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.jack...@citrix.com>
Cc: Julien Grall <julien.gr...@arm.com>
Cc: Bjorn Andersson <bjorn.anders...@linaro.org>
Cc: Avaneesh Kumar Dwivedi <akdwi...@codeaurora.org>
Signed-off-by: Stephen Boyd <swb...@chromium.org>
---
 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 0c63495cf269..153f13f72bac 100644
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -443,7 +443,8 @@ 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;
@@ -458,11 +459,10 @@ 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) +
@@ -475,28 +475,26 @@ 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, sizeof(srcvm_bits))
+               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 d0aecc04c54b..1d406403c843 100644
--- a/include/linux/qcom_scm.h
+++ b/include/linux/qcom_scm.h
@@ -57,8 +57,9 @@ 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);
@@ -95,8 +96,8 @@ 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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