2019-03-06 21:14:59

by tedheadster

Subject: [PATCH] x86/CPU: Use correct macros for Cyrix calls on Geode processors

There are comments in processor-cyrix.h advising you to _not_ make calls
using the deprecated macros in this style:

setCx86_old(CX86_CCR4, getCx86_old(CX86_CCR4) | 0x80);

This is because it expands the macro into a non-functioning calling
sequence. The calling order must be:

outb(CX86_CCR2, 0x22);
inb(0x23);

From the comments:

* When using the old macros a line like
* setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x88);
* gets expanded to:
* do {
* outb((CX86_CCR2), 0x22);
* outb((({
* outb((CX86_CCR2), 0x22);
* inb(0x23);
* }) | 0x88), 0x23);
* } while (0);

The new macros fix this problem, so use them instead. Tested on an
actual Geode processor.

Signed-off-by: Matthew Whitehead <[email protected]>
---
arch/x86/kernel/cpu/cyrix.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/cpu/cyrix.c b/arch/x86/kernel/cpu/cyrix.c
index d12226f..1d9b8aa 100644
--- a/arch/x86/kernel/cpu/cyrix.c
+++ b/arch/x86/kernel/cpu/cyrix.c
@@ -124,7 +124,7 @@ static void set_cx86_reorder(void)
setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN */

/* Load/Store Serialize to mem access disable (=reorder it) */
- setCx86_old(CX86_PCR0, getCx86_old(CX86_PCR0) & ~0x80);
+ setCx86(CX86_PCR0, getCx86(CX86_PCR0) & ~0x80);
/* set load/store serialize from 1GB to 4GB */
ccr3 |= 0xe0;
setCx86(CX86_CCR3, ccr3);
@@ -135,11 +135,11 @@ static void set_cx86_memwb(void)
pr_info("Enable Memory-Write-back mode on Cyrix/NSC processor.\n");

/* CCR2 bit 2: unlock NW bit */
- setCx86_old(CX86_CCR2, getCx86_old(CX86_CCR2) & ~0x04);
+ setCx86(CX86_CCR2, getCx86(CX86_CCR2) & ~0x04);
/* set 'Not Write-through' */
write_cr0(read_cr0() | X86_CR0_NW);
/* CCR2 bit 2: lock NW bit and set WT1 */
- setCx86_old(CX86_CCR2, getCx86_old(CX86_CCR2) | 0x14);
+ setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x14);
}

/*
@@ -153,14 +153,14 @@ static void geode_configure(void)
local_irq_save(flags);

/* Suspend on halt power saving and enable #SUSP pin */
- setCx86_old(CX86_CCR2, getCx86_old(CX86_CCR2) | 0x88);
+ setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x88);

ccr3 = getCx86(CX86_CCR3);
setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN */


/* FPU fast, DTE cache, Mem bypass */
- setCx86_old(CX86_CCR4, getCx86_old(CX86_CCR4) | 0x38);
+ setCx86(CX86_CCR4, getCx86(CX86_CCR4) | 0x38);
setCx86(CX86_CCR3, ccr3); /* disable MAPEN */

set_cx86_memwb();
@@ -296,7 +296,7 @@ static void init_cyrix(struct cpuinfo_x86 *c)
/* GXm supports extended cpuid levels 'ala' AMD */
if (c->cpuid_level == 2) {
/* Enable cxMMX extensions (GX1 Datasheet 54) */
- setCx86_old(CX86_CCR7, getCx86_old(CX86_CCR7) | 1);
+ setCx86(CX86_CCR7, getCx86(CX86_CCR7) | 1);

/*
* GXm : 0x30 ... 0x5f GXm datasheet 51
@@ -319,7 +319,7 @@ static void init_cyrix(struct cpuinfo_x86 *c)
if (dir1 > 7) {
dir0_msn++; /* M II */
/* Enable MMX extensions (App note 108) */
- setCx86_old(CX86_CCR7, getCx86_old(CX86_CCR7)|1);
+ setCx86(CX86_CCR7, getCx86(CX86_CCR7)|1);
} else {
/* A 6x86MX - it has the bug. */
set_cpu_bug(c, X86_BUG_COMA);
--
1.8.3.1

2019-03-06 21:15:35

by Thomas Gleixner

Subject: Re: [PATCH] x86/CPU: Use correct macros for Cyrix calls on Geode processors

Matthew,

On Wed, 6 Mar 2019, Matthew Whitehead wrote:

> There are comments in processor-cyrix.h advising you to _not_ make calls
> using the deprecated macros in this style:
>
> setCx86_old(CX86_CCR4, getCx86_old(CX86_CCR4) | 0x80);
>
> This is because it expands the macro into a non-functioning calling
> sequence. The calling order must be:
>
> outb(CX86_CCR2, 0x22);
> inb(0x23);
>
> >From the comments:
>
> * When using the old macros a line like
> * setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x88);
> * gets expanded to:
> * do {
> * outb((CX86_CCR2), 0x22);
> * outb((({
> * outb((CX86_CCR2), 0x22);
> * inb(0x23);
> * }) | 0x88), 0x23);
> * } while (0);
>
> The new macros fix this problem, so use them instead. Tested on an
> actual Geode processor.

Thanks for cleaning that up, but now the old macros are unused, so please
remove them entirely including the comment.

Thanks,

tglx