1 files changed, 314 insertions, 0 deletions

diff --git a/drivers/net/ipa/ipa_mem.c b/drivers/net/ipa/ipa_mem.c
new file mode 100644
index 000000000000..42d2c29d9f0c
--- /dev/null
+++ b/drivers/net/ipa/ipa_mem.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2019-2020 Linaro Ltd.
+ */
+
+#include <linux/types.h>
+#include <linux/bitfield.h>
+#include <linux/bug.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+
+#include "ipa.h"
+#include "ipa_reg.h"
+#include "ipa_cmd.h"
+#include "ipa_mem.h"
+#include "ipa_data.h"
+#include "ipa_table.h"
+#include "gsi_trans.h"
+
+/* "Canary" value placed between memory regions to detect overflow */
+#define IPA_MEM_CANARY_VAL		cpu_to_le32(0xdeadbeef)
+
+/* Add an immediate command to a transaction that zeroes a memory region */
+static void
+ipa_mem_zero_region_add(struct gsi_trans *trans, const struct ipa_mem *mem)
+{
+	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
+	dma_addr_t addr = ipa->zero_addr;
+
+	if (!mem->size)
+		return;
+
+	ipa_cmd_dma_shared_mem_add(trans, mem->offset, mem->size, addr, true);
+}
+
+/**
+ * ipa_mem_setup() - Set up IPA AP and modem shared memory areas
+ *
+ * Set up the shared memory regions in IPA local memory.  This involves
+ * zero-filling memory regions, and in the case of header memory, telling
+ * the IPA where it's located.
+ *
+ * This function performs the initial setup of this memory.  If the modem
+ * crashes, its regions are re-zeroed in ipa_mem_zero_modem().
+ *
+ * The AP informs the modem where its portions of memory are located
+ * in a QMI exchange that occurs at modem startup.
+ *
+ * @Return:	0 if successful, or a negative error code
+ */
+int ipa_mem_setup(struct ipa *ipa)
+{
+	dma_addr_t addr = ipa->zero_addr;
+	struct gsi_trans *trans;
+	u32 offset;
+	u16 size;
+
+	/* Get a transaction to define the header memory region and to zero
+	 * the processing context and modem memory regions.
+	 */
+	trans = ipa_cmd_trans_alloc(ipa, 4);
+	if (!trans) {
+		dev_err(&ipa->pdev->dev, "no transaction for memory setup\n");
+		return -EBUSY;
+	}
+
+	/* Initialize IPA-local header memory.  The modem and AP header
+	 * regions are contiguous, and initialized together.
+	 */
+	offset = ipa->mem[IPA_MEM_MODEM_HEADER].offset;
+	size = ipa->mem[IPA_MEM_MODEM_HEADER].size;
+	size += ipa->mem[IPA_MEM_AP_HEADER].size;
+
+	ipa_cmd_hdr_init_local_add(trans, offset, size, addr);
+
+	ipa_mem_zero_region_add(trans, &ipa->mem[IPA_MEM_MODEM_PROC_CTX]);
+
+	ipa_mem_zero_region_add(trans, &ipa->mem[IPA_MEM_AP_PROC_CTX]);
+
+	ipa_mem_zero_region_add(trans, &ipa->mem[IPA_MEM_MODEM]);
+
+	gsi_trans_commit_wait(trans);
+
+	/* Tell the hardware where the processing context area is located */
