KVM: PPC: Book3S HV: simplify kvm_cma_reserve()

Patch series "memblock: seasonal cleaning^w cleanup", v3.

These patches simplify several uses of memblock iterators and hide some of
the memblock implementation details from the rest of the system.

This patch (of 17):

The memory size calculation in kvm_cma_reserve() traverses memblock.memory
rather than simply call memblock_phys_mem_size().  The comment in that
function suggests that at some point there should have been call to
memblock_analyze() before memblock_phys_mem_size() could be used.  As of
now, there is no memblock_analyze() at all and memblock_phys_mem_size()
can be used as soon as cold-plug memory is registered with memblock.

Replace loop over memblock.memory with a call to memblock_phys_mem_size().

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Emil Renner Berthing <kernel@esmil.dk>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Link: https://lkml.kernel.org/r/20200818151634.14343-1-rppt@kernel.org
Link: https://lkml.kernel.org/r/20200818151634.14343-2-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/powerpc/kvm/book3s_hv_builtin.c

@@ -95,23 +95,15 @@ EXPORT_SYMBOL_GPL(kvm_free_hpt_cma);
 void __init kvm_cma_reserve(void)
 {
 	unsigned long align_size;
-	struct memblock_region *reg;
-	phys_addr_t selected_size = 0;
+	phys_addr_t selected_size;
 
 	/*
 	 * We need CMA reservation only when we are in HV mode
 	 */
 	if (!cpu_has_feature(CPU_FTR_HVMODE))
 		return;
-	/*
-	 * We cannot use memblock_phys_mem_size() here, because
-	 * memblock_analyze() has not been called yet.
-	 */
-	for_each_memblock(memory, reg)
-		selected_size += memblock_region_memory_end_pfn(reg) -
-				 memblock_region_memory_base_pfn(reg);
 
-	selected_size = (selected_size * kvm_cma_resv_ratio / 100) << PAGE_SHIFT;
+	selected_size = PAGE_ALIGN(memblock_phys_mem_size() * kvm_cma_resv_ratio / 100);
 	if (selected_size) {
 		pr_info("%s: reserving %ld MiB for global area\n", __func__,
 			 (unsigned long)selected_size / SZ_1M);