target/mips32: update mips32 config register parsing

Enhance `mips32_read_config_regs` to better detect MIPS32 ISA,
DSP, and FPU features, allowing user to get more detailed
target information.
Most of these information will be used in MIPS m/iAptiv support.

Change-Id: I23571a626ec64fa019acac91bdbfcb434373bfc1
Signed-off-by: Walter Ji <walter.ji@oss.cipunited.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/7911
Tested-by: jenkins
Reviewed-by: Oleksij Rempel <linux@rempel-privat.de>

2 files changed, 321 insertions, 7 deletions

diff --git a/src/target/mips32.c b/src/target/mips32.c
index 99688b0..5c346c4 100644
--- a/src/target/mips32.c
+++ b/src/target/mips32.c
@@ -805,15 +805,82 @@ int mips32_cpu_probe(struct target *target)
 	return ERROR_OK;
 }
 
+/* reads dsp implementation info from CP0 Config3 register {DSPP, DSPREV}*/
+void mips32_read_config_dsp(struct mips32_common *mips32, struct mips_ejtag *ejtag_info)
+{
+	uint32_t dsp_present = ((ejtag_info->config[3] & MIPS32_CONFIG3_DSPP_MASK) >> MIPS32_CONFIG3_DSPP_SHIFT);
+	if (dsp_present) {
+		mips32->dsp_imp = ((ejtag_info->config[3] & MIPS32_CONFIG3_DSPREV_MASK) >> MIPS32_CONFIG3_DSPREV_SHIFT) + 1;
+		LOG_USER("DSP implemented: %s, rev %d", "yes", mips32->dsp_imp);
+	} else {
+		LOG_USER("DSP implemented: %s", "no");
+	}
+}
+
+/* read fpu implementation info from CP0 Config1 register {CU1, FP}*/
+int mips32_read_config_fpu(struct mips32_common *mips32, struct mips_ejtag *ejtag_info)
+{
+	int retval;
+	uint32_t fp_imp = (ejtag_info->config[1] & MIPS32_CONFIG1_FP_MASK) >> MIPS32_CONFIG1_FP_SHIFT;
+	char buf[60] = {0};
+	if (!fp_imp) {
+		LOG_USER("FPU implemented: %s", "no");
+		mips32->fp_imp = MIPS32_FP_IMP_NONE;
+		return ERROR_OK;
+	}
+	uint32_t status_value;
+	bool status_fr, status_cu1;
+
+	retval = mips32_cp0_read(ejtag_info, &status_value, MIPS32_C0_STATUS, 0);
+	if (retval != ERROR_OK) {
+		LOG_ERROR("Failed to read cp0 status register");
+		return retval;
+	}
+
+	status_fr = (status_value >> MIPS32_CP0_STATUS_FR_SHIFT) & 0x1;
+	status_cu1 = (status_value >> MIPS32_CP0_STATUS_CU1_SHIFT) & 0x1;
+	if (status_cu1) {
+		/* TODO: read fpu(cp1) config register for current operating mode.
+		 * Now its set to 32 bits by default. */
+		snprintf(buf, sizeof(buf), "yes");
+		fp_imp = MIPS32_FP_IMP_32;
+	} else {
+		snprintf(buf, sizeof(buf), "yes, disabled");
+		fp_imp = MIPS32_FP_IMP_UNKNOWN;
+	}
+
+	mips32->fpu_in_64bit = status_fr;
+	mips32->fpu_enabled = status_cu1;
+
+	LOG_USER("FPU implemented: %s", buf);
+	mips32->fp_imp = fp_imp;
+
+	return ERROR_OK;
+}
+
+/* Checks if current target implements Common Device Memory Map and therefore Fast Debug Channel (MD00090) */
+void mips32_read_config_fdc(struct mips32_common *mips32, struct mips_ejtag *ejtag_info, uint32_t dcr)
+{
+	if (((ejtag_info->config[3] & MIPS32_CONFIG3_CDMM_MASK) != 0) && ((dcr & EJTAG_DCR_FDC) != 0)) {
+		mips32->fdc = 1;
+		mips32->semihosting = 1;
+	} else {
+		mips32->fdc = 0;
+		mips32->semihosting = 0;
+	}
+}
+
 /* read config to config3 cp0 registers and log isa implementation */
 int mips32_read_config_regs(struct target *target)
 {
 	struct mips32_common *mips32 = target_to_mips32(target);
 	struct mips_ejtag *ejtag_info = &mips32->ejtag_info;
+	char buf[60] = {0};
+	int retval;
 
