arm64: Get rid of struct cpu_table

struct cpu_table is an artifact left from the (very) early days of
the arm64 port, and its only real use is to allow the most beautiful
"AArch64 Processor" string to be displayed at boot time.

Really? Yes, really.

Let's get rid of it. In order to avoid another BogoMips-gate, the
aforementioned string is preserved.
Acked-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

arch/arm64/include/asm/cputable.h

-/*
- * arch/arm64/include/asm/cputable.h
- *
- * Copyright (C) 2012 ARM Ltd.
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-#ifndef __ASM_CPUTABLE_H
-#define __ASM_CPUTABLE_H
-
-struct cpu_info {
-	unsigned int	cpu_id_val;
-	unsigned int	cpu_id_mask;
-	const char	*cpu_name;
-	unsigned long	(*cpu_setup)(void);
-};
-
-extern struct cpu_info *lookup_processor_type(unsigned int);
-
-#endif

arch/arm64/kernel/Makefile

@@ -12,7 +12,7 @@ CFLAGS_REMOVE_insn.o = -pg
 CFLAGS_REMOVE_return_address.o = -pg
 
 # Object file lists.
-arm64-obj-y		:= cputable.o debug-monitors.o entry.o irq.o fpsimd.o	\
+arm64-obj-y		:= debug-monitors.o entry.o irq.o fpsimd.o		\
 			   entry-fpsimd.o process.o ptrace.o setup.o signal.o	\
 			   sys.o stacktrace.o time.o traps.o io.o vdso.o	\
 			   hyp-stub.o psci.o psci-call.o cpu_ops.o insn.o	\

arch/arm64/kernel/asm-offsets.c

@@ -24,7 +24,6 @@
 #include <linux/kvm_host.h>
 #include <asm/thread_info.h>
 #include <asm/memory.h>
-#include <asm/cputable.h>
 #include <asm/smp_plat.h>
 #include <asm/suspend.h>
 #include <asm/vdso_datapage.h>
@@ -71,9 +70,6 @@ int main(void)
   BLANK();
   DEFINE(PAGE_SZ,	       	PAGE_SIZE);
   BLANK();
-  DEFINE(CPU_INFO_SZ,		sizeof(struct cpu_info));
-  DEFINE(CPU_INFO_SETUP,	offsetof(struct cpu_info, cpu_setup));
-  BLANK();
   DEFINE(DMA_BIDIRECTIONAL,	DMA_BIDIRECTIONAL);
   DEFINE(DMA_TO_DEVICE,		DMA_TO_DEVICE);
   DEFINE(DMA_FROM_DEVICE,	DMA_FROM_DEVICE);

arch/arm64/kernel/cputable.c

-/*
- * arch/arm64/kernel/cputable.c
- *
- * Copyright (C) 2012 ARM Ltd.
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <linux/init.h>
-
-#include <asm/cputable.h>
-
-extern unsigned long __cpu_setup(void);
-
-struct cpu_info cpu_table[] = {
-	{
-		.cpu_id_val	= 0x000f0000,
-		.cpu_id_mask	= 0x000f0000,
-		.cpu_name	= "AArch64 Processor",
-		.cpu_setup	= __cpu_setup,
-	},
-	{ /* Empty */ },
-};

arch/arm64/kernel/head.S

@@ -245,22 +245,12 @@ ENTRY(stext)
 	bl	__calc_phys_offset		// x24=PHYS_OFFSET, x28=PHYS_OFFSET-PAGE_OFFSET
 	bl	set_cpu_boot_mode_flag
 	mrs	x22, midr_el1			// x22=cpuid
-	mov	x0, x22
-	bl	lookup_processor_type
-	mov	x23, x0				// x23=current cpu_table
-	/*
-	 * __error_p may end up out of range for cbz if text areas are
-	 * aligned up to section sizes.
-	 */
-	cbnz	x23, 1f				// invalid processor (x23=0)?
-	b	__error_p
-1:
+
 	bl	__vet_fdt
 	bl	__create_page_tables		// x25=TTBR0, x26=TTBR1
 	/*
-	 * The following calls CPU specific code in a position independent
-	 * manner. See arch/arm64/mm/proc.S for details. x23 = base of
-	 * cpu_info structure selected by lookup_processor_type above.
+	 * The following calls CPU setup code, see arch/arm64/mm/proc.S for
+	 * details.
 	 * On return, the CPU will be ready for the MMU to be turned on and
 	 * the TCR will have been set.
 	 */
@@ -268,9 +258,7 @@ ENTRY(stext)
 						// MMU has been enabled
 	adrp	lr, __enable_mmu		// return (PIC) address
 	add	lr, lr, #:lo12:__enable_mmu
-	ldr	x12, [x23, #CPU_INFO_SETUP]
-	add	x12, x12, x28			// __virt_to_phys
-	br	x12				// initialise processor
+	b	__cpu_setup			// initialise processor
 ENDPROC(stext)
 
