linux/arch/mips/lib/dump_tlb.c
Kees Cook 3f649ab728 treewide: Remove uninitialized_var() usage
Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
	xargs perl -pi -e \
		's/\buninitialized_var\(([^\)]+)\)/\1/g;
		 s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-16 12:35:15 -07:00

200 lines
5.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Dump R4x00 TLB for debugging purposes.
*
* Copyright (C) 1994, 1995 by Waldorf Electronics, written by Ralf Baechle.
* Copyright (C) 1999 by Silicon Graphics, Inc.
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <asm/hazards.h>
#include <asm/mipsregs.h>
#include <asm/mmu_context.h>
#include <asm/page.h>
#include <asm/tlbdebug.h>
void dump_tlb_regs(void)
{
const int field = 2 * sizeof(unsigned long);
pr_info("Index : %0x\n", read_c0_index());
pr_info("PageMask : %0x\n", read_c0_pagemask());
if (cpu_has_guestid)
pr_info("GuestCtl1: %0x\n", read_c0_guestctl1());
pr_info("EntryHi : %0*lx\n", field, read_c0_entryhi());
pr_info("EntryLo0 : %0*lx\n", field, read_c0_entrylo0());
pr_info("EntryLo1 : %0*lx\n", field, read_c0_entrylo1());
pr_info("Wired : %0x\n", read_c0_wired());
switch (current_cpu_type()) {
case CPU_R10000:
case CPU_R12000:
case CPU_R14000:
case CPU_R16000:
pr_info("FrameMask: %0x\n", read_c0_framemask());
break;
}
if (cpu_has_small_pages || cpu_has_rixi || cpu_has_xpa)
pr_info("PageGrain: %0x\n", read_c0_pagegrain());
if (cpu_has_htw) {
pr_info("PWField : %0*lx\n", field, read_c0_pwfield());
pr_info("PWSize : %0*lx\n", field, read_c0_pwsize());
pr_info("PWCtl : %0x\n", read_c0_pwctl());
}
}
static inline const char *msk2str(unsigned int mask)
{
switch (mask) {
case PM_4K: return "4kb";
case PM_16K: return "16kb";
case PM_64K: return "64kb";
case PM_256K: return "256kb";
#ifdef CONFIG_CPU_CAVIUM_OCTEON
case PM_8K: return "8kb";
case PM_32K: return "32kb";
case PM_128K: return "128kb";
case PM_512K: return "512kb";
case PM_2M: return "2Mb";
case PM_8M: return "8Mb";
case PM_32M: return "32Mb";
#endif
#ifndef CONFIG_CPU_VR41XX
case PM_1M: return "1Mb";
case PM_4M: return "4Mb";
case PM_16M: return "16Mb";
case PM_64M: return "64Mb";
case PM_256M: return "256Mb";
case PM_1G: return "1Gb";
#endif
}
return "";
}
static void dump_tlb(int first, int last)
{
unsigned long s_entryhi, entryhi, asid, mmid;
unsigned long long entrylo0, entrylo1, pa;
unsigned int s_index, s_pagemask, s_guestctl1 = 0;
unsigned int pagemask, guestctl1 = 0, c0, c1, i;
unsigned long asidmask = cpu_asid_mask(&current_cpu_data);
int asidwidth = DIV_ROUND_UP(ilog2(asidmask) + 1, 4);
unsigned long s_mmid;
#ifdef CONFIG_32BIT
bool xpa = cpu_has_xpa && (read_c0_pagegrain() & PG_ELPA);
int pwidth = xpa ? 11 : 8;
int vwidth = 8;
#else
bool xpa = false;
int pwidth = 11;
int vwidth = 11;
#endif
s_pagemask = read_c0_pagemask();
s_entryhi = read_c0_entryhi();
s_index = read_c0_index();
if (cpu_has_mmid)
asid = s_mmid = read_c0_memorymapid();
else
asid = s_entryhi & asidmask;
if (cpu_has_guestid)
s_guestctl1 = read_c0_guestctl1();
for (i = first; i <= last; i++) {
write_c0_index(i);
mtc0_tlbr_hazard();
tlb_read();
tlb_read_hazard();
pagemask = read_c0_pagemask();
entryhi = read_c0_entryhi();
entrylo0 = read_c0_entrylo0();
entrylo1 = read_c0_entrylo1();
if (cpu_has_mmid)
mmid = read_c0_memorymapid();
else
mmid = entryhi & asidmask;
if (cpu_has_guestid)
guestctl1 = read_c0_guestctl1();
/* EHINV bit marks entire entry as invalid */
if (cpu_has_tlbinv && entryhi & MIPS_ENTRYHI_EHINV)
continue;
/*
* Prior to tlbinv, unused entries have a virtual address of
* CKSEG0.
