Index: kernel/arch/ppc32/include/mm/tlb.h =================================================================== --- kernel/arch/ppc32/include/mm/tlb.h (revision 7c98874c78674dda91c9fbaf0590416e0fa1c587) +++ kernel/arch/ppc32/include/mm/tlb.h (revision 896ad9f900f2434342a878312aa1a5cb22bdf135) @@ -60,5 +60,5 @@ extern void pht_refill(int n, istate_t *istate); -extern bool pht_real_refill(int n, istate_t *istate) __attribute__ ((section("K_UNMAPPED_TEXT_START"))); +extern bool pht_refill_real(int n, istate_t *istate) __attribute__ ((section("K_UNMAPPED_TEXT_START"))); extern void pht_init(void); Index: kernel/arch/ppc32/src/exception.S =================================================================== --- kernel/arch/ppc32/src/exception.S (revision 7c98874c78674dda91c9fbaf0590416e0fa1c587) +++ kernel/arch/ppc32/src/exception.S (revision 896ad9f900f2434342a878312aa1a5cb22bdf135) @@ -226,5 +226,5 @@ mr r4, sp addi r4, r4, 8 - bl pht_real_refill + bl pht_refill_real cmpwi r3, 0 @@ -238,5 +238,5 @@ mr r4, sp addi r4, r4, 8 - bl pht_real_refill + bl pht_refill_real cmpwi r3, 0 @@ -282,5 +282,4 @@ iret_real: - lwz r0, 8(sp) lwz r2, 12(sp) Index: kernel/arch/ppc32/src/mm/tlb.c =================================================================== --- kernel/arch/ppc32/src/mm/tlb.c (revision 7c98874c78674dda91c9fbaf0590416e0fa1c587) +++ kernel/arch/ppc32/src/mm/tlb.c (revision 896ad9f900f2434342a878312aa1a5cb22bdf135) @@ -41,4 +41,8 @@ #include #include + + +static unsigned int seed = 10; +static unsigned int seed_real __attribute__ ((section("K_UNMAPPED_DATA_START"))) = 42; @@ -126,4 +130,17 @@ +/** Pseudorandom generator + * + * A pretty standard linear congruential pseudorandom + * number generator (m = 2^32). + * + */ +#define RANDI(seed) \ + ({ \ + (seed) = 1103515245 * (seed) + 12345; \ + (seed); \ + }) + + static void pht_insert(const uintptr_t vaddr, const pte_t *pte) { @@ -181,8 +198,6 @@ if (!found) - i = page % 8; - } - - + i = RANDI(seed) % 8; + } phte[base + i].v = 1; @@ -195,77 +210,4 @@ phte[base + i].wimg = (pte->page_cache_disable ? WIMG_NO_CACHE : 0); phte[base + i].pp = 2; // FIXME -} - - -static void pht_real_insert(const uintptr_t vaddr, const pfn_t pfn) -{ - uint32_t page = (vaddr >> 12) & 0xffff; - uint32_t api = (vaddr >> 22) & 0x3f; - - uint32_t vsid; - asm volatile ( - "mfsrin %0, %1\n" - : "=r" (vsid) - : "r" (vaddr) - ); - - uint32_t sdr1; - asm volatile ( - "mfsdr1 %0\n" - : "=r" (sdr1) - ); - phte_t *phte_physical = (phte_t *) (sdr1 & 0xffff0000); - - /* Primary hash (xor) */ - uint32_t h = 0; - uint32_t hash = vsid ^ page; - uint32_t base = (hash & 0x3ff) << 3; - uint32_t i; - bool found = false; - - /* Find unused or colliding PTE in PTEG */ - for (i = 0; i < 8; i++) { - if ((!phte_physical[base + i].v) || - ((phte_physical[base + i].vsid == vsid) - && (phte_physical[base + i].api == api) - && (phte_physical[base + i].h == 0))) { - found = true; - break; - } - } - - if (!found) { - /* Secondary