+	iowrite32(ipa->mem_offset + offset,
+		  ipa->reg_virt + IPA_REG_LOCAL_PKT_PROC_CNTXT_BASE_OFFSET);
+
+	return 0;
+}
+
+void ipa_mem_teardown(struct ipa *ipa)
+{
+	/* Nothing to do */
+}
+
+#ifdef IPA_VALIDATE
+
+static bool ipa_mem_valid(struct ipa *ipa, enum ipa_mem_id mem_id)
+{
+	const struct ipa_mem *mem = &ipa->mem[mem_id];
+	struct device *dev = &ipa->pdev->dev;
+	u16 size_multiple;
+
+	/* Other than modem memory, sizes must be a multiple of 8 */
+	size_multiple = mem_id == IPA_MEM_MODEM ? 4 : 8;
+	if (mem->size % size_multiple)
+		dev_err(dev, "region %u size not a multiple of %u bytes\n",
+			mem_id, size_multiple);
+	else if (mem->offset % 8)
+		dev_err(dev, "region %u offset not 8-byte aligned\n", mem_id);
+	else if (mem->offset < mem->canary_count * sizeof(__le32))
+		dev_err(dev, "region %u offset too small for %hu canaries\n",
+			mem_id, mem->canary_count);
+	else if (mem->offset + mem->size > ipa->mem_size)
+		dev_err(dev, "region %u ends beyond memory limit (0x%08x)\n",
+			mem_id, ipa->mem_size);
+	else
+		return true;
+
+	return false;
+}
+
+#else /* !IPA_VALIDATE */
+
+static bool ipa_mem_valid(struct ipa *ipa, enum ipa_mem_id mem_id)
+{
+	return true;
+}
+
+#endif /*! IPA_VALIDATE */
+
+/**
+ * ipa_mem_config() - Configure IPA shared memory
+ *
+ * @Return:	0 if successful, or a negative error code
+ */
+int ipa_mem_config(struct ipa *ipa)
+{
+	struct device *dev = &ipa->pdev->dev;
+	enum ipa_mem_id mem_id;
+	dma_addr_t addr;
+	u32 mem_size;
+	void *virt;
+	u32 val;
+
+	/* Check the advertised location and size of the shared memory area */
+	val = ioread32(ipa->reg_virt + IPA_REG_SHARED_MEM_SIZE_OFFSET);
+
+	/* The fields in the register are in 8 byte units */
+	ipa->mem_offset = 8 * u32_get_bits(val, SHARED_MEM_BADDR_FMASK);
+	/* Make sure the end is within the region's mapped space */
+	mem_size = 8 * u32_get_bits(val, SHARED_MEM_SIZE_FMASK);
+
+	/* If the sizes don't match, issue a warning */
+	if (ipa->mem_offset + mem_size > ipa->mem_size) {
+		dev_warn(dev, "ignoring larger reported memory size: 0x%08x\n",
+			mem_size);
+	} else if (ipa->mem_offset + mem_size < ipa->mem_size) {
+		dev_warn(dev, "limiting IPA memory size to 0x%08x\n",
+			 mem_size);
+		ipa->mem_size = mem_size;
+	}
+
+	/* Prealloc DMA memory for zeroing regions */
+	virt = dma_alloc_coherent(dev, IPA_MEM_MAX, &addr, GFP_KERNEL);
+	if (!virt)
+		return -ENOMEM;
+	ipa->zero_addr = addr;
+	ipa->zero_virt = virt;
+	ipa->zero_size = IPA_MEM_MAX;
+
+	/* Verify each defined memory region is valid, and if indicated
+	 * for the region, write "canary" values in the space prior to
+	 * the region's base address.
