firmware: qcom_scm: Dynamically support SMCCC and legacy conventions

Dynamically support SMCCCC and legacy conventions by detecting which
convention to use at runtime. qcom_scm_call_atomic and qcom_scm_call can
then be moved in qcom_scm.c and use underlying convention backend as
appropriate. Thus, rename qcom_scm-64,-32 to reflect that they are
backends for -smc and -legacy, respectively.

Also add support for making SCM calls earlier than when SCM driver
probes to support use cases such as qcom_scm_set_cold_boot_addr. Support
is added by lazily initializing the convention and guarding the query
with a spin lock.  The limitation of these early SCM calls is that they
cannot use DMA, as in the case of >4 arguments for SMC convention and
any non-atomic call for legacy convention.

Tested-by: Brian Masney <masneyb@onstation.org> # arm32
Tested-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Elliot Berman <eberman@codeaurora.org>
Link: https://lore.kernel.org/r/1578431066-19600-18-git-send-email-eberman@codeaurora.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

1 files changed, 0 insertions, 263 deletions

diff --git a/drivers/firmware/qcom_scm-32.c b/drivers/firmware/qcom_scm-32.c
deleted file mode 100644
index 08220e7f2167..000000000000
--- a/drivers/firmware/qcom_scm-32.c
+++ /dev/null
@@ -1,263 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/* Copyright (c) 2010,2015,2019 The Linux Foundation. All rights reserved.
- * Copyright (C) 2015 Linaro Ltd.
- */
-
-#include <linux/slab.h>
-#include <linux/io.h>
-#include <linux/module.h>
-#include <linux/mutex.h>
-#include <linux/errno.h>
-#include <linux/err.h>
-#include <linux/qcom_scm.h>
-#include <linux/arm-smccc.h>
-#include <linux/dma-mapping.h>
-
-#include "qcom_scm.h"
-
-static DEFINE_MUTEX(qcom_scm_lock);
-
-
-/**
- * struct arm_smccc_args
- * @args:	The array of values used in registers in smc instruction
- */
-struct arm_smccc_args {
-	unsigned long args[8];
-};
-
-#define SCM_LEGACY_FNID(s, c)	(((s) << 10) | ((c) & 0x3ff))
-
-/**
- * struct scm_legacy_command - one SCM command buffer
- * @len: total available memory for command and response
- * @buf_offset: start of command buffer
- * @resp_hdr_offset: start of response buffer
- * @id: command to be executed
- * @buf: buffer returned from scm_legacy_get_command_buffer()
- *
- * An SCM command is laid out in memory as follows:
- *
- *	------------------- <--- struct scm_legacy_command
- *	| command header  |
- *	------------------- <--- scm_legacy_get_command_buffer()
- *	| command buffer  |
- *	------------------- <--- struct scm_legacy_response and
- *	| response header |      scm_legacy_command_to_response()
- *	------------------- <--- scm_legacy_get_response_buffer()
- *	| response buffer |
- *	-------------------
- *
- * There can be arbitrary padding between the headers and buffers so
- * you should always use the appropriate scm_legacy_get_*_buffer() routines
- * to access the buffers in a safe manner.
- */
-struct scm_legacy_command {
-	__le32 len;
-	__le32 buf_offset;
-	__le32 resp_hdr_offset;
-	__le32 id;
-	__le32 buf[0];
-};
-
-/**
- * struct scm_legacy_response - one SCM response buffer
- * @len: total available memory for response
- * @buf_offset: start of response data relative to start of scm_legacy_response
- * @is_complete: indicates if the command has finished processing
- */
-struct scm_legacy_response {
-	__le32 len;
-	__le32 buf_offset;
-	__le32 is_complete;
-};
-
-/**
- * scm_legacy_command_to_response() - Get a pointer to a scm_legacy_response
- * @cmd: command
- *
- * Returns a pointer to a response for a command.
- */
-static inline struct scm_legacy_response *scm_legacy_command_to_response(
-		const struct scm_legacy_command *cmd)
-{
-	return (void *)cmd + le32_to_cpu(cmd->resp_hdr_offset);
-}
-
-/**
- * scm_legacy_get_command_buffer() - Get a pointer to a command buffer
- * @cmd: command
- *
- * Returns a pointer to the command buffer of a command.
- */
-static inline void *scm_legacy_get_command_buffer(
-		const struct scm_legacy_command *cmd)
-{
-	return (void *)cmd->buf;
-}
-
-/**
- * scm_legacy_get_response_buffer() - Get a pointer to a response buffer
- * @rsp: response
- *
- * Returns a pointer to a response buffer of a response.
- */
-static inline void *scm_legacy_get_response_buffer(
-		const struct scm_legacy_response *rsp)
-{
-	return (void *)rsp + le32_to_cpu(rsp->buf_offset);
-}
-
-static void __scm_legacy_do(const struct arm_smccc_args *smc,
