Re: [PATCH 1/3] iommu/fsl: Fix PAMU window size check.
On Tue, Jun 24, 2014 at 07:27:15PM +0530, Varun Sethi wrote: /* window size is 2^(WSE+1) bytes */ - return __ffs(addrspace_size) - 1; + return fls64(addrspace_size) - 2; This looks bogus, why do you replace ffs (find-first-bit) by fls (find-last-bit)? Joerg ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
RE: [PATCH 1/3] iommu/fsl: Fix PAMU window size check.
-Original Message- From: Joerg Roedel [mailto:j...@8bytes.org] Sent: Friday, July 04, 2014 4:15 PM To: Sethi Varun-B16395 Cc: io...@lists.linux-foundation.org; linux-ker...@vger.kernel.org; linuxppc-dev@lists.ozlabs.org; alex.william...@redhat.com Subject: Re: [PATCH 1/3] iommu/fsl: Fix PAMU window size check. On Tue, Jun 24, 2014 at 07:27:15PM +0530, Varun Sethi wrote: /* window size is 2^(WSE+1) bytes */ - return __ffs(addrspace_size) - 1; + return fls64(addrspace_size) - 2; This looks bogus, why do you replace ffs (find-first-bit) by fls (find- last-bit)? Address space size is always a power of 2. This change was required to handle address sizes 32bit width on 32 bit architectures. -Varun ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH 1/3] iommu/fsl: Fix PAMU window size check.
On 06/24/2014 08:57 AM, Varun Sethi wrote: is_power_of_2 requires an unsigned long parameter which would lead to truncation of 64 bit values on 32 bit architectures. __ffs also expects an unsigned long parameter thus won't work for 64 bit values on 32 bit architectures. Signed-off-by: Varun Sethi varun.se...@freescale.com --- drivers/iommu/fsl_pamu.c|8 drivers/iommu/fsl_pamu_domain.c |2 +- 2 files changed, 5 insertions(+), 5 deletions(-) Tested-by: Emil Medve emilian.me...@freescale.com On a P4080 DS (i.e. 32-bit SoC) Cheers, ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
RE: [PATCH 1/3] iommu/fsl: Fix PAMU window size check.
Thanks Emil. -Original Message- From: Emil Medve [mailto:emilian.me...@freescale.com] Sent: Wednesday, July 02, 2014 1:16 PM To: Sethi Varun-B16395; io...@lists.linux-foundation.org; j...@8bytes.org; linux-ker...@vger.kernel.org; linuxppc- d...@lists.ozlabs.org; alex.william...@redhat.com Subject: Re: [PATCH 1/3] iommu/fsl: Fix PAMU window size check. On 06/24/2014 08:57 AM, Varun Sethi wrote: is_power_of_2 requires an unsigned long parameter which would lead to truncation of 64 bit values on 32 bit architectures. __ffs also expects an unsigned long parameter thus won't work for 64 bit values on 32 bit architectures. Signed-off-by: Varun Sethi varun.se...@freescale.com --- drivers/iommu/fsl_pamu.c|8 drivers/iommu/fsl_pamu_domain.c |2 +- 2 files changed, 5 insertions(+), 5 deletions(-) Tested-by: Emil Medve emilian.me...@freescale.com On a P4080 DS (i.e. 32-bit SoC) Cheers, ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
[PATCH 1/3] iommu/fsl: Fix PAMU window size check.
is_power_of_2 requires an unsigned long parameter which would
lead to truncation of 64 bit values on 32 bit architectures.
__ffs also expects an unsigned long parameter thus won't work
for 64 bit values on 32 bit architectures.
Signed-off-by: Varun Sethi varun.se...@freescale.com
---
drivers/iommu/fsl_pamu.c|8
drivers/iommu/fsl_pamu_domain.c |2 +-
2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/iommu/fsl_pamu.c b/drivers/iommu/fsl_pamu.c
index b99dd88..bb446d7 100644
--- a/drivers/iommu/fsl_pamu.c
+++ b/drivers/iommu/fsl_pamu.c
@@ -170,10 +170,10 @@ int pamu_disable_liodn(int liodn)
static unsigned int map_addrspace_size_to_wse(phys_addr_t addrspace_size)
{
/* Bug if not a power of 2 */
- BUG_ON(!is_power_of_2(addrspace_size));
+ BUG_ON((addrspace_size (addrspace_size - 1)));
/* window size is 2^(WSE+1) bytes */
- return __ffs(addrspace_size) - 1;
+ return fls64(addrspace_size) - 2;
}
/* Derive the PAACE window count encoding for the subwindow count */
@@ -351,7 +351,7 @@ int pamu_config_ppaace(int liodn, phys_addr_t win_addr,
phys_addr_t win_size,
struct paace *ppaace;
unsigned long fspi;
- if (!is_power_of_2(win_size) || win_size PAMU_PAGE_SIZE) {
+ if ((win_size (win_size - 1)) || win_size PAMU_PAGE_SIZE) {
pr_debug(window size too small or not a power of two %llx\n,
win_size);
return -EINVAL;
}
@@ -464,7 +464,7 @@ int pamu_config_spaace(int liodn, u32 subwin_cnt, u32
subwin,
return -ENOENT;
}
- if (!is_power_of_2(subwin_size) || subwin_size PAMU_PAGE_SIZE) {
+ if ((subwin_size (subwin_size - 1)) || subwin_size PAMU_PAGE_SIZE) {
pr_debug(subwindow size out of range, or not a power of 2\n);
return -EINVAL;
}
diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c
index 93072ba..3dd0b8e 100644
--- a/drivers/iommu/fsl_pamu_domain.c
+++ b/drivers/iommu/fsl_pamu_domain.c
@@ -301,7 +301,7 @@ static int check_size(u64 size, dma_addr_t iova)
* Size must be a power of two and at least be equal
* to PAMU page size.
*/
- if (!is_power_of_2(size) || size PAMU_PAGE_SIZE) {
+ if ((size (size - 1)) || size PAMU_PAGE_SIZE) {
pr_debug(%s: size too small or not a power of two\n,
__func__);
return -EINVAL;
}
--
1.7.9.5
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