/* * Copyright (C) 2008-2009 ST-Ericsson AB * License terms: GNU General Public License (GPL) version 2 * TCM memory handling for ARM systems * * Author: Linus Walleij * Author: Rickard Andersson */ #include #include #include #include #include #include #include /* memcpy */ #include #include #include #include #include #define TCMTR_FORMAT_MASK 0xe0000000U static struct gen_pool *tcm_pool; static bool dtcm_present; static bool itcm_present; /* TCM section definitions from the linker */ extern char __itcm_start, __sitcm_text, __eitcm_text; extern char __dtcm_start, __sdtcm_data, __edtcm_data; /* These will be increased as we run */ u32 dtcm_end = DTCM_OFFSET; u32 itcm_end = ITCM_OFFSET; /* * TCM memory resources */ static struct resource dtcm_res = { .name = "DTCM RAM", .start = DTCM_OFFSET, .end = DTCM_OFFSET, .flags = IORESOURCE_MEM }; static struct resource itcm_res = { .name = "ITCM RAM", .start = ITCM_OFFSET, .end = ITCM_OFFSET, .flags = IORESOURCE_MEM }; static struct map_desc dtcm_iomap[] __initdata = { { .virtual = DTCM_OFFSET, .pfn = __phys_to_pfn(DTCM_OFFSET), .length = 0, .type = MT_MEMORY_RW_DTCM } }; static struct map_desc itcm_iomap[] __initdata = { { .virtual = ITCM_OFFSET, .pfn = __phys_to_pfn(ITCM_OFFSET), .length = 0, .type = MT_MEMORY_RWX_ITCM, } }; /* * Allocate a chunk of TCM memory */ void *tcm_alloc(size_t len) { unsigned long vaddr; if (!tcm_pool) return NULL; vaddr = gen_pool_alloc(tcm_pool, len); if (!vaddr) return NULL; return (void *) vaddr; } EXPORT_SYMBOL(tcm_alloc); /* * Free a chunk of TCM memory */ void tcm_free(void *addr, size_t len) { gen_pool_free(tcm_pool, (unsigned long) addr, len); } EXPORT_SYMBOL(tcm_free); bool tcm_dtcm_present(void) { return dtcm_present; } EXPORT_SYMBOL(tcm_dtcm_present); bool tcm_itcm_present(void) { return itcm_present; } EXPORT_SYMBOL(tcm_itcm_present); static int __init setup_tcm_bank(u8 type, u8 bank, u8 banks, u32 *offset) { const int tcm_sizes[16] = { 0, -1, -1, 4, 8, 16, 32, 64, 128, 256, 512, 1024, -1, -1, -1, -1 }; u32 tcm_region; int tcm_size; /* * If there are more than one TCM bank of this type, * select the TCM bank to operate on in the TCM selection * register. */ if (banks > 1) asm("mcr p15, 0, %0, c9, c2, 0" : /* No output operands */ : "r" (bank)); /* Read the special TCM region register c9, 0 */ if (!type) asm("mrc p15, 0, %0, c9, c1, 0" : "=r" (tcm_region)); else asm("mrc p15, 0, %0, c9, c1, 1" : "=r" (tcm_region)); tcm_size = tcm_sizes[(tcm_region >> 2) & 0x0f]; if (tcm_size < 0) { pr_err("CPU: %sTCM%d of unknown size\n", type ? "I" : "D", bank); return -EINVAL; } else if (tcm_size > 32) { pr_err("CPU: %sTCM%d larger than 32k found\n", type ? "I" : "D", bank); return -EINVAL; } else { pr_info("CPU: found %sTCM%d %dk @ %08x, %senabled\n", type ? "I" : "D", bank, tcm_size, (tcm_region & 0xfffff000U), (tcm_region & 1) ? "" : "not "); } /* Not much fun you can do with a size 0 bank */ if (tcm_size == 0) return 0; /* Force move the TCM bank to where we want it, enable */ tcm_region = *offset | (tcm_region & 0x00000ffeU) | 1; if (!type) asm("mcr p15, 0, %0, c9, c1, 0" : /* No output operands */ : "r" (tcm_region)); else asm("mcr p15, 0, %0, c9, c1, 1" : /* No output operands */ : "r" (tcm_region)); /* Increase offset */ *offset += (tcm_size << 10); pr_info("CPU: moved %sTCM%d %dk to %08x, enabled\n", type ? "I" : "D", bank, tcm_size, (tcm_region & 0xfffff000U)); return 0; } /* * When we are running in the non-secure world and the secure world * has not explicitly given us access to the TCM we will get