hash (not) */ - uint32_t base2 = (~hash & 0x3ff) << 3; - - /* Find unused or colliding PTE in PTEG */ - for (i = 0; i < 8; i++) { - if ((!phte_physical[base2 + i].v) || - ((phte_physical[base2 + i].vsid == vsid) - && (phte_physical[base2 + i].api == api) - && (phte_physical[base2 + i].h == 1))) { - found = true; - base = base2; - h = 1; - break; - } - } - - if (!found) { - i = page % 8; - base = base2; - h = 1; - } - } - - phte_physical[base + i].v = 1; - phte_physical[base + i].vsid = vsid; - phte_physical[base + i].h = h; - phte_physical[base + i].api = api; - phte_physical[base + i].rpn = pfn; - phte_physical[base + i].r = 0; - phte_physical[base + i].c = 0; - phte_physical[base + i].wimg = 0; - phte_physical[base + i].pp = 2; // FIXME } @@ -337,5 +279,5 @@ * */ -bool pht_real_refill(int n, istate_t *istate) +bool pht_refill_real(int n, istate_t *istate) { uintptr_t badvaddr; @@ -352,10 +294,79 @@ ); - if ((badvaddr >= PA2KA(0)) && (badvaddr < PA2KA(physmem))) { - pht_real_insert(badvaddr, KA2PA(badvaddr) >> 12); - return true; - } - - return false; + if ((badvaddr < PA2KA(0)) || (badvaddr >= PA2KA(physmem))) + return false; + + uint32_t page = (badvaddr >> 12) & 0xffff; + uint32_t api = (badvaddr >> 22) & 0x3f; + + uint32_t vsid; + asm volatile ( + "mfsrin %0, %1\n" + : "=r" (vsid) + : "r" (badvaddr) + ); + + uint32_t sdr1; + asm volatile ( + "mfsdr1 %0\n" + : "=r" (sdr1) + ); + phte_t *phte_real = (phte_t *) (sdr1 & 0xffff0000); + + /* Primary hash (xor) */ + uint32_t h = 0; + uint32_t hash = vsid ^ page; + uint32_t base = (hash & 0x3ff) << 3; + uint32_t i; + bool found = false; + + /* Find unused or colliding PTE in PTEG */ + for (i = 0; i < 8; i++) { + if ((!phte_real[base + i].v) || + ((phte_real[base + i].vsid == vsid) + && (phte_real[base + i].api == api) + && (phte_real[base + i].h == 0))) { + found = true; + break; + } + } + + if (!found) { + /* Secondary hash (not) */ + uint32_t base2 = (~hash & 0x3ff) << 3; + + /* Find unused or colliding PTE in PTEG */ + for (i = 0; i < 8; i++) { + if ((!phte_real[base2 + i].v) || + ((phte_real[base2 + i].vsid == vsid) + && (phte_real[base2 + i].api == api) + && (phte_real[base2 + i].h == 1))) { + found = true; + base = base2; + h = 1; + break; + } + } + + if (!found) { + /* Use secondary hash to avoid collisions + with usual PHT refill handler. */ + i = RANDI(seed_real) % 8; + base = base2; + h = 1; + } + } + + phte_real[base + i].v = 1; + phte_real[base + i].vsid = vsid; + phte_real[base + i].h = h; + phte_real[base + i].api = api; + phte_real[base + i].rpn = KA2PA(badvaddr) >> 12; + phte_real[base + i].r = 0; + phte_real[base + i].c = 0; + phte_real[base + i].wimg = 0; + phte_real[base + i].pp = 2; // FIXME + + return true; } @@ -439,5 +450,5 @@ : "r" (sr << 28) ); - printf("vsid[%d]: VSID=%.*p (ASID=%d)%s%s\n", sr, + printf("sr[%02u]: vsid=%.*p (asid=%u)%s%s\n", sr, sizeof(vsid) * 2, vsid & 0xffffff, (vsid & 0xffffff) >> 4, ((vsid >> 30) & 1) ? " supervisor" : "",