Commit 1037d186 authored by Stafford Horne's avatar Stafford Horne
Browse files

openrisc: Implement fixmap to fix earlycon 



With commit 53c98e35 ("openrisc: mm: remove unneeded early ioremap
code") it was commented that early ioremap was not used in OpenRISC.  I
acked this but was wrong, earlycon was using it.  Earlycon setup now
fails with the below trace:

    Kernel command line: earlycon
    ------------[ cut here ]------------
    WARNING: CPU: 0 PID: 0 at mm/ioremap.c:23
    generic_ioremap_prot+0x118/0x130
    Modules linked in:
    CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted
    6.11.0-rc5-00001-gce02fd891c38-dirty #141
    Call trace:
    [<(ptrval)>] dump_stack_lvl+0x7c/0x9c
    [<(ptrval)>] dump_stack+0x1c/0x2c
    [<(ptrval)>] __warn+0xb4/0x108
    [<(ptrval)>] ? generic_ioremap_prot+0x118/0x130
    [<(ptrval)>] warn_slowpath_fmt+0x60/0x98
    [<(ptrval)>] generic_ioremap_prot+0x118/0x130
    [<(ptrval)>] ioremap_prot+0x20/0x30
    [<(ptrval)>] of_setup_earlycon+0xd4/0x2e0
    [<(ptrval)>] early_init_dt_scan_chosen_stdout+0x18c/0x1c8
    [<(ptrval)>] param_setup_earlycon+0x3c/0x60
    [<(ptrval)>] do_early_param+0xb0/0x118
    [<(ptrval)>] parse_args+0x184/0x4b8
    [<(ptrval)>] ? start_kernel+0x0/0x78c
    [<(ptrval)>] parse_early_options+0x40/0x50
    [<(ptrval)>] ? do_early_param+0x0/0x118
    [<(ptrval)>] parse_early_param+0x48/0x68
    [<(ptrval)>] ? start_kernel+0x318/0x78c
    [<(ptrval)>] ? start_kernel+0x0/0x78c
    ---[ end trace 0000000000000000 ]---

To fix this we could either implement early_ioremap again or implement
fixmap.  In this patch we choose the later option of implementing basic
fixmap support.

While fixing this we also remove the old FIX_IOREMAP slots that were
used by early ioremap code.  That code was also removed by commit
53c98e35 ("openrisc: mm: remove unneeded early ioremap code") but
these definitions were not cleaned up.

Fixes: 53c98e35 ("openrisc: mm: remove unneeded early ioremap code")
Signed-off-by: default avatarStafford Horne <shorne@gmail.com>
parent 5be63fc1

arch/openrisc/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -65,6 +65,9 @@ config STACKTRACE_SUPPORT 
config LOCKDEP_SUPPORT

	def_bool  y



config FIX_EARLYCON_MEM

	def_bool y



menu "Processor type and features"



choice

arch/openrisc/include/asm/fixmap.h

+5 −16
Original line number Diff line number Diff line
@@ -26,29 +26,18 @@ 
#include <linux/bug.h>

#include <asm/page.h>



/*

 * On OpenRISC we use these special fixed_addresses for doing ioremap

 * early in the boot process before memory initialization is complete.

 * This is used, in particular, by the early serial console code.

 *

 * It's not really 'fixmap', per se, but fits loosely into the same

 * paradigm.

 */

enum fixed_addresses {

	/*

	 * FIX_IOREMAP entries are useful for mapping physical address

	 * space before ioremap() is useable, e.g. really early in boot

	 * before kmalloc() is working.

	 */

#define FIX_N_IOREMAPS  32

	FIX_IOREMAP_BEGIN,

	FIX_IOREMAP_END = FIX_IOREMAP_BEGIN + FIX_N_IOREMAPS - 1,

	FIX_EARLYCON_MEM_BASE,

	__end_of_fixed_addresses

};



#define FIXADDR_SIZE		(__end_of_fixed_addresses << PAGE_SHIFT)

/* FIXADDR_BOTTOM might be a better name here... */

#define FIXADDR_START		(FIXADDR_TOP - FIXADDR_SIZE)

#define FIXMAP_PAGE_IO		PAGE_KERNEL_NOCACHE



extern void __set_fixmap(enum fixed_addresses idx,

			 phys_addr_t phys, pgprot_t flags);



#include <asm-generic/fixmap.h>

arch/openrisc/mm/init.c

+37 −0
Original line number Diff line number Diff line
@@ -207,6 +207,43 @@ void __init mem_init(void) 
	return;

}



static int __init map_page(unsigned long va, phys_addr_t pa, pgprot_t prot)

{

	p4d_t *p4d;

	pud_t *pud;

	pmd_t *pmd;

	pte_t *pte;



	p4d = p4d_offset(pgd_offset_k(va), va);

	pud = pud_offset(p4d, va);

	pmd = pmd_offset(pud, va);

	pte = pte_alloc_kernel(pmd, va);



	if (pte == NULL)

		return -ENOMEM;



	if (pgprot_val(prot))

		set_pte_at(&init_mm, va, pte, pfn_pte(pa >> PAGE_SHIFT, prot));

	else

		pte_clear(&init_mm, va, pte);



	local_flush_tlb_page(NULL, va);

	return 0;

}



void __init __set_fixmap(enum fixed_addresses idx,

			 phys_addr_t phys, pgprot_t prot)

{

	unsigned long address = __fix_to_virt(idx);



	if (idx >= __end_of_fixed_addresses) {

		BUG();

		return;

	}



	map_page(address, phys, prot);

}



static const pgprot_t protection_map[16] = {

	[VM_NONE]					= PAGE_NONE,

	[VM_READ]					= PAGE_READONLY_X,