kern: optimize userspace access asm to use cheaper instruction in io memory loops

This commit is contained in:
Michael Scire 2023-02-21 03:25:55 -07:00
parent 154d61f55f
commit b7846247aa

View file

@ -596,8 +596,11 @@ _ZN3ams4kern4arch5arm6415UserspaceAccess17ReadIoMemory32BitEPvPKvm:
/* Save our return address. */
mov x8, x30
/* Prepare return address for read failure. */
adr x10, 4f
1: /* Set our return address so that on read failure we continue as though we read -1. */
adr x30, 4f
mov x30, x10
/* Read the word from io. */
ldtr w9, [x5]
@ -643,8 +646,11 @@ _ZN3ams4kern4arch5arm6415UserspaceAccess17ReadIoMemory16BitEPvPKvm:
/* Save our return address. */
mov x8, x30
/* Prepare return address for read failure. */
adr x10, 4f
1: /* Set our return address so that on read failure we continue as though we read -1. */
adr x30, 4f
mov x30, x10
/* Read the word from io. */
ldtrh w9, [x5]
@ -690,8 +696,11 @@ _ZN3ams4kern4arch5arm6415UserspaceAccess16ReadIoMemory8BitEPvPKvm:
/* Save our return address. */
mov x8, x30
/* Prepare return address for read failure. */
adr x10, 4f
1: /* Set our return address so that on read failure we continue as though we read -1. */
adr x30, 4f
mov x30, x10
/* Read the word from io. */
ldtrb w9, [x5]
@ -737,11 +746,14 @@ _ZN3ams4kern4arch5arm6415UserspaceAccess18WriteIoMemory32BitEPvPKvm:
/* Save our return address. */
mov x8, x30
/* Prepare return address for failure. */
adr x10, 2f
1: /* Read the word from normal memory. */
ldtr w9, [x5]
/* Set our return address so that on read failure we continue. */
adr x30, 2f
/* Set our return address so that on failure we continue. */
mov x30, x10
/* Write the word to io. */
sttr w9, [x5]
@ -779,11 +791,14 @@ _ZN3ams4kern4arch5arm6415UserspaceAccess18WriteIoMemory16BitEPvPKvm:
/* Save our return address. */
mov x8, x30
/* Prepare return address for failure. */
adr x10, 2f
1: /* Read the word from normal memory. */
ldtrh w9, [x5]
/* Set our return address so that on read failure we continue. */
adr x30, 2f
/* Set our return address so that on failure we continue. */
mov x30, x10
/* Write the word to io. */
sttrh w9, [x5]
@ -821,11 +836,14 @@ _ZN3ams4kern4arch5arm6415UserspaceAccess17WriteIoMemory8BitEPvPKvm:
/* Save our return address. */
mov x8, x30
/* Prepare return address for failure. */
adr x10, 2f
1: /* Read the word from normal memory. */
ldtrb w9, [x5]
/* Set our return address so that on read failure we continue. */
adr x30, 2f
/* Set our return address so that on failure we continue. */
mov x30, x10
/* Write the word to io. */
sttrb w9, [x5]