Initial commit of Open Source release

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 248 insertions, 0 deletions

diff --git a/core/nvram.c b/core/nvram.c
new file mode 100644
index 00000000..f25d6aa6
--- /dev/null
+++ b/core/nvram.c
@@ -0,0 +1,248 @@
+/* Copyright 2013-2014 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * 	http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <skiboot.h>
+#include <fsp.h>
+#include <opal.h>
+#include <lock.h>
+#include <device.h>
+#include <platform.h>
+
+static void *nvram_image;
+static uint32_t nvram_size;
+static bool nvram_ready;
+
+static int64_t opal_read_nvram(uint64_t buffer, uint64_t size, uint64_t offset)
+{
+	if (!nvram_ready)
+		return OPAL_HARDWARE;
+	if (offset >= nvram_size || (offset + size) > nvram_size)
+		return OPAL_PARAMETER;
+
+	memcpy((void *)buffer, nvram_image + offset, size);
+	return OPAL_SUCCESS;
+}
+opal_call(OPAL_READ_NVRAM, opal_read_nvram, 3);
+
+static int64_t opal_write_nvram(uint64_t buffer, uint64_t size, uint64_t offset)
+{
+	if (!nvram_ready)
+		return OPAL_HARDWARE;
+	if (offset >= nvram_size || (offset + size) > nvram_size)
+		return OPAL_PARAMETER;
+	memcpy(nvram_image + offset, (void *)buffer, size);
+	if (platform.nvram_write)
+		platform.nvram_write(offset, nvram_image + offset, size);
+	return OPAL_SUCCESS;
+}
+opal_call(OPAL_WRITE_NVRAM, opal_write_nvram, 3);
+
+struct chrp_nvram_hdr {
+	uint8_t		sig;
+	uint8_t		cksum;
+	uint16_t	len;
+	char		name[12];
+};
+
+#define NVRAM_SIG_FW_PRIV	0x51
+#define NVRAM_SIG_SYSTEM	0x70
+#define NVRAM_SIG_FREE		0x7f
+
+#define NVRAM_NAME_COMMON	"common"
+#define NVRAM_NAME_FW_PRIV	"ibm,skiboot"
+#define NVRAM_NAME_FREE		"wwwwwwwwwwww"
+
+/* 64k should be enough, famous last words... */
+#define NVRAM_SIZE_COMMON	0x10000
+
+/* 4k should be enough, famous last words... */
+#define NVRAM_SIZE_FW_PRIV	0x1000
+
+static uint8_t chrp_nv_cksum(struct chrp_nvram_hdr *hdr)
+{
+	struct chrp_nvram_hdr h_copy = *hdr;
+	uint8_t b_data, i_sum, c_sum;
+	uint8_t *p = (uint8_t *)&h_copy;
+	unsigned int nbytes = sizeof(h_copy);
+
+	h_copy.cksum = 0;
+	for (c_sum = 0; nbytes; nbytes--) {
+		b_data = *(p++);
+		i_sum = c_sum + b_data;
+		if (i_sum < c_sum)
+			i_sum++;
+		c_sum = i_sum;
+	}
+	return c_sum;
+}
+
+static void nvram_format(void)
+{
+	struct chrp_nvram_hdr *h;
+	unsigned int offset = 0;
+
+	prerror("NVRAM: Re-initializing\n");
+	memset(nvram_image, 0, nvram_size);
+
+	/* Create private partition */
+	h = nvram_image + offset;
+	h->sig = NVRAM_SIG_FW_PRIV;
+	h->len = NVRAM_SIZE_FW_PRIV >> 4;
+	strcpy(h->name, NVRAM_NAME_FW_PRIV);
+	h->cksum = chrp_nv_cksum(h);
+	offset += NVRAM_SIZE_FW_PRIV;
+
+	/* Create common partition */
+	h = nvram_image + offset;
+	h->sig = NVRAM_SIG_SYSTEM;
+	h->len = NVRAM_SIZE_COMMON >> 4;
+	strcpy(h->name, NVRAM_NAME_COMMON);
+	h->cksum = chrp_nv_cksum(h);
+	offset += NVRAM_SIZE_COMMON;
+
+	/* Create free space partition */
+	h = nvram_image + offset;
+	h->sig = NVRAM_SIG_FREE;
+	h->len = (nvram_size - offset) >> 4;