 	if (ejtag_info->config_regs == 0)
 		for (int i = 0; i != 4; i++) {
-			int retval = mips32_cp0_read(ejtag_info, &ejtag_info->config[i], 16, i);
+			retval = mips32_cp0_read(ejtag_info, &ejtag_info->config[i], 16, i);
 			if (retval != ERROR_OK) {
 				LOG_ERROR("isa info not available, failed to read cp0 config register: %" PRId32, i);
 				ejtag_info->config_regs = 0;
@@ -828,27 +895,56 @@ int mips32_read_config_regs(struct target *target)
 
 	LOG_DEBUG("read  %"PRIu32" config registers", ejtag_info->config_regs);
 
+	mips32->isa_rel = (ejtag_info->config[0] & MIPS32_CONFIG0_AR_MASK) >> MIPS32_CONFIG0_AR_SHIFT;
+	snprintf(buf, sizeof(buf), ", release %s(AR=%d)",
+			mips32->isa_rel == MIPS32_RELEASE_1 ? "1"
+			: mips32->isa_rel == MIPS32_RELEASE_2 ? "2"
+			: mips32->isa_rel == MIPS32_RELEASE_6 ? "6"
+			: "unknown", mips32->isa_rel);
+
 	if (ejtag_info->impcode & EJTAG_IMP_MIPS16) {
 		mips32->isa_imp = MIPS32_MIPS16;
-		LOG_USER("MIPS32 with MIPS16 support implemented");
-
+		LOG_USER("ISA implemented: %s%s", "MIPS32, MIPS16", buf);
 	} else if (ejtag_info->config_regs >= 4) {	/* config3 implemented */
 		unsigned isa_imp = (ejtag_info->config[3] & MIPS32_CONFIG3_ISA_MASK) >> MIPS32_CONFIG3_ISA_SHIFT;
 		if (isa_imp == 1) {
 			mips32->isa_imp = MMIPS32_ONLY;
-			LOG_USER("MICRO MIPS32 only implemented");
+			LOG_USER("ISA implemented: %s%s", "microMIPS32", buf);
 
 		} else if (isa_imp != 0) {
 			mips32->isa_imp = MIPS32_MMIPS32;
-			LOG_USER("MIPS32 and MICRO MIPS32 implemented");
+			LOG_USER("ISA implemented: %s%s", "MIPS32, microMIPS32", buf);
 		}
+	} else if (mips32->isa_imp == MIPS32_ONLY)	{
+		/* initial default value */
+		LOG_USER("ISA implemented: %s%s", "MIPS32", buf);
 	}
 
-	if (mips32->isa_imp == MIPS32_ONLY)	/* initial default value */
-		LOG_USER("MIPS32 only implemented");
+	/* Retrieve DSP info */
+	mips32_read_config_dsp(mips32, ejtag_info);
+
+	/* Retrieve if Float Point CoProcessor Implemented */
+	retval = mips32_read_config_fpu(mips32, ejtag_info);
+	if (retval != ERROR_OK) {
+		LOG_ERROR("fpu info is not available, error while reading cp0 status");
+		mips32->fp_imp = MIPS32_FP_IMP_NONE;
+		return retval;
+	}
+
+	uint32_t dcr;
+
+	retval = target_read_u32(target, EJTAG_DCR, &dcr);
+	if (retval != ERROR_OK) {
+		LOG_ERROR("failed to read EJTAG_DCR register");
+		return retval;
+	}
+
+	/* Determine if FDC and CDMM are implemented for this core */
+	mips32_read_config_fdc(mips32, ejtag_info, dcr);
 
