On 11/5/23 20:55, Michael Kelley wrote:
From: Abhinav Singh <singhabhinav9051571833@xxxxxxxxx> Sent: Monday, October 30, 2023 3:50 PM
This patch fixes two sparse warnings
1. sparse complaining about the removal of __iomem address
space when casting the return value of this ioremap_cache(...)
from `void __ioremap*` to `void*`.
Fixed this by replacing the ioremap_cache(...)
by memremap(...) and using MEMREMAP_DEC and MEMREMAP_WB flag for
making
sure the memory is always decrypted and it will support full write back
cache.
2. sparse complaining `expected void volatile [noderef] __iomem *addr`
when calling iounmap with a non __iomem pointer.
Fixed this by replacing iounmap(...) with memumap(...).
Signed-off-by: Abhinav Singh <singhabhinav9051571833@xxxxxxxxx>
Since Nischala has posted her more comprehensive patch,
this patch can be dropped. But see one comment below for
future reference.
---
v1:
https://lore.kernel.org/all/19cec6f0-e176-4bcc-95a0-9d6eb0261ed1@xxxxxxxxx/T/
v1 to v2:
1. Fixed the comment which was earlier describing ioremap_cache(...).
2. Replaced iounmap(...) with memremap(...) inside function hv_cpu_die(...).
arch/x86/hyperv/hv_init.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 21556ad87f4b..2a14928b8a36 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -68,9 +68,11 @@ static int hyperv_init_ghcb(void)
*/
rdmsrl(MSR_AMD64_SEV_ES_GHCB, ghcb_gpa);
- /* Mask out vTOM bit. ioremap_cache() maps decrypted */
+ /* Mask out vTOM bit.
+ MEMREMAP_WB full write back cache
+ MEMREMAP_DEC maps decrypted memory */
This isn't the right style for multi-line patches. Correct would be:
/*
* Mask out vTOM bit.
* MEMREMAP_WB full write back cache
* MEMREMAP_DEC maps decrypted memory
*/
Section 8 of coding-style.rst under Documentation/process covers
these details. Note that the style is slightly different for code
under net and drivers/net.
Michael
ghcb_gpa &= ~ms_hyperv.shared_gpa_boundary;
- ghcb_va = (void *)ioremap_cache(ghcb_gpa, HV_HYP_PAGE_SIZE);
+ ghcb_va = memremap(ghcb_gpa, HV_HYP_PAGE_SIZE, MEMREMAP_WB | MEMREMAP_DEC);
if (!ghcb_va)
return -ENOMEM;
@@ -238,7 +240,7 @@ static int hv_cpu_die(unsigned int cpu)
if (hv_ghcb_pg) {
ghcb_va = (void **)this_cpu_ptr(hv_ghcb_pg);
if (*ghcb_va)
- iounmap(*ghcb_va);
+ memunmap(*ghcb_va);
*ghcb_va = NULL;
}
--
2.39.2
Thanks a lot for taking a look and the suggestion, will keep this in
mind in future patches.
Thanks,
Abhinav
