capp/phb: Introduce 'struct capp' to hold capp related info in 'struc…

…t phb'

Previously struct proc_chip member 'capp_phb3_attached_mask' was used
for Power-8 to keep track of PHB attached to the single CAPP on the
chip. CAPP on that chip supported a flexible PHB assignment
scheme. However since then new chips only support a static assignment
i.e a CAPP can only be attached to a specific PEC.

Hence instead of using 'proc_chip.capp_phb4_attached_mask' to manage
CAPP <-> PEC assignments which needs a global lock (capi_lock) to be
updated, we introduce a new struct named 'capp' a pointer to which
resides inside struct 'phb4'. Since updates to struct 'phb4' already
happen in context of phb_lock; this eliminates the
need to use mutex 'capi_lock' while updating
'capp_phb4_attached_mask'.

This struct is also used to hold CAPP specific variables such as
pointer to the 'struct phb' to which the CAPP is attached,
'capp_xscom_offset' which is the xscom offset to be added to CAPP
registers in case there are more than 1 on the chip, 'capp_index'
which is the index of the CAPP on the chip, and attached_pe' which is
the process endpoint index to which CAPP is attached. Finally member
'chip_id' holds the chip-id thats used for performing xscom
read/writes.

Also new helpers named capp_xscom_read()/write() are introduced to
make access to CAPP xscom registers easier.

Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>

hw/capp.c

@@ -240,3 +240,15 @@ int64_t capp_get_info(int chip_id, struct phb *phb, struct capp_info *info)
 
 	return OPAL_PARAMETER;
 }
+
+int64_t capp_xscom_read(struct capp *capp, int64_t off, uint64_t *val)
+{
+	return capp == NULL ? OPAL_PARAMETER :
+		xscom_read(capp->chip_id, off + capp->capp_xscom_offset, val);
+}
+
+int64_t capp_xscom_write(struct capp *capp, int64_t off, uint64_t val)
+{
+	return capp == NULL ? OPAL_PARAMETER :
+		xscom_write(capp->chip_id, off + capp->capp_xscom_offset, val);
+}

hw/phb4.c

@@ -3880,13 +3880,13 @@ static int64_t phb4_get_capp_info(int chip_id, struct phb *phb,
 				  struct capp_info *info)
 {
 	struct phb4 *p = phb_to_phb4(phb);
-	struct proc_chip *chip = get_chip(p->chip_id);
 	uint32_t offset;
 
 	if (chip_id != p->chip_id)
 		return OPAL_PARAMETER;
 
-	if (!((1 << p->index) & chip->capp_phb4_attached_mask))
+	/* Check is CAPP is attached to the PHB */
+	if (p->capp == NULL || p->capp->phb != phb)
 		return OPAL_PARAMETER;
 
 	offset = PHB4_CAPP_REG_OFFSET(p);
@@ -4397,23 +4397,63 @@ static int64_t enable_capi_mode(struct phb4 *p, uint64_t pe_number,
 	return OPAL_SUCCESS;
 }
 
+
+static int64_t phb4_init_capp(struct phb4 *p)
+{
+	struct capp *capp;
+	int rc;
+
+	if (p->index != CAPP0_PHB_INDEX &&
+	    p->index != CAPP1_PHB_INDEX)
+		return OPAL_UNSUPPORTED;
+
+	capp = zalloc(sizeof(struct capp));
+	if (capp == NULL)
+		return OPAL_NO_MEM;
+
+	if (p->index == CAPP0_PHB_INDEX) {
+		capp->capp_index = 0;
+		capp->capp_xscom_offset = 0;
+
+	} else if (p->index == CAPP1_PHB_INDEX) {
+		capp->capp_index = 1;
+		capp->capp_xscom_offset = CAPP1_REG_OFFSET;
+	}
+
+	capp->attached_pe = phb4_get_reserved_pe_number(&p->phb);
+	capp->chip_id = p->chip_id;
+
+	/* Load capp microcode into the capp unit */
+	rc = load_capp_ucode(p);
+
+	if (rc == OPAL_SUCCESS)
+		p->capp = capp;
+	else
+		free(capp);
+
+	return rc;
+}
+
 static int64_t phb4_set_capi_mode(struct phb *phb, uint64_t mode,
 				  uint64_t pe_number)
 {
 	struct phb4 *p = phb_to_phb4(phb);
 	struct proc_chip *chip = get_chip(p->chip_id);
+	struct capp *capp = p->capp;
 	uint64_t reg, ret;
 	uint32_t offset;
 
+	if (capp == NULL)
+		return OPAL_UNSUPPORTED;
 
 	if (!capp_ucode_loaded(chip, p->index)) {
 		PHBERR(p, "CAPP: ucode not loaded\n");
 		return OPAL_RESOURCE;
 	}
 
-	lock(&capi_lock);
-	chip->capp_phb4_attached_mask |= 1 << p->index;
-	unlock(&capi_lock);
+	/* mark the capp attached to the phb */
+	capp->phb = phb;
+	capp->attached_pe = pe_number;
 
 	offset = PHB4_CAPP_REG_OFFSET(p);
 	xscom_read(p->chip_id, CAPP_ERR_STATUS_CTRL + offset, &reg);
@@ -5595,8 +5635,8 @@ static void phb4_create(struct dt_node *np)
 	/* Get the HW up and running */
 	phb4_init_hw(p);
 
-	/* Load capp microcode into capp unit */
-	load_capp_ucode(p);
+	/* init capp that might get attached to the phb */
+	phb4_init_capp(p);
 
 	/* Compute XIVE source flags depending on PHB revision */
 	irq_flags = 0;

include/capp.h

@@ -79,6 +79,14 @@ struct capp_ops {
 	int64_t (*get_capp_info)(int, struct phb *, struct capp_info *);
 };
 
+struct capp {
+	struct phb *phb;
+	unsigned int capp_index;
+	uint64_t capp_xscom_offset;
+	uint64_t attached_pe;
+	uint64_t chip_id;
+};
+
 struct proc_chip;
 extern struct lock capi_lock;
 extern struct capp_ops capi_ops;
@@ -96,4 +104,8 @@ extern int64_t capp_load_ucode(unsigned int chip_id, uint32_t opal_id,
 extern int64_t capp_get_info(int chip_id, struct phb *phb,
 			     struct capp_info *info);
 
+
+/* Helpers to read/write capp registers */
+extern int64_t capp_xscom_read(struct capp *capp, int64_t off, uint64_t *val);
+extern int64_t capp_xscom_write(struct capp *capp, int64_t off, uint64_t val);
 #endif /* __CAPP_H */

include/chip.h

@@ -197,7 +197,6 @@ struct proc_chip {
 
 	/* Must hold capi_lock to change */
 	uint8_t			capp_phb3_attached_mask;
-	uint8_t			capp_phb4_attached_mask;
 	uint8_t			capp_ucode_loaded;
 
 	/* Used by hw/centaur.c */

include/phb4.h

@@ -232,6 +232,9 @@ struct phb4 {
 	/* Current NPU2 relaxed ordering state */
 	bool			ro_state;
 
+	/* Any capp instance attached to the PHB4 */
+	struct capp		*capp;
+
 	struct phb		phb;
 };