 	return ERROR_OK;
 }
+
 int mips32_checksum_memory(struct target *target, target_addr_t address,
 		uint32_t count, uint32_t *checksum)
 {
diff --git a/src/target/mips32.h b/src/target/mips32.h
index 7bf6384..d072eb9 100644
--- a/src/target/mips32.h
+++ b/src/target/mips32.h
@@ -46,9 +46,21 @@
 #define MIPS32_CONFIG0_AR_SHIFT 10
 #define MIPS32_CONFIG0_AR_MASK (0x7 << MIPS32_CONFIG0_AR_SHIFT)
 
+#define MIPS32_CONFIG1_FP_SHIFT	0
+#define MIPS32_CONFIG1_FP_MASK	BIT(MIPS32_CONFIG1_FP_SHIFT)
+
 #define MIPS32_CONFIG1_DL_SHIFT 10
 #define MIPS32_CONFIG1_DL_MASK (0x7 << MIPS32_CONFIG1_DL_SHIFT)
 
+#define MIPS32_CONFIG3_CDMM_SHIFT	3
+#define MIPS32_CONFIG3_CDMM_MASK	BIT(MIPS32_CONFIG3_CDMM_SHIFT)
+
+#define MIPS32_CONFIG3_DSPP_SHIFT	10
+#define MIPS32_CONFIG3_DSPP_MASK	BIT(MIPS32_CONFIG3_DSPP_SHIFT)
+
+#define MIPS32_CONFIG3_DSPREV_SHIFT	11
+#define MIPS32_CONFIG3_DSPREV_MASK	BIT(MIPS32_CONFIG3_DSPREV_SHIFT)
+
 #define MIPS32_CONFIG3_ISA_SHIFT	14
 #define MIPS32_CONFIG3_ISA_MASK		(3 << MIPS32_CONFIG3_ISA_SHIFT)
 
@@ -57,6 +69,8 @@
 
 #define MIPS32_SCAN_DELAY_LEGACY_MODE 2000000
 
+#define MIPS32_NUM_DSPREGS		9
+
 /* Bit Mask indicating CP0 register supported by this core */
 #define	MIPS_CP0_MK4		0x0001
 #define	MIPS_CP0_MAPTIV_UC	0x0002
@@ -237,6 +251,31 @@ enum mips32_isa_imp {
 	MIPS32_MMIPS32 = 3,
 };
 
+/* Release 2~5 does not have much change regarding to the ISA under User mode,
+* therefore no new Architecture Revision(AR) level is assigned to them.
+* Release 6 changed some instruction's encoding/mnemonic, removed instructions that
+* has lost its purposes/none are using, and added some new instructions as well.
+*/
+enum mips32_isa_rel {
+	MIPS32_RELEASE_1 = 0,
+	MIPS32_RELEASE_2 = 1,
+	MIPS32_RELEASE_6 = 2,
+	MIPS32_RELEASE_UNKNOWN,
+};
+
+enum mips32_fp_imp {
+	MIPS32_FP_IMP_NONE = 0,
+	MIPS32_FP_IMP_32 = 1,
+	MIPS32_FP_IMP_64 = 2,
+	MIPS32_FP_IMP_UNKNOWN = 3,
+};
+
+enum mips32_dsp_imp {
+	MIPS32_DSP_IMP_NONE = 0,
+	MIPS32_DSP_IMP_REV1 = 1,
+	MIPS32_DSP_IMP_REV2 = 2,
+};
+
 struct mips32_comparator {
 	int used;
 	uint32_t bp_value;
@@ -261,6 +300,18 @@ struct mips32_common {
 
 	enum mips32_isa_mode isa_mode;
 	enum mips32_isa_imp isa_imp;
+	enum mips32_isa_rel isa_rel;
+	enum mips32_fp_imp fp_imp;
+	enum mips32_dsp_imp dsp_imp;
+
+	int fdc;
+	int semihosting;
+	uint32_t cp0_mask;
+
+	/* FPU enabled (cp0.status.cu1) */
+	bool fpu_enabled;
+	/* FPU mode (cp0.status.fr) */
+	bool fpu_in_64bit;
 
