platform/x86/intel/sdsi: Support different GUIDs

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].

Link: https://github.com/intel/intel-sdsi/blob/master/os-interface.rst
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20221119002343.1281885-4-david.e.box@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/drivers/platform/x86/intel/sdsi.c b/drivers/platform/x86/intel/sdsi.c
index bca05b4..9cd4339 100644 (file)
--- a/drivers/platform/x86/intel/sdsi.c
+++ b/drivers/platform/x86/intel/sdsi.c
@@ -27,9 +27,8 @@
 #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)
 
 /*
@@ -76,6 +75,13 @@
 #define DT_TBIR                                GENMASK(2, 0)
 #define DT_OFFSET(v)                   ((v) & GENMASK(31, 3))
 
+#define SDSI_GUID_V1                   0x006DD191
+#define GUID_V1_CNTRL_SIZE             8
+#define GUID_V1_REGS_SIZE              72
+#define SDSI_GUID_V2                   0xF210D9EF
+#define GUID_V2_CNTRL_SIZE             16
+#define GUID_V2_REGS_SIZE              80
+
 enum sdsi_command {
        SDSI_CMD_PROVISION_AKC          = 0x04,
        SDSI_CMD_PROVISION_CAP          = 0x08,
@@ -100,6 +106,9 @@ 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 +453,18 @@ 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 +517,24 @@ 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 = GUID_V1_CNTRL_SIZE;
+               priv->registers_size = GUID_V1_REGS_SIZE;
+               break;
+       case SDSI_GUID_V2:
+               priv->control_size = GUID_V2_CNTRL_SIZE;
+               priv->registers_size = GUID_V2_REGS_SIZE;
+               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 +576,7 @@ 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 +611,11 @@ 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)