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Commit bbf72fdc authored by Elliot Berman's avatar Elliot Berman
Browse files

firmware: qcom_scm: Use qtee_shmbridge if available 



Secure world imposed that buffer exchanges between secure and non-secure
worlds be allocated from qtee_shmbridge, so add a function to allocate
buffer space using shmbridge for extra arguments. Change helps in
dealing with early scm calls when the driver is not initialized.

Change-Id: I270b4aef9d33ec6d7ea0897ddcc0944ac9e1833f
Signed-off-by: default avatarElliot Berman <eberman@codeaurora.org>
parent 4d0fbd6b

drivers/firmware/qcom_scm-smc.c

+35 −18
Original line number Diff line number Diff line
@@ -12,6 +12,10 @@ 
#include <linux/arm-smccc.h>

#include <linux/dma-mapping.h>



#include <asm/cacheflush.h>



#include <linux/qtee_shmbridge.h>



#include "qcom_scm.h"



#define MAX_QCOM_SCM_ARGS 10
@@ -180,17 +184,17 @@ static int qcom_scm_call_smccc(struct device *dev, 
				  struct qcom_scm_desc *desc, bool atomic)

{

	int arglen = desc->arginfo & 0xf;

	int i;

	dma_addr_t args_phys = 0;

	void *args_virt = NULL;

	int i, ret;

	size_t alloc_len;

	gfp_t flag = atomic ? GFP_ATOMIC : GFP_KERNEL;

	gfp_t flag = atomic ? GFP_ATOMIC : GFP_NOIO;

	u32 smccc_call_type = atomic ? ARM_SMCCC_FAST_CALL : ARM_SMCCC_STD_CALL;

	u32 qcom_smccc_convention =

		(qcom_smc_convention == SMC_CONVENTION_ARM_32) ?

		ARM_SMCCC_SMC_32 : ARM_SMCCC_SMC_64;

	struct arm_smccc_res res;

	struct arm_smccc_args smc = {{0}};

	struct qtee_shm shm = {0};

	bool use_qtee_shmbridge;



	smc.a[0] = ARM_SMCCC_CALL_VAL(

		smccc_call_type,
@@ -206,34 +210,43 @@ static int qcom_scm_call_smccc(struct device *dev, 
			return -EPROBE_DEFER;



		alloc_len = SMCCC_N_EXT_ARGS * sizeof(u64);

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



		if (!args_virt)

		use_qtee_shmbridge = qtee_shmbridge_is_enabled();

		if (use_qtee_shmbridge) {

			ret = qtee_shmbridge_allocate_shm(alloc_len, &shm);

			if (ret)

				return ret;

		} else {

			shm.vaddr = kzalloc(alloc_len, flag);

			if (!shm.vaddr)

				return -ENOMEM;

		}



		if (qcom_smc_convention == SMC_CONVENTION_ARM_32) {

			__le32 *args = args_virt;

			__le32 *args = shm.vaddr;



			for (i = 0; i < SMCCC_N_EXT_ARGS; i++)

				args[i] = cpu_to_le32(desc->args[i +

						      SMCCC_FIRST_EXT_IDX]);

		} else {

			__le64 *args = args_virt;

			__le64 *args = shm.vaddr;



			for (i = 0; i < SMCCC_N_EXT_ARGS; i++)

				args[i] = cpu_to_le64(desc->args[i +

						      SMCCC_FIRST_EXT_IDX]);

		}



		args_phys = dma_map_single(dev, args_virt, alloc_len,

		shm.paddr = dma_map_single(dev, shm.vaddr, alloc_len,

						DMA_TO_DEVICE);



		if (dma_mapping_error(dev, args_phys)) {

			kfree(args_virt);

		if (dma_mapping_error(dev, shm.paddr)) {

			if (use_qtee_shmbridge)

				qtee_shmbridge_free_shm(&shm);

			else

				kfree(shm.vaddr);

			return -ENOMEM;

		}



		smc.a[SMCCC_LAST_REG_IDX] = args_phys;

		smc.a[SMCCC_LAST_REG_IDX] = shm.paddr;

	}



	if (atomic) {
@@ -256,9 +269,13 @@ static int qcom_scm_call_smccc(struct device *dev, 
		} while (res.a0 == QCOM_SCM_V2_EBUSY);

	}



	if (args_virt) {

		dma_unmap_single(dev, args_phys, alloc_len, DMA_TO_DEVICE);

		kfree(args_virt);

	if (unlikely(arglen > SMCCC_N_REG_ARGS)) {

		dma_unmap_single(dev, shm.paddr, alloc_len,

					DMA_TO_DEVICE);

		if (use_qtee_shmbridge)

			qtee_shmbridge_free_shm(&shm);

		else

			kfree(shm.vaddr);

	}



	desc->res[0] = res.a1;

drivers/firmware/qcom_scm.c

+6 −0
Original line number Diff line number Diff line
@@ -580,6 +580,12 @@ static int qcom_scm_probe(struct platform_device *pdev) 


	__qcom_scm_init();



#if CONFIG_ARM64

	ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));

	if (ret)

		return ret;

#endif



	/*

	 * If requested enable "download mode", from this point on warmboot

	 * will cause the the boot stages to enter download mode, unless