 	/* processor identification register */
 	uint32_t prid;
@@ -560,6 +611,173 @@ struct mips32_algorithm {
 
 #define MIPS16_SDBBP(isa)			(isa ? MMIPS16_SDBBP : MIPS16_ISA_SDBBP)
 
+/*
+ * MIPS32 Config1 Register (CP0 Register 16, Select 1)
+ */
+#define MIPS32_CFG1_M			0x80000000		/* Config2 implemented */
+#define MIPS32_CFG1_MMUSMASK		0x7e000000		/* mmu size - 1 */
+#define MIPS32_CFG1_MMUSSHIFT		25
+#define MIPS32_CFG1_ISMASK		0x01c00000		/* icache lines 64<<n */
+#define MIPS32_CFG1_ISSHIFT		22
+#define MIPS32_CFG1_ILMASK		0x00380000		/* icache line size 2<<n */
+#define MIPS32_CFG1_ILSHIFT		19
+#define MIPS32_CFG1_IAMASK		0x00070000		/* icache ways - 1 */
+#define MIPS32_CFG1_IASHIFT		16
+#define MIPS32_CFG1_DSMASK		0x0000e000		/* dcache lines 64<<n */
+#define MIPS32_CFG1_DSSHIFT		13
+#define MIPS32_CFG1_DLMASK		0x00001c00		/* dcache line size 2<<n */
+#define MIPS32_CFG1_DLSHIFT		10
+#define MIPS32_CFG1_DAMASK		0x00000380		/* dcache ways - 1 */
+#define MIPS32_CFG1_DASHIFT		7
+#define MIPS32_CFG1_C2			0x00000040		/* Coprocessor 2 present */
+#define MIPS32_CFG1_MD			0x00000020		/* MDMX implemented */
+#define MIPS32_CFG1_PC			0x00000010		/* performance counters implemented */
+#define MIPS32_CFG1_WR			0x00000008		/* watch registers implemented */
+#define MIPS32_CFG1_CA			0x00000004		/* compression (mips16) implemented */
+#define MIPS32_CFG1_EP			0x00000002		/* ejtag implemented */
+#define MIPS32_CFG1_FP			0x00000001		/* fpu implemented */
+
+/*
+ * MIPS32 Coprocessor 0 register numbers
+ */
+#define MIPS32_C0_INDEX			0
+#define MIPS32_C0_INX			0
+#define MIPS32_C0_RANDOM		1
+#define MIPS32_C0_RAND			1
+#define MIPS32_C0_ENTRYLO0		2
+#define MIPS32_C0_TLBLO0		2
+#define MIPS32_C0_ENTRYLO1		3
+#define MIPS32_C0_TLBLO1		3
+#define MIPS32_C0_CONTEXT		4
+#define MIPS32_C0_CTXT			4
+#define MIPS32_C0_PAGEMASK		5
+#define MIPS32_C0_PAGEGRAIN		(5, 1)
+#define MIPS32_C0_WIRED			6
+#define MIPS32_C0_HWRENA		7
+#define MIPS32_C0_BADVADDR		8
+#define MIPS32_C0_VADDR			8
+#define MIPS32_C0_COUNT			9
+#define MIPS32_C0_ENTRYHI		10
+#define MIPS32_C0_TLBHI			10
+#define MIPS32_C0_GUESTCTL1		10
+#define MIPS32_C0_COMPARE		11
+#define MIPS32_C0_STATUS		12
+#define MIPS32_C0_SR			12
+#define MIPS32_C0_INTCTL		(12, 1)
+#define MIPS32_C0_SRSCTL		(12, 2)
+#define MIPS32_C0_SRSMAP		(12, 3)
+#define MIPS32_C0_CAUSE			13
+#define MIPS32_C0_CR			13
+#define MIPS32_C0_EPC			14
+#define MIPS32_C0_PRID			15
+#define MIPS32_C0_EBASE			(15, 1)
+#define MIPS32_C0_CONFIG		16