+	strncpy(h->name, NVRAM_NAME_FREE, 12);
+	h->cksum = chrp_nv_cksum(h);
+
+	/* Write the whole thing back */
+	if (platform.nvram_write)
+		platform.nvram_write(0, nvram_image, nvram_size);
+}
+
+/*
+ * Check that the nvram partition layout is sane and that it
+ * contains our required partitions. If not, we re-format the
+ * lot of it
+ */
+static void nvram_check(void)
+{
+	unsigned int offset = 0;
+	bool found_common = false;
+	bool found_skiboot = false;
+
+	while (offset + sizeof(struct chrp_nvram_hdr) < nvram_size) {
+		struct chrp_nvram_hdr *h = nvram_image + offset;
+
+		if (chrp_nv_cksum(h) != h->cksum) {
+			prerror("NVRAM: Partition at offset 0x%x"
+				" has bad checksum\n", offset);
+			goto failed;
+		}
+		if (h->len < 1) {
+			prerror("NVRAM: Partition at offset 0x%x"
+				" has incorrect 0 length\n", offset);
+			goto failed;
+		}
+
+		if (h->sig == NVRAM_SIG_SYSTEM &&
+		    strcmp(h->name, NVRAM_NAME_COMMON) == 0)
+			found_common = true;
+
+		if (h->sig == NVRAM_SIG_FW_PRIV &&
+		    strcmp(h->name, NVRAM_NAME_FW_PRIV) == 0)
+			found_skiboot = true;
+
+		offset += h->len << 4;
+		if (offset > nvram_size) {
+			prerror("NVRAM: Partition at offset 0x%x"
+				" extends beyond end of nvram !\n", offset);
+			goto failed;
+		}
+	}
+	if (!found_common) {
+			prerror("NVRAM: Common partition not found !\n");
+		goto failed;
+	}
+	if (!found_skiboot) {
+			prerror("NVRAM: Skiboot private partition "
+				"not found !\n");
+		goto failed;
+	}
+
+	prerror("NVRAM: Layout appears sane\n");
+	return;
+ failed:
+	nvram_format();
+}
+
+void nvram_read_complete(bool success)
+{
+	struct dt_node *np;
+
+	/* Read not successful, error out and free the buffer */
+	if (!success) {
+		free(nvram_image);
+		nvram_size = 0;
+		return;
+	}
+
+	/* Check and maybe format nvram */
+	nvram_check();
+
+	/* Add nvram node */
+	np = dt_new(opal_node, "nvram");
+	dt_add_property_cells(np, "#bytes", nvram_size);
+	dt_add_property_string(np, "compatible", "ibm,opal-nvram");
+
+	/* Mark ready */
+	nvram_ready = true;
+}
+
+void nvram_init(void)
+{
+	int rc;
+
+	if (!platform.nvram_info)
+		return;
+	rc = platform.nvram_info(&nvram_size);
+	if (rc) {
+		prerror("NVRAM: Error %d retrieving nvram info\n", rc);
+		return;
+	}
+	printf("NVRAM: Size is %d KB\n", nvram_size >> 10);
+	if (nvram_size > 0x100000) {
+		printf("NVRAM: Cropping to 1MB !\n");
+		nvram_size = 0x100000;
+	}
+
+	/*
+	 * We allocate the nvram image with 4k alignment to make the
+	 * FSP backend job's easier
+	 */
+	nvram_image = memalign(0x1000, nvram_size);
+	if (!nvram_image) {
+		prerror("NVRAM: Failed to allocate nvram image\n");
+		nvram_size = 0;
+		return;
+	}
+
+	/* Read it in */
+	rc = platform.nvram_start_read(nvram_image, 0, nvram_size);
+	if (rc) {
+		prerror("NVRAM: Failed to read NVRAM from FSP !\n");
+		nvram_size = 0;
+		free(nvram_image);
+		return;
+	}
+
+	/*
+	 * We'll get called back later (or recursively from
+	 * nvram_start_read) in nvram_read_complete()
+	 */
+}