openrisc: fix PTRS_PER_PGD define (f4770609) · Commits · 戴 / test

On OpenRISC, with its 8k pages, PAGE_SHIFT is defined to be 13. That makes the expression (1UL << (PAGE_SHIFT-2)) evaluate to 2048. The correct value for PTRS_PER_PGD should be 256. Correcting the PTRS_PER_PGD define unveiled a bug in map_ram(), where PTRS_PER_PGD was used when the intent was to iterate over a set of page table entries. This patch corrects that issue as well. Signed-off-by:

Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Acked-by:

Jonas Bonn <jonas@southpole.se> Tested-by:

Guenter Roeck <linux@roeck-us.net> Signed-off-by:

Stafford Horne <shorne@gmail.com>

arch/openrisc/include/asm/pgtable.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -69,7 +69,7 @@ extern void paging_init(void);
		*/
		#define PTRS_PER_PTE (1UL << (PAGE_SHIFT-2))

		#define PTRS_PER_PGD (1UL << (PAGE_SHIFT-2))
		#define PTRS_PER_PGD (1UL << (32-PGDIR_SHIFT))

		/* calculate how many PGD entries a user-level program can use
		* the first mappable virtual address is 0

arch/openrisc/mm/init.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -110,7 +110,7 @@ static void __init map_ram(void)
		set_pmd(pme, __pmd(_KERNPG_TABLE + __pa(pte)));

		/* Fill the newly allocated page with PTE'S */
		for (j = 0; p < e && j < PTRS_PER_PGD;
		for (j = 0; p < e && j < PTRS_PER_PTE;
		v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) {
		if (v >= (u32) _e_kernel_ro \|\|
		v < (u32) _s_kernel_ro)

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