Re: [PATCH -V3 07/11] arch/powerpc: Increase the slice range to 64TB
From: Paul Mackerras <hidden>
Date: 2012-07-23 00:00:48
On Mon, Jul 09, 2012 at 06:43:37PM +0530, Aneesh Kumar K.V wrote:
From: "Aneesh Kumar K.V" <redacted> This patch makes the high psizes mask as an unsigned char array so that we can have more than 16TB. Currently we support upto 64TB
Some comments inline...
quoted hunk ↗ jump to hunk
@@ -804,16 +804,19 @@ unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap) #ifdef CONFIG_PPC_MM_SLICES unsigned int get_paca_psize(unsigned long addr) { - unsigned long index, slices; + u64 lpsizes; + unsigned char *hpsizes; + unsigned long index, mask_index; if (addr < SLICE_LOW_TOP) { - slices = get_paca()->context.low_slices_psize; + lpsizes = get_paca()->context.low_slices_psize; index = GET_LOW_SLICE_INDEX(addr); - } else { - slices = get_paca()->context.high_slices_psize; - index = GET_HIGH_SLICE_INDEX(addr); + return (lpsizes >> (index * 4)) & 0xF; } - return (slices >> (index * 4)) & 0xF; + hpsizes = get_paca()->context.high_slices_psize; + index = GET_HIGH_SLICE_INDEX(addr) >> 1; + mask_index = GET_HIGH_SLICE_INDEX(addr) - (index << 1); + return (hpsizes[index] >> (mask_index * 4)) & 0xF;
The last 3 lines here feel awkward. How about:
+ index = GET_HIGH_SLICE_INDEX(addr); + mask_index = index & 1; + return (hpsizes[index >> 1] >> (mask_index * 4)) & 0xF;
static struct slice_mask slice_mask_for_size(struct mm_struct *mm, int psize)
{
+ unsigned char *hpsizes;
+ int index, mask_index;
struct slice_mask ret = { 0, 0 };
unsigned long i;
- u64 psizes;
+ u64 lpsizes;
- psizes = mm->context.low_slices_psize;
+ lpsizes = mm->context.low_slices_psize;
for (i = 0; i < SLICE_NUM_LOW; i++)
- if (((psizes >> (i * 4)) & 0xf) == psize)
+ if (((lpsizes >> (i * 4)) & 0xf) == psize)
ret.low_slices |= 1u << i;
- psizes = mm->context.high_slices_psize;
- for (i = 0; i < SLICE_NUM_HIGH; i++)
- if (((psizes >> (i * 4)) & 0xf) == psize)
+ hpsizes = mm->context.high_slices_psize;
+ for (i = 0; i < SLICE_NUM_HIGH; i++) {
+ index = i >> 1;
+ mask_index = i - (index << 1);Again, seems like a complicated way to do mask_index = i & 1 (or even i % 2, if you prefer, but then make i an unsigned type). Paul.