an * undefined error when reading the TCM region register in the * setup_tcm_bank function (above). * * There are two variants of this register read that we need to trap, * the read for the data TCM and the read for the instruction TCM: * c0370628: ee196f11 mrc 15, 0, r6, cr9, cr1, {0} * c0370674: ee196f31 mrc 15, 0, r6, cr9, cr1, {1} * * Our undef hook mask explicitly matches all fields of the encoded * instruction other than the destination register. The mask also * only allows operand 2 to have the values 0 or 1. * * The undefined hook is defined as __init and __initdata, and therefore * must be removed before tcm_init returns. * * In this particular case (MRC with ARM condition code ALways) the * Thumb-2 and ARM instruction encoding are identical, so this hook * will work on a Thumb-2 kernel. * * See A8.8.107, DDI0406C_C ARM Architecture Reference Manual, Encoding * T1/A1 for the bit-by-bit details. * * mrc p15, 0, XX, c9, c1, 0 * mrc p15, 0, XX, c9, c1, 1 * | | | | | | | +---- opc2 0|1 = 000|001 * | | | | | | +------- CRm 0 = 0001 * | | | | | +----------- CRn 0 = 1001 * | | | | +--------------- Rt ? = ???? * | | | +------------------- opc1 0 = 000 * | | +----------------------- coproc 15 = 1111 * | +-------------------------- condition ALways = 1110 * +----------------------------- instruction MRC = 1110 * * Encoding this as per A8.8.107 of DDI0406C, Encoding T1/A1, yields: * 1111 1111 1111 1111 0000 1111 1101 1111 Required Mask * 1110 1110 0001 1001 ???? 1111 0001 0001 mrc p15, 0, XX, c9, c1, 0 * 1110 1110 0001 1001 ???? 1111 0011 0001 mrc p15, 0, XX, c9, c1, 1 * [ ] [ ] [ ]| [ ] [ ] [ ] [ ]| +--- CRm * | | | | | | | | +----- SBO * | | | | | | | +------- opc2 * | | | | | | +----------- coproc * | | | | | +---------------- Rt * | | | | +--------------------- CRn * | | | +------------------------- SBO * | | +--------------------------- opc1 * | +------------------------------- instruction * +------------------------------------ condition */ #define TCM_REGION_READ_MASK 0xffff0fdf #define TCM_REGION_READ_INSTR 0xee190f11 #define DEST_REG_SHIFT 12 #define DEST_REG_MASK 0xf static int __init tcm_handler(struct pt_regs *regs, unsigned int instr) { regs->uregs[(instr >> DEST_REG_SHIFT) & DEST_REG_MASK] = 0; regs->ARM_pc += 4; return 0; } static struct undef_hook tcm_hook __initdata = { .instr_mask = TCM_REGION_READ_MASK, .instr_val = TCM_REGION_READ_INSTR, .cpsr_mask = MODE_MASK, .cpsr_val = SVC_MODE, .fn = tcm_handler }; /* * This initializes the TCM memory */ void __init tcm_init(void) { u32 tcm_status; u8 dtcm_banks; u8 itcm_banks; size_t dtcm_code_sz = &__edtcm_data - &__sdtcm_data; size_t itcm_code_sz = &__eitcm_text - &__sitcm_text; char *start; char *end; char *ram; int ret; int i; /* * Prior to ARMv5 there is no TCM, and trying to read the status * register will hang the processor. */ if (cpu_architecture() < CPU_ARCH_ARMv5) { if (dtcm_code_sz || itcm_code_sz) pr_info("CPU TCM: %u bytes of DTCM and %u bytes of " "ITCM code compiled in, but no TCM present " "in pre-v5 CPU\n", dtcm_code_sz, itcm_code_sz); return; } tcm_status = read_cpuid_tcmstatus(); /* * This code only supports v6-compatible TCMTR implementations. */ if (tcm_status & TCMTR_FORMAT_MASK) return; dtcm_banks = (tcm_status >> 16) & 0x03; itcm_banks = (tcm_status & 0x03); register_undef_hook(&tcm_hook); /* Values greater than 2 for D/ITCM banks are "reserved" */ if (dtcm_banks > 2) dtcm_banks = 0; if (itcm_banks > 2) itcm_banks = 0; /* Setup DTCM if present */ if (dtcm_banks > 0) { for (i = 0; i < dtcm_banks; i++) { ret = setup_tcm_bank(0, i, dtcm_banks, &dtcm_end); if (ret) goto unregister; } /* This means you compiled more code than fits into DTCM */ if (dtcm_code_sz > (dtcm_end - DTCM_OFFSET)) { pr_info("CPU DTCM: %u bytes of code compiled to " "DTCM but only %lu bytes of DTCM present\n", dtcm_code_sz, (dtcm_end - DTCM_OFFSET)); goto no_dtcm; } /* * This means that the DTCM sizes were 0 or the DTCM banks * were inaccessible due to TrustZone configuration. */ if (!