Commit 449d0d84 authored by Bartosz Golaszewski's avatar Bartosz Golaszewski Committed by Bjorn Andersson
Browse files

firmware: qcom: scm: smc: switch to using the SCM allocator 



We need to allocate, map and pass a buffer to the trustzone if we have
more than 4 arguments for a given SCM call. Let's use the new TrustZone
allocator for that memory and shrink the code in process.

As this code lives in a different compilation unit than the rest of the
SCM code, we need to provide a helper in the form of
qcom_scm_get_tzmem_pool() that allows the SMC low-level routines to
access the SCM memory pool.

Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: default avatarAndrew Halaney <ahalaney@redhat.com>
Tested-by: Andrew Halaney <ahalaney@redhat.com> # sc8280xp-lenovo-thinkpad-x13s
Tested-by: Deepti Jaggi <quic_djaggi@quicinc.com> #sa8775p-ride
Reviewed-by: default avatarElliot Berman <quic_eberman@quicinc.com>
Link: https://lore.kernel.org/r/20240527-shm-bridge-v10-4-ce7afaa58d3a@linaro.org


Signed-off-by: default avatarBjorn Andersson <andersson@kernel.org>
parent 40289e35

drivers/firmware/qcom/qcom_scm-smc.c

+8 −22
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
/* Copyright (c) 2015,2019 The Linux Foundation. All rights reserved.

 */



#include <linux/cleanup.h>

#include <linux/io.h>

#include <linux/errno.h>

#include <linux/delay.h>
@@ -9,6 +10,7 @@ 
#include <linux/slab.h>

#include <linux/types.h>

#include <linux/firmware/qcom/qcom_scm.h>

#include <linux/firmware/qcom/qcom_tzmem.h>

#include <linux/arm-smccc.h>

#include <linux/dma-mapping.h>
@@ -150,11 +152,10 @@ int __scm_smc_call(struct device *dev, const struct qcom_scm_desc *desc, 
		   enum qcom_scm_convention qcom_convention,

		   struct qcom_scm_res *res, bool atomic)

{

	struct qcom_tzmem_pool *mempool = qcom_scm_get_tzmem_pool();

	int arglen = desc->arginfo & 0xf;

	int i, ret;

	dma_addr_t args_phys = 0;

	void *args_virt = NULL;

	size_t alloc_len;

	void *args_virt __free(qcom_tzmem) = NULL;

	gfp_t flag = atomic ? GFP_ATOMIC : GFP_KERNEL;

	u32 smccc_call_type = atomic ? ARM_SMCCC_FAST_CALL : ARM_SMCCC_STD_CALL;

	u32 qcom_smccc_convention = (qcom_convention == SMC_CONVENTION_ARM_32) ?
@@ -172,9 +173,9 @@ int __scm_smc_call(struct device *dev, const struct qcom_scm_desc *desc, 
		smc.args[i + SCM_SMC_FIRST_REG_IDX] = desc->args[i];



	if (unlikely(arglen > SCM_SMC_N_REG_ARGS)) {

		alloc_len = SCM_SMC_N_EXT_ARGS * sizeof(u64);

		args_virt = kzalloc(PAGE_ALIGN(alloc_len), flag);



		args_virt = qcom_tzmem_alloc(mempool,

					     SCM_SMC_N_EXT_ARGS * sizeof(u64),

					     flag);

		if (!args_virt)

			return -ENOMEM;
@@ -192,25 +193,10 @@ int __scm_smc_call(struct device *dev, const struct qcom_scm_desc *desc, 
						      SCM_SMC_FIRST_EXT_IDX]);

		}



		args_phys = dma_map_single(dev, args_virt, alloc_len,

					   DMA_TO_DEVICE);



		if (dma_mapping_error(dev, args_phys)) {

			kfree(args_virt);

			return -ENOMEM;

		}



		smc.args[SCM_SMC_LAST_REG_IDX] = args_phys;

		smc.args[SCM_SMC_LAST_REG_IDX] = qcom_tzmem_to_phys(args_virt);

	}



	/* ret error check follows after args_virt cleanup*/

	ret = __scm_smc_do(dev, &smc, &smc_res, atomic);



	if (args_virt) {

		dma_unmap_single(dev, args_phys, alloc_len, DMA_TO_DEVICE);

		kfree(args_virt);

	}



	if (ret)

		return ret;

drivers/firmware/qcom/qcom_scm.c

+5 −0
Original line number Diff line number Diff line
@@ -203,6 +203,11 @@ static void qcom_scm_bw_disable(void) 
enum qcom_scm_convention qcom_scm_convention = SMC_CONVENTION_UNKNOWN;

static DEFINE_SPINLOCK(scm_query_lock);



struct qcom_tzmem_pool *qcom_scm_get_tzmem_pool(void)

{

	return __scm->mempool;

}



static enum qcom_scm_convention __get_convention(void)

{

	unsigned long flags;

drivers/firmware/qcom/qcom_scm.h

+3 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
#define __QCOM_SCM_INT_H



struct device;

struct qcom_tzmem_pool;



enum qcom_scm_convention {

	SMC_CONVENTION_UNKNOWN,
@@ -78,6 +79,8 @@ int scm_legacy_call_atomic(struct device *dev, const struct qcom_scm_desc *desc, 
int scm_legacy_call(struct device *dev, const struct qcom_scm_desc *desc,

		    struct qcom_scm_res *res);



struct qcom_tzmem_pool *qcom_scm_get_tzmem_pool(void);



#define QCOM_SCM_SVC_BOOT		0x01

#define QCOM_SCM_BOOT_SET_ADDR		0x01

#define QCOM_SCM_BOOT_TERMINATE_PC	0x02