+#define MIPS32_C0_CONFIG0		(16, 0)
+#define MIPS32_C0_CONFIG1		(16, 1)
+#define MIPS32_C0_CONFIG2		(16, 2)
+#define MIPS32_C0_CONFIG3		(16, 3)
+#define MIPS32_C0_LLADDR		17
+#define MIPS32_C0_WATCHLO		18
+#define MIPS32_C0_WATCHHI		19
+#define MIPS32_C0_DEBUG			23
+#define MIPS32_C0_DEPC			24
+#define MIPS32_C0_PERFCNT		25
+#define MIPS32_C0_ERRCTL		26
+#define MIPS32_C0_CACHEERR		27
+#define MIPS32_C0_TAGLO			28
+#define MIPS32_C0_ITAGLO		28
+#define MIPS32_C0_DTAGLO		(28, 2)
+#define MIPS32_C0_TAGLO2		(28, 4)
+#define MIPS32_C0_DATALO		(28, 1)
+#define MIPS32_C0_IDATALO		(28, 1)
+#define MIPS32_C0_DDATALO		(28, 3)
+#define MIPS32_C0_DATALO2		(28, 5)
+#define MIPS32_C0_TAGHI			29
+#define MIPS32_C0_ITAGHI		29
+#define MIPS32_C0_DATAHI		(29, 1)
+#define MIPS32_C0_ERRPC			30
+#define MIPS32_C0_DESAVE		31
+
+/*
+ * MIPS32 MMU types
+ */
+#define MIPS32_MMU_TLB			1
+#define MIPS32_MMU_BAT			2
+#define MIPS32_MMU_FIXED		3
+#define MIPS32_MMU_DUAL_VTLB_FTLB	4
+
+enum mips32_cpu_vendor {
+	MIPS32_CPU_VENDOR_MTI,
+	MIPS32_CPU_VENDOR_ALCHEMY,
+	MIPS32_CPU_VENDOR_BROADCOM,
+	MIPS32_CPU_VENDOR_ALTERA,
+	MIPS32_CPU_VENDOR_LEXRA,
+};
+
+enum mips32_isa_supported {
+	MIPS16,
+	MIPS32,
+	MIPS64,
+	MICROMIPS_ONLY,
+	MIPS32_AT_RESET_AND_MICROMIPS,
+	MICROMIPS_AT_RESET_AND_MIPS32,
+};
+
+struct mips32_cpu_features {
+	/* Type of CPU	(4Kc, 24Kf, etc.) */
+	uint32_t cpu_core;
+
+	/* Internal representation of cpu type */
+	uint32_t cpu_type;
+
+	/* Processor vendor */
+	enum mips32_cpu_vendor vendor;
+
+	/* Supported ISA and boot config */
+	enum mips32_isa_supported isa;
+
+	/* PRID */
+	uint32_t prid;
+
+	/* Processor implemented the MultiThreading ASE */
+	bool mtase;
+
+	/* Processor implemented the DSP ASE */
+	bool dspase;
+
+	/* Processor implemented the SmartMIPS ASE */
+	bool smase;
+
+	/* Processor implemented the MIPS16[e] ASE */
+	bool m16ase;
+
+	/* Processor implemented the microMIPS ASE */
+	bool micromipsase;
+
+	/* Processor implemented the Virtualization ASE */
+	uint32_t vzase;
+
+	uint32_t vz_guest_id_width;
+
+	/* ebase.cpuid number */
+	uint32_t cpuid;
+
+	uint32_t inst_cache_size;
+	uint32_t data_cache_size;
+	uint32_t mmu_type;
+	uint32_t tlb_entries;
+	uint32_t num_shadow_regs;
+
+	/* Processor implemented the MSA module */
+	bool msa;
+
+	/* Processor implemented mfhc0 and mthc0 instructions */
+	bool mvh;
+
+	bool guest_ctl1_present;
+	bool cdmm;
+};
+
 extern const struct command_registration mips32_command_handlers[];
 
 int mips32_arch_state(struct target *target);