Messages in this thread | | | Subject | Re: [PATCH 2/3] powperc/mm: read TLB Block Invalidate Characteristics | From | Laurent Dufour <> | Date | Thu, 12 Sep 2019 21:26:59 +0200 |
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Le 12/09/2019 à 16:44, Aneesh Kumar K.V a écrit : > Laurent Dufour <ldufour@linux.ibm.com> writes: > >> The PAPR document specifies the TLB Block Invalidate Characteristics which >> is telling which couple base page size / page size is supported by the >> H_BLOCK_REMOVE hcall. >> >> A new set of feature is added to the mmu_psize_def structure to record per >> base page size which page size is supported by H_BLOCK_REMOVE. >> >> A new init service is added to read the characteristics. The size of the >> buffer is set to twice the number of known page size, plus 10 bytes to >> ensure we have enough place. >> >> Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com> >> --- >> arch/powerpc/include/asm/book3s/64/mmu.h | 3 + >> arch/powerpc/platforms/pseries/lpar.c | 107 +++++++++++++++++++++++ >> 2 files changed, 110 insertions(+) >> >> diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h >> index 23b83d3593e2..675895dfe39f 100644 >> --- a/arch/powerpc/include/asm/book3s/64/mmu.h >> +++ b/arch/powerpc/include/asm/book3s/64/mmu.h >> @@ -12,11 +12,14 @@ >> * sllp : is a bit mask with the value of SLB L || LP to be or'ed >> * directly to a slbmte "vsid" value >> * penc : is the HPTE encoding mask for the "LP" field: >> + * hblk : H_BLOCK_REMOVE supported block size for this page size in >> + * segment who's base page size is that page size. >> * >> */ >> struct mmu_psize_def { >> unsigned int shift; /* number of bits */ >> int penc[MMU_PAGE_COUNT]; /* HPTE encoding */ >> + int hblk[MMU_PAGE_COUNT]; /* H_BLOCK_REMOVE support */ >> unsigned int tlbiel; /* tlbiel supported for that page size */ >> unsigned long avpnm; /* bits to mask out in AVPN in the HPTE */ >> union { >> diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c >> index 4f76e5f30c97..375e19b3cf53 100644 >> --- a/arch/powerpc/platforms/pseries/lpar.c >> +++ b/arch/powerpc/platforms/pseries/lpar.c >> @@ -1311,6 +1311,113 @@ static void do_block_remove(unsigned long number, struct ppc64_tlb_batch *batch, >> (void)call_block_remove(pix, param, true); >> } >> >> +static inline void __init set_hblk_bloc_size(int bpsize, int psize, >> + unsigned int block_size) >> +{ >> + struct mmu_psize_def *def = &mmu_psize_defs[bpsize]; >> + >> + if (block_size > def->hblk[psize]) >> + def->hblk[psize] = block_size; >> +} >> + >> +static inline void __init check_lp_set_hblk(unsigned int lp, >> + unsigned int block_size) >> +{ >> + unsigned int bpsize, psize; >> + >> + >> + /* First, check the L bit, if not set, this means 4K */ >> + if ((lp & 0x80) == 0) { >> + set_hblk_bloc_size(MMU_PAGE_4K, MMU_PAGE_4K, block_size); >> + return; >> + } >> + >> + /* PAPR says to look at bits 2-7 (0 = MSB) */ >> + lp &= 0x3f; >> + for (bpsize = 0; bpsize < MMU_PAGE_COUNT; bpsize++) { >> + struct mmu_psize_def *def = &mmu_psize_defs[bpsize]; >> + >> + for (psize = 0; psize < MMU_PAGE_COUNT; psize++) { >> + if (def->penc[psize] == lp) { >> + set_hblk_bloc_size(bpsize, psize, block_size); >> + return; >> + } >> + } >> + } >> +} >> + >> +#define SPLPAR_TLB_BIC_TOKEN 50 >> +#define SPLPAR_TLB_BIC_MAXLENGTH (MMU_PAGE_COUNT*2 + 10) >> +static int __init read_tlbbi_characteristics(void) >> +{ >> + int call_status; >> + unsigned char local_buffer[SPLPAR_TLB_BIC_MAXLENGTH]; >> + int len, idx, bpsize; >> + >> + if (!firmware_has_feature(FW_FEATURE_BLOCK_REMOVE)) { >> + pr_info("H_BLOCK_REMOVE is not supported"); >> + return 0; >> + } >> + >> + memset(local_buffer, 0, SPLPAR_TLB_BIC_MAXLENGTH); >> + >> + spin_lock(&rtas_data_buf_lock); >> + memset(rtas_data_buf, 0, RTAS_DATA_BUF_SIZE); >> + call_status = rtas_call(rtas_token("ibm,get-system-parameter"), 3, 1, >> + NULL, >> + SPLPAR_TLB_BIC_TOKEN, >> + __pa(rtas_data_buf), >> + RTAS_DATA_BUF_SIZE); >> + memcpy(local_buffer, rtas_data_buf, SPLPAR_TLB_BIC_MAXLENGTH); >> + local_buffer[SPLPAR_TLB_BIC_MAXLENGTH - 1] = '\0'; >> + spin_unlock(&rtas_data_buf_lock); >> + >> + if (call_status != 0) { >> + pr_warn("%s %s Error calling get-system-parameter (0x%x)\n", >> + __FILE__, __func__, call_status); >> + return 0; >> + } >> + >> + /* >> + * The first two (2) bytes of the data in the buffer are the length of >> + * the returned data, not counting these first two (2) bytes. >> + */ >> + len = local_buffer[0] * 256 + local_buffer[1] + 2; >> + if (len >= SPLPAR_TLB_BIC_MAXLENGTH) { >> + pr_warn("%s too large returned buffer %d", __func__, len); >> + return 0; >> + } >> + >> + idx = 2; >> + while (idx < len) { >> + unsigned int block_size = local_buffer[idx++]; >> + unsigned int npsize; >> + >> + if (!block_size) >> + break; >> + >> + block_size = 1 << block_size; >> + if (block_size != 8) >> + /* We only support 8 bytes size TLB invalidate buffer */ >> + pr_warn("Unsupported H_BLOCK_REMOVE block size : %d\n", >> + block_size); > > Should we skip setting block size if we find block_size != 8? Also can > we avoid doing that pr_warn in loop and only warn if we don't find > block_size 8 in the invalidate characteristics array?
My idea here is to fully read and process the data returned by the hcall, and to put the limitation to 8 when checking before calling H_BLOCK_REMOVE. The warning is there because I want it to be displayed once at boot.
> >> + >> + for (npsize = local_buffer[idx++]; npsize > 0; npsize--) >> + check_lp_set_hblk((unsigned int) local_buffer[idx++], >> + block_size); >> + } >> + >> + for (bpsize = 0; bpsize < MMU_PAGE_COUNT; bpsize++) >> + for (idx = 0; idx < MMU_PAGE_COUNT; idx++) >> + if (mmu_psize_defs[bpsize].hblk[idx]) >> + pr_info("H_BLOCK_REMOVE supports base psize:%d psize:%d block size:%d", >> + bpsize, idx, >> + mmu_psize_defs[bpsize].hblk[idx]); >> + >> + return 0; >> +} >> +machine_arch_initcall(pseries, read_tlbbi_characteristics); >> + >> /* >> * Take a spinlock around flushes to avoid bouncing the hypervisor tlbie >> * lock. >> -- >> 2.23.0
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