(dtcm_end - DTCM_OFFSET)) goto no_dtcm; dtcm_res.end = dtcm_end - 1; request_resource(&iomem_resource, &dtcm_res); dtcm_iomap[0].length = dtcm_end - DTCM_OFFSET; iotable_init(dtcm_iomap, 1); /* Copy data from RAM to DTCM */ start = &__sdtcm_data; end = &__edtcm_data; ram = &__dtcm_start; memcpy(start, ram, dtcm_code_sz); pr_debug("CPU DTCM: copied data from %p - %p\n", start, end); dtcm_present = true; } else if (dtcm_code_sz) { pr_info("CPU DTCM: %u bytes of code compiled to DTCM but no " "DTCM banks present in CPU\n", dtcm_code_sz); } no_dtcm: /* Setup ITCM if present */ if (itcm_banks > 0) { for (i = 0; i < itcm_banks; i++) { ret = setup_tcm_bank(1, i, itcm_banks, &itcm_end); if (ret) goto unregister; } /* This means you compiled more code than fits into ITCM */ if (itcm_code_sz > (itcm_end - ITCM_OFFSET)) { pr_info("CPU ITCM: %u bytes of code compiled to " "ITCM but only %lu bytes of ITCM present\n", itcm_code_sz, (itcm_end - ITCM_OFFSET)); goto unregister; } /* * This means that the ITCM sizes were 0 or the ITCM banks * were inaccessible due to TrustZone configuration. */ if (!(itcm_end - ITCM_OFFSET)) goto unregister; itcm_res.end = itcm_end - 1; request_resource(&iomem_resource, &itcm_res); itcm_iomap[0].length = itcm_end - ITCM_OFFSET; iotable_init(itcm_iomap, 1); /* Copy code from RAM to ITCM */ start = &__sitcm_text; end = &__eitcm_text; ram = &__itcm_start; memcpy(start, ram, itcm_code_sz); pr_debug("CPU ITCM: copied code from %p - %p\n", start, end); itcm_present = true; } else if (itcm_code_sz) { pr_info("CPU ITCM: %u bytes of code compiled to ITCM but no " "ITCM banks present in CPU\n", itcm_code_sz); } unregister: unregister_undef_hook(&tcm_hook); } /* * This creates the TCM memory pool and has to be done later, * during the core_initicalls, since the allocator is not yet * up and running when the first initialization runs. */ static int __init setup_tcm_pool(void) { u32 dtcm_pool_start = (u32) &__edtcm_data; u32 itcm_pool_start = (u32) &__eitcm_text; int ret; /* * Set up malloc pool, 2^2 = 4 bytes granularity since * the TCM is sometimes just 4 KiB. NB: pages and cache * line alignments does not matter in TCM! */ tcm_pool = gen_pool_create(2, -1); pr_debug("Setting up TCM memory pool\n"); /* Add the rest of DTCM to the TCM pool */ if (dtcm_present) { if (dtcm_pool_start < dtcm_end) { ret = gen_pool_add(tcm_pool, dtcm_pool_start, dtcm_end - dtcm_pool_start, -1); if (ret) { pr_err("CPU DTCM: could not add DTCM " \ "remainder to pool!\n"); return ret; } pr_debug("CPU DTCM: Added %08x bytes @ %08x to " \ "the TCM memory pool\n", dtcm_end - dtcm_pool_start, dtcm_pool_start); } } /* Add the rest of ITCM to the TCM pool */ if (itcm_present) { if (itcm_pool_start < itcm_end) { ret = gen_pool_add(tcm_pool, itcm_pool_start, itcm_end - itcm_pool_start, -1); if (ret) { pr_err("CPU ITCM: could not add ITCM " \ "remainder to pool!\n"); return ret; } pr_debug("CPU ITCM: Added %08x bytes @ %08x to " \ "the TCM memory pool\n", itcm_end - itcm_pool_start, itcm_pool_start); } } return 0; } core_initcall(setup_tcm_pool);