powerpc: Remove klimit

klimit is a global variable initialised at build time with the
value of _end.

This variable is never modified, so _end symbol can be used directly.

Remove klimit.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/9fa9ba6807c17f93f35a582c199c646c4a8bfd9c.1622800638.git.christophe.leroy@csgroup.eu

arch/powerpc/include/asm/setup.h

@@ -10,7 +10,6 @@ extern void ppc_printk_progress(char *s, unsigned short hex);
 extern unsigned int rtas_data;
 extern unsigned long long memory_limit;
 extern bool init_mem_is_free;
-extern unsigned long klimit;
 extern void *zalloc_maybe_bootmem(size_t size, gfp_t mask);
 
 struct device_node;

arch/powerpc/kernel/head_book3s_32.S

@@ -766,9 +766,6 @@ PerformanceMonitor:
  * the kernel image to physical address PHYSICAL_START.
  */
 relocate_kernel:
-	addis	r9,r26,klimit@ha	/* fetch klimit */
-	lwz	r25,klimit@l(r9)
-	addis	r25,r25,-KERNELBASE@h
 	lis	r3,PHYSICAL_START@h	/* Destination base address */
 	li	r6,0			/* Destination offset */
 	li	r5,0x4000		/* # bytes of memory to copy */
@@ -776,7 +773,8 @@ relocate_kernel:
 	addi	r0,r3,4f@l		/* jump to the address of 4f */
 	mtctr	r0			/* in copy and do the rest. */
 	bctr				/* jump to the copy */
-4:	mr	r5,r25
+4:	lis	r5,_end-KERNELBASE@h
+	ori	r5,r5,_end-KERNELBASE@l
 	bl	copy_and_flush		/* copy the rest */
 	b	turn_on_mmu
 

arch/powerpc/kernel/prom.c

@@ -758,7 +758,7 @@ void __init early_init_devtree(void *params)
 		first_memblock_size = min_t(u64, first_memblock_size, memory_limit);
 	setup_initial_memory_limit(memstart_addr, first_memblock_size);
 	/* Reserve MEMBLOCK regions used by kernel, initrd, dt, etc... */
-	memblock_reserve(PHYSICAL_START, __pa(klimit) - PHYSICAL_START);
+	memblock_reserve(PHYSICAL_START, __pa(_end) - PHYSICAL_START);
 	/* If relocatable, reserve first 32k for interrupt vectors etc. */
 	if (PHYSICAL_START > MEMORY_START)
 		memblock_reserve(MEMORY_START, 0x8000);

arch/powerpc/kernel/setup-common.c

@@ -91,8 +91,6 @@ EXPORT_SYMBOL_GPL(boot_cpuid);
 int dcache_bsize;
 int icache_bsize;
 
-unsigned long klimit = (unsigned long) _end;
-
 /*
  * This still seems to be needed... -- paulus
  */ 
@@ -930,7 +928,7 @@ void __init setup_arch(char **cmdline_p)
 	init_mm.start_code = (unsigned long)_stext;
 	init_mm.end_code = (unsigned long) _etext;
 	init_mm.end_data = (unsigned long) _edata;
-	init_mm.brk = klimit;
+	init_mm.brk = (unsigned long)_end;
 
 	mm_iommu_init(&init_mm);
 	irqstack_early_init();

arch/powerpc/platforms/powermac/bootx_init.c

@@ -433,7 +433,7 @@ static void __init btext_welcome(boot_infos_t *bi)
 	bootx_printf("\nframe buffer at  : 0x%x", bi->dispDeviceBase);
 	bootx_printf(" (phys), 0x%x", bi->logicalDisplayBase);
 	bootx_printf(" (log)");
-	bootx_printf("\nklimit           : 0x%x",(unsigned long)klimit);
+	bootx_printf("\nklimit           : 0x%x",(unsigned long)_end);
 	bootx_printf("\nboot_info at     : 0x%x", bi);
 	__asm__ __volatile__ ("mfmsr %0" : "=r" (flags));
 	bootx_printf("\nMSR              : 0x%x", flags);