This is a note to let you know that I've just added the patch titled
cxl: Wait Memory_Info_Valid before access memory related info
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cxl-wait-memory_info_valid-before-access-memory-related-info.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ce17ad0d54985e2595a3e615fda31df61808a08c Mon Sep 17 00:00:00 2001
From: Dave Jiang <dave.jiang@xxxxxxxxx>
Date: Thu, 18 May 2023 14:54:34 -0700
Subject: cxl: Wait Memory_Info_Valid before access memory related info
From: Dave Jiang <dave.jiang@xxxxxxxxx>
commit ce17ad0d54985e2595a3e615fda31df61808a08c upstream.
The Memory_Info_Valid bit (CXL 3.0 8.1.3.8.2) indicates that the CXL
Range Size High and Size Low registers are valid. The bit must be set
within 1 second of reset deassertion to the device. Check valid bit
before we check the Memory_Active bit when waiting for
cxl_await_media_ready() to ensure that the memory info is valid for
consumption. Also ensures both DVSEC ranges 1 and 2 are ready if DVSEC
Capability indicates they are both supported.
Fixes: 523e594d9cc0 ("cxl/pci: Implement wait for media active")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Link: https://lore.kernel.org/r/168444687469.3134781.11033518965387297327.stgit@djiang5-mobl3
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/cxl/core/pci.c | 85 +++++++++++++++++++++++++++++++++++++++++++------
drivers/cxl/cxlpci.h | 2 +
2 files changed, 78 insertions(+), 9 deletions(-)
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -103,23 +103,57 @@ int devm_cxl_port_enumerate_dports(struc
}
EXPORT_SYMBOL_NS_GPL(devm_cxl_port_enumerate_dports, CXL);
-/*
- * Wait up to @media_ready_timeout for the device to report memory
- * active.
- */
-int cxl_await_media_ready(struct cxl_dev_state *cxlds)
+static int cxl_dvsec_mem_range_valid(struct cxl_dev_state *cxlds, int id)
+{
+ struct pci_dev *pdev = to_pci_dev(cxlds->dev);
+ int d = cxlds->cxl_dvsec;
+ bool valid = false;
+ int rc, i;
+ u32 temp;
+
+ if (id > CXL_DVSEC_RANGE_MAX)
+ return -EINVAL;
+
+ /* Check MEM INFO VALID bit first, give up after 1s */
+ i = 1;
+ do {
+ rc = pci_read_config_dword(pdev,
+ d + CXL_DVSEC_RANGE_SIZE_LOW(id),
+ &temp);
+ if (rc)
+ return rc;
+
+ valid = FIELD_GET(CXL_DVSEC_MEM_INFO_VALID, temp);
+ if (valid)
+ break;
+ msleep(1000);
+ } while (i--);
+
+ if (!valid) {
+ dev_err(&pdev->dev,
+ "Timeout awaiting memory range %d valid after 1s.\n",
+ id);
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
+static int cxl_dvsec_mem_range_active(struct cxl_dev_state *cxlds, int id)
{
struct pci_dev *pdev = to_pci_dev(cxlds->dev);
int d = cxlds->cxl_dvsec;
bool active = false;
- u64 md_status;
int rc, i;
+ u32 temp;
- for (i = media_ready_timeout; i; i--) {
- u32 temp;
+ if (id > CXL_DVSEC_RANGE_MAX)
+ return -EINVAL;
+ /* Check MEM ACTIVE bit, up to 60s timeout by default */
+ for (i = media_ready_timeout; i; i--) {
rc = pci_read_config_dword(
- pdev, d + CXL_DVSEC_RANGE_SIZE_LOW(0), &temp);
+ pdev, d + CXL_DVSEC_RANGE_SIZE_LOW(id), &temp);
if (rc)
return rc;
@@ -136,6 +170,39 @@ int cxl_await_media_ready(struct cxl_dev
return -ETIMEDOUT;
}
+ return 0;
+}
+
+/*
+ * Wait up to @media_ready_timeout for the device to report memory
+ * active.
+ */
+int cxl_await_media_ready(struct cxl_dev_state *cxlds)
+{
+ struct pci_dev *pdev = to_pci_dev(cxlds->dev);
+ int d = cxlds->cxl_dvsec;
+ int rc, i, hdm_count;
+ u64 md_status;
+ u16 cap;
+
+ rc = pci_read_config_word(pdev,
+ d + CXL_DVSEC_CAP_OFFSET, &cap);
+ if (rc)
+ return rc;
+
+ hdm_count = FIELD_GET(CXL_DVSEC_HDM_COUNT_MASK, cap);
+ for (i = 0; i < hdm_count; i++) {
+ rc = cxl_dvsec_mem_range_valid(cxlds, i);
+ if (rc)
+ return rc;
+ }
+
+ for (i = 0; i < hdm_count; i++) {
+ rc = cxl_dvsec_mem_range_active(cxlds, i);
+ if (rc)
+ return rc;
+ }
+
md_status = readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET);
if (!CXLMDEV_READY(md_status))
return -EIO;
--- a/drivers/cxl/cxlpci.h
+++ b/drivers/cxl/cxlpci.h
@@ -31,6 +31,8 @@
#define CXL_DVSEC_RANGE_BASE_LOW(i) (0x24 + (i * 0x10))
#define CXL_DVSEC_MEM_BASE_LOW_MASK GENMASK(31, 28)
+#define CXL_DVSEC_RANGE_MAX 2
+
/* CXL 2.0 8.1.4: Non-CXL Function Map DVSEC */
#define CXL_DVSEC_FUNCTION_MAP 2
Patches currently in stable-queue which might be from dave.jiang@xxxxxxxxx are
queue-6.1/cxl-wait-memory_info_valid-before-access-memory-related-info.patch
