remoteproc: qcom: Introduce helper to store pil info in IMEM
A region in IMEM is used to communicate load addresses of remoteproc to
post mortem debug tools. Implement a helper function that can be used to
store this information in order to enable these tools to process
collected ramdumps.
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20200622191942.255460-3-bjorn.andersson@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
diff --git a/drivers/remoteproc/qcom_pil_info.c b/drivers/remoteproc/qcom_pil_info.c
new file mode 100644
index 0000000..0536e39
--- /dev/null
+++ b/drivers/remoteproc/qcom_pil_info.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2019-2020 Linaro Ltd.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_address.h>
+#include "qcom_pil_info.h"
+
+/*
+ * The PIL relocation information region is used to communicate memory regions
+ * occupied by co-processor firmware for post mortem crash analysis.
+ *
+ * It consists of an array of entries with an 8 byte textual identifier of the
+ * region followed by a 64 bit base address and 32 bit size, both little
+ * endian.
+ */
+#define PIL_RELOC_NAME_LEN 8
+#define PIL_RELOC_ENTRY_SIZE (PIL_RELOC_NAME_LEN + sizeof(__le64) + sizeof(__le32))
+
+struct pil_reloc {
+ void __iomem *base;
+ size_t num_entries;
+};
+
+static struct pil_reloc _reloc __read_mostly;
+static DEFINE_MUTEX(pil_reloc_lock);
+
+static int qcom_pil_info_init(void)
+{
+ struct device_node *np;
+ struct resource imem;
+ void __iomem *base;
+ int ret;
+
+ /* Already initialized? */
+ if (_reloc.base)
+ return 0;
+
+ np = of_find_compatible_node(NULL, NULL, "qcom,pil-reloc-info");
+ if (!np)
+ return -ENOENT;
+
+ ret = of_address_to_resource(np, 0, &imem);
+ of_node_put(np);
+ if (ret < 0)
+ return ret;
+
+ base = ioremap(imem.start, resource_size(&imem));
+ if (!base) {
+ pr_err("failed to map PIL relocation info region\n");
+ return -ENOMEM;
+ }
+
+ memset_io(base, 0, resource_size(&imem));
+
+ _reloc.base = base;
+ _reloc.num_entries = resource_size(&imem) / PIL_RELOC_ENTRY_SIZE;
+
+ return 0;
+}
+
+/**
+ * qcom_pil_info_store() - store PIL information of image in IMEM
+ * @image: name of the image
+ * @base: base address of the loaded image
+ * @size: size of the loaded image
+ *
+ * Return: 0 on success, negative errno on failure
+ */
+int qcom_pil_info_store(const char *image, phys_addr_t base, size_t size)
+{
+ char buf[PIL_RELOC_NAME_LEN];
+ void __iomem *entry;
+ int ret;
+ int i;
+
+ mutex_lock(&pil_reloc_lock);
+ ret = qcom_pil_info_init();
+ if (ret < 0) {
+ mutex_unlock(&pil_reloc_lock);
+ return ret;
+ }
+
+ for (i = 0; i < _reloc.num_entries; i++) {
+ entry = _reloc.base + i * PIL_RELOC_ENTRY_SIZE;
+
+ memcpy_fromio(buf, entry, PIL_RELOC_NAME_LEN);
+
+ /*
+ * An empty record means we didn't find it, given that the
+ * records are packed.
+ */
+ if (!buf[0])
+ goto found_unused;
+
+ if (!strncmp(buf, image, PIL_RELOC_NAME_LEN))
+ goto found_existing;
+ }
+
+ pr_warn("insufficient PIL info slots\n");
+ mutex_unlock(&pil_reloc_lock);
+ return -ENOMEM;
+
+found_unused:
+ memcpy_toio(entry, image, PIL_RELOC_NAME_LEN);
+found_existing:
+ /* Use two writel() as base is only aligned to 4 bytes on odd entries */
+ writel(base, entry + PIL_RELOC_NAME_LEN);
+ writel(base >> 32, entry + PIL_RELOC_NAME_LEN + 4);
+ writel(size, entry + PIL_RELOC_NAME_LEN + sizeof(__le64));
+ mutex_unlock(&pil_reloc_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(qcom_pil_info_store);
+
+static void __exit pil_reloc_exit(void)
+{
+ mutex_lock(&pil_reloc_lock);
+ iounmap(_reloc.base);
+ _reloc.base = NULL;
+ mutex_unlock(&pil_reloc_lock);
+}
+module_exit(pil_reloc_exit);
+
+MODULE_DESCRIPTION("Qualcomm PIL relocation info");
+MODULE_LICENSE("GPL v2");