-			    struct arm_smccc_res *res)
-{
-	do {
-		arm_smccc_smc(smc->args[0], smc->args[1], smc->args[2],
-			      smc->args[3], smc->args[4], smc->args[5],
-			      smc->args[6], smc->args[7], res);
-	} while (res->a0 == QCOM_SCM_INTERRUPTED);
-}
-
-/**
- * qcom_scm_call() - Sends a command to the SCM and waits for the command to
- * finish processing.
- *
- * A note on cache maintenance:
- * Note that any buffers that are expected to be accessed by the secure world
- * must be flushed before invoking qcom_scm_call and invalidated in the cache
- * immediately after qcom_scm_call returns. Cache maintenance on the command
- * and response buffers is taken care of by qcom_scm_call; however, callers are
- * responsible for any other cached buffers passed over to the secure world.
- */
-int qcom_scm_call(struct device *dev, const struct qcom_scm_desc *desc,
-			 struct qcom_scm_res *res)
-{
-	u8 arglen = desc->arginfo & 0xf;
-	int ret = 0, context_id;
-	unsigned int i;
-	struct scm_legacy_command *cmd;
-	struct scm_legacy_response *rsp;
-	struct arm_smccc_args smc = {0};
-	struct arm_smccc_res smc_res;
-	const size_t cmd_len = arglen * sizeof(__le32);
-	const size_t resp_len = MAX_QCOM_SCM_RETS * sizeof(__le32);
-	size_t alloc_len = sizeof(*cmd) + cmd_len + sizeof(*rsp) + resp_len;
-	dma_addr_t cmd_phys;
-	__le32 *arg_buf;
-	const __le32 *res_buf;
-
-	cmd = kzalloc(PAGE_ALIGN(alloc_len), GFP_KERNEL);
-	if (!cmd)
-		return -ENOMEM;
-
-	cmd->len = cpu_to_le32(alloc_len);
-	cmd->buf_offset = cpu_to_le32(sizeof(*cmd));
-	cmd->resp_hdr_offset = cpu_to_le32(sizeof(*cmd) + cmd_len);
-	cmd->id = cpu_to_le32(SCM_LEGACY_FNID(desc->svc, desc->cmd));
-
-	arg_buf = scm_legacy_get_command_buffer(cmd);
-	for (i = 0; i < arglen; i++)
-		arg_buf[i] = cpu_to_le32(desc->args[i]);
-
-	rsp = scm_legacy_command_to_response(cmd);
-
-	cmd_phys = dma_map_single(dev, cmd, alloc_len, DMA_TO_DEVICE);
-	if (dma_mapping_error(dev, cmd_phys)) {
-		kfree(cmd);
-		return -ENOMEM;
-	}
-
-	smc.args[0] = 1;
-	smc.args[1] = (unsigned long)&context_id;
-	smc.args[2] = cmd_phys;
-
-	mutex_lock(&qcom_scm_lock);
-	__scm_legacy_do(&smc, &smc_res);
-	if (smc_res.a0)
-		ret = qcom_scm_remap_error(smc_res.a0);
-	mutex_unlock(&qcom_scm_lock);
-	if (ret)
-		goto out;
-
-	do {
-		dma_sync_single_for_cpu(dev, cmd_phys + sizeof(*cmd) + cmd_len,
-					sizeof(*rsp), DMA_FROM_DEVICE);
-	} while (!rsp->is_complete);
-
-	dma_sync_single_for_cpu(dev, cmd_phys + sizeof(*cmd) + cmd_len +
-				le32_to_cpu(rsp->buf_offset),
-				resp_len, DMA_FROM_DEVICE);
-
-	if (res) {
-		res_buf = scm_legacy_get_response_buffer(rsp);
-		for (i = 0; i < MAX_QCOM_SCM_RETS; i++)
-			res->result[i] = le32_to_cpu(res_buf[i]);
-	}
-out:
-	dma_unmap_single(dev, cmd_phys, alloc_len, DMA_TO_DEVICE);
-	kfree(cmd);
-	return ret;
-}
-
-#define SCM_LEGACY_ATOMIC_N_REG_ARGS	5
-#define SCM_LEGACY_ATOMIC_FIRST_REG_IDX	2
-#define SCM_LEGACY_CLASS_REGISTER		(0x2 << 8)
-#define SCM_LEGACY_MASK_IRQS		BIT(5)
-#define SCM_LEGACY_ATOMIC_ID(svc, cmd, n) \
-				((SCM_LEGACY_FNID(svc, cmd) << 12) | \
-				SCM_LEGACY_CLASS_REGISTER | \
-				SCM_LEGACY_MASK_IRQS | \
-				(n & 0xf))
-
-/**
- * qcom_scm_call_atomic() - Send an atomic SCM command with up to 5 arguments
- * and 3 return values
- * @desc: SCM call descriptor containing arguments
- * @res:  SCM call return values
- *
- * This shall only be used with commands that are guaranteed to be
- * uninterruptable, atomic and SMP safe.
- */
-int qcom_scm_call_atomic(struct device *unused,
-			 const struct qcom_scm_desc *desc,
-			 struct qcom_scm_res *res)
-{
-	int context_id;
-	struct arm_smccc_res smc_res;
-	size_t arglen = desc->arginfo & 0xf;
-
-	BUG_ON(arglen > SCM_LEGACY_ATOMIC_N_REG_ARGS);
-
-	arm_smccc_smc(SCM_LEGACY_ATOMIC_ID(desc->svc, desc->cmd, arglen),
-		      (unsigned long)&context_id,
-		      desc->args[0], desc->args[1], desc->args[2],
-		      desc->args[3], desc->args[4], 0, &smc_res);
-
-	if (res) {
-		res->result[0] = smc_res.a1;
-		res->result[1] = smc_res.a2;
-		res->result[2] = smc_res.a3;
-	}
-
-	return smc_res.a0;
-}
-
-int __qcom_scm_is_call_available(struct device *dev, u32 svc_id, u32 cmd_id)
-{
-	int ret;
-	struct qcom_scm_desc desc = {
-		.svc = QCOM_SCM_SVC_INFO,
-		.cmd = QCOM_SCM_INFO_IS_CALL_AVAIL,
-		.args[0] = SCM_LEGACY_FNID(svc_id, cmd_id),
-		.arginfo = QCOM_SCM_ARGS(1),
-	};
-	struct qcom_scm_res res;
-
-	ret = qcom_scm_call(dev, &desc, &res);
-
-	return ret ? : res.result[0];
-}
-
-void __qcom_scm_init(void)
-{
-}