1 #include "fwcfg.h" 2 #include "smp.h" 3 #include "libcflat.h" 4 5 static struct spinlock lock; 6 7 static long fw_override[FW_CFG_MAX_ENTRY]; 8 static bool fw_override_done; 9 10 bool no_test_device; 11 12 static void read_cfg_override(void) 13 { 14 const char *str; 15 int i; 16 17 /* Initialize to negative value that would be considered as invalid */ 18 for (i = 0; i < FW_CFG_MAX_ENTRY; i++) 19 fw_override[i] = -1; 20 21 if ((str = getenv("NR_CPUS"))) 22 fw_override[FW_CFG_NB_CPUS] = atol(str); 23 24 /* MEMSIZE is in megabytes */ 25 if ((str = getenv("MEMSIZE"))) 26 fw_override[FW_CFG_RAM_SIZE] = atol(str) * 1024 * 1024; 27 28 if ((str = getenv("TEST_DEVICE"))) 29 no_test_device = !atol(str); 30 31 fw_override_done = true; 32 } 33 34 static uint64_t fwcfg_get_u(uint16_t index, int bytes) 35 { 36 uint64_t r = 0; 37 uint8_t b; 38 int i; 39 40 if (!fw_override_done) 41 read_cfg_override(); 42 43 if (index < FW_CFG_MAX_ENTRY && fw_override[index] >= 0) 44 return fw_override[index]; 45 46 spin_lock(&lock); 47 asm volatile ("out %0, %1" : : "a"(index), "d"((uint16_t)BIOS_CFG_IOPORT)); 48 for (i = 0; i < bytes; ++i) { 49 asm volatile ("in %1, %0" : "=a"(b) : "d"((uint16_t)(BIOS_CFG_IOPORT + 1))); 50 r |= (uint64_t)b << (i * 8); 51 } 52 spin_unlock(&lock); 53 return r; 54 } 55 56 uint8_t fwcfg_get_u8(unsigned index) 57 { 58 return fwcfg_get_u(index, 1); 59 } 60 61 uint16_t fwcfg_get_u16(unsigned index) 62 { 63 return fwcfg_get_u(index, 2); 64 } 65 66 uint32_t fwcfg_get_u32(unsigned index) 67 { 68 return fwcfg_get_u(index, 4); 69 } 70 71 uint64_t fwcfg_get_u64(unsigned index) 72 { 73 return fwcfg_get_u(index, 8); 74 } 75 76 unsigned fwcfg_get_nb_cpus(void) 77 { 78 return fwcfg_get_u16(FW_CFG_NB_CPUS); 79 } 80