From af311ff9a69189a03548efd5a47d4bb44644fd45 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Fri, 17 May 2019 14:09:22 -0700 Subject: [PATCH] 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 Cc: Julien Grall Cc: Bjorn Andersson Cc: Avaneesh Kumar Dwivedi Tested-by: Bjorn Andersson Signed-off-by: Stephen Boyd [bjorn: Changed for_each_set_bit() size to BITS_PER_LONG] Signed-off-by: Bjorn Andersson --- drivers/firmware/qcom_scm.c | 34 ++++++++++++++++------------------ include/linux/qcom_scm.h | 9 +++++---- 2 files changed, 21 insertions(+), 22 deletions(-) diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c index c7e63af91567..4802ab170fe5 100644 --- a/drivers/firmware/qcom_scm.c +++ b/drivers/firmware/qcom_scm.c @@ -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, diff --git a/include/linux/qcom_scm.h b/include/linux/qcom_scm.h index 3f12cc77fb58..2d5eff506e13 100644 --- a/include/linux/qcom_scm.h +++ b/include/linux/qcom_scm.h @@ -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