[PATCH 3/9] platform/x86/intel/sdsi: Support different GUIDs

David E. Box
2022-11-01T19:11:10Z

Newer versions of Intel On Demand hardware may have an expanded list of
registers to support new features. The register layout is identified by a
unique GUID that's read during driver probe. Add support for handling
different GUIDs and add support for current GUIDs [1].

[1] https://github.com/intel/intel-sdsi/blob/master/os-interface.rst

Signed-off-by: David E. Box <david.e.box@linux.intel.com>
---
drivers/platform/x86/intel/sdsi.c | 47 +++++++++++++++++++++++++++++--
1 file changed, 44 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/x86/intel/sdsi.c b/drivers/platform/x86/intel/sdsi.c
index bca05b4dd983..ab1f65919fc5 100644
--- a/drivers/platform/x86/intel/sdsi.c
+++ b/drivers/platform/x86/intel/sdsi.c
@@ -27,10 +27,10 @@
#define ACCESS_TYPE_LOCAL 3

#define SDSI_MIN_SIZE_DWORDS 276
-#define SDSI_SIZE_CONTROL 8
#define SDSI_SIZE_MAILBOX 1024
-#define SDSI_SIZE_REGS 72
+#define SDSI_SIZE_REGS 80
#define SDSI_SIZE_CMD sizeof(u64)
+#define SDSI_SIZE_MAILBOX 1024

/*
* Write messages are currently up to the size of the mailbox
@@ -76,6 +76,9 @@
#define DT_TBIR GENMASK(2, 0)
#define DT_OFFSET(v) ((v) & GENMASK(31, 3))

+#define SDSI_GUID_V1 0x006DD191
+#define SDSI_GUID_V2 0xF210D9EF
+
enum sdsi_command {
SDSI_CMD_PROVISION_AKC = 0x04,
SDSI_CMD_PROVISION_CAP = 0x08,
@@ -100,6 +103,9 @@ struct sdsi_priv {
void __iomem *control_addr;
void __iomem *mbox_addr;
void __iomem *regs_addr;
+ int control_size;
+ int maibox_size;
+ int registers_size;
u32 guid;
u32 features;
};
@@ -444,6 +450,18 @@ static ssize_t registers_read(struct file *filp, struct kobject *kobj,
struct device *dev = kobj_to_dev(kobj);
struct sdsi_priv *priv = dev_get_drvdata(dev);
void __iomem *addr = priv->regs_addr;
+ int size = priv->registers_size;
+
+ /*
+ * The check below is performed by the sysfs caller based on the static
+ * file size. But this may be greater than the actual size which is based
+ * on the GUID. So check here again based on actual size before reading.
+ */
+ if (off >= size)
+ return 0;
+
+ if (off + count > size)
+ count = size - off;

memcpy_fromio(buf, addr + off, count);

@@ -496,6 +514,24 @@ static const struct attribute_group sdsi_group = {
};
__ATTRIBUTE_GROUPS(sdsi);

+static int sdsi_get_layout(struct sdsi_priv *priv, struct disc_table *table)
+{
+ switch (table->guid) {
+ case SDSI_GUID_V1:
+ priv->control_size = 8;
+ priv->registers_size = 72;
+ break;
+ case SDSI_GUID_V2:
+ priv->control_size = 16;
+ priv->registers_size = 80;
+ break;
+ default:
+ dev_err(priv->dev, "Unrecognized GUID 0x%x\n", table->guid);
+ return -EINVAL;
+ }
+ return 0;
+}
+
static int sdsi_map_mbox_registers(struct sdsi_priv *priv, struct pci_dev *parent,
struct disc_table *disc_table, struct resource *disc_res)
{
@@ -537,7 +573,7 @@ static int sdsi_map_mbox_registers(struct sdsi_priv *priv, struct pci_dev *paren
if (IS_ERR(priv->control_addr))
return PTR_ERR(priv->control_addr);

- priv->mbox_addr = priv->control_addr + SDSI_SIZE_CONTROL;
+ priv->mbox_addr = priv->control_addr + priv->control_size;
priv->regs_addr = priv->mbox_addr + SDSI_SIZE_MAILBOX;

priv->features = readq(priv->regs_addr + SDSI_ENABLED_FEATURES_OFFSET);
@@ -572,6 +608,11 @@ static int sdsi_probe(struct auxiliary_device *auxdev, const struct auxiliary_de

priv->guid = disc_table.guid;

+ /* Get guid based layout info */
+ ret = sdsi_get_layout(priv, &disc_table);
+ if (ret)
+ return ret;
+
/* Map the SDSi mailbox registers */
ret = sdsi_map_mbox_registers(priv, intel_cap_dev->pcidev, &disc_table, disc_res);
if (ret)
--
2.25.1