+	 */
+	for (mem_id = 0; mem_id < IPA_MEM_COUNT; mem_id++) {
+		const struct ipa_mem *mem = &ipa->mem[mem_id];
+		u16 canary_count;
+		__le32 *canary;
+
+		/* Validate all regions (even undefined ones) */
+		if (!ipa_mem_valid(ipa, mem_id))
+			goto err_dma_free;
+
+		/* Skip over undefined regions */
+		if (!mem->offset && !mem->size)
+			continue;
+
+		canary_count = mem->canary_count;
+		if (!canary_count)
+			continue;
+
+		/* Write canary values in the space before the region */
+		canary = ipa->mem_virt + ipa->mem_offset + mem->offset;
+		do
+			*--canary = IPA_MEM_CANARY_VAL;
+		while (--canary_count);
+	}
+
+	/* Make sure filter and route table memory regions are valid */
+	if (!ipa_table_valid(ipa))
+		goto err_dma_free;
+
+	/* Validate memory-related properties relevant to immediate commands */
+	if (!ipa_cmd_data_valid(ipa))
+		goto err_dma_free;
+
+	/* Verify the microcontroller ring alignment (0 is OK too) */
+	if (ipa->mem[IPA_MEM_UC_EVENT_RING].offset % 1024) {
+		dev_err(dev, "microcontroller ring not 1024-byte aligned\n");
+		goto err_dma_free;
+	}
+
+	return 0;
+
+err_dma_free:
+	dma_free_coherent(dev, IPA_MEM_MAX, ipa->zero_virt, ipa->zero_addr);
+
+	return -EINVAL;
+}
+
+/* Inverse of ipa_mem_config() */
+void ipa_mem_deconfig(struct ipa *ipa)
+{
+	struct device *dev = &ipa->pdev->dev;
+
+	dma_free_coherent(dev, ipa->zero_size, ipa->zero_virt, ipa->zero_addr);
+	ipa->zero_size = 0;
+	ipa->zero_virt = NULL;
+	ipa->zero_addr = 0;
+}
+
+/**
+ * ipa_mem_zero_modem() - Zero IPA-local memory regions owned by the modem
+ *
+ * Zero regions of IPA-local memory used by the modem.  These are configured
+ * (and initially zeroed) by ipa_mem_setup(), but if the modem crashes and
+ * restarts via SSR we need to re-initialize them.  A QMI message tells the
+ * modem where to find regions of IPA local memory it needs to know about
+ * (these included).
+ */
+int ipa_mem_zero_modem(struct ipa *ipa)
+{
+	struct gsi_trans *trans;
+
+	/* Get a transaction to zero the modem memory, modem header,
+	 * and modem processing context regions.
+	 */
+	trans = ipa_cmd_trans_alloc(ipa, 3);
+	if (!trans) {
+		dev_err(&ipa->pdev->dev,
+			"no transaction to zero modem memory\n");
+		return -EBUSY;
+	}
+
+	ipa_mem_zero_region_add(trans, &ipa->mem[IPA_MEM_MODEM_HEADER]);
+
+	ipa_mem_zero_region_add(trans, &ipa->mem[IPA_MEM_MODEM_PROC_CTX]);
+
+	ipa_mem_zero_region_add(trans, &ipa->mem[IPA_MEM_MODEM]);
+
+	gsi_trans_commit_wait(trans);
+
+	return 0;
+}
+
+/* Perform memory region-related initialization */
+int ipa_mem_init(struct ipa *ipa, u32 count, const struct ipa_mem *mem)
+{
+	struct device *dev = &ipa->pdev->dev;
+	struct resource *res;
+	int ret;
+
+	if (count > IPA_MEM_COUNT) {
+		dev_err(dev, "to many memory regions (%u > %u)\n",
+			count, IPA_MEM_COUNT);
+		return -EINVAL;
+	}
+
+	ret = dma_set_mask_and_coherent(&ipa->pdev->dev, DMA_BIT_MASK(64));
+	if (ret) {
+		dev_err(dev, "error %d setting DMA mask\n", ret);
+		return ret;
+	}
+
+	res = platform_get_resource_byname(ipa->pdev, IORESOURCE_MEM,
+					   "ipa-shared");
+	if (!res) {
+		dev_err(dev,
+			"DT error getting \"ipa-shared\" memory property\n");
+		return -ENODEV;
+	}
+
+	ipa->mem_virt = memremap(res->start, resource_size(res), MEMREMAP_WC);
+	if (!ipa->mem_virt) {
+		dev_err(dev, "unable to remap \"ipa-shared\" memory\n");
+		return -ENOMEM;
+	}
+
+	ipa->mem_addr = res->start;
+	ipa->mem_size = resource_size(res);
+
+	/* The ipa->mem[] array is indexed by enum ipa_mem_id values */
+	ipa->mem = mem;
+
+	return 0;
+}
+
+/* Inverse of ipa_mem_init() */
+void ipa_mem_exit(struct ipa *ipa)
+{
+	memunmap(ipa->mem_virt);
+}