From 0ad10f26c94a86a0c9c3970e53f9a9f6a744055d Mon Sep 17 00:00:00 2001
From: "Nikunj A. Dadhania" <nikunj@linux.vnet.ibm.com>
Date: Tue, 16 Oct 2012 11:49:51 +0530
Subject: SLOF: Support PAPR NVRAM RTAS calls

BenH still need to ACK this though.

From: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com>

* Determines size of the flash using device tree.
* Provides nvram access functions for RTAS_NVRAM
* Allocates temporary buffer of nvram in SLOF code and use that in C.
  (sbrk not available)
* NVRAM_LENGTH is used at various places, make sure it is well guarded
  and also use dynamically determined size once an RTAS-NVRAM is
  found.
* Use NVRAM_LENGTH as a variable in case of RTAS_NVRAM, not very
  elegant though

Signed-off-by: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com>

--

Changelog from v1:
* #define cleanups suggested by Thomas/Benh
* Fix makefile which missed passing $FLAG for building llfw
* renamed vio-nvram.fs as rtas-nvram.fs
---
 lib/libnvram/nvram.c | 88 +++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 80 insertions(+), 8 deletions(-)

(limited to 'lib/libnvram/nvram.c')

diff --git a/lib/libnvram/nvram.c b/lib/libnvram/nvram.c
index 048ec0f..2cb83dc 100644
--- a/lib/libnvram/nvram.c
+++ b/lib/libnvram/nvram.c
@@ -12,6 +12,7 @@
 
 #include "cache.h"
 #include "nvram.h"
+#include "../libhvcall/libhvcall.h"
 
 #include <stdio.h>
 #include <stdarg.h>
@@ -20,9 +21,38 @@
 #include <nvramlog.h>
 #include <byteorder.h>
 
+#ifdef RTAS_NVRAM
+static uint32_t fetch_token;
+static uint32_t store_token;
+static uint32_t NVRAM_LENGTH;
+static char *nvram_buffer; /* use buffer allocated by SLOF code */
+#else
 #ifndef NVRAM_LENGTH
 #define NVRAM_LENGTH	0x10000
 #endif
+/*
+ * This is extremely ugly, but still better than implementing 
+ * another sbrk() around it.
+ */
+static char nvram_buffer[NVRAM_LENGTH];
+#endif
+
+static uint8_t nvram_buffer_locked=0x00;
+
+void nvram_init(uint32_t _fetch_token, uint32_t _store_token, 
+		long _nvram_length, void* nvram_addr)
+{
+#ifdef RTAS_NVRAM
+	fetch_token = _fetch_token;
+	store_token = _store_token;
+	NVRAM_LENGTH = _nvram_length;
+	nvram_buffer = nvram_addr;
+
+	printf("\nNVRAM: size=%d, fetch=%x, store=%x\n", 
+	       NVRAM_LENGTH, fetch_token, store_token);
+#endif
+}
+
 
 void asm_cout(long Character,long UART,long NVRAM);
 
@@ -48,6 +78,46 @@ static volatile uint8_t nvram[NVRAM_LENGTH]; /* FAKE */
 		*pos = data;					\
 	}
 
+#elif defined(RTAS_NVRAM)
+
+static inline void nvram_fetch(unsigned int offset, void *buf, unsigned int len)
+{
+ 	struct hv_rtas_call rtas = {
+		.token = fetch_token,
+		.nargs = 3,
+		.nrets = 2,
+		.argret = { offset, (uint32_t)(unsigned long)buf, len },
+	};
+	h_rtas(&rtas);
+}
+
+static inline void nvram_store(unsigned int offset, void *buf, unsigned int len)
+{
+	struct hv_rtas_call rtas = {
+		.token = store_token,
+		.nargs = 3,
+		.nrets = 2,
+		.argret = { offset, (uint32_t)(unsigned long)buf, len },
+	};
+	h_rtas(&rtas);
+}
+
+#define nvram_access(type,size,name) 				\
+	type nvram_read_##name(unsigned int offset)		\
+	{							\
+		type val;					\
+		if (offset > (NVRAM_LENGTH - sizeof(type)))	\
+			return 0;				\
+		nvram_fetch(offset, &val, size / 8);		\
+		return val;					\
+	}							\
+	void nvram_write_##name(unsigned int offset, type data)	\
+	{							\
+		if (offset > (NVRAM_LENGTH - sizeof(type)))	\
+			return;					\
+		nvram_store(offset, &data, size / 8);		\
+	}
+
 #else	/* DISABLE_NVRAM */
 
 static volatile uint8_t *nvram = (volatile uint8_t *)SB_NVRAM_adr;
@@ -83,12 +153,7 @@ nvram_access(uint16_t, 16, word)
 nvram_access(uint32_t, 32, dword)
 nvram_access(uint64_t, 64, qword)
 
-/*
- * This is extremely ugly, but still better than implementing 
- * another sbrk() around it.
- */
-static char nvram_buffer[NVRAM_LENGTH];
-static uint8_t nvram_buffer_locked=0x00;
+
 
 /**
  * This function is a minimal abstraction for our temporary
@@ -184,7 +249,7 @@ static char * get_partition_name(int offset)
 	for (i=0; i<12; i++)
 		name[i]=nvram_read_byte(offset+4+i);
 
-	// DEBUG("name: \"%s\"\n", name);
+	DEBUG("name: \"%s\"\n", name);
 	return name;
 }
 
@@ -217,7 +282,7 @@ static int calc_used_nvram_space(void)
 		}
 
 		len=get_partition_len(walk);
-		// DEBUG("... part len=%x, %x\n", len, len*16);
+		DEBUG("... part len=%x, %x\n", len, len*16);
 
 		if(!len) {
 			/* If there's a partition type but no len, bail out.
@@ -546,6 +611,13 @@ void reset_nvram(void)
 
 void nvram_debug(void)
 {
+#ifndef RTAS_NVRAM
 	printf("\nNVRAM_BASE: %p\n", nvram);
 	printf("NVRAM_LEN: 0x%x\n", NVRAM_LENGTH);
+#endif
+}
+
+unsigned int get_nvram_size(void)
+{
+	return NVRAM_LENGTH;
 }
-- 
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