 /*
@@ -634,15 +622,9 @@ ENTRY(secondary_startup)
 	 * Common entry point for secondary CPUs.
 	 */
 	mrs	x22, midr_el1			// x22=cpuid
-	mov	x0, x22
-	bl	lookup_processor_type
-	mov	x23, x0				// x23=current cpu_table
-	cbz	x23, __error_p			// invalid processor (x23=0)?
 
 	pgtbl	x25, x26, x28			// x25=TTBR0, x26=TTBR1
-	ldr	x12, [x23, #CPU_INFO_SETUP]
-	add	x12, x12, x28			// __virt_to_phys
-	blr	x12				// initialise processor
+	bl	__cpu_setup			// initialise processor
 
 	ldr	x21, =secondary_data
 	ldr	x27, =__secondary_switched	// address to jump to after enabling the MMU
@@ -708,51 +690,3 @@ ENDPROC(__calc_phys_offset)
 	.align 3
 1:	.quad	.
 	.quad	PAGE_OFFSET
-
-/*
- * Exception handling. Something went wrong and we can't proceed. We ought to
- * tell the user, but since we don't have any guarantee that we're even
- * running on the right architecture, we do virtually nothing.
- */
-__error_p:
-ENDPROC(__error_p)
-
-__error:
-1:	nop
-	b	1b
-ENDPROC(__error)
-
-/*
- * This function gets the processor ID in w0 and searches the cpu_table[] for
- * a match. It returns a pointer to the struct cpu_info it found. The
- * cpu_table[] must end with an empty (all zeros) structure.
- *
- * This routine can be called via C code and it needs to work with the MMU
- * both disabled and enabled (the offset is calculated automatically).
- */
-ENTRY(lookup_processor_type)
-	adr	x1, __lookup_processor_type_data
-	ldp	x2, x3, [x1]
-	sub	x1, x1, x2			// get offset between VA and PA
-	add	x3, x3, x1			// convert VA to PA
-1:
-	ldp	w5, w6, [x3]			// load cpu_id_val and cpu_id_mask
-	cbz	w5, 2f				// end of list?
-	and	w6, w6, w0
-	cmp	w5, w6
-	b.eq	3f
-	add	x3, x3, #CPU_INFO_SZ
-	b	1b
-2:
-	mov	x3, #0				// unknown processor
-3:
-	mov	x0, x3
-	ret
-ENDPROC(lookup_processor_type)
-
-	.align	3
-	.type	__lookup_processor_type_data, %object
-__lookup_processor_type_data:
-	.quad	.
-	.quad	cpu_table
-	.size	__lookup_processor_type_data, . - __lookup_processor_type_data

arch/arm64/kernel/setup.c

@@ -50,7 +50,6 @@
 #include <asm/cpu.h>
 #include <asm/cputype.h>
 #include <asm/elf.h>
-#include <asm/cputable.h>
 #include <asm/cpufeature.h>
 #include <asm/cpu_ops.h>
 #include <asm/sections.h>
@@ -84,7 +83,6 @@ unsigned int compat_elf_hwcap2 __read_mostly;
 
 DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
 
-static const char *cpu_name;
 phys_addr_t __fdt_pointer __initdata;
 
 /*
@@ -234,22 +232,12 @@ void __init up_late_init(void)
 
 static void __init setup_processor(void)
 {
-	struct cpu_info *cpu_info;
 	u64 features, block;
 	u32 cwg;
 	int cls;
 
-	cpu_info = lookup_processor_type(read_cpuid_id());
-	if (!cpu_info) {
-		printk("CPU configuration botched (ID %08x), unable to continue.\n",
-		       read_cpuid_id());
-		while (1);
-	}
-
-	cpu_name = cpu_info->cpu_name;
-
-	printk("CPU: %s [%08x] revision %d\n",
-	       cpu_name, read_cpuid_id(), read_cpuid_id() & 15);
+	printk("CPU: AArch64 Processor [%08x] revision %d\n",
+	       read_cpuid_id(), read_cpuid_id() & 15);
 
 	sprintf(init_utsname()->machine, ELF_PLATFORM);
 	elf_hwcap = 0;