*/
if ((entryhi & ~0x1ffffUL) == CKSEG0)
continue;
/*
* ASID takes effect in absence of G (global) bit.
* We check both G bits, even though architecturally they should
* match one another, because some revisions of the SB1 core may
* leave only a single G bit set after a machine check exception
* due to duplicate TLB entry.
*/
if (!((entrylo0 | entrylo1) & ENTRYLO_G) && (mmid != asid))
continue;
/*
* Only print entries in use
*/
printk("Index: %2d pgmask=%s ", i, msk2str(pagemask));
c0 = (entrylo0 & ENTRYLO_C) >> ENTRYLO_C_SHIFT;
c1 = (entrylo1 & ENTRYLO_C) >> ENTRYLO_C_SHIFT;
pr_cont("va=%0*lx asid=%0*lx",
vwidth, (entryhi & ~0x1fffUL),
asidwidth, mmid);
if (cpu_has_guestid)
pr_cont(" gid=%02lx",
(guestctl1 & MIPS_GCTL1_RID)
>> MIPS_GCTL1_RID_SHIFT);
/* RI/XI are in awkward places, so mask them off separately */
pa = entrylo0 & ~(MIPS_ENTRYLO_RI | MIPS_ENTRYLO_XI);
if (xpa)
pa |= (unsigned long long)readx_c0_entrylo0() << 30;
pa = (pa << 6) & PAGE_MASK;
pr_cont("\n\t[");
if (cpu_has_rixi)
pr_cont("ri=%d xi=%d ",
(entrylo0 & MIPS_ENTRYLO_RI) ? 1 : 0,
(entrylo0 & MIPS_ENTRYLO_XI) ? 1 : 0);
pr_cont("pa=%0*llx c=%d d=%d v=%d g=%d] [",
pwidth, pa, c0,
(entrylo0 & ENTRYLO_D) ? 1 : 0,
(entrylo0 & ENTRYLO_V) ? 1 : 0,
(entrylo0 & ENTRYLO_G) ? 1 : 0);
/* RI/XI are in awkward places, so mask them off separately */
pa = entrylo1 & ~(MIPS_ENTRYLO_RI | MIPS_ENTRYLO_XI);
if (xpa)
pa |= (unsigned long long)readx_c0_entrylo1() << 30;
pa = (pa << 6) & PAGE_MASK;
if (cpu_has_rixi)
pr_cont("ri=%d xi=%d ",
(entrylo1 & MIPS_ENTRYLO_RI) ? 1 : 0,
(entrylo1 & MIPS_ENTRYLO_XI) ? 1 : 0);
pr_cont("pa=%0*llx c=%d d=%d v=%d g=%d]\n",
pwidth, pa, c1,
(entrylo1 & ENTRYLO_D) ? 1 : 0,
(entrylo1 & ENTRYLO_V) ? 1 : 0,
(entrylo1 & ENTRYLO_G) ? 1 : 0);
}
printk("\n");
write_c0_entryhi(s_entryhi);
write_c0_index(s_index);
write_c0_pagemask(s_pagemask);
if (cpu_has_guestid)
write_c0_guestctl1(s_guestctl1);
}
void dump_tlb_all(void)
{
dump_tlb(0, current_cpu_data.tlbsize - 1);
}