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#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/file.h>
#include "model.h"
#include "error.h"
#include "kmem.h"
#include "pcilib.h"
#include "pci.h"
typedef struct pcilib_software_register_bank_context_s pcilib_software_register_bank_context_t;
struct pcilib_software_register_bank_context_s {
pcilib_register_bank_context_t bank_ctx; /**< the bank context associated with the software registers */
pcilib_kmem_handle_t *kmem; /**< the kernel memory for software registers */
void *addr; /**< the virtual adress of the allocated kernel memory*/
};
/**
* pcilib_software_registers_close
* this function clear the kernel memory space that could have been allocated for software registers
* @param[in] bank_ctx the bank context running that we get from the initialisation function
*/
void pcilib_software_registers_close(pcilib_t *ctx, pcilib_register_bank_context_t *bank_ctx) {
if (((pcilib_software_register_bank_context_t*)bank_ctx)->kmem)
pcilib_free_kernel_memory(ctx, ((pcilib_software_register_bank_context_t*)bank_ctx)->kmem, PCILIB_KMEM_FLAG_REUSE);
free(bank_ctx);
}
/**
* pcilib_software_registers_open
* this function initializes the kernel space memory and stores in it the default values of the registers of the given bank index, if it was not initialized by a concurrent process, and return a bank context containing the adress of this kernel space. It the kernel space memory was already initialized by a concurrent process, then this function just return the bank context with the adress of this kernel space already used
* @param[in] ctx the pcilib_t structure running
* @param[in] bank the bank index that will permits to get the bank we want registers from
* @param[in] model not used
* @param[in] args not used
* @return a bank context with the adress of the kernel space memory related to it
*/
pcilib_register_bank_context_t* pcilib_software_registers_open(pcilib_t *ctx, pcilib_register_bank_t bank, const char* model, const void *args) {
int err;
pcilib_software_register_bank_context_t *bank_ctx;
pcilib_kmem_handle_t *handle;
pcilib_lock_t *lock;
pcilib_kmem_reuse_state_t reused;
const pcilib_register_bank_description_t *bank_desc = ctx->banks + bank;
if (bank_desc->size > PCILIB_KMEM_PAGE_SIZE) {
pcilib_error("Currently software register banks are limited to %lu bytes, but %lu requested", PCILIB_KMEM_PAGE_SIZE, bank_desc->size);
return NULL;
}
bank_ctx = calloc(1, sizeof(pcilib_software_register_bank_context_t));
if (!bank_ctx) {
pcilib_error("Memory allocation for bank context has failed");
return NULL;
}
lock = pcilib_get_lock(ctx, PCILIB_LOCK_FLAGS_DEFAULT, "softreg/%s", bank_desc->name);
if (!lock) {
pcilib_software_registers_close(ctx, (pcilib_register_bank_context_t*)bank_ctx);
pcilib_error("Failed to initialize a lock to protect bank %s with software registers", bank_desc->name);
return NULL;
}
err = pcilib_lock(lock);
if (err) {
pcilib_return_lock(ctx, PCILIB_LOCK_FLAGS_DEFAULT, lock);
pcilib_software_registers_close(ctx, (pcilib_register_bank_context_t*)bank_ctx);
pcilib_error("Error (%i) obtaining lock on bank %s with software registers", err, bank_desc->name);
return NULL;
}
handle = pcilib_alloc_kernel_memory(ctx, PCILIB_KMEM_TYPE_PAGE, 1, PCILIB_KMEM_PAGE_SIZE, 0, PCILIB_KMEM_USE(PCILIB_KMEM_USE_SOFTWARE_REGISTERS, bank_desc->addr), PCILIB_KMEM_FLAG_REUSE|PCILIB_KMEM_FLAG_PERSISTENT);
if (!handle) {
pcilib_unlock(lock);
pcilib_return_lock(ctx, PCILIB_LOCK_FLAGS_DEFAULT, lock);
pcilib_software_registers_close(ctx, (pcilib_register_bank_context_t*)bank_ctx);
pcilib_error("Allocation of kernel memory for software registers has failed");
return NULL;
}
bank_ctx->kmem = handle;
bank_ctx->addr = pcilib_kmem_get_block_ua(ctx, handle, 0);
reused = pcilib_kmem_is_reused(ctx, handle);
if ((reused & PCILIB_KMEM_REUSE_REUSED) == 0) {
pcilib_register_t i;
if (reused & PCILIB_KMEM_REUSE_PARTIAL) {
pcilib_unlock(lock);
pcilib_return_lock(ctx, PCILIB_LOCK_FLAGS_DEFAULT, lock);
pcilib_software_registers_close(ctx, (pcilib_register_bank_context_t*)bank_ctx);
pcilib_error("Inconsistent software registers are found (only part of required buffers is available)");
return NULL;
}
for (i = 0; ctx->model_info.registers[i].name != NULL; i++) {
if ((ctx->model_info.registers[i].bank == ctx->banks[bank].addr)&&(ctx->model_info.registers[i].type == PCILIB_REGISTER_STANDARD)) {
*(pcilib_register_value_t*)(bank_ctx->addr + ctx->model_info.registers[i].addr) = ctx->model_info.registers[i].defvalue;
}
}
}
pcilib_unlock(lock);
pcilib_return_lock(ctx, PCILIB_LOCK_FLAGS_DEFAULT, lock);
return (pcilib_register_bank_context_t*)bank_ctx;
}
/**
* pcilib_software_registers_read
* this function read the value of a said register in the kernel space
* @param[in] ctx the pcilib_t structure runnning
* @param[in] bank_ctx the bank context that was returned by the initialisation function
* @param[in] addr the adress of the register we want to read
* @param[out] value the value of the register
* @return 0 in case of success
*/
int pcilib_software_registers_read(pcilib_t *ctx, pcilib_register_bank_context_t *bank_ctx, pcilib_register_addr_t addr, pcilib_register_value_t *value){
if ((addr + sizeof(pcilib_register_value_t)) > bank_ctx->bank->size) {
pcilib_error("Trying to access space outside of the define register bank (bank: %s, addr: 0x%lx)", bank_ctx->bank->name, addr);
return PCILIB_ERROR_INVALID_ADDRESS;
}
// we consider this atomic operation and, therefore, do no locking
*value = *(pcilib_register_value_t*)(((pcilib_software_register_bank_context_t*)bank_ctx)->addr + addr);
return 0;
}
/**
* pcilib_software_registers_write
* this function write the said value to a said register in the kernel space
* @param[in] ctx the pcilib_t structure runnning
* @param[in] bank_ctx the bank context that was returned by the initialisation function
* @param[in] addr the adress of the register we want to write in
* @param[out] value the value we want to write in the register
* @return 0 in case of success
*/
int pcilib_software_registers_write(pcilib_t *ctx, pcilib_register_bank_context_t *bank_ctx, pcilib_register_addr_t addr, pcilib_register_value_t value) {
if ((addr + sizeof(pcilib_register_value_t)) > bank_ctx->bank->size) {
pcilib_error("Trying to access space outside of the define register bank (bank: %s, addr: 0x%lx)", bank_ctx->bank->name, addr);
return PCILIB_ERROR_INVALID_ADDRESS;
}
// we consider this atomic operation and, therefore, do no locking
*(pcilib_register_value_t*)(((pcilib_software_register_bank_context_t*)bank_ctx)->addr + addr) = value;
return 0;
}
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