From e701d269aa28996f3502780951fe1b12d5d66b49 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 30 Oct 2007 09:46:06 +1100 Subject: [POWERPC] 4xx: Fix 4xx flush_tlb_page() On 4xx CPUs, the current implementation of flush_tlb_page() uses a low level _tlbie() assembly function that only works for the current PID. Thus, invalidations caused by, for example, a COW fault triggered by get_user_pages() from a different context will not work properly, causing among other things, gdb breakpoints to fail. This patch adds a "pid" argument to _tlbie() on 4xx processors, and uses it to flush entries in the right context. FSL BookE also gets the argument but it seems they don't need it (their tlbivax form ignores the PID when invalidating according to the document I have). Signed-off-by: Benjamin Herrenschmidt Acked-by: Kumar Gala Signed-off-by: Josh Boyer --- arch/powerpc/mm/fault.c | 2 +- arch/powerpc/mm/mmu_decl.h | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/powerpc/mm') diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index a18fda361cc..8135da06e0a 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -309,7 +309,7 @@ good_area: set_bit(PG_arch_1, &page->flags); } pte_update(ptep, 0, _PAGE_HWEXEC); - _tlbie(address); + _tlbie(address, mm->context.id); pte_unmap_unlock(ptep, ptl); up_read(&mm->mmap_sem); return 0; diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h index c94a64fd3c0..eb3a732e91d 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -61,12 +61,12 @@ extern unsigned long total_lowmem; #define mmu_mapin_ram() (0UL) #elif defined(CONFIG_4xx) -#define flush_HPTE(X, va, pg) _tlbie(va) +#define flush_HPTE(pid, va, pg) _tlbie(va, pid) extern void MMU_init_hw(void); extern unsigned long mmu_mapin_ram(void); #elif defined(CONFIG_FSL_BOOKE) -#define flush_HPTE(X, va, pg) _tlbie(va) +#define flush_HPTE(pid, va, pg) _tlbie(va, pid) extern void MMU_init_hw(void); extern unsigned long mmu_mapin_ram(void); extern void adjust_total_lowmem(void); -- cgit v1.2.3 From b98ac05d5e460301fbea24cceed0f2a601c82e22 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 31 Oct 2007 16:42:19 +1100 Subject: [POWERPC] 4xx: Deal with 44x virtually tagged icache The 44x family has an interesting "feature" which is a virtually tagged instruction cache (yuck !). So far, we haven't dealt with it properly, which means we've been mostly lucky or people didn't report the problems, unless people have been running custom patches in their distro... This is an attempt at fixing it properly. I chose to do it by setting a global flag whenever we change a PTE that was previously marked executable, and flush the entire instruction cache upon return to user space when that happens. This is a bit heavy handed, but it's hard to do more fine grained flushes as the icbi instruction, on those processor, for some very strange reasons (since the cache is virtually mapped) still requires a valid TLB entry for reading in the target address space, which isn't something I want to deal with. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Josh Boyer --- arch/powerpc/mm/44x_mmu.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/powerpc/mm') diff --git a/arch/powerpc/mm/44x_mmu.c b/arch/powerpc/mm/44x_mmu.c index c3df5047653..04dc08798d3 100644 --- a/arch/powerpc/mm/44x_mmu.c +++ b/arch/powerpc/mm/44x_mmu.c @@ -35,6 +35,7 @@ */ unsigned int tlb_44x_index; /* = 0 */ unsigned int tlb_44x_hwater = PPC44x_TLB_SIZE - 1 - PPC44x_EARLY_TLBS; +int icache_44x_need_flush; /* * "Pins" a 256MB TLB entry in AS0 for kernel lowmem -- cgit v1.2.3 From bd942ba3db60d3bd4e21febbe7c5e339d973d5a8 Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Wed, 31 Oct 2007 17:41:20 +1100 Subject: [POWERPC] ppc405 Fix arithmatic rollover bug when memory size under 16M mmu_mapin_ram() loops over total_lowmem to setup page tables. However, if total_lowmem is less that 16M, the subtraction rolls over and results in a number just under 4G (because total_lowmem is an unsigned value). This patch rejigs the loop from countup to countdown to eliminate the bug. Special thanks to Magnus Hjorth who wrote the original patch to fix this bug. This patch improves on his by making the loop code simpler (which also eliminates the possibility of another rollover at the high end) and also applies the change to arch/powerpc. Signed-off-by: Grant Likely Signed-off-by: Josh Boyer --- arch/powerpc/mm/40x_mmu.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) (limited to 'arch/powerpc/mm') diff --git a/arch/powerpc/mm/40x_mmu.c b/arch/powerpc/mm/40x_mmu.c index e067df836be..3899ea97fbd 100644 --- a/arch/powerpc/mm/40x_mmu.c +++ b/arch/powerpc/mm/40x_mmu.c @@ -98,13 +98,12 @@ unsigned long __init mmu_mapin_ram(void) v = KERNELBASE; p = PPC_MEMSTART; - s = 0; + s = total_lowmem; - if (__map_without_ltlbs) { - return s; - } + if (__map_without_ltlbs) + return 0; - while (s <= (total_lowmem - LARGE_PAGE_SIZE_16M)) { + while (s >= LARGE_PAGE_SIZE_16M) { pmd_t *pmdp; unsigned long val = p | _PMD_SIZE_16M | _PAGE_HWEXEC | _PAGE_HWWRITE; @@ -116,10 +115,10 @@ unsigned long __init mmu_mapin_ram(void) v += LARGE_PAGE_SIZE_16M; p += LARGE_PAGE_SIZE_16M; - s += LARGE_PAGE_SIZE_16M; + s -= LARGE_PAGE_SIZE_16M; } - while (s <= (total_lowmem - LARGE_PAGE_SIZE_4M)) { + while (s >= LARGE_PAGE_SIZE_4M) { pmd_t *pmdp; unsigned long val = p | _PMD_SIZE_4M | _PAGE_HWEXEC | _PAGE_HWWRITE; @@ -128,8 +127,8 @@ unsigned long __init mmu_mapin_ram(void) v += LARGE_PAGE_SIZE_4M; p += LARGE_PAGE_SIZE_4M; - s += LARGE_PAGE_SIZE_4M; + s -= LARGE_PAGE_SIZE_4M; } - return s; + return total_lowmem - s; } -- cgit v1.2.3