[Skiboot] [PATCH v2 3/4] Advertise the self-save and self-restore attributes in the device tree

[Pratik Rajesh Sampat]

Support for self save and self restore interface is advertised in the
device tree, along with the list of SPRs it supports for each.

The Special Purpose Register identification is encoded in a 2048 bitmask
structure, where each bit signifies the identification key of that SPR
which is consistent with that of the POWER architecture set for that
register.

Signed-off-by: Pratik Rajesh Sampat <psampat at linux.ibm.com>
---
 hw/slw.c                        | 82 +++++++++++++++++++++++++++++++++
 include/skiboot.h               |  1 +
 libpore/p8_pore_table_gen_api.H |  1 +
 3 files changed, 84 insertions(+)

diff --git a/hw/slw.c b/hw/slw.c
index 14dbce47..ebb70729 100644
--- a/hw/slw.c
+++ b/hw/slw.c
@@ -23,12 +23,15 @@
 #include <nvram.h>
 #include <sbe-p8.h>
 #include <xive.h>
+#include <bitmap.h>
 
 #include <p9_stop_api.H>
 #include <p8_pore_table_gen_api.H>
 #include <sbe_xip_image.h>
 
 static uint32_t slw_saved_reset[0x100];
+#define MAX_RESET_PATCH_SIZE	64
+#define SPR_BITMAP_LENGTH	2048
 
 static bool slw_current_le = false;
 
@@ -750,6 +753,84 @@ static void slw_late_init_p9(struct proc_chip *chip)
 	}
 }
 
+/* Add device tree properties to determine self-save | restore */
+void add_cpu_self_save_properties()
+{
+	int i;
+	struct dt_node *self_restore, *self_save, *power_mgt;
+	bitmap_t *self_restore_map, *self_save_map;
+
+	const uint64_t self_restore_regs[] = {
+		P8_SPR_HRMOR,
+		P8_SPR_HMEER,
+		P8_SPR_PMICR,
+		P8_SPR_PMCR,
+		P8_SPR_HID0,
+		P8_SPR_HID1,
+		P8_SPR_HID4,
+		P8_SPR_HID5,
+		P8_SPR_HSPRG0,
+		P8_SPR_LPCR,
+		P8_SPR_PSSCR,
+		P8_MSR_MSR
+	};
+
+	const uint64_t self_save_regs[] = {
+		P9_STOP_SPR_DAWR,
+		P9_STOP_SPR_HSPRG0,
+		P9_STOP_SPR_LDBAR,
+		P9_STOP_SPR_LPCR,
+		P9_STOP_SPR_PSSCR,
+		P9_STOP_SPR_MSR,
+		P9_STOP_SPR_HRMOR,
+		P9_STOP_SPR_HMEER,
+		P9_STOP_SPR_PMCR,
+		P9_STOP_SPR_PTCR
+	};
+
+	self_save_map = zalloc(BITMAP_BYTES(SPR_BITMAP_LENGTH));
+	self_restore_map = zalloc(BITMAP_BYTES(SPR_BITMAP_LENGTH));
+
+	for (i = 0; i < ARRAY_SIZE(self_save_regs); i++)
+		bitmap_set_bit(*self_save_map, self_save_regs[i]);
+
+	for (i = 0; i < ARRAY_SIZE(self_restore_regs); i++)
+		bitmap_set_bit(*self_restore_map, self_restore_regs[i]);
+
+	power_mgt = dt_find_by_path(dt_root, "/ibm,opal/power-mgt");
+	if (!power_mgt) {
+		prerror("OCC: dt node /ibm,opal/power-mgt not found\n");
+		goto bail;
+	}
+
+	self_restore = dt_new(power_mgt, "self-restore");
+	if (!self_restore) {
+		prerror("OCC: Failed to create self restore node");
+		goto bail;
+	}
+	dt_add_property_string(self_restore, "status", "enabled");
+
+	dt_add_property(self_restore, "sprn-bitmask", *self_restore_map,
+			SPR_BITMAP_LENGTH / 8);
+
+	self_save = dt_new(power_mgt, "self-save");
+	if (!self_save) {
+		prerror("OCC: Failed to create self save node");
+		goto bail;
+	}
+	if (proc_gen == proc_gen_p9) {
+		dt_add_property_string(self_save, "status", "enabled");
+
+		dt_add_property(self_save, "sprn-bitmask", *self_save_map,
+				SPR_BITMAP_LENGTH / 8);
+	} else {
+		dt_add_property_string(self_save, "status", "disabled");
+	}
+bail:
+	free(self_save_map);
+	free(self_restore_map);
+}
+
 /* Add device tree properties to describe idle states */
 void add_cpu_idle_state_properties(void)
 {
@@ -1563,4 +1644,5 @@ void slw_init(void)
 		}
 	}
 	add_cpu_idle_state_properties();
+	add_cpu_self_save_properties();
 }
diff --git a/include/skiboot.h b/include/skiboot.h
index 1ed8464e..43ee9c75 100644
--- a/include/skiboot.h
+++ b/include/skiboot.h
@@ -209,6 +209,7 @@ extern void early_uart_init(void);
 extern void homer_init(void);
 extern void slw_init(void);
 extern void add_cpu_idle_state_properties(void);
+extern void add_cpu_self_save_properties(void);
 extern void lpc_rtc_init(void);
 
 /* flash support */
diff --git a/libpore/p8_pore_table_gen_api.H b/libpore/p8_pore_table_gen_api.H
index 63081ca5..d72fee90 100644
--- a/libpore/p8_pore_table_gen_api.H
+++ b/libpore/p8_pore_table_gen_api.H
@@ -233,6 +233,7 @@ enum  {
   P8_SPR_HRMOR  =  313,
   P8_SPR_HMEER  =  337,
   P8_SPR_PMICR  =  852,
+  P8_SPR_PSSCR  =  855,
   P8_SPR_PMCR   =  884,
   P8_SPR_HID0   = 1008,
   P8_SPR_HID1   = 1009,
-- 
2.24.1