firmware_init */
 	get_platform_config(dd);
 
@@ -14686,10 +14691,6 @@ struct hfi1_devdata *hfi1_init_dd(struct pci_dev *pdev,
 	if (ret)
 		goto bail_free_cntrs;
 
-	ret = eprom_init(dd);
-	if (ret)
-		goto bail_free_rcverr;
-
 	goto bail;
 
 bail_free_rcverr:
diff --git a/drivers/infiniband/hw/hfi1/platform.c b/drivers/infiniband/hw/hfi1/platform.c
index 965c8ae..2024331 100644
--- a/drivers/infiniband/hw/hfi1/platform.c
+++ b/drivers/infiniband/hw/hfi1/platform.c
@@ -47,29 +47,39 @@
 
 #include "hfi.h"
 #include "efivar.h"
+#include "eprom.h"
 
 void get_platform_config(struct hfi1_devdata *dd)
 {
 	int ret = 0;
 	unsigned long size = 0;
 	u8 *temp_platform_config = NULL;
+	u32 esize;
+
+	ret = eprom_read_platform_config(dd, (void **)&temp_platform_config,
+					 &esize);
+	if (!ret) {
+		/* success */
+		size = esize;
+		goto success;
+	}
+	/* fail, try EFI variable */
 
 	ret = read_hfi1_efi_var(dd, "configuration", &size,
 				(void **)&temp_platform_config);
-	if (ret) {
-		dd_dev_info(dd,
-			    "%s: Failed to get platform config from UEFI, falling back to request firmware\n",
-			    __func__);
-		/* fall back to request firmware */
-		platform_config_load = 1;
-		goto bail;
-	}
+	if (!ret)
+		goto success;
+
+	dd_dev_info(dd,
+		    "%s: Failed to get platform config from UEFI, falling back to request firmware\n",
+		    __func__);
+	/* fall back to request firmware */
+	platform_config_load = 1;
+	return;
 
+success:
 	dd->platform_config.data = temp_platform_config;
 	dd->platform_config.size = size;
-
-bail:
-	/* exit */;
 }
 
 void free_platform_config(struct hfi1_devdata *dd)

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Re: [PATCH 1/4] IB/hfi1: Restore EPROM read ability

[Jason Gunthorpe]

On Sun, Sep 25, 2016 at 07:49:29AM -0700, Dennis Dalessandro wrote:
> +	for (offset = 0; offset < len; offset += EP_PAGE_SIZE) {
> +		read_page(dd, start + offset, buffer);
> +		if (copy_to_user((void __user *)(addr + offset),

If it is not being used by userpsace then do not call copy_to_user...

Jason
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RE: [PATCH 1/4] IB/hfi1: Restore EPROM read ability

[Luick, Dean]

> -----Original Message-----
> From: Jason Gunthorpe [mailto:jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org]
> Sent: Monday, September 26, 2016 11:53 AM
> To: Dalessandro, Dennis <dennis.dalessandro-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> Cc: dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org; linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; Hariharan, Easwar
> <easwar.hariharan-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>; Luick, Dean <dean.luick-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> Subject: Re: [PATCH 1/4] IB/hfi1: Restore EPROM read ability
> 
> On Sun, Sep 25, 2016 at 07:49:29AM -0700, Dennis Dalessandro wrote:
> > +	for (offset = 0; offset < len; offset += EP_PAGE_SIZE) {
> > +		read_page(dd, start + offset, buffer);
> > +		if (copy_to_user((void __user *)(addr + offset),
> 
> If it is not being used by userpsace then do not call copy_to_user...

The first patch in the series is a straight (partial) restore of the old code.  This is what you are commenting on.  The second patch does a "fixup" of the restored code and removes this call.  Should we squash patches 1 and 2 so that this never shows up?  It is a question of how much "show your work" is desired.

Dean
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Re: [PATCH 1/4] IB/hfi1: Restore EPROM read ability

[Jason Gunthorpe]

> > If it is not being used by userpsace then do not call copy_to_user...
> 
> The first patch in the series is a straight (partial) restore of the
> old code.  This is what you are commenting on.  The second patch
> does a "fixup" of the restored code and removes this call.  Should
> we squash patches 1 and 2 so that this never shows up?  It is a
> question of how much "show your work" is desired.

Yes, squish them - do not make patches that are wrong and then fix
them up later in the series without a really good reason...

Jason
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