Commit af311ff9 authored by Stephen Boyd's avatar Stephen Boyd Committed by Bjorn Andersson
Browse files

firmware: qcom_scm: Cleanup code in qcom_scm_assign_mem() 



There are some questionable coding styles in this function. It looks
quite odd to deref a pointer with array indexing that only uses the
first element. Also, destroying an input/output variable halfway through
the function and then overwriting it on success is not clear. It's
better to use a local variable and the kernel macros to step through
each bit set in a bitmask and clearly show where outputs are set.

Cc: Ian Jackson <ian.jackson@citrix.com>
Cc: Julien Grall <julien.grall@arm.com>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Avaneesh Kumar Dwivedi <akdwived@codeaurora.org>
Tested-by: default avatarBjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: default avatarStephen Boyd <swboyd@chromium.org>
[bjorn: Changed for_each_set_bit() size to BITS_PER_LONG]
Signed-off-by: default avatarBjorn Andersson <bjorn.andersson@linaro.org>
parent c8b08fc0

drivers/firmware/qcom_scm.c

+16 −18
Original line number Diff line number Diff line
@@ -434,7 +434,8 @@ EXPORT_SYMBOL(qcom_scm_set_remote_state); 
 */

int qcom_scm_assign_mem(phys_addr_t mem_addr, size_t mem_sz,

			unsigned int *srcvm,

			struct qcom_scm_vmperm *newvm, int dest_cnt)

			const struct qcom_scm_vmperm *newvm,

			unsigned int dest_cnt)

{

	struct qcom_scm_current_perm_info *destvm;

	struct qcom_scm_mem_map_info *mem_to_map;
@@ -449,11 +450,10 @@ int qcom_scm_assign_mem(phys_addr_t mem_addr, size_t mem_sz, 
	int next_vm;

	__le32 *src;

	void *ptr;

	int ret;

	int len;

	int i;

	int ret, i, b;

	unsigned long srcvm_bits = *srcvm;



	src_sz = hweight_long(*srcvm) * sizeof(*src);

	src_sz = hweight_long(srcvm_bits) * sizeof(*src);

	mem_to_map_sz = sizeof(*mem_to_map);

	dest_sz = dest_cnt * sizeof(*destvm);

	ptr_sz = ALIGN(src_sz, SZ_64) + ALIGN(mem_to_map_sz, SZ_64) +
@@ -466,28 +466,26 @@ int qcom_scm_assign_mem(phys_addr_t mem_addr, size_t mem_sz, 


	/* Fill source vmid detail */

	src = ptr;

	len = hweight_long(*srcvm);

	for (i = 0; i < len; i++) {

		src[i] = cpu_to_le32(ffs(*srcvm) - 1);

		*srcvm ^= 1 << (ffs(*srcvm) - 1);

	}

	i = 0;

	for_each_set_bit(b, &srcvm_bits, BITS_PER_LONG)

		src[i++] = cpu_to_le32(b);



	/* Fill details of mem buff to map */

	mem_to_map = ptr + ALIGN(src_sz, SZ_64);

	mem_to_map_phys = ptr_phys + ALIGN(src_sz, SZ_64);

	mem_to_map[0].mem_addr = cpu_to_le64(mem_addr);

	mem_to_map[0].mem_size = cpu_to_le64(mem_sz);

	mem_to_map->mem_addr = cpu_to_le64(mem_addr);

	mem_to_map->mem_size = cpu_to_le64(mem_sz);



	next_vm = 0;

	/* Fill details of next vmid detail */

	destvm = ptr + ALIGN(mem_to_map_sz, SZ_64) + ALIGN(src_sz, SZ_64);

	dest_phys = ptr_phys + ALIGN(mem_to_map_sz, SZ_64) + ALIGN(src_sz, SZ_64);

	for (i = 0; i < dest_cnt; i++) {

		destvm[i].vmid = cpu_to_le32(newvm[i].vmid);

		destvm[i].perm = cpu_to_le32(newvm[i].perm);

		destvm[i].ctx = 0;

		destvm[i].ctx_size = 0;

		next_vm |= BIT(newvm[i].vmid);

	for (i = 0; i < dest_cnt; i++, destvm++, newvm++) {

		destvm->vmid = cpu_to_le32(newvm->vmid);

		destvm->perm = cpu_to_le32(newvm->perm);

		destvm->ctx = 0;

		destvm->ctx_size = 0;

		next_vm |= BIT(newvm->vmid);

	}



	ret = __qcom_scm_assign_mem(__scm->dev, mem_to_map_phys, mem_to_map_sz,

include/linux/qcom_scm.h

+5 −4
Original line number Diff line number Diff line
@@ -49,8 +49,9 @@ extern int qcom_scm_pas_mem_setup(u32 peripheral, phys_addr_t addr, 
extern int qcom_scm_pas_auth_and_reset(u32 peripheral);

extern int qcom_scm_pas_shutdown(u32 peripheral);

extern int qcom_scm_assign_mem(phys_addr_t mem_addr, size_t mem_sz,

			       unsigned int *src, struct qcom_scm_vmperm *newvm,

			       int dest_cnt);

			       unsigned int *src,

			       const struct qcom_scm_vmperm *newvm,

			       unsigned int dest_cnt);

extern void qcom_scm_cpu_power_down(u32 flags);

extern u32 qcom_scm_get_version(void);

extern int qcom_scm_set_remote_state(u32 state, u32 id);
@@ -87,8 +88,8 @@ qcom_scm_pas_auth_and_reset(u32 peripheral) { return -ENODEV; } 
static inline int qcom_scm_pas_shutdown(u32 peripheral) { return -ENODEV; }

static inline int qcom_scm_assign_mem(phys_addr_t mem_addr, size_t mem_sz,

				      unsigned int *src,

				      struct qcom_scm_vmperm *newvm,

				      int dest_cnt) { return -ENODEV; }

				      const struct qcom_scm_vmperm *newvm,

				      unsigned int dest_cnt) { return -ENODEV; }

static inline void qcom_scm_cpu_power_down(u32 flags) {}

static inline u32 qcom_scm_get_version(void) { return 0; }

static inline u32

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