CXL rev3.0 8.1.3.8.2 Memory_Info_valid field
The Memory_Info_Valid bit 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.
Fixes: 2e4ba0ec9783 ("cxl/pci: Move cxl_await_media_ready() to the core")
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
---
v2:
- Check both ranges. (Jonathan)
---
drivers/cxl/core/pci.c | 83 +++++++++++++++++++++++++++++++++++++++++++-----
drivers/cxl/cxlpci.h | 2 +
2 files changed, 77 insertions(+), 8 deletions(-)
diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index 9d5a0addbef2..0c314fb8b42c 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -101,21 +101,55 @@ int devm_cxl_port_enumerate_dports(struct cxl_port *port)
}
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);
if (rc)
@@ -134,6 +168,39 @@ int cxl_await_media_ready(struct cxl_dev_state *cxlds)
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;
diff --git a/drivers/cxl/cxlpci.h b/drivers/cxl/cxlpci.h
index ff4c2d10ca4a..cca86a76bd75 100644
--- a/drivers/cxl/cxlpci.h
+++ b/drivers/cxl/cxlpci.h
@@ -32,6 +32,8 @@
#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
