microblaze: add support for handling PVR data

Add helper code for PVR (Processor Version Register) data handling. It
will be used by the UCLASS_CPU driver to populate cpuinfo fields at
runtime.

Signed-off-by: Ovidiu Panait <ovpanait@gmail.com>
Link: https://lore.kernel.org/r/20220531181435.3473549-13-ovpanait@gmail.com
Signed-off-by: Michal Simek <michal.simek@amd.com>

arch/microblaze/cpu/Makefile

@@ -7,4 +7,5 @@ extra-y	= start.o
 obj-y	= irq.o
 obj-y	+= interrupts.o cache.o exception.o timer.o cpuinfo.o
 obj-$(CONFIG_STATIC_RELA)	+= relocate.o
+obj-$(CONFIG_XILINX_MICROBLAZE0_PVR) += pvr.o
 obj-$(CONFIG_SPL_BUILD)	+= spl.o

arch/microblaze/cpu/pvr.c

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2022, Ovidiu Panait <ovpanait@gmail.com>
+ */
+#include <common.h>
+#include <asm/asm.h>
+#include <asm/pvr.h>
+
+int microblaze_cpu_has_pvr_full(void)
+{
+	u32 msr, pvr0;
+
+	MFS(msr, rmsr);
+	if (!(msr & PVR_MSR_BIT))
+		return 0;
+
+	get_pvr(0, pvr0);
+	debug("%s: pvr0 is 0x%08x\n", __func__, pvr0);
+
+	if (!(pvr0 & PVR0_PVR_FULL_MASK))
+		return 0;
+
+	return 1;
+}
+
+void microblaze_get_all_pvrs(u32 pvr[PVR_FULL_COUNT])
+{
+	get_pvr(0, pvr[0]);
+	get_pvr(1, pvr[1]);
+	get_pvr(2, pvr[2]);
+	get_pvr(3, pvr[3]);
+	get_pvr(4, pvr[4]);
+	get_pvr(5, pvr[5]);
+	get_pvr(6, pvr[6]);
+	get_pvr(7, pvr[7]);
+	get_pvr(8, pvr[8]);
+	get_pvr(9, pvr[9]);
+	get_pvr(10, pvr[10]);
+	get_pvr(11, pvr[11]);
+	get_pvr(12, pvr[12]);
+}

arch/microblaze/include/asm/pvr.h

@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2022, Ovidiu Panait <ovpanait@gmail.com>
+ */
+
+#ifndef __ASM_MICROBLAZE_PVR_H
+#define __ASM_MICROBLAZE_PVR_H
+
+#include <asm/asm.h>
+
+#define PVR_FULL_COUNT 13 /* PVR0 - PVR12 */
+
+#define __get_pvr(val, reg)						\
+	__asm__ __volatile__ ("mfs %0," #reg : "=r" (val) :: "memory")
+#define get_pvr(pvrid, val)						\
+	__get_pvr(val, rpvr ## pvrid)
+
+#define PVR_MSR_BIT			0x00000400
+
+/* PVR0 masks */
+#define PVR0_PVR_FULL_MASK		0x80000000
+#define PVR0_VERSION_MASK		0x0000FF00
+
+/* PVR4 masks - ICache configs */
+#define PVR4_ICACHE_LINE_LEN_MASK	0x00E00000 /* ICLL */
+#define PVR4_ICACHE_BYTE_SIZE_MASK	0x001F0000 /* ICBS */
+
+/* PVR5 masks - DCache configs */
+#define PVR5_DCACHE_LINE_LEN_MASK	0x00E00000 /* DCLL */
+#define PVR5_DCACHE_BYTE_SIZE_MASK	0x001F0000 /* DCBS */
+
+/* PVR10 masks - FPGA family */
+#define PVR10_TARGET_FAMILY_MASK	0xFF000000
+
+/* PVR11 masks - MMU */
+#define PVR11_USE_MMU			0xC0000000
+
+/* PVR access macros */
+#define PVR_VERSION(pvr)						\
+	((pvr[0] & PVR0_VERSION_MASK) >> 8)
+
+#define PVR_ICACHE_LINE_LEN(pvr)					\
+	((1 << ((pvr[4] & PVR4_ICACHE_LINE_LEN_MASK) >> 21)) << 2)
+#define PVR_ICACHE_BYTE_SIZE(pvr)					\
+	(1 << ((pvr[4] & PVR4_ICACHE_BYTE_SIZE_MASK) >> 16))
+
+#define PVR_DCACHE_LINE_LEN(pvr)					\
+	((1 << ((pvr[5] & PVR5_DCACHE_LINE_LEN_MASK) >> 21)) << 2)
+#define PVR_DCACHE_BYTE_SIZE(pvr)					\
+	(1 << ((pvr[5] & PVR5_DCACHE_BYTE_SIZE_MASK) >> 16))
+
+#define PVR_USE_MMU(pvr)						\
+	((pvr[11] & PVR11_USE_MMU) >> 30)
+
+#define PVR_TARGET_FAMILY(pvr)						\
+	((pvr[10] & PVR10_TARGET_FAMILY_MASK) >> 24)
+
+/**
+ * microblaze_cpu_has_pvr_full() - Check for full PVR support
+ *
+ * Check MSR register for PVR support and, if applicable, check the PVR0
+ * register for full PVR support.
+ *
+ * Return: 1 if there is full PVR support, 0 otherwise.
+ */
+int microblaze_cpu_has_pvr_full(void);
+
+/**
+ * microblaze_get_all_pvrs() - Copy PVR0-PVR12 to destination array
+ *
+ * @pvr: destination array of size PVR_FULL_COUNT
+ */
+void microblaze_get_all_pvrs(u32 pvr[PVR_FULL_COUNT]);
+
+#endif	/* __ASM_MICROBLAZE_PVR_H */

board/xilinx/microblaze-generic/Kconfig

@@ -109,4 +109,12 @@ config XILINX_MICROBLAZE0_ICACHE_SIZE
 	  the device tree, or when the instruction cache is flushed very early
 	  in the boot process, before device tree is available.
 
+config XILINX_MICROBLAZE0_PVR
+	bool "MicroBlaze PVR support"
+	help
+	  Enables helper functions and macros needed to manipulate PVR
+	  (Processor Version Register) data. Currently, only the microblaze
+	  UCLASS_CPU driver makes use of this feature to retrieve CPU info at
+	